Even when I did not post much last week I was very busy converting all the old XNA 1.0 games to XNA 2.0. I did not only convert all projects (8 games in total, see below), but I also tested them extensively on Windows XP, Vista (32 and 64 bit) and the Xbox 360. Additionally a lot of usability improvements have been implemented in the games, for example the XNA Shooter is now much easier (was almost impossible to even reach 50% of the level) and a lot more fun due better balancing. The XNA Racing Game has now a better physic engine and will not longer let the car fly out of the track or leave ground in loopings. Due the better input control and fixed physics the cars drive now much faster and it is more challenging to complete the tracks in shorter time frames.

Games in this article:

• Chapter1Game
• Xna Pong
• Xna Breakout
• Xna Tetris
• Rocket Commander Xna
• Xna Shooter
• Xna Racing Game
• Dungeon Quest GDC

Please read my previous post about Converting XNA 1.0 games to XNA 2.0 for all technical tips. All the games can also be found on http://XnaProjects.net, but I will also make them easier accessible on this blog soon, which has an update overdue (need to clean up the left and right sides) ^^

Thanks to the great VS2005 support of XNA 2.0 all games have now just one single solution file, which works on Windows and the Xbox 360. The projects can be opened in XNA Game Studio 2.0 and Visual Studio 2005 without having to convert the files over and over again like in the past. The Icons for all games were also improved. Lets take a look at the Icons (.ico files) on Windows:


For the Xbox 360 game icons the .png files (usually named GameThumbnail.png) are used:


Ok, let's take a look at the games and what has changed for them. Most games are pretty much the same as for XNA 1.0, but a lot of smaller bugs were fixed and they have been tested more.

• Chapter1Game: This application is not really a game, but a test project to check out if XNA 2.0 is properly working on both Windows and the Xbox 360. It is from the first chapter of my book "Professional XNA Game Programming". BTW: The second edition of the book is coming out soon, there are 3 more chapters about Multiplayer game programming and a cool new role playing game.
  
  
  • Game Installer: Chapter1GameSetup.exe (210 KB)
  • Source Code and Game Content: Chapter1GameSourceCode.zip (57 KB)
  • Screenshot:
    
    
    
• Xna Pong: Xna Pong is a simple clone of the favorite pong game from 1978. It is just a few hunderd lines of code and should be very easy to understand.
  
  This game is from the book "Professional XNA Game Programming" by Benjamin Nitschke. For more information read chapter 2. (2008-02-10: Now updated to XNA 2.0)
  
  
  • Game Installer: XnaPongSetup.exe (309 KB)
  • Source Code and Game Content: XnaPongSourceCode.zip (258 KB)
  • Screenshot:
    
    
    
• Xna Breakout: XNA Breakout is a simple Breakout/Arcanoid game based on the XNA Pong game from the previous chapter.
  
  It is fully described and covered in Chapter 3 of my book "Professional XNA Game Programming". The code is quite short and should be easy to understand. (2008-02-10: Now updated to XNA 2.0)
  
  
  • Game Installer: XnaBreakoutSetup.exe (383 KB)
  • Source Code and Game Content: XnaBreakoutSourceCode.zip (316 KB)
  • Screenshot:
    
    
    
• Xna Tetris: This is a simple, but highly addictive Tetris game. You can control the blocks with your cursor keys, aswd or a game pad and the game works both on Windows and the Xbox 360. Reaching levels above 5 is really hard. My highest level was 9, try to reach more :) (2008-02-10: Now updated to XNA 2.0)
  
  This game introduces the helper classes (chapter 4 of my book) and makes more use of unit testing and game components in XNA.
  
  
  • Game Installer: XnaTetrisSetup.exe (310 KB)
  • Source Code and Game Content: XnaTetrisSourceCode.zip (277 KB)
  • Screenshot:
    
    
    
• Rocket Commander Xna: XNA port of the famous Rocket Commander game. The game principle stayed the same, but the controls were a little bit simplified to make it more fun on the Xbox 360.
  
  If you want to learn more about the Rocket Commander game, check out its official website www.RocketCommander.com and check out the Video Tutorials on Coding4Fun by MSDN. (2008-02-10: Now updated to XNA 2.0, also supports very big resolutions now and runs faster on the Xbox 360)
  
  
  • Game Installer: RocketCommanderXnaSetup.exe (16.5 MB)
  • Source Code and Game Content: RocketCommanderXnaSourceCode.zip (52.8 MB)
  • Screenshot:
    
    
    
• Xna Shooter: Shoot'n'up game specifically created for my book "Professional XNA Game Programming". It features full HDTV support, runs on Windows and the Xbox 360, 5 weapon types, 5 enemy types, a powerful ship and some power ups. It is quite fun to play and it gets harder and harder the longer you play. Based partly on the Rocket Commander XNA engine, but also features lots of new effects and shaders. (2008-02-10: Now updated to XNA 2.0, also much easier and balanced)
  
  This game and the racing game are the most improved. The game works now much better in high resolutions and on the Xbox 360. But most importantly the game is now much easier, balanced and more fun. Additionally a level percentage is now visible on the bottom and more EMP bombs can be picked up to make it easier at the end of the level.
  
  • Game Installer: XnaShooterSetup.exe (14.9 MB)
  • Source Code and Game Content: XnaShooterSourceCode.zip (32.2 MB)
  • Screenshot:
    
    
    
• Xna Racing Game: XNA Racing Game Starter Kit I wrote for http://creators.xna.com. More information and more downloads can be found on http://XnaRacingGame.com. It runs best on the Xbox 360 in HDTV (1920x1200), but it also runs fine on the PC. (2008-02-10: Now updated to XNA 2.0, driving also improved a lot, better tested on Xbox 360 and fixed some issues).
  
  Following things were improved: Shadow mapping on very big resolutions works now (crashed before), more options for lower quality settings, fixed physics, car now always stays on the road, fixed loopings, cars are much faster now, winning conditions work better now, and fixed several other bugs.
  
  • Game Installer: XnaRacingGameSetup.exe (40.2 MB)
  • Source Code and Game Content: XnaRacingGameSourceCode.zip (95.4 MB)
  • Screenshot:
    
    
    
• Dungeon Quest GDC: And finally the Dungeon Quest XNA Game, which was developed in just 4 days on the GDC 2007 at the XNA Contest. Dungeon Quest GDC is a relatively complex 3D role playing game (at least for just 4 days of work). An early version even supported coop multiplayer on the Xbox 360 via splitscreen. The game was developed by Benjamin Nitschke (abi.exDream.com) and Christoph Rienaecker (WAII). (2008-02-10: Now updated to XNA 2.0). This is NOT the full Dungeon Quest game (see www.DungeonQuestGame.com for that), this is just the GDC version.
  
  Please note that the level was reduced to allow loading on the Xbox 360 (which otherwise crashes with an OutOfMemoryException), the game is not fully playable, only the first part is implemented. You can also press F2 to toggle the Options menu and some minor bugs were fixed. But this game is no longer supported, I will not improve it anymore! Please check out the new Dungeon Quest game from www.DungeonQuestGame.com, which is coming in a month or so.
  
  • Game Installer: DungeonQuestGDCSetup.exe (25.6 MB)
  • Source Code and Game Content: DungeonQuestGDCSourceCode.zip (67.2 MB)
  • Screenshot:
    
    
    

Have fun with all the games :)

When I wrote this (a little bit each day while working on converting the old XNA projects) I was very aware about the disappointment of my blog readers about the fact that I did not blog much in the last couple of months, especially on XNA. I not only got a lot of emails about that, but also quite a lot of questions, especially since XNA 2.0 was released. I made yet another promise to myself to change that and finally blog more, maybe not only when something very interesting pops up, but instead about the everyday issues I run into.

Some Notes about XNA 2.0: More solid, lots of little new features, networking, while it may not be a very complete solution, at least it is now possible on the Xbox 360 and overall I have the feeling even more people are interested in XNA than a year ago. Plus the guys at the XNA Team doing a great job and are constantly improving the XNA Creators Club website for us game programmers and artists :)


Several people had problems using the old XNA 1.0 code of my games and make them work with XNA 2.0, so here is a little help in case you want to convert XNA 1.0 projects to XNA 2.0. You will also notice this if you go to any XNA community site as most samples will still be in XNA 1.0 and not work out of the box in XNA 2.0, and many of those will probably never be changed since they are not longer actively being developed.

For most games almost all of the code can stay unchanged, you just have to poke at a few things that have changed in the framework or were improved. More information about converting projects can be found here (read this first, this article is based on the stuff there). You can also use the Cross-Platform Game Project Converter from XNA 2.0 to add a Xbox 360 project to your existing Windows XNA project without having to create a separate project (it is helpful, but I used pretty much the same trick for all of my XNA 1.0 games anyway).

Let's go through the steps:

1. Either use the XNA project conversion utility (can be found on the XNA Creators Club website) or just create a new XNA 2.0 project in VS 2005.
   
   
2. If you created a new project, drag all source code files into the project and seperate the content files out and put them all in the existing Content directory (only there the content pipeline is activated). If you just converted a project and the content files did not move, move them yourself to the content directory. Gladly all my projects with more than 5 content files had a special content directory anyway, so no need to change anything content-wise for them. If you don't want some of the files to be compiled to .xnb files, you have to change the build action from "compile" to "content" (and then use the "copy to output directory" switch) or to "none" if you want them to be ignored like for .wav files, which are automatically processed by the .xct (XACT) file for you.
   
   
3. Find the line content = new ContentManager(Services); and replace it with Content.RootDirectory = "Content";. If you do that, get rid of the content manager in your game class since you can now use the build-in Content property to access the underlying Game content manager. In case you don't want to do that or if you need an extra variable, replace the above line with content = new ContentManager(Services, "Content");. Both ways will make sure all the content is now loaded from the content directory instead from the main directory of the application. In more complex XNA games you can also change the BaseGameDirectory to the content directory, but then you would also have to move all other resource files to this directory (config files, save games, levels, etc.). It is usually a good idea to separate the compiled (.xnb) content from the content the user can change (config, levels, etc.), so I suggest just redirecting the content directory of the content manager.
   
   
4. Replace the LoadGraphicsContent(bool) method with LoadContent, remove all the if (loadAllContent) commands (was never false anyway, just let the content of the if loop stay) and also remove the call to base.LoadGraphicsContent(bool) (does not do anything like all the Load or Unload methods in the XNA Game class, they are just empty virtual methods). You can also ignore this and the next step since it will only generate depreciated warnings, but I suggest cleaning up your source code whenever an opportunity like this presents itself. I also added some missing region blocks to the code and some comments here and there were they were missing.
   
   
5. Finally delete the UnloadGraphicsContent method unless it did anything beside base.Unload and base.UnloadGraphicsContent. In my XNA games the UnloadGraphicsContent usually looked like this and can be safely removed now (at least if nothing else is in there):

/// <summary>
/// Unload graphic content if the device gets lost.
/// </summary>
/// <param name="unloadAllContent">Unload everything?</param>
protected override void UnloadGraphicsContent(bool unloadAllContent)
{
  if (unloadAllContent == true)
    content.Unload();

  base.UnloadGraphicsContent(unloadAllContent);
} // UnloadGraphicsContent(loadAllContent)



6. In case you load sound and music via the AudioEngine, you have to change the directory to the content directory too, which will not be done automatically for you since you load the .xct file directly in the AudioEngine constructor. Basically just exchange the following code:
   
   

   audioEngine = new AudioEngine("YourSound.xgs");
   waveBank = new WaveBank(audioEngine, "Wave Bank.xwb");
   soundBank = new SoundBank(audioEngine, "Sound Bank.xsb");
   

   with:
   

   audioEngine = new AudioEngine("Content\\YourSound.xgs");
   waveBank = new WaveBank(audioEngine, "Content\\Wave Bank.xwb");
   soundBank = new SoundBank(audioEngine, "Content\\Sound Bank.xsb");

      
   
7. In case you have used the StorageDevice and specifically the ShowStorageDeviceGuide helper method, it is gone now in XNA 2.0. I had it in some helper classes, but never actually used it. In case you want to show a save game dialog (or some network game select dialog for example), please follow the XNA 2.0 help instructions to do this asynchronously now.
   
   
8. In case you use any ResourceUsage enum, replace it with TextureUsage instead or remove it if the issue is not texture related. You can also safely remove any ResourceManagementMode.Automatic parameters, which are not longer supported. Everything is now automatic anyway. Just if you have been using ResourceUsage.RenderTarget you will need to change the Texture2D class to a ResolveTexture2D class in order to archive the same behaviour as before. Some calls to the device (e.g. ResolveBackBuffer) have also changed and require a ResolveTexture2D now. You may also want to check if you have any manual texture management or disposing, which you can remove or simplify.
   
   
9. For simpler games (2D) games you should be done now. More complex games using render targets and other features that have changed in XNA 2.0 will require some more changes, but after you have done them once (or know where to change what) this is also a quick process.

The following only applies to the RocketCommanderXna, XnaShooter and XnaRacingGame engines, but you might find similarities with other XNA games and the converting process:

1. First of all make sure the old XNA 1.1 code gets compileable by going though the changes mentioned above (e.g. replacing ResourceUsage with TextureUsage or BufferUsage) and removing everything that does not exist anymore (like ResourceManagementMode.Automatic). If a method is non-existent in XNA 2.0 like ResolveRenderTarget, comment it out and remember where it happened.
   
   
2. You might go through other issues, but you have to come back to the RenderTarget issue. This took the most time in the converting process for me (probably half of all my issues come by something related to changes with RenderTargets in XNA 2.0). For that reason always make sure that rendering to textures still works while you make changing. I always used the TestCreateRenderToTexture unit test inside the RenderToTexture class to figure things out.
   
   
3. Additionally to making some changes in the BaseGame class (loading content via LoadContent, using the base.Content instead of creating a new content manager, etc.) I also removed all the RenderTarget helper methods and fields from the BaseGame class (SetRenderTarget, ResetRenderTarget, etc.) and moved them into the RenderToTexture class. While this makes the code more clean and restructured by making a few more fields private, if you do not call the new InitializeDepthBufferFormatAndMultisampling of the RenderToTexture class the calls to SetRenderTarget and ResetRenderTarget will not work correctly and will not restore the default depth buffer (which has to be remembered first). If you get the following exception it means the DepthBuffer Device.DepthStencilBuffer was set to null, but is obviously still used. In order to fix that make sure the remDepthBuffer variable is set to a correct value in the InitializeDepthBufferFormatAndMultisampling method!
   


An error has occurred during the Clear operation while trying to clear the depth or stencil buffer, no DepthStencilBuffer surface exists.
System.InvalidOperationException: An error has occurred during the Clear operation while trying to clear the depth or stencil buffer, no DepthStencilBuffer surface exists.
at Microsoft.Xna.Framework.Graphics.GraphicsDevice.Clear(ClearOptions options, Color color, Single depth, Int32 stencil, Rectangle[] regions)
at Microsoft.Xna.Framework.Graphics.GraphicsDevice.Clear(Color color)

   

4. 4. Even if you have now done everything, the app may still crash when you are trying to clear a render target (which usually happens at the start of each pre or post screen shader). The reason for the following error is the multi sampling format, which might be set to the background buffer, but not to the render targets:
   

   
   The active render target and depth stencil surface must have the same pixel size and multisampling type.
   System.InvalidOperationException: The active render target and depth stencil surface must have the same pixel size and multisampling type.
   at Microsoft.Xna.Framework.Graphics.GraphicsDevice.VerifyDepthRenderTargetCompat()
   at Microsoft.Xna.Framework.Graphics.GraphicsDevice.Clear(ClearOptions options, Color color, Single depth, Int32 stencil, Rectangle[] regions)

      
   In order to get rid of this error without changing the RenderToTexture class a lot, you can just comment out the line where multi sampling is activated in BaseGame:
   

   //this.graphics.PreferMultiSampling = true;

There are probably even more things that I forgot while converting the projects (converted 8 games and about 15 projects in total now), but the above list should be helpful. Especially for me because I always forget some of those little things and having this checklist is very helpful.

Tomorrow I will probably test all the XNA 2.0 games on my Xbox 360 and make some final adjustments and then post them all on http://XnaProjects.net (and here).

Hi everyone,

I prepared some new exciting blog posts, especially about XNA and I will post them shortly and also quite a few things will change at this blog. Stay tuned.

Recently one of my companies (namely realis) moved to Hamburg and I have a new PC at the new office, where I installed Visual Studio 2008 and everything else I needed. After I downloaded the latest source code files from Team System, I ran into some problems. BTW: The Team System trial will end next month and I will probably not switch back to SubVersion, but instead go back to Visual SourceSafe since the integration is the best in Visual Studio. Team System is nice to have but absolutely not something important for me as I'm most of the time the only guy using it anyways.

Back to the Problem. After I loaded the main solution the 2 web applications in it were unable to be loaded. The rest of the projects did load fine and worked after a while until I had all the missing Assemblies installed (xunit, Ajax stuff, Silverlight, IronPython, EntitySpaces, etc.). But even after making sure Silverlight and the Silverlight Tools for Visual Studio Alpha was installed and working (checked it by creating a new Silverlight project, which worked fine), I was still unable to load those projects. I thought at first maybe something went wrong when I checked in or out all the files, but after testing it on my laptop this was not the issue, all files are intact. Everything worked just fine on my laptop, where I had done most of my work during the move and first weeks until everything was finally working here.

After digging around a bit I went back to the IIS were those 2 websites should run on and they did not run yet (not compiled yet, no wonder). But even after I pointed to some dummy website the IIS did throw out some errors (first some dlls were missing, they were quickly replaced, then some security issues with Vista, also easy). Then I pointed back to the location of the projects and made sure IIS was working this time. Now I could go back to Visual Studio and finally load the web projects.

If you have such a InteropServices.COMException, try to see if you have missed something like the Silverlight Tools for Visual Studio Alpha and then figure out if your IIS is working. You can also edit the .csproj file and remove the references to IIS at the very end of the file to see if the project can then be loaded (using IIS again is not hard through the project properties).

Hope this helps (phase stolen from ScottGu, btw: really cool stuff going on over there, the ASP.NET MVC framework is nice and the .NET Framework SourceCode is very helpful!)

As mentioned here in the official press message from Microsoft XNA 2.0 was released today after a very short beta phase which did only run for a few weeks.

You can download XNA 2.0 from Creators.Xna.Com, but for now it just says "XNA Game Studio 2.0 will be available early morning, Thursday Dec 13th, 2007 PST.". This will hopefully change soon ^^

http://creators.xna.com/Education/GettingStarted.aspx

Since XNA 2.0 is now out I will talk about some of its new features shortly and comment a little bit about the new networking API and Xbox LIVE features. Stay tuned.

The long awaited XNA Game Studio 2.0 beta is now available and can be downloaded from the XNA Creators Club website: http://creators.xna.com/beta/betahome.aspx

My first impression of the new multiplayer API is not that good. While it is very nice to have the ability to use networking on the Xbox 360, it is not only too hard to make it work on just a Windows PC and secondly you cannot expect that your gamers will both have a Xbox LIVE Gold membership AND a XNA Creators Club membership (both cost money). This means if you really want to do networking on a Windows XNA 2.0 game, you have to use System.Net and write it all yourself or no one will ever play your game on Windows except some XNA developers maybe.

Other than that XNA 2.0 is a great improvement, but it does only work with VS2005 yet, maybe they missed the VS2008 release earlier yesterday ^^ But it will probably be possible to modify the .csproj files again to make it work in VS2008 (without the extra XNA features and content pipeline).

Ziggyware has a good overview of the XNA 2.0 announcements and GameFest conference sessions in the following post. Check it out if you are interested in the new XNA 2.0 features (mainly networking, which is really a big step forward). It is also nice to see so many new XNA games and development efforts :)

http://www.ziggyware.com/news.php?readmore=407

Microsoft XNA: Ready for Prime Time?

is the name of the Article of the CoDe Magazine. It is very well written and a really long (9 pages) read with tons of information in it.
Together with 6 other guys I was interviewed about my experiences with XNA and the development process of the
XNA Racing Game and Dungeon Quest, which are 2 of the best looking XNA games so far :)

Check it out, good work Nick Landry.

Hey! Finally some News about Game Development again. All this Silverlight and VS2008 stuff is nice, but XNA has become pretty popular recently (lots of posts in blogs, more articles everywhere and a lot more news).

Anyway, I wanted to release the Dungeon Quest Source Code for several months now, but I never found the time to package everything up, do some cleanup and release it. Recently some people have requested the source code and emails keep coming in. To finally make everyone happy, here is the new Dungeon Quest version with some nice additions, much cleaner code with quite a lot of refactoring and some nice unit tests (see below). This version also does not require PS3.0 anymore, you can now run Dungeon Quest on a PS2.0 graphic card!

First of all: The downloads, all of them can be found on XnaProjects.net too:

• DungeonQuestSetup.exe (40 MB): Game installer for Windows with everything you need to play.
  
  
• DungeonQuestSourceCodeAndContent.zip (103 MB): Full Dungeon Quest source code with all content files.
  Please note that the collada files (xml text format) and the sound/music are very big (extracted ~200 MB).
  This download also contains the full game in the bin/debug/ directory, you only need to download this file
  for development and testing.
  Contains solution and project files for VS2005, VC# Express (XNA Express) and Xbox 360!
  
  
• DungeonQuest.wmv (21 MB): Higher quality version of the YouTube video below
  
  

Here is the good old YouTube video from the game to give you a first view if you don't know about Dungeon Quest yet.



If you want to drive into the source code I highly recommend starting all the unit tests in Program.cs after checking out the directory structure of the project:

• UIManager.TestUI();
  Show the graphical user interface of the game (boxes for health, player values, rpg levels, etc.)
  
  

• ShaderTests.TestNormalMappingShader();
  Test the normal mapping shader, for more shader tests check out the XNA Rocket Commander and XNA Racing Game projects.
  
  

• ColladaModel.TestCaveColladaModelScene();
  This tests the big cave collada file (80 MB) and renders it with the cave shader. Looks very nice.
  
  

• ColladaModel.TestLoadStaticModel();
  This is straight from the SkiningColladaModelsWithXNA project from February. This test show shows a static collada model.
  
  

• AnimatedColladaModel.TestPlayerColladaModelScene();
  Also from the SkinningColladaModelsWithXNA project. This shows the player or the goblins running, dying, staying, etc.
  This is a useful unit test to test animations for skinned collada models.
  
  

• PostScreenGlow.TestPostScreenGlow();
  Test post screen glow, more details can be found in the Rocket Commander tutorials and most of my XNA projects.
  
  

• PlaneRenderer.TestRenderingPlaneXY();
  Test to render a plane on the ground, which is also used in some other tests. Also good for testing shaders.
  
  

• ShadowMapShader.TestShadowMapping();
  Test Shadow Mapping unit test, pretty complex stuff, but kinda nice for this game. More details can be found in my book, this is a complex topic and involves a lot of finetuning to get it right.
  
  

• EffectManager.TestEffects();
  Since DungeonQuest uses some effects for fire, smoke, blood, etc. it has a simple effect system build in. Use this test to see whats possible and to extend the effect system.
  
  

• StringHelper.TestConvertStringToFloatArray();
  An example of a dynamic unit test, which can also be started from NUnit or TestDriven.Net (right click if you have the addin installed).
  
  

• Sound.TestPlaySounds();
  And another test to play the sound effects used in the game, just press A, B, 1, 2, 3, etc. to play sounds.
  
  

• ColladaModel.TestCaveColladaModelSceneSplitScreen();
  This test shows how the engine supports split screen support, but it was never fully implemented into the game itself yet.
  To finish this the game logic + handling input from 2nd player has to be implemented.

Some Screenshots from the last post on my blog about Dungeon Quest:

Ok, let's get started. What is this guy doing there. He doesn't look very friendly, maybe it is better to hit him in the head!

First quest completed. This key is important to open the door to the second level.

Nonstop fighting action. Well, at least if you don't lose your way.

This is how it looks like after I got angry. I told those guys, don't start any fights!

Ohh no. I did not use all my skills (see right side) and this Ogre killed me too quickly. I guess I have to start over.

The credit screen when the game ends. Notice my book :)

No reason to stop, let's start over and try again. The fight is continuing. The game is not that hard, you just have to use all skills and avoid being hit by fireballs or big enemies when you have low hit points.

I hope you like Dungeon Quest and that the source code can be useful for your XNA projects. Enjoy!

I wrote a little tool almost a year ago to help me coding XNA directly in VS 2005 instead of using XNA Game Studio Express, which does not support addins. I wrote a little bit about that back then, but for some strange reason I never published my tool. I also wrote about it in my book "Professional XNA Game Programming" in chapter 1 at the end.

Recently I got some emails requesting this tool and I still had to test it for the final XNA version and I also want to add support for VS 2008 (also called orcas; vs 2008 beta 2 comes next week hopefully, yay!).

This tool does not do much, but it is still very useful like the AnnoyingFilesRemover. I use it almost daily when developing and testing XNA projects. It converts projects from VS Express to VS 2005 and VS 2008 and back, you can also use it for VS 2008 (Orcas) projects, which can be openend in VS 2005 again (and compile if you don't use .NET 3.5, but even that works to a certain degree with the LINQ May 2006 CTP). I will try to update this tool when newer versions of XNA (like the XNA Game Studio 2.0) and VS 2008 (like the beta 2 next week) come out, exciting times are ahead :)

The tool looks like this, the most useful button is "Save and Open Project", which convert and then starts the selected VS version:

And here is the installer plus source code:

• XnaProjectChangerSetup.zip (79.76 KB)

• XnaProjectChanger.zip (34.95 KB)

PS: VS2005 and VS2008 both do NOT support the XNA Content Pipeline. I suggest just starting to write XNA games in VS2005/VS2008 and then switch to XNA Game Studio Express when you need and want to use the content pipeline (or use a library in VS2005 and write the game with XNA Game Studio Express).

You can also use the also use the XNA Content Builder to create .xnb files yourself:
http://www.codeplex.com/xnadevru/Wiki/View.aspx?title=XNA%20Content%20Builder%20(XCB)

Today I got the Wired Magazine in my mail and on site 80 there is a nice article about the development process of the XNA Challenge game Dungeon Quest from the GDC 2007. It was written by Mary Jane Irwin from the Wired Games Blog, thanks :). There is also a nice picture gallery with 21 images from the 4 days, which nicely shows the advancements we made each day. Enjoy!

PS: There is probably more information on this and other XNA projects on the huge Wired.com website, but every time I search for XNA or my name, I just find too many articles. Test for yourself.

I heard about all the Silverlight fuss from the MIX2007 conference last week, but I did not have time to check it out with all the stress and projects I'm currently involved in. I already use VS Orcas for a while (see post from last month) and I played around with WPF in the past (formerly Avalon, now Silverlight, which is still in beta, but will be released this summer finally), but I did not find anything compelling for a game programmer since we use DirectX or XNA anyway. But with the ability to build websites with Silverlight and still allowing the .NET framework to exist in that environment while simplifying the development process and getting away from building static html like pages with some dynamic features (ajax or not, it is still somewhat static and hard to do), Silverlight gets much sexier than just WPF on a windows app by itself.

Why is Silverlight cool? It is .NET, it runs on Firefox, IE, Safari, Mac, etc. it is just 2 MB download, it is amazingly fast, it has many cool new features, it allows many windows-only apps to be developed for the browser in a more natural way, it will be pushed like crazy and a lot of people will have it till the end of this year, there are already some cool tools out there including the Expression toolkit and Visual Studio Orcas, and probably a lot of other reasons you can checkout yourself!

Maybe it is even possible to interop with some DirectX or XNA stuff somehow. I have no idea if this is possible at all or if there are security issues or this kind of functionality is not possible at all, but instead of waiting for another week until I find a few minutes to test this out, why not announce it here first that this would be cool and maybe someone else can test it for me :)

Even for just doing websites, Silverlight will definitely become a BIG competitor to Flash based websites, developing in .NET will be a lot easier than working with Flash/Actionscript/whatever and I would bet that there are more VB/C# developers that can now do some great websites without having to learn much while creating Flash sites or even doing ASP.NET (with or without Ajax) development is much harder and less compelling for certain kinds of applications. Great examples are the FOX Movies site and some widgets on MSDN or some early test controls from Telerik.

BTW: Archor wrote me an email about his Cyber Car XNA game he wanted to submit to the XnaProjects.Net site I made last week. This is actually a Racing Game Mod, I first guessed he used the simple racing game version, but this one is based on the full racing game from the XNA creators website. Pretty cool style in my opinion. Thanks Archor!

http://xbox360.archor.com/

Yes. My XNA book is finally out and some people even got an early version last week. There is also some discussion going on in the XNA Forums and on the official Wrox forum for the book.

The coolest thing yesterday that my book was on Rank #16 for Computer/Technical books on Amazon.com and on Rank 500 something for all books. Quite impressive if you ask me, hopefully it will continue to stay high and make me filthy rich .. just kidding.

Yesterday I wanted to put all the samples from the book on my blog, but it is already way to overloaded here with screenshots and games, adding another 10 games will not make anything better. Instead I had a crazy idea to create a XNA Community site in one day. It is called XnaProjects.Net. The idea is for everyone to submit their games and links. News are grabbed with Google Blog Search and more features will come in July 2007 when I got more than 5 minutes time in a row.

Anyway, check out this great new website, submit your games and links and check out whats already submitted by me (10 Games so far, yes, thats a lot of XNA games I did in the past few months):

• XNA Pong
• XNA Breakout
• XNA Tetris
• Rocket Commander XNA
• XNA Shooter
• XNA Racing Game
• SimpleRacingGame
• SpeedyRacer
• Dungeon Quest
• Skinning with Collada Models in XNA

You can find source code and game installers for all of these games, including some nice screenshots and a YouTube video for each of them on the XnaProjects.Net website. Check it out:

I have put together a little website for the XNA Racing Game Starter Kit released yesterday on
http://creators.xna.com/Education/StarterKits.aspx

Here you go: http://www.XnaRacingGame.com




A little rant about the XNA Racing Game Starter Kit download: The download file is 130 MB in size and will eat up almost 290 MB of your hard disk space extracted. It is also only available in the .vsi format and can't be used in anything but XNA Game Studio Express or Visual C# Express. The main reason for this incredible size is the Textures directory, with uses mainly uncompressed .TGA files. The original Racing Game version had only about 50-70 MB in total with DDS textures and the Simple Racing Game version from my book is even smaller (30 MB I think, but a lot of content is not in there, its a also a much smaller and simplified project).

Microsoft has also removed all credits of me, all readmes, all unit tests, most comments, some screens like the credit screens. It's a little bit sad for me because all references to me or my website were removed and I'm not even mentioned on the starter kit download page :( I think the starter kit is now much harder to understand because there are no unit tests in the code to test anything out. Anyway, I just hope the XNA Racing Game Starter Kit is useful for you guys, it helps XNA and everyone wins

Update 2007-05-01: I'm now mentioned on http://creators.xna.com and happy :)

Nice one. The Racing Game Starter kit for XNA Game Studio Express I made last year is now available on
http://creators.xna.com/Education/StarterKits.aspx

More information will be available shortly on the in-official website for the Racing Game (link to the xna creators club, screenshots, mod support and forums later):
http://www.XnaRacingGame.com

Enjoy the Racing Game

My book Professional XNA Game Programming for the Xbox 360 and Windows seems to be out too. I have not received a copy myself yet, but I received some emails about other guys already holding it in their hands ^^ If you try to download the source code for the book from the Wrox website and encounter problems, please be aware that the download link is currently pointing to an older version, which still has some issues. I will try to sort that out as soon as possible. The official release date was 11 May, 2007, but Amazon says it is already available, while their own release date is stated as 30 April, 2007. Confusing, isn't it?

If you find any issues with the starter kit or the book download please write me a message so I can fix it as soon as possible. Many thanks to ZMan (Andy Dunn) for an early bug report.

I originally wanted to finish this at Monday or Tuesday, but I had not enough time this week to improve much on the Dungeon Quest game. Many of the cool features of the game were already implemented in some unit tests at the GDC like splitscreen support and shadow mapping, but we had not time to test and finetune all that. There were also a lot of bugs and smaller issues in the beta version. Below is a long list of all changes and some new screenshots. When the XNA Update is available that allows deploying to the Xbox 360 with just binaries I will provide an updated version that runs on the Xbox 360 too and supports splitscreen multiplayer gaming.

Download the game installer here (40 MB): DungeonQuestSetup.zip
Alternative download (slow! from this site): DungeonQuestSetup.zip

Note: This game requires a Shader Model 3.0 GPU as it was build for the Xbox 360 and optimized that way. For lower end PCs it pushes way too many polygons each frame anyway so that it will be too slow. If you have a low end SM 3.0 GPU (like the Nvidia GeForce 6600), make sure you run in a lower resolution (see below for details).

Here is a little video from the current version of the game. Enjoy!

Screenshots:

Ok, let's get started. What is this guy doing there. He doesn't look very friendly, maybe it is better to hit him in the head!

First quest completed. This key is important to open the door to the second level.

Nonstop fighting action. Well, at least if you don't lose your way.

This is how it looks like after I got angry. I told those guys, don't start any fights!

Ohh no. I did not use all my skills (see right side) and this Ogre killed me too quickly. I guess I have to start over.

The credit screen when the game ends. Notice my book :)

No reason to stop, let's start over and try again. The fight is continuing. The game is not that hard, you just have to use all skills and avoid being hit by fireballs or big enemies when you have low hit points.

Improvements:

• Improved performance a lot by optimizing some internal code and using all ps3.0 shaders now (sad thing is it only runs with ps3.0 hardware now).
  TIPP: If you have a low spec ps3.0 graphic card (like the GeForce 6600 or lower) use a smaller resolution, the game will run much faster. Use the DungeonQuestSettings.xml file and enter a smaller resolution there (e.g. 800x600). The game is heavily GPU bound (like all my games) and it pushes several million polygons each frame (scene alone has almost a million polygons, but it has to be rendered 3 times for all shadow mapping and post processing effects). Runs on XBox 360 or GeForce 7x hardware very good with 100fps and more.
• Fixed parallax mapping for the cave and improved the specular effects, looks much nicer now. Also increased view distance and light affect range.
• Improved the music and sound effects, also added a lot more events and little sounds.
• Added many text messages to help the player understand the game better
• Check if computer can do ps 3.0, else shows big message on screen.
• Support for 64 bit systems (did not start before)
• Reduced glow in post screen (see comments of beta version)
• Fixed game logic and quests (did not work at all in the beta)
• All game actions get a nice message now in the center (killed ogre, got key, quest complete, new weapon, etc.)
• Implemented several new animations for hitting and dying
• Fixed text size in 3:4 resolutions (did only look correct in 16:9)
• Improved gravity (much stronger now) and fixed several collision bugs
• Fixed collecting key, added it to the UI and also allowing dropping weapons now
• Allow switching weapons (right/left shoulder buttons or Q/E or Mouse wheel)
• Selected enemy ring to help you see which enemy is attacted
• Rumble Xbox 360 controller when hit/getting hit
• Added end screen and credits with book link, credits
• Improved weapons, damages and made the game more balanced.
• Show high score list when game over
• Mouse support for dungeon quest (shooter like, just asdw for moving)
• Block door when we don't got key! Also added sphere collision for monsters (they don't intersect anymore)
• Fixed shadow mapping and added a lot of cool shadow effects and pseudo point light sources.
• Added nice looking vista compatible icon, also tested the whole game on vista, runs fine :)
• Added some grunt sounds and an ambient theme in the background!
• And many more ..

The source code is not yet released. I will probably work a little bit more on on when the XNA Update comes out and then maybe release it. Sorry for now, I know many people want to take a look right now ^^

Here are some more pictures from the last few days of the GDC. We did not have enough time to go through all the pictures in the last days.

Chris and me are currently working on the last issues with Dungeon Quest, an updated version will be finished soon.


This was at the beginning of Day 3, when we still got over 14 hours left. You can see our sign from the XNA Challenge and a little sign for my upcoming book :)

The Lobby of the Moscone North Building, which was also the XNA Lobby and the place we stayed all day to finish our game. The Gears of War theme music was getting annoying after hearing it a few times, but after hearing it for 4 straight days I guess I need a few weeks of silence before I can ever play Gears of War again ^^

Two of the other teams working hard on their XNA games.

Gabe Ahn from Sony introducing us at the COLLADA round table I was speaking at on Wednesday (left to right): Shaun Leach from Zipper Interactive, Ken Normann from EA (working on the Sims team) and me (some XNA guy from exDream in Germany? ^^)

The panel discussion was good IMO, hopefully more and more people get attracted to COLLADA and start using it for their tools.

The outside world at day 4, it might not look very bright to you, but after 2 days with just 2-3 hours of sleep this looked incredible bright and it was hard to open the eyes out here. But the weather was nice all week and it was warm enough to wear t-shirts all the time except at night.

A picture from Microsoft's XNA Party at Thursday evening. It was still early and we prepared our presentation of the XNA game we did in 4 days: Dungeon Quest. We had many problems in the last two days and just skipped some of our features, but we got it done and it looks really good, especially for the short time frame we had to develop the game.

Christoph and me standing proudly in front of our game at the XNA Party. Many people came and played and congratulated us on the great result.

One final picture from Saturday morning before we were leaving to the airport to head back to Germany. The trip was 25 hours for me and after that I felt as tired as Friday, I probably need to sleep for a week now .. but I got work to do ..

Just a couple of quick notes. I have been awake for over 25 hours now (all that traveling) and my PC at home does not like my anymore (it just won't go on). I probably have to repair it first thing tomorrow.

- This server (handling this website) was not prepared for the huge number of people trying to log on here and especially not for all the download request. I added a faster server below for the Dungeon Quest Beta download

- The Dungeon Quest game has not been tested well and we turned many features off (multiplayer splitscreen, xbox testing, some shadow mapping, quest solving, etc.) just to make it run at the party at Thursday. Tomorrow we are going to fix all that issues and test a little bit more and then will release the full version, which is hopefully more fun :)

- I need sleep and a computer that works, grml :(

- All the photos we made will be posted tomorrow too (well, not all, its like 200, but we got some nice ones in the last few days).


Thanks to Microsoft for the contest and opportunity and the GDC was a nice event overall (was Chris and my first time going over there). We did not check out many sessions, but there are many clips on GameTrailers, YouTube and probably a lot of papers from the usual sites (gamedev, nvidia, ati, etc.).

Hey everyone, we finally finished the game yesterday for the Microsoft XNA Party here at the GDC.

For some strange reason my main server in germany went offline today and I finally got it up and running again (thanks to Leif, he had to run over to the office and restart the server in the middle of the night ^^).

Here is a little screenshot of the final game. I will post more later and do a video too.

If you want an real early preview of the version so far, you can download it here (with installer and everything, about 38 MB). We will fix some issues today and make an update this weekend. There are many more features we had implemented (splitscreen, shadowing, quest solving), but we removed all that to just make the version run because there were still some issues. Anyway, enjoy the game so far. Thanks for all the nice comments.

Update: Fast Download from new Server: Dungeon Quest Beta (38 MB) (Day 4 GDC version)
Original Server (slow): Dungeon Quest Beta (38 MB) (Day 4 GDC version) (WARNING: slow download from this website)

Tomorrow there will be an update and all the beta issues will be fixed + more features will come, stay tuned!

.. have no time .. got no sleep .. have to finish game today ..

This is the screen from yesterday/this morning (day 3):

Really short post for yesterday. I had not much time today to post and we are half a day behind. But tonight we are going to improve our game a lot.

Tomorrow I will post another screen for today and talk about what happened today (I spoke at the Collada panel, that was a lot of fun and we took some new pictures).

Our Dungeon Quest Game still looks pretty good and we advancing a lot, at least with the graphics. Keep in mind that we started with nothing, no real engine, I have never done point lights before and all the texture and 3d models were created in the last 2 days.

Some parts of the game are also implemented, but we will still have a lot of work to get all the quests, monsters and AI working properly and there are still some heavy issues like implementing shadow maps indoor with point lights (uff) and I still have no idea how to get the split screen stuff working efficiently.

Here is the screen shot for day 2 (yesterday), it shows the player model and the cave.

Stay tuned, more to come!

Sorry for not blogging yesterday. We were working all day on our game here on the GDC 2007 and it was very noisy and distracting here. If you want to watch us work: We are in the Moscone North Lobby and shouldn't be hard to find. Anyway, I will probably just blog at the morning of the next day for each day here.

Our game is called Dungeon Quest and we are absolutely insane because we want to create a Multiplayer Role Playing Game in just 4 days and we haven't even thought of all the distractions here. I will try to give you a screen per day and tell you want we have done so far.

Yesterday we worked purely on the environment, the level and the general game idea and some smaller details. As I said before we started with nothing, I just created a new project and Christoph did just open up 3DS Max and started working, there are no textures or models we have already done. And we both have never worked on a role playing game before.

In the morning we still had a lot of problems getting our computers up and running (3DS Max wasn't starting, I needed lots of plugins and tools, stuff like that). It usually takes a day or more to set up a development machine in our opinion. Probably a week until you got all the important tools installed you forgot in the first day. Anyway, we finally started to build the cave, create new custom collada exporter for that and placed lights. While Christoph was working on the 3D cave I was getting the engine up and running and noticed that there are many things that have to be done:

• Like just rendering some text on the screen,
• Finding a good font for that,
• Creating a bitmap font,
• Also making other UI elements (selected monster, health, level up, etc.)
• Rendering shaders and playing around with point lights
• Working on many other smaller issues like effects, billboards, vertex formats, etc.
• Most unit tests require a good camera and testing the cave level itself was very hard, so I already created the ThridPersonCamera class we going to use for this game.

I started with most classes that are required for that and I also could drop in some Texture/Font code from Rocket Commander XNA, but most of the shader and collada import classes had to be created from scratch. Then we spend all evening and even this morning tweaking the shaders, getting all the lights working, adding fog, figuring out how to do 6 complex light passes in one shader, and so on.

Today we will focus on building the main character, getting some collision detection working and some basic game logic (keys, doors, monster state machines, player behaviour and animations). Hopefully I can provide you with a nicer screenshot tomorrow, just an empty level is pretty boring.

And here are some pictures from yesterday for your enjoyment.

This is the lobby of the Moscone North building at the GDC. The GDC Expo hall is below us and on Monday the Serious Games Summit was here, but we hadn't had any time to even check out who is speaking at the actual GDC. At wednesday I will be at some Collada round table speaking about Collada and issues we had with it so far ^^

There are many art galleries here in San Francisco and the Asian population is also huge. It was not hard to find an Asian Art Gallery.

Here you can see an ad for Microsoft's Vista Operating System directly in front of the big Mac building here (seems a lot of people got one here). There is nothing interesting about a Mac for a game developer IMO.

Alcatraz at day time. I already showed you a picture at night earlier.

A view from my desk at the Hotel over San Francisco. Its still impressive every day you wake up ^^

And some picture of a place I don't know the name of. Usually I would look it up, but I have to go back to work. Cya tomorrow!

                  

Every year in march the GDC is San Francisco or San Joe and we all are reading the announcements, papers and articles coming from there. It was always interesting to read about the stuff going on there (gamedev.net has a good coverage each year), but I could never attend. The cost of flying over there and staying there for a week plus the incredible high attendee fees kept me out of this conference in the past. As you can read on www.exDream.com we usually attend the CeBIT here in Hannover instead and go to all the other conferences and fairs here in Germany ^^

Anyway, a few weeks ago Microsoft asked me to come to the GDC and be part of one of their XNA "Dream Team"s. The idea for these teams is to build a game while we are on the conference in 3-4 days (from Monday to Thursday) and that sounds crazy enough for me (who the hell wants to make a game in 3-4 days? and how?).

There will be a big party Thursday night and all the XNA games will be presented there. Some information about that can be found on the XNA Team Blog.

My idea was to create one of the most complex game types there is: A multiplayer roleplaying game. And yes in just 3 days and starting from scratch ^^
It will probably be a little like Zelda, but we are focusing our efforts on creating one cool looking level and with some enemies and maybe a few quests. Everyone I told this idea said the same thing you are thinking right now: Impossible. Yeah, I know, but it is fun anyway to try. Hopefully we will come up with something good looking till Thursday then.

I will blog every day with screenshots and the daily development process directly from the GDC and you can see how far we get. My friend Christoph Rienaecker (WAII) is also coming with me and helping me out modeling the player and enemies as well as the level so I can focus on programming

If you are also attending the GDC and want to meet with me, drop me an email or write in the comments. See ya there, or not ^^ but as usual I will make pictures and document my experiences for all of you who won't attend.

Don't ask me how I managed to not post anything this week. My plan was certainly different, but I didn't want to post my problem with this little project too early. To make up with the lack of blog posts this year until now this is going to be a very long and hopefully very useful article

Content

• Video, Screenshot and Downloads
• Introduction and why Collada?
• Class Overview
• Loading collada files
• Problems with the animation data
• Optimizing vertices
• Optimizing the Optimization
• Adjusting the shaders for skinned meshes
• Post screen shaders for the final result
• References and Links

Video, Screenshot and Downloads

First of all, here is a video for the project I'm talking about here:

Screenshot of the same scene (better quality since youtube videos just suck quality wise):

Before you start reading this article I suggest you download the executable and source code first in case you want to try it out directly while reading. The whole project is based on the RocketCommanderXNA engine and just adds the ColladaModel.cs class, which does all the amazing stuff you see in the video The video above shows shadowing from the XNA Shooter engine, which is not yet released and their fore not included in the downloads. The rest of the code is the same, just the shadow map rendering was removed. More details about shadow mapping in XNA can also be found in my book (plug plug plug ^^).

• The source code is about 2.6 MB and contains projects for XNA Game Studio Windows and the Xbox platform, as well as a project for Visual Studio 2005. It was tested on Windows XP and Vista 32 and 64 bit as well as on the Xbox 360.
  SkinningWithColladaModelsInXnaSourceCode.zip (2.6 MB)
• The executable contains the output (32 bit Windows, but runs on 64 bit and Vista too) from the project in case you just want to try it out or do not have XNA Game Studio Express installed yet. You still need the XNA Framework for this program, download it here, if you do not have it installed yet! You also need a Shader Model 2.0 capable graphic card.
  SkinningWithColladaModelsInXnaExecuteable.zip (2.5 MB)
  
  Update 2007-02-26: Fixed time steps, in release mode with more than 200-300 fps the animation was getting too slow. Now works flawless :)
  

Please note that the 3D Goblin Model was created by my friend Christoph Rienaecker (WAII) and if you want to use it, please credit him (see Readme.txt). The source code and collada loading class can be used freely too, but I want some credits too (at least in the source code ^^).

Introduction and why Collada?

OK, let's get started. I talked a lot about the XNA Content Pipeline and its problems on my blog, and in several recent interviews and also in my upcoming XNA book. For projects like Rocket Commander or even the Racing Game it was sometimes a little bit annoying, but I could do everything I needed by loading X files and adding some features to it to fix the tangents, load the correct shader techniques, etc.
However XNA does not support loading animation data or gives you a way to display them. You have to do all that work by yourself. This includes static mesh animations (like it was used in Rocket Commander, I just left it out in Rocket Commander XNA), but also skeletal animation with bones and skinned meshes.

There is a nice project on CodePlex called XNA Animation Component Library, but it only support FBX and ASCII X files (and recently BVH, ASF and AMC formats) and I could not get any of my test models to work with this library. The main thing missing here is good shader support and it also has a lot of problems with complex animated models. Other than that exporting 3D Models as X files is really a pain in the ass, no matter which exporter you use (Panda Exporter for 3dsMax was good a year ago, I still use it, now kiloWatt X file Exporter for 3dsMax is better, and the Microsoft X File Exporter for Max always sucked). Simple models might work, but the more complex 3D models get and the more meshes and animation data is stored in a scene, the more problems you will have. Sometimes it is not possible to reconstruct everything correctly on your importer side.

Anyway, at the very beginning of the Racing Game development there was no content pipeline in XNA (it was Beta 1) and I implemented loading 3D Models with help of the collada file format, which is basically just XML and very easy to read. For that reason it was relatively simple to get some 3D data loaded and displayed in the early XNA versions with help of vertex buffers. There were some problems with shader settings and I had to try many different exporters and ended up with the one from Feeling Software. Back then it had still some problems loading shaders and using the correct techniques, but the recent version (3.0.2) is much better and works like a charm.

After Microsoft had implemented the content pipeline and made it possible to load X and FBX files indirectly by going over the content pipeline I had to remove most of my collada code and re implement the model loading with the new framework. Loading and displaying 3D models was much simpler this way and especially some early unit tests were really simple, but as soon I tried shaders and loading tangents there were a bunch of problems. I reported many bugs back then and it has gotten a lot better, but I still had to fix several issues in the Racing Game and Rocket Commander XNA myself like finding out the correct shader technique and fixing tangent data with help of a custom model processor.

Some things like the level loading in the Racing Game just do not work with X or FBX files because they use splines, which are not exported at all in these formats. Collada came as the rescue again because it is really no big problem for this format. Later versions of the Racing Game removed the collada level loading and introduced a binary format for the levels, but the importer still accepts collada files.

Recently I wanted to test a couple of animated models and use skinning since it can often be more useful than static animations and it usually looks much better, especially for organic 3D models. As I said above I could not get anything working with the XNA Animation Component Library and I especially do not like the way they still use the content pipeline and the project is too complicated for me anyway (I just do not need 6 different file formats, I just want one and it should work perfectly with all the features I need).

After some searching I saw some guy called remi from the collada forum was working on importing collada models too and I posted some thoughts there too (maybe this was a mistake, I got many emails asking me about tips ^^). Here is the thread about that in the collada forum. He has provided a test project with some models and it works nice for static meshes without shader information, but that was not really what I was searching for.

This was a month ago and I had not much time working on any of these issues, but after restarting my blog earlier this week I thought this would be a nice topic to talk about. I'm still pretty busy with Arena Wars Reloaded, but I worked a couple of hours every day on this little test program for the past few days. The rest of this article explains the project and into which problems I ran.

Class Overview

Before we go into the details here is a little class overview of the project. As I said before the Rocket Commander XNA engine was used to get up and running with the project without having to re implement the basics. Most of the classes were already in place and had not to be changed. ColladaModel and SkinnedTangentVertex are the 2 new classes and to help us out with the XML loading of the collada files the XmlHelper class was also brought into the project.

I wrote the ColladaModel file from scratch, but I could reuse some of the static mesh loading code I had done last year. All of the bone and animation loading code was just try and error and I only used the collada specifications as a source of help, but most stuff had to be tested with the unit tests at the end of the class many many times.

The main program just calls the unit tests TestGoblinColladaModelScene or TestShowBones, there is no real game here, its just a test program. The unit test then calls several Standard Engine classes for doing all the post screen processing, rendering the ground plane, etc. More importantly the ColladaModel class itself basically just provides a constructor and a Render method, everything else is private and will be handled automatically for you. Most people might ignore this, but this is always the most important thing about my classes, the use should be as simple as possible and when I look at the projects mentioned above I really ask myself why people sometimes think so complicated.

The internal Bone class inside ColladaModel is used to store all the bones in a flat list, but each entry has a parent and a list old children bones. This way the list can be used both in a simple for loop, but you can also go through it recursively (which is obviously slower and often more complicated). We will talk about the loading process in a minute.

All the mesh data is stored in vertices, which is just a list of SkinnedTangentVertex structs. The SkinnedTangentVertex struct is very much like the standard TangentVertex struct used in Rocket Commander XNA, but it has 2 new members: blendIndices and blendWeights. Both are in the form of Vector3 and their fore can hold 3 values allowing us to interpolate up to 3 bone influences for each vertex in the shader. More is often not required and we have to re normalize all bone weights anyway, so skipping the least important bone weights is not a big deal. My test models use mostly max. 2-3 influences. Please also note that the vertex shader has now a lot more work to do with all that skinning and you should really optimize it as much as possible. Both the number of vertices we have to process is important (we will talk about optimizing that in the optimizing part of this article) and also the number of instructions the vertex shader has, both numbers should be as low as possible. The GPU is really fast processing this data, but if you do not have animated geometry with bones, there is no reason to let it process all that data (which can make the vertex shader 2-3 times longer and slower). The ground of our test scene does not use a skinning shader as an example.

And finally there are some additions to the ShaderEffect class. First of all we got a new shader called "SkinnedNormalMapping", which does the same thing as the normal mapping (or parallax mapping) shader, but it has an array of 80 bone matrices we can use for skinning. These matrices are set with help of the SetBoneMatrices method in the Set Parameter region of ShaderEffect.cs.

Loading collada files

Before we go into the details of the loading process, lets make sure we read the summary of the class first because it clearly states what we can do and can't do with this class. This is just a test project and I wanted to make things as simple as possible for both you as the reader and for my requirements.

   /// <summary>
   /// Collada model. Supports bones and animation for collada (.dae) exported
   /// 3D Models from 3D Studio Max (8 or 9).
   /// This class is just for testing and it will only display one single mesh
   /// with bone and skinning support, the mesh also can only have one single
   /// material. Bones can be either in matrix mode or stored with transform
   /// and rotation values. SkinnedTangentVertex is used to store the vertices.
   /// </summary>
   class ColladaModel : IDisposable

OK, with that said let's go directly into the loading code, which is located in the constructor of this class. All variables used in these class are just for internal use, all you need to know are the vertices and bone lists, which I have already mentioned, and the vertex and index buffers, which are used for rendering. All the rest of the variables are just there to help us loading the collada file (don't worry, there are not many variables anyway and most methods are short too).

    #region Constructor
    /// <summary>
    /// Create a model from a collada file
    /// </summary>
    /// <param name="setName">Set name</param>
    public ColladaModel(string setName)
    {
        // Set name to identify this model and build the filename
        name = setName;
        string filename = Path.Combine(ColladaDirectory,
            StringHelper.ExtractFilename(name, true) + "." +
            ColladaExtension);

        // Load file
        Stream file = File.OpenRead(filename);
        string colladaXml = new StreamReader(file).ReadToEnd();
        XmlNode colladaFile = XmlHelper.LoadXmlFromText(colladaXml);

        // Load material (we only support one)
        LoadMaterial(colladaFile);
        
        // Load bones
        LoadBones(colladaFile);

        // Load mesh (vertices data, combine with bone weights)
        LoadMesh(colladaFile);

        // And finally load bone animation data
        LoadAnimation(colladaFile);

        // Close file, we are done.
        file.Close();
    } // ColladaModel(setFilename)
    #endregion

As you can see first of all the filename is constructed and we just load the file as a text file and throw it to the XmlHelper.LoadXmlFromText helper method (which just uses the existing XmlDocument functionality to load xml from a string). We now get the main collada node, which contains all the children nodes we need for loading the materials, bones, meshes, etc.

Next all the materials are loaded, but we are only going to use the first one we find because we only support one single mesh anyway. The LoadMaterial method goes through all used textures and shader effects from the collada file and constructs the material at the end of the method with help of a new constructor in the Material class itself. While this is cool and a lot easier than loading material data from x files, it is not very exciting code, so let's move along.

Even through the bones are located at the end of the collada file, we have to load them first because all our other loading methods, specifically LoadMesh and LoadAnimation need the bone tree structure and the overall bone list to work. All bones are loaded in sequential order because we want to make sure that we can use the animation matrices later in an easy way without having to check the parent order all the time. Only this way we can be sure that going through our flat bones list we still respect the internal tree structure and always initialize the parents first because the children bones matrices are always multiplied with the parent bones.

    foreach (XmlNode boneNode in boneNodes)
        if (boneNode.Name == "node" &&
            (XmlHelper.GetXmlAttribute(boneNode, "id").Contains("Bone") ||
            XmlHelper.GetXmlAttribute(boneNode, "type").Contains("JOINT")))
        {
            // [...] get matrix
            matrix = LoadColladaMatrix(...);

            // Create this node, use the current number of bones as number.
            Bone newBone = new Bone(matrix, parentBone, bones.Count,
                XmlHelper.GetXmlAttribute(boneNode, "sid"));

            // Add to our global bones list
            bones.Add(newBone);
            // And to our parent, this way we have a tree and a flat list in
            // the bones list :)
            if (parentBone != null)
                parentBone.children.Add(newBone);

            // Create all children (will do nothing if there are no sub bones)
            FillBoneNodes(newBone, boneNode);
        } // foreach if (boneNode.Name)

As you can see the code uses the XmlHelper class extensively because otherwise the code would look much uglier and complex. Next we have to load the mesh itself, this is probably the longest method and not easy to figure out if you work with collada for the first time. Good thing I had already done that in the past and I only had to add the code for getting the blend weights and indices. The following code does load all the weights, which we will use later to fill the blendWeights and blendIndices members of the SkinnedTangentVertex struct vertices list. The code for that is actually a little bit more complicated because we have to find out which weights are the top 3 weights for each vertex in case more than 3 are given.

    #region Load weights
    float[] weights = null;
    foreach (XmlNode sourceNode in skinNode)
    {
        // Get all inv bone skin matrices
        if (sourceNode.Name == "source" &&
            XmlHelper.GetXmlAttribute(sourceNode, "id").Contains("bind_poses"))
        {
            // Get inner float array
            float[] mat = StringHelper.ConvertStringToFloatArray(
                XmlHelper.GetChildNode(sourceNode, "float_array").InnerText);
            for (int boneNum = 0; boneNum < bones.Count; boneNum++)
                if (mat.Length / 16 > boneNum)
                {
                    bones[boneArrayOrder[boneNum]].invBoneSkinMatrix =
                        LoadColladaMatrix(mat, boneNum * 16);
                } // for if
        } // if

        // Get all weights
        if (sourceNode.Name == "source" &&
            XmlHelper.GetXmlAttribute(sourceNode, "id").Contains("skin-weights"))
        {
            // Get inner float array
            weights = StringHelper.ConvertStringToFloatArray(
                XmlHelper.GetChildNode(sourceNode, "float_array").InnerText);
        } // if
    } // foreach

    if (weights == null)
        throw new InvalidOperationException(
            "No weights were found in our skin, unable to continue!");
    #endregion

For more information about the mesh loading please check out the last region in the LoadMesh method, it should explain all the important steps in case you want to add something there or just look how it works.

Problems with the animation data

Getting the animation data was not so easy. First of all I never had done this before because my collada files for the Racing Game were all just static meshes and I really did not need any animation there. Everything that is actually animated in the Racing Game was done directly in XNA, not in 3D Studio.

The first problem is the many formats that animation data can be in. You can have rotations around any axis or translations and even scalings, but most of your bones will only use one or two of these if they are animated at all. Alternatively all the animation data can be computed directly by the exporter plugin in 3D Studio Max and this way you can make sure that all the animation data is in the correct format. It makes testing certainly a lot harder and if you don't even know the format the matrices are in or how to apply them to each other in which order, you are in a world of trouble.

This is exactly what happened to me, I had most of my test models with rotation animation data only, but the Goblin above from my friend Christoph was done with another technique and the exporter could only export the matrices, so I had to support that too. After some try and error I managed to get the basic animations for my test models working. They are all in the project, feel free to load and test them. To test the bone animations I used the following unit test:

    #region Unit Testing
    // Note: Allow calling all this even in release mode (see Program.cs)
    #region TestShowBones
    /// <summary>
    /// TestShowBones
    /// </summary>
    public static void TestShowBones()
    {
        ColladaModel model = null;
        PlaneRenderer groundPlane = null;
        // Bone colors for displaying bone lines.
        Color[] BoneColors = new Color[]
            { Color.Blue, Color.Red, Color.Yellow, Color.White, Color.Teal,
            Color.RosyBrown, Color.Orange, Color.Olive, Color.Maroon, Color.Lime,
            Color.LightBlue, Color.LightGreen, Color.Lavender, Color.Green,
            Color.Firebrick, Color.DarkKhaki, Color.BlueViolet, Color.Beige };

        TestGame.Start("TestLoadColladaModel",
            delegate
            {
                // Load our goblin here, you can also load one of my test models!
                model = new ColladaModel(
                    //"Goblin");
                    //"test_bones_simple_baked");
                    //"test_bones_advanced_baked");
                    "test_man_baked");

                // And load ground plane
                groundPlane = new PlaneRenderer(
                    new Vector3(0, 0, -0.001f),
                    new Plane(new Vector3(0, 0, 1), 0),
                    new Material(
                        "GroundStone", "GroundStoneNormal", "GroundStoneHeight"),
                    50);
            },
            delegate
            {
                // Show ground
                groundPlane.Render(ShaderEffect.parallaxMapping, "DiffuseSpecular20");

                // Show bones without rendering the model itself
                if (model.bones.Count == 0)
                    return;

                // Update bone animation.
                model.UpdateAnimation(Matrix.Identity);

                // Show bones (all endpoints)
                foreach (Bone bone in model.bones)
                {
                    foreach (Bone childBone in bone.children)
                        BaseGame.DrawLine(
                            bone.finalMatrix.Translation,
                            childBone.finalMatrix.Translation,
                            BoneColors[bone.num % BoneColors.Length]);
                } // foreach (bone)
            });
    } // TestShowBones()
    #endregion

The most important call here is the call to UpdateAnimations, which goes through the list of bones and updates the so called finalMatrix from the Bone class for each of the bones. In earlier versions this code was horribly complicated and still had a lot of problems, but as soon as I removed all the rotation, translation, scaling, etc. animation support and just allow loading the correctly baked matrices from the collada files, the code has become much simpler (the actual code does have some optimizations in it, but it is basically the same as the posted code here):

    #region Update animation
    /// <summary>
    /// Update animation.
    /// </summary>
    private void UpdateAnimation(Matrix renderMatrix)
    {
        int aniMatrixNum = (int)(BaseGame.TotalTime * frameRate)) % numOfAnimations;

        foreach (Bone bone in bones)
        {
            // Just assign the final matrix from the animation matrices.
            bone.finalMatrix = bone.animationMatrices[aniMatrixNum];

            // Also use parent matrix if we got one
            // This will always work because all the bones are in order.
            if (bone.parent != null)
                bone.finalMatrix *=
                    bone.parent.finalMatrix;
        } // foreach
    } // UpdateAnimation()
    #endregion

For the loading itself we just have to make sure that the animationMatrices are the correct ones. Collada saves them in a absolute mode. Earlier code from me constructed relative matrices (relative to the initial bone matrix), it was easier to construct relative matrices from the rotation, translation, etc. animation data, but much harder to use these matrices later for the animation. Having these absolute matrices makes the UpdateAnimation code so much easier, so make sure you always use them this way.

However, when rendering the vertices later we can't use the absolute matrices because the vertices have to transformed first to get into a relative space to the bones, rotations should not be around the origin, but around the bone positions. Luckily for us (and you should have seen my face when I finally found out that these matrices already exist in collada and I did not have to create them myself in my own over complicated way ^^) collada stores the so called invBoneSkin matrices for each bone. By applying these matrices we can easily get the bone matrices we need for rendering, these are directly passed to our shader (as compressed 4x3 matrices BTW to save shader constants, the code for that is a little bit more complex, please check out ShaderEffect.cs and the SkinnedNormalMapping.fx shader itself for details).

    #region GetBoneMatrices
    /// <summary>
    /// Get bone matrices for the shader. We have to apply the invBoneSkinMatrix
    /// to each final matrix, which is the recursively created matrix from
    /// all the animation data (see UpdateAnimation).
    /// </summary>
    /// <returns></returns>
    private Matrix[] GetBoneMatrices(Matrix renderMatrix)
    {
        // Update the animation data in case it is not up to date anymore.
        UpdateAnimation(renderMatrix);

        // And get all bone matrices, we support max. 80 (see shader).
        Matrix[] matrices = new Matrix[Math.Min(80, bones.Count)];
        for (int num = 0; num < matrices.Length; num++)
            // The matrices are constructed from the invBoneSkinMatrix and
            // the finalMatrix, which holds the recursively added animation matrices
            // and finally we add the render matrix too here.
            matrices[num] =
                bones[num].invBoneSkinMatrix * bones[num].finalMatrix * renderMatrix;

        return matrices;
    } // GetBoneMatrices()
    #endregion

And this is what you finally get after executing the TestShowBones unit test. I had not implemented mesh loading or the shader itself at this point. I just was loading and testing the bones itself.

 

Optimizing the vertices

One major problem with the loaded mesh is the high vertices count, I had two test models with 30k and 60k vertices and as you can imagine this will slow down the vertex shader quite a lot and it is really not necessary to process all these vertices because many of them are exactly the same. The reason we end up with an unoptimized vertices list anyway is because collada stores seperate lists for each component we have to put together at the end of the LoadMesh method. By doing so we have to duplicate the data many times and we just can't know how often each part is reused and how often the overall vertex changes. If just the texture coordinate or normal differs, we have a completely different vertex, which will produce different results in the vertex shader, so just merging everything together is not that simple.

The rendering uses an index buffer anway, but for the data constructed in LoadMesh it would just be sequential (0, 1, 2 form the first polygon, 3, 4, 5 the next, etc.). Instead of having one index for each vertex, we can often reuse the same vertex 3 or 4 times and reducing the number of vertices drastically. This has also the advantage that we can store much more vertices and complexer meshes even if we still use ushort (16 bit) for our indices (which is half the size of ints and their fore faster). For example if you have 150,000 vertices, but you can reduce them to 40-50,000 optimized vertices, they all can be indexed with ushorts

The easy solution is just to optimize all the vertices after all of them have been loaded, if you have a binary format and do not use collada directly, this solution is absolutely great, but it still will take a lot of time processing the collada models if they just have many vertices because we have to check each vertex against each other one and that can be a lot of compares if you have 60 or 70 thousand vertices in a mesh. It actually takes up to a whole minute just to compute that and I have no slow computer ^^ Here is the method that does all that for us:

    #region OptimizeVertexBufferSlow
    /// <summary>
    /// Optimize vertex buffer. Note: The vertices list array will be changed
    /// and shorted quite a lot here. We are also going to create the indices
    /// for the index buffer here (we don't have them yet, they are just
    /// sequential from the loading process above).
    ///
    /// Note: Slow version because we have to check each vertex against
    /// each other vertex, which makes this method exponentially slower
    /// the more vertices we have. Takes 10 seconds for 30k vertices,
    /// and over 40 seconds for 60k vertices. It is much easier to understand,
    /// but it produces the same output as the fast OptimizeVertexBuffer
    /// method and you should always use that one (it only requires a couple
    /// of miliseconds instead of the many seconds this method will spend).
    /// </summary>
    /// <returns>ushort array for the optimized indices</returns>
    private ushort[] OptimizeVertexBufferSlow()
    {
        List<SkinnedTangentVertex> newVertices =
            new List<SkinnedTangentVertex>();
        List<ushort> newIndices = new List<ushort>();

        // Go over all vertices (indices are currently 1:1 with the vertices)
        for (int num = 0; num < vertices.Count; num++)
        {
            // Try to find already existing vertex in newVertices list that
            // matches the vertex of the current index.
            SkinnedTangentVertex currentVertex = vertices[FlipIndexOrder(num)];
            bool reusedExistingVertex = false;
            for (int checkNum = 0; checkNum < newVertices.Count; checkNum++)
            {
                if (SkinnedTangentVertex.NearlyEquals(
                    currentVertex, newVertices[checkNum]))
                {
                    // Reuse the existing vertex, don't add it again, just
                    // add another index for it!
                    newIndices.Add((ushort)checkNum);
                    reusedExistingVertex = true;
                    break;
                } // if (TangentVertex.NearlyEquals)
            } // for (checkNum)

            if (reusedExistingVertex == false)
            {
                // Add the currentVertex and set it as the current index
                newIndices.Add((ushort)newVertices.Count);
                newVertices.Add(currentVertex);
            } // if (reusedExistingVertex)
        } // for (num)

        // Reassign the vertices, we might have deleted some duplicates!
        vertices = newVertices;

        // And return index list for the caller
        return newIndices.ToArray();
    } // OptimizeVertexBufferSlow()
    #endregion

 

Optimizing the Optimization

While this is all nice and dandy and we just optimized the rendering code by 20-30% (I tested with 9 goblins and using 3 passes for them, 2 for shadowing and 1 for the rendering), but the loading now takes painfully long. The main idea here is to not compare every single vertex against every other possible vertex because it does not make much sense, most of the vertices (>99,9%) will always be different. We only need to check the ones that share at least the same position.

I started with comparing neighboring vertices, but since the vertices are stored in index order, they are totally messed up, vertex 1 and 4383 can be equal, but if we just check -10 to +10 we are going to miss it. Instead we have to know which vertices come from the same position data, which we know since collada saves unique positions. All we have to do is to keep a list of all vertices that share the same position and then we can optimize the comparsions later on. Usually only up to 4 to 6 vertices share the same position, this way the whole comparison process just needs 60,000 * 6 comparisons, not 60,000*60,000 anymore.

    // Initialize reuseVertexPositions and reverseReuseVertexPositions
    // to make it easier to use them below
    reuseVertexPositions = new int[trianglecount * 3];
    reverseReuseVertexPositions = new List<int>[positions.Count / 3];
    for (int i = 0; i < reverseReuseVertexPositions.Length; i++)
        reverseReuseVertexPositions[i] = new List<int>();

    // We have to use int indices here because we often have models
    // with more than 64k triangles (even if that gets optimized later).
    for (int i = 0; i < trianglecount * 3; i++)
    {
        // [...] vertex construction

        // Remember pos for optimizing the vertices later more easily.
        reuseVertexPositions[i] = pos / 3;
        reverseReuseVertexPositions[pos / 3].Add(i);
    } // for (ushort)

And then finally the fast vesion of OptimizeVertexBuffer, which uses that data:

    #region OptimizeVertexBuffer
    /// <summary>
    /// Optimize vertex buffer. Note: The vertices list array will be changed
    /// and shorted quite a lot here. We are also going to create the indices
    /// for the index buffer here (we don't have them yet, they are just
    /// sequential from the loading process above).
    ///
    /// Note: This method is highly optimized for speed, it performs
    /// hundred of times faster than OptimizeVertexBufferSlow, see below!
    /// </summary>
    /// <returns>ushort array for the optimized indices</returns>
    private ushort[] OptimizeVertexBuffer()
    {
        List<SkinnedTangentVertex> newVertices =
            new List<SkinnedTangentVertex>();
        List<ushort> newIndices = new List<ushort>();

        // Helper to only search already added newVertices and for checking the
        // old position indices by transforming them into newVertices indices.
        List<int> newVerticesPositions = new List<int>();

        // Go over all vertices (indices are currently 1:1 with the vertices)
        for (int num = 0; num < vertices.Count; num++)
        {
            // Get current vertex
            SkinnedTangentVertex currentVertex = vertices[num];
            bool reusedExistingVertex = false;

            // Find out which position index was used, then we can compare
            // all other vertices that share this position. They will not
            // all be equal, but some of them can be merged.
            int sharedPos = reuseVertexPositions[num];
            foreach (int otherVertexIndex in reverseReuseVertexPositions[sharedPos])
            {
                // Only check the indices that have already been added!
                if (otherVertexIndex != num &&
                    // Make sure we already are that far in our new index list
                    otherVertexIndex < newIndices.Count &&
                    // And make sure this index has been added to newVertices yet!
                    newIndices[otherVertexIndex] < newVertices.Count &&
                    // Then finally compare vertices (this call is slow, but thanks to
                    // all the other optimizations we don't have to call it that often)
                    SkinnedTangentVertex.NearlyEquals(
                    currentVertex, newVertices[newIndices[otherVertexIndex]]))
                {
                    // Reuse the existing vertex, don't add it again, just
                    // add another index for it!
                    newIndices.Add((ushort)newIndices[otherVertexIndex]);
                    reusedExistingVertex = true;
                    break;
                } // if (TangentVertex.NearlyEquals)
            } // foreach (otherVertexIndex)

            if (reusedExistingVertex == false)
            {
                // Add the currentVertex and set it as the current index
                newIndices.Add((ushort)newVertices.Count);
                newVertices.Add(currentVertex);
            } // if (reusedExistingVertex)
        } // for (num)

        // Finally flip order of all triangles to allow us rendering
        // with CullCounterClockwiseFace (default for XNA) because all the data
        // is in CullClockwiseFace format right now!
        for (int num = 0; num < newIndices.Count / 3; num++)
        {
            ushort swap = newIndices[num * 3 + 1];
            newIndices[num * 3 + 1] = newIndices[num * 3 + 2];
            newIndices[num * 3 + 2] = swap;
        } // for

        // Reassign the vertices, we might have deleted some duplicates!
        vertices = newVertices;

        // And return index list for the caller
        return newIndices.ToArray();
    } // OptimizeVertexBuffer()
    #endregion

With this optimization loading is now pretty fast and rendering performs also nicely thanks to the quick shaders we will discuss below. When running ANTS Profiler over the new project the slowest line of code becomes the actual text parsing, actually the conversion of the long strings for all vertices data into the actual vertices float data, especially the positions array. But we can't do anything about that without loading the data binary and not parsing them ourselfs. It takes maybe half a second for a 50k vertices model to load, not great, but ok for our little test app.

Adjusting the shaders for skinned meshes

Now we got a bunch of vertices we can render, but as you know we need a shader to do anything in XNA, there is no fixed function pipeline. There are also no animation helper classes like in DirectX, but they won't help you anyway if you want to render with shaders. Transforming the vertices on the CPU may sometimes be a choice if you do not have many vertices and not many skinned models overall or if they all have to be updated the same way. But generally it is a much better idea to transform all the vertices on the GPU, which costs a little bit more instructions in the vertex shader, but the rest of the rendering stays the same. Most graphic apps are pixel shader bound anyway and I use fairly complex pixel shaders too. Additionally on Shader Model 4.0 cards like the GeForce 8800 with up to 128 parallel unified shader units you can do very complex vertex shaders and use simpler pixel shaders and it will just use more units for the vertex shaders automatically :)

We already have defined the bones matrix array for skinning above and we limited it to 80 bones per mesh, which is quite a lot. Even if you would spend 3 bones per finger and 20-30 bones for the body you would still have plenty of bones left for complex animations. Sure modelers will now say "thats not enough sometimes" ... well, you can always split up the mesh into several meshes with up to 80 bones each if you really need more. My graphic artists are happy with 80 bones ^^

If we want full Shader Model 2.0 support we can only be sure that we got at least 256 shader constants. NVidia has usually more (1024), but you still want your game to run on ATI cards too, especially older ones. Each constant can hold a float4 and we need 4 constants for each 4x4 matrix. This means we can only have up to 64 matrices with this limit and we still need some constants for the world, view, and projection matrices, the light and material values and anything else we want to do in our shader. You should reserve 10-20 constants for that and now we are down to less than 60 matrices, which might sometimes be too little.

Instead of splitting the mesh or providing a different code path in case the GPU can do more constants (I couldn't get that do work in XNA for some reason, not sure if there is some limit or if I made a mistake, my GPU should be able to do at least 1024 constants, and even 2048 for the 8800), there is a trick to save only a 3x4 matrix. The last colum is always 0, 0, 0, 1 if we have correctly applied the invBoneMatrix and the animation matrix (see GetBoneMatrices in ColladaModel for details and the order of the matrices). But saving 4 float3 values still needs 4 shader constants per matrix so we have to save it as 4x3 matrices instead.

My first idea was to grab the .w values and reconstruct the translation part of the matrix this way. This worked, but the resulting shader had 80 instructions (from abount 20 without skinning), which is not good for the resulting performance when rendering many skinned 3D models.

float4x4 RebuildSkinMatrix(float index)
{
    return float4x4(
        float4(skinnedMatricesVS20[index*3+0].xyz, 0),
        float4(skinnedMatricesVS20[index*3+1].xyz, 0),
        float4(skinnedMatricesVS20[index*3+2].xyz, 0),
        float4(
            skinnedMatricesVS20[index*3+0].w,
            skinnedMatricesVS20[index*3+1].w,
            skinnedMatricesVS20[index*3+2].w, 1));
} // RebuildSkinMatrix(.)

A better idea is to use the 4x3 matrix as a 3x4 matrix by just reversing the order we call mul. This involves some changes to the vertex shader code and looks a little bit confusing sometimes, but if you make sure you transform the world matrix the same way and use it in this reversed mul order too, everything works just fine. Another thing that can be optimized is to pre-multiply the indices of blendIndices for each vertex at the loading time. These indices never change and they don't really care if they are 0, 1, 2 or 0, 3, 6, etc. We save one instruction per matrix we are going to reconstruct (the rest is optimized out by the compiler). This is the much easier version of RebuildSkinMatrix, for more details take a look at the SkinnedNormalMapping.fx file:

// Note: This returns a transposed matrix, use it in reversed order.
// First tests used a 3x3 matrix +3 w values for the transpose values, but
// reconstructing this in the shader costs 20+ extra instructions and after
// some testing I found out this is finally the best way to use 4x3 matrices
// for skinning :)
float4x4 RebuildSkinMatrix(float index)
{
    return float4x4(
        skinnedMatricesVS20[index+0],
        skinnedMatricesVS20[index+1],
        skinnedMatricesVS20[index+2],
        float4(0, 0, 0, 1));
} // RebuildSkinMatrix(.)

This results in a vertex shader that has almost half as many instructions as before and their fore is twice as fast :) Good work. Performance tests showed that I could increase the framerate from 220 fps to 270 fps just by doing that (test scene with 9 goblins). The following code is actually more or less the only part you have to replace in an existing shader if you want to make it skinnable (plus providing the helper method and the skinned matrices too of course).

    // First transform position with bones that affect this vertex
    // Use the 3 indices and blend weights we have precalculated.
    float4x4 skinMatrix =
        RebuildSkinMatrix(In.blendIndices.x) * In.blendWeights.x +
        RebuildSkinMatrix(In.blendIndices.y) * In.blendWeights.y +
        RebuildSkinMatrix(In.blendIndices.z) * In.blendWeights.z;
    
    // Calculate local world matrix with help of the skinning matrix
    float4x4 localWorld = mul(world, skinMatrix);
    
    // Now calculate final screen position with world and viewProj matrices.
    float4 worldPos = mul(localWorld, float4(In.pos, 1));
    Out.pos = mul(worldPos, viewProj);

 

Post screen shaders for the final result

All the skinning code and bone transformations are nice once you get them done, but without a cool model and some post screen shaders to make the scene look more cool, it is only half the fun. Good think I got the Goblin 3D Model, thanks to Christoph (WAII) again. I also had a couple of other test models and another more complex 3D Model (big evil monster ^^) which was good for some stress testing, but the material just did not look that cool.

As you can see on the following image 6 render targets are used to accomplish the final image. Most shader passes do several things at once and the list of operations (see right side of the image) is longer than the list of used passes. Most of this was just trying to get the best looking values together quickly. If you are an experienced artist you can probably do much better than me, I'm just playing around with the shader parameters until I get bored and then I leave it the way it is. The sceneMap (render target nummero three) shows the unmodified scene without applying the post screen shaders. It does not look half as cool as the final result.

I hope you enjoyed this article and that you are not as tired as I am writing this all at once (uff). It was a fun project, I have already another one in mind for next week Take care. If you have problems, post a comment. Please note that not all collada models will work, you have to follow the rules of ColladaModel or improve the class a bit for other use

 

References and Links

• SkinningWithColladaModelsInXnaSourceCode.zip (2.6 MB) from this article
• SkinningWithColladaModelsInXnaExecuteable.zip (2.5 MB) from this article
• XNA Animation Component Library
• Panda Exporter for 3dsMax
• kiloWatt X file Exporter for 3dsMax
• Official Collada site from the Khronos Group
• Feeling Software Collada Plugins for 3dsMax and Maya, best exporters ever!
• Public Forum of Collada.org
• Wikipedia on Collada
• Collada Forum post about remi's Collada for XNA project
• COLLADA 1.4.1 Specification (PDF)

 

 

Well, I was posting less and less on this blog and this gonna change now. From now on I will try to post often, maybe even daily. The blog posts will not be as long as before, I will just talk about whats on my mind each day. Initially this blog was started as a little diary for me and I will return to that initial idea.

As you can see I've updated my blog, added a couple of features and changed some pictures and styles. At the top you see a little collage of current game projects I'm working on. Most graphics are from Arena Wars Reloaded and the XNA Racing Game. I hope you like the overall design

I will talk more about my current projects (see right side) in the next couple of posts and catch up with a couple of topics I have on my mind but not blogged about yet (FxCop stuff, CgFX, using Collada in XNA, etc.).

Not much going on here on my blog, but in reality I was quite busy finishing some projects.
Our whole team at exDream is also working hard on our upcoming game Arena Wars Reloaded.
But it will take another month until we can release some cool looking screenshots that will make you excited.

In the meantime you can check out this nice article with lots of interviews on gamecareerguide.com.
On page 3 I do answer some questions and talk about current projects I'm involved in, including the
Professional XNA Game Development book I've done. The book will come out in early may this year.

The article is 5 pages long and a nice read:
http://www.gamecareerguide.com/features/328/microsoft_xna_.php





While we are at it, I decided to finally post some high quality (1920x1200) Racing Game screenshots (formerly known as XNA Racer).
I don't know yet when it will be released, but it shouldn't take much longer

Screenshot 1:


Screenshot 2:


Screenshot 3:


Screenshot 4:




Lately I'm also playing around with the Visual Studio "Orcas" CTP which was released a week ago. Runs fine side by side with all my other
Visual Studio versions, but some plugins do not work and most language extensions I have installed (like LinQ or ASP.NET Ajax) are just
missing, not sure yet how to fix that or if I will really develop with VS Orcas right now, there is not really an advantage yet.

And finally there is a big fight coming up: Me vs FxCop. I will discuss my experiences with FxCop in a few days after I have converted
Arena Wars Reloaded and fought agains the 7000+ warnings ^^
In smaller projects I had worked with FxCop before and some warnings are annoying, but usually easy to fix. It was a little harder in
the Racing Game XNA starter kit (see screenshots above) because that thing has already over 20,000 lines of code and many warnings were
just about my unit tests, which FxCop can't figure out (lots of uncalled methods). But I will discuss all of this in a few days. Not sure
if any other game development team even uses FxCop or similar tools. At least I have never seen a game (or even a big app) pass the crazy
FxCop rules.

I developed a little Shoot'n'up game in the last couple of days. It is actually quite fun to play. It is just one level and is kind of a prototype. The game will be released together with my XNA Professional Game Development book in a few months (it will be freely available from my website shortly after that). My book features many other games too, it is not just about one game, there are many arcade, action and other games in the book (about 8 games or so) and they will be described as I explain all the important aspects of Game Programming and the XNA Framework.

For now I can only give you a little video about XNA Shooter. I hope you like it.

A "little" 1920x1200 screenshot:

These days there are a lot of discussions about XNA, especially in the GameDev.net boards and of course in the official XNA forum by Microsoft.
http://www.gamedev.net/community/forums/topic.asp?topic_id=430119
http://forums.microsoft.com/msdn/showforum.aspx?forumid=846

I also want to mention a great article by the .NET Compact Framework team about the .NET performance on the Xbox 360 with the XNA Framework. The main issue here is the Garbage Collector, which is not generational and theirfore can only collect all the objects in the GC at once and not in 3 levels like in the normal .NET Framework, which can handle a lot more dead objects and more complicated situations.

Here are the links to the .NET Compact Framework on XNA article:
http://blogs.msdn.com/netcfteam/archive/2006/12/22/
managed-code-performance-on-xbox-360-for-the-xna-framework-1-0.aspx
http://blogs.msdn.com/netcfteam/archive/2006/12/22/
managed-code-performance-on-xbox-360-for-xna-part-2-gc-and-tools.aspx

From my experience there are a couple of things you have to remember when developing XNA games on the Xbox 360. All of these issue are not a big deal on the PC, but they can cost some extra time until you get them right. One of the main problems is that if you develop your game on the PC only and then test it on the Xbox 360 only at the end a lot of things may go wrong (bad performance on the .NET Compact Framework, UI elements at the border of the screen, which are just not visible on some TVs, bad Xbox 360 controller support, which is the main input device for Xbox 360s, etc.).

• Test test test. This is the most important tip. Write unit tests and constantly test them on your PC AND your Xbox 360. I keep 2 projects open at the same time (both of them use the same files, but I only develop the PC solution and use the Xbox 360 solution for deploying and testing only). Almost all of my classes have unit tests and I constantly test them until they are completed.
• Don't use foreach loops, especially not in tight render loops. This may sound a little crazy since it does not matter on a PC game and todays CPUs are fast enough to handle the creation and deletion of many thousand objects each frame, which most games don't even need. But on the compact framework you will spam the memory even with things like foreach loops because a new enumerator instance is created everytime you start a foreach loop. After a while there will be a lot of dead objects, which have to be collected. This can take some time and slow your game down immensely. The PC version might run at over 200 frames, but your Xbox 360 version is stuck at something like 30-40 frames. Avoiding creation of new data each frame and avoiding foreach loops (just replace them with normal for loops, it is mostly just 1 line of extra code) can improve your performance by a factor of 100% or more.
• In Arena Wars I never created any data during the game. All objects were created at the beginning of each mission and they were reused (which was no big deal since the game principle did not allow an infinite number of units, it always stayed around the same because you get your money back from dead units to build new units). In later project I did not care so much about creating new objects and I coded just the easy way because unit tests drive you into a direction to quickly develop solutions, which work and are tested, but may not be the best in other situations like for the Xbox 360 .NET Compact Framework. That is ok because we can now use the unit tests to check if other solutions work just they way we expect them to work. For XNA Shooter and XNA Racer (and a couple of other new game projects) I now make sure that most of the game data is created at the beginning of each level and not dynamically during the game.
• Save-Regions on TVs can be a pain in the ass. Just google for Xbox 360 screenshots and you will notice that the GUI (graphical user interface) looks a lot different from most PC games. PC games have often UI at the screen border showing you tips, little buttons and other not so important things. If you do that in your Xbox 360 game all of these UI elements may be cut of on a regular TV. For the XNA Shooter I had to rework all the UI elements because they just did not fit on a TV screen and it was not practical to put them in a bar (like the windows task bar) because it looks so different on the PC and certain TV monitors. Instead I put all UI elements in floating bars, which will be adjusted depending on the screen the user is looking at.
  These are some of the Save-Regions I have encountered:
  
  • PC: 100% visible
  • Xbox 360 connected through a VGA cable: 100% (or close to 100%) visible.
  • Xbox 360 connected to an old style monitor with SCART: around 92% visible.
  • Xbox 360 connected through Component cables to my new Dell 24" Monitor (yeah HDTV): around 93-95% visible (depends on the resolution).
  • Some old TV sets (according to the XNA docs and tips on the web) have a save region of 80-90%, but I never saw the 80% case, that is probably the worst case scenario.
  The important thing is to keep the important UI element in this inner 90% (or 93% if you want to be close to the edges) rectangle. This means instead of using a full 1920x1080 pixel resolution you only use 90% of it (1728x945). Or just start rendering UI elements at about 5% of the screen (x coordinate: 96, y coordinate: 54). This pixel locations obviously depend on the screen resolution, just calculate them in your main class and use them whenever you render UI.
• There are probably a lot more tips I can give, but I'm to lazy right now. Maybe more in a little while :)

Btw: I currently also do a lot of OpenGL development again and I have to say I have totally forgotten about the way you can program OpenGL. It is often a lot easier, it only gets hard if something does not work the way you expect it to be (but thats hard in DirectX too). Well, the most annoying part is of course that you have to wrap all OpenGL methods through PInvoke and that just costs time. On the other hand if you already have a robust framework (like I have with Arena Wars, hehe), it is relatively easy to plug in new features. It also took not long to learn the differences between glsl and hlsl. I do currently also test out the FX Composer 2.0 (alpha), which has a great idea behind it, but it is too much like Render Monkey and that is never a good thing. Render Monkey by ATI is just overcomplicated and hard to use (and was not updated for 2 years, which shows that no one even uses it anymore). The great thing about FX Composer 1 was the fact it was so easy to use and it did only support a very limited feature set. It is not the best tool ever, but it was certainly a lot easier to use than FX Composer 2.0, which will hopefully be improved before NVidia release it.
I have confidence that NVidia will deliver a great tool as always, but they have lost a lot of fans in the last months because of the lack of drivers for Vista, especially for the Geforce 8800, which does not work at all in Vista, but it is the only card on the market that even supports Direct3D 10 (and the new cool unified shader technology in DirectX). The only way you can currently use the new graphic card features is to program them yourself natively with OpenGL ... but my 8800 is in repair anyway, else I would have tried out some of the new features by now.

ArenaWars Reloaded - Coming Soon

Hey now!

Before you read on (I guess this is going to be a long post) please also check out www.exDream.com. We made some pictures from our new office and we recently announced ArenaWars Reloaded (see image on the right), a new game with a new graphic engine and many new cool features based on the original Arena Wars idea (the game play and levels will be similar, but look much better).

My little Christmas present for you is the new port of Rocket Commander to the XNA Framework. It allows you to play the popular Rocket Commander (113 000 played games already can't be wrong) on your Xbox 360 for the first time. You just need an Xbox 360 and have XNA on there. Here are the downloads, the file sizes are are little bit bigger than the original game (my comments are below):

• Rocket Commander XNA on Windows (16 MB): Includes Setup, that will automatically install DirectX Dec 2006 and the XNA Framework if you don't have it yet!
• Rocket Commander XNA on the Xbox 360 cannot be redistributed. You currently have to download the source code and run it in XNA Game Studio Express to even get it on your Xbox. Once you have Rocket Commander XNA deployed with help of the XNA Launcher you can start it anytime you want to without having your PC on or having to redeploy it.
• Full Rocket Commander XNA source code (53 MB): All Content, Sound and Music files are included in this download, this is all you need to compile and run the game on Windows and Xbox 360. The music files are almost 50MB (5MB as mp3, which is not supported in XNA).
• Rocket Commander XNA source code only (213 KB). No content files (models, textures, sounds, etc.) in here, just the .cs, .csproj, .sln and .fx files.

Update: 2007-01-03: Fixed some Bugs with the Input, PostScreenGlow and when device loses focus. Works now more stable. Also cleaned up some of the source code.

Note: Use RocketCommanderXna.sln to compile and run the game on Windows and RocketCommanderXnaXbox360.sln to compile and deploy it to your Xbox 360. For additional details please read the XNA documentation.

The game runs at a very good performance on the Xbox 360, you still got over 60 fps in HDTV 1920x1050 (1080p) with full AA enabled.

Check out some of the new screenshots. Warning, all of them are big, HDTV 1080p resolution. Actually I could not capture any images from the Xbox 360 directly, which runs at 60fps on 1920x1050 and uses fullscreen Antialiasing and using the highest settings. These screenshots are from my PC hooked up to my new 1920x1200 monitor, also nice :)

The main menu. Not much happend here.

The ingame HUD and general user experience has changed a bit. There is also a new object for the goal since creating a sphere dynamically is not that easy in XNA.

Rocket Commander is still fast and it pumps up your adrenaline even more in combination with a big monitor :)

Another screenshot from the last level. Please note that you can see more asteroids at the same time than in the original game. You can also look a lot farther and see more items from great distances.

The explosion is unchanged. It still looks the same crappy way, but the AnimationTexture class had to be reimplemented to work with XNA textures now.

Initially I thought "Hey, this is easy, let's port Rocket Commander to XNA.". The initial port attempt was pretty good, it took only 3-4 days to port the 25 000+ lines of code used in Rocket Commander. I could remove some classes and I also simplified some classes, the total number of lines got smaller (~20 000 lines), but after adding some new features and some new unit tests and some testing code for multithreading it is about 22 000 lines of code, still less than the original. XNA is definately the future, MDX was great, but it was not updated for a long time and if you start something new, go with the fresh XNA Framework!

Here are some of my experiences from the process of writing Rocket Commander XNA. Please note that some of these comments were written while I was developing and kinda sleep deprived. Beware of the harsh tone, in the end all worked out great :)
++ means this topic was great and better than MDX.
+ means it was good and nice to work with.
- means I did not like that feature or it was easier in MDX.
-- means this was really annoying and should be improved in the future.

By the way: I did Rocket Commander XNA just for fun, but it also proves how great XNA performs on the Xbox 360. Try to find any other game with this many polygons and effects running in 1080p (1920x1080) with AA enabled on the Xbox 360 ^^ It does not look as good as Gears of War or Halo 3, but it took only 1 man and a short time to develop and it still pushes up to 80-100mio polys each second to the GPU (in some early unit tests, the game runs fine with 20-30 mio polys per second most of the time, check out the model class and its unit tests for more details).

I also use the Rocket Commander XNA engine for 2 other smaller projects because I like the fact that I can test and play these games on the Xbox 360 too and having a complete engine up and running is always a great plus, even if you know how to do a game. It is just easier if you got all the basics covered.

Topic	Rating	Comments
Sound	++	Very easy to use, 1 short class instead of 2 complex ones I had in MDX. Once you get used to XAct you learn that it is a good tool for sound effects, at least if they don't have to be loaded dynamically. The porting process was very simple for sound effect files, they just had to be dragged to XACT and then the project had to be saved, that's it.
Music	--	A lot of converting, different formats, hard to handle, a lot to test, bad documentation. The music from RC was below 5 MB, now it is over 50 MB, which just blows up the source code. Even the compressed take up 13 MB on the PC (ADPCM) and 9 MB on the Xbox 360 (XMA), both in a quality below the original. The rest of the game content (5MB compressed textures, models, effects, sound, etc.) stayed almost the same and could be reused for the most parts.
Unit Testing	-	Harder to use on the Xbox 360, no edit and continue support in the compact .NET framework. There are also no unit testing tools available and all you can do is to call static unit tests from the program class, which is still useful, but harder to do. I still prefer to test on windows. One great thing about the Xbox 360 is the fact that you get multimonitor debugging for free if you have a TV screen and your PC screen. Debug and step through code on your PC and see the result on the TV screen :)
Window handling	++	No extra code required, I could remove several classes and even the helper classes that are still in Rocket Commander Xna are not required for the most parts. Except for some of the game component classes and the design that is not really useful (more about that below) the Game class is really easy to use and simplifies the process to create a new game in a few minutes.
Shaders	++	Everything in XNA is shader based. The original Rocket Commander runs on fixed pipeline only hardware too, but it was a lot of work to handle 2 ways to render everything. With XNA you just have to write the shaders once and just use them. They work perfectly on the PC (Shader Model 1.1 up to 3.0) and on the Xbox 360, all fx files compiled without any problems. Some shaders had to be adjusted to be right-handed now instead of left-handed like in MDX, but that did just take a few minutes to change and all the rest of the shader code could be reused. In the last few months of XNA development I never had once a problem with shaders in XNA, thats really great :)
IDE Features	-	MDX is much older and was never made popular by Microsoft. XNA is new, fresh and great, but it is missing some serious features like Animations for Models. You can implement it yourself, but why even bother with the content pipeline, do it all yourself. It will be much easier and you can extend it in any way you need in the future. XNA development is currently also only avialable with XNA Game Studio Express, which is painful if you are a pure Visual Studio 2005 Professional developer and have lots of plugins you rely on every day (source code management, code rush, testdriven, slickedit, explorer, and many more). This will change in the future and XNA will grow up and dominate the whole world one day :)
Content	--	Sorry, I just don't like the content pipeline (and I have been using it for several months now)! It is bad for dynamically loading textures or shaders or reloadindg them after changes (just not possible with compile-time generated content). On the windows platform you can still load textures and shaders the normal way, which is good, but loading .x file models is just not possible, you have to use the content pipeline. And the content pipeline sucks feature-wise, you have to implement all of stuff yourself. This is my main problem, why should I re-implement generating tangents, shader technique indices, fixing other x file problems, etc. all by myself in a custom content processor, which is not easy to write IMO (bad docu again). By the time I did all that I would have implemented a much more flexible and vesatile custom importer like from .collada files, which are very popular these days ...
Performance	+	The overall performance especially when just doing some benchmarks and performance tests is absolutely perfect on both Windows and the Xbox 360. The GPU is pushed to its limits and there is no reason why you should be afraid of managed code. Windows performance is especially great, all my programs and games are completely GPU bound even in low resolutions and even when they only have one thread. On the Xbox 360 the performance is much worse and you have to take many things into consideration, which is hard because there is again not much documentation around. For example the worst thing you can do on the Xbox 360 is to generate new data each frame, even if you just create an enumerator by executing a foreach loop, it will affect your performance. The good thing is that you have 3 cores (and 6 hardware threads) at your fingertips, which allow you to optimize performance. It was possible for the Rocket Commander game to optimize the game loop a lot because the physics and update threads eat up almost 50% of the CPU time. On the PC it does not matter much because my GPU is slowing everything down (see image below), but on the Xbox 360 I was able to almost double the framerate using multiple threads, nice :) Click Image for to maximize it.
Usability	-	It gets a little easier though all the game helper classes, but the game component class is pretty useless, you can implement something like that in 5 minutes yourself. There is also a DrawableGameComponent class, but you have to call Draw yourself, whats the point here? My classes have some Draw or Render method anyway, I don't need to derive them from GameComponent, I can implement my own interfaces and implement exactly the features I need. Often it is easier to give the Render method a few parameters or even call it several times with different parameters, all that is not possible with DrawableGameComponent. Next there is the content pipeline, which is just a pain in the ass for 3d models. This makes the usability very bad, especially if you develop on Visual Studio 2005 (not Express), which does not support the content pipeline. Also if you are a Vista-Developer XNA Game Studio Express will also not run as expected and my intern hates now both Vista and XNA. It should not happen that someone can get so angry about such great pieces of software, just because they don't work together ^^
Porting	+	If you have written a XNA game or have some XNA code flying around (like the Rocket Commander XNA source code) it is very easy to port existing MDX code to XNA. If you do it from the scratch it is a lot more work and testing until everything works out the way you expect it, but overall it is easy to port from MDX to XNA. Thats very cool, thank the main MDX man Tom Miller for that, who architected parts of XNA too. Porting is easy, but getting the game to work the way you want on the Xbox 360 is not that easy. First of all you got that annoying content pipeline again (I keep repeating myself, maybe I'm too angry ^^), then you have to make sure that you don't render important User Interface on the none-visible area of a monitor that is plugged into a Xbox 360. For example Rocket Commander was only designed for 1 resolution to look good, it had a very small font for some texts on the screen, which is unreadable on TV monitors. Rocket Commander did also not scale well on Widescreen monitors and it rendered a lot of UI elements at the screen borders, which were cut off on TV monitors. The porting took maybe 3-4 days, but I spend at least 4 more days for fixing UI elments and improving the code on the Xbox 360, optimizing asteroid rendering, physics and multithreading. I did not expect that it would take that long and I had only some time in the evenings to even get some XNA work done.
Most annoying		Porting left-handed models, matrices and other complicated math functions over to the right handed system that XNA uses. Maybe it would be easier to use left handed matrices like in the original Rocket Commander for XNA too, but XNA does not provide them and I did think getting it to work with a right handed system would be easier. Then there is of course the problem getting the models into the content pipeline. I used a special content processor, which is also included in the Rocket Commander source code and it can be used for other projects too (I use it for everything I do with XNA). Another annoying thing is the re-deploying of existing game content to the Xbox 360. If you just have 5 files it will not matter to you, but if you got over 50 (Rocket Commander) or even several hundert content files and sometimes due some crazy bug all these files get re-compiled or re-deployed over and over again, it gets really annoying. It takes 30-60 seconds and is not fun ... good think it does not happen that often, but it is still annoying me. Maybe the main reason for regenerating the content on my PC is the fact that I often switch between the Xbox 360 and Windows platforms to test if everything is working the same way on both systems.
Missing features		The XNA version does have all the features from the original Rocket Commander game, including all levels, sub menus and the whole game play. It does not have animated models however because it is not supported out of the box in XNA and I did not have time to reimplement this feature. It does also not support polygon based collision checking for asteroids, which can sometimes be annoying if you fly near asteroids or if you want to fly through the donut asteroid. The problem here is that the mesh intersection methods are missing, all you can do is render models, not much else. Last but not least XNA does not support any network code. On the windows platform it would be possible to still use the Webservice to upload and get highscores, but for compatibility with the Xbox 360 the code is currently commented out. If you want to play with online highscores, just play the original Rocket Commander game. There are also some smaller issues like getting the bitmap data of a texture on the Xbox 360. There is method called GetData in the texture class, but it is not supported on the Xbox 360. There is also no bitmap class in XNA because you would need the System.Windows.Forms namespace, which is not included in the .NET compact framework. I ended up saving the level data into a custom file (.level) and then loading it again with help of standard IO methods (byte by byte, but the loading process is still fast, less than 1 second for all textures, levels, models and sounds). The Rocket Commander Mods are also not supported yet, but porting them should be easy with the existing Rocket Commander XNA source code.
Improvements		The controls, especially for the Xbox 360 Controller have been improved. It is now much easier to fly the rocket, the speed was increased and you can look at up to 4 times as much asteroids thanks to several optimizations and the great performance gain of using multiple threads on the Xbox 360. There are also many smaller improvements to the UI, the structure and some classes in the game, but the game looks still very similar (see screenshots above).

Maybe I will write a little more next week. I should get some sleep now, in a few hours it is christmas time and I have not packed any presents yet.

Now have fun with Rocket Commander XNA and have a nice christmas of course

PS: I know my blog has currently some problems (posting and comments do not work as they should), I will fix that in a week or two, have currently not much time to investigate this issue.

Microsoft released their XNA Framework 1.0 and XNA Game Studio Express today, which allow you to build games for Windows and the Xbox 360. To compile and play your XNA games on the Xbox 360 you will need to join the "XNA Creators Club" (for $49 per 4 months or $99 anually). There you will have access to additional starter kits, features, etc.

I ported the Rocket Commander game to XNA, just for fun .. and it runs great. It is optimized to run on all 3 cores of the Xbox 360 and I will finetune it a bit in the next few days to run perfectly on the XNA 1.0 release. The performance is really good, the current build has over 800 fps in PAL on the Xbox 360, in very high resolutions (have only 1600x1200 monitor, but I will test it on 1920x1080 too later this week) it still runs good with more than enough frames.

Here is a little preview picture, it shows about 8 times more asteroids and runs at over 200 fps here. I will try to post some of the porting problems in the next few days, for example all the network and internet code had to be ripped out from the Xbox 360 build and the sound features are a little stripped down in XNA (no 3d listener support, not easy or not even possible to do any stereo or surround sound, looks like playback is all mono :-( ).

Early alpha screenshot of Rocket Commander XNA:

Someone recorded XNA Racer, which was shown at some Tokio Gameshow named "kotaku".

Here is the original link. Some harsh tone in those comments, no you don't have to pay 99 dollars to play this game, it will be completly free. And about the "boring" gameplay, hey it was not done, this was just an alpha preview and the game looks much better now and is getting better physics and levels as we speak. Well, at least some are comparing it to AAA titles, thats always nice (and totally crazy, you wouldn't compare a house build by 1 guy to a scyscrapper).

Thanks for posting about it to ZMan and Ultrahead.

I guess I have to release a video of the game myself, these leaked videos look not very pretty and showing off an early alpha version has its disadvantages (almost 90% of the ingame objects are missing, the video shows the second track, which is not done yet, completely dummy and it was an early alpha version, the game runs now about 3 times faster).

As some of you (like ZMan) already found out, there is also an XNA book coming out written by me. I just started a few weeks back writing it (but it will be complete by the end of the year). Funny you can already order it on amazon. I will write more about it when its done. You will not only learn about game programming and XNA, but there will be plenty of practical examples in the book. In every of the 14 chapters a new game is introduced and you go though the process of writing a game from start to finish.

One final note: Canyon Commander is a lot of fun, it is a new mod, which will come out in the next days.


Btw: The Coding4Fun site was redesigned in the last weeks and most of the old links do not work anymore (which is something MSDN usually never does). But now most of the content is back and can be found in the new categories (Rocket Commander is under Games -> Arcade). I also updated the link on www.RocketCommander.com and the link for the video tutorials is:
http://msdn.microsoft.com/coding4fun/gaming/arcade/article.aspx?articleid=997852

Update: The old link works now too, I guess the MSDN relinking system is working as expected now :)

It was nice in Seattle and a great experience meeting the Microsoft XNA Team and people I met like ZMan. But I'm glad I'm back home. There is nothing like the good old home PC, I can type 700 times faster here and it feels much better to do any work here (or at the office here).

Well, the day started yesterday for me, I have not slept yet. Let's get started with some pictures. This is me leaving from the Hotel and waiting for a taxi. It took forever because the traffic was so bad again in Seattle.

Bye bye Seattle and all you friendly people in it.

Checking in at the airport. Had to be there 3 hours earlier than the flight departures. Was only 2 hours before that there (bad traffic and I got up a little late ^^).

But I had to wait 2 hours anyway. The security checks were no big deal anymore. Getting into the USA was much harder. Now it was just taking your shoes off, unpacking the laptop and I was done.

A plane is getting filled up and loaded (my plane was a little bigger and on the other side).

After 9 and a half hours flying around the world (from Amsterdam to Seattle took almost 2 hours more) we landed in Amsterdam and it was already Tuesday morning here. Btw: You can see me in the picture holding my crappy cell phone and using it as a camera.

The Amsterdam Airport and more security checks, but not so long waiting times in the morning, much nicer.

After adding 9 hours to my clock it was Tuesday morning too. I had to wait over 2 hours for my plane to Hannover and was really tired right now. But everything went fine and I landed in germany on schedule.

The plane is ready to "hop" to my "city" ^^ just took 45 minutes, pretty quick.

Getting a train ticket to finally get home. Hey, public transportation again, yeah

Back in Hannover everything looked so small, we don't have any high skyscrappers here. Strange how quickly I got used to that. Hope I can get rid of my adopted coffee habit too.

Time for some sleep. Got so many emails and stuff I have to do after I weak up, I better sleep for 20 hours now

The day started off rainy and stayed that way. This is my last day in Seattle. I will fly back to germany tomorrow.

I went to the Seattle Center Park again, I thought maybe the weather gets a little better later to go up to the Space Needle and take some photos.

The streets and parking lots are not as filled as in the week. The skyline of Seattle looks nice as always.

After checking out the park for a while I also found 2 big supermarkets right beside each other. According to google maps they are the only supermarkets in a 5km radius. Yeah, pretty clever to build them right beside each other .. omg.

The food in the USA is crazy, 500 different kind of chips, milk or bread, but not many different articles. In a german store you find much more different products in a smaller market. The products are also more expensive, about twice as much. You also can't buy small portions, everything is superlarge, megapack and labeled to let you buy 3 to save a few cents. The personal is incredible friendly and kinda annoying if you are not used to it like me ^^ Other than that it was a nice experience to see Americans go shopping.

There is the monorail line again.

And the monorail train, which is coming into the station.

Nice wobbly effect on that wall :)

The skyline again, but the weather is not looking good.

I checked out some movie theatres on the internet, but I was confused that some of them only show 1 movie at a time. I was not interested in the movie showing at the IMAX or that other big theatre, so I went to the Cineplex.

Watching the movie was pretty nice. It does not cost more than in germany and there are just a few minutes of commericals in the beginning, not half an hour like back home.

After the movie I went back to the Seattle Center Park, but it was raining too much and I lost any interest to go to any other attractions. I went back to the hotel and I will code a little bit right now.

Some more photos from my journey back tomorrow.

Here are some pictures of my little tour through Seattle today. I made like 150 photos, but I don't want to post that many. Instead of doing an introduction here, lets just go to the photos.

After a rude wakeup from the housekeeping lady that didn't see me in my bed (how is that even possible?) I collected some tourist info brochures and checked out where I want to go today. Later I met up with Christina and Jerry and had some brunch. Not only do Americans go out to eat in the evening, lunch and even breakfast/brunch is popular too. I guess I can never adapt to that, it just costs so much time going out all the time ..

Anyway, we ended up in the Fremont District. This is the Aurora Ave. North (99) Highway.

And under it there is a troll eating and stealing cars. Its not a myth, there he is, good thing I don't own a car.

And the other direction. Nice HDR effect btw. It does also look a little nicer than my XNA Racer game from below the road, but well, the game is above the road and it looks good there.

Now thats a pretty interesting sign. It does not only tell you about the local directions, it has also Taiwan, the Guggenheim museum in New York and the center of the world on it. Just in case you forgot about any of these.

There is the Seattle Space Needle at daylight and the Seattle Center Park it is in. We will come back to that later.

The skyline of Seattle at daylight. This picture was taken from the bay area. I'm on my way to the Seattle Aquarium.

Yay, some water .. But it is very cold all year, you can't even swim in the ocean in the summer time.

Here are some pictures from inside the Seattle Aquarium. This are 2 sea otters having some fun.

And some seals swimming around. Good thing no sharks are here. Hey wait a second, a little further along they might be some.

This room is pretty cool. It is basically a sphere with little windows in every direction. And it is underwater, which would make sense in an aquarium with all these fishes swimming around.

Where are all these bubbles are coming from, and why is there a yellow tube going down?

Oh, a scuba diver is doing some fishing. Well, that is not really a big challenge with all these fish in this tank.

Some starfish, which can be touched. They are rock solid.

But there were also a lot of wobbly and soft fishes and plants in the water, which felt strange.

Ahhh, there is a shark above me. Ohh, its just plastic.

Hey, wait a second, this ones are not plastic. I wounder if they are strong enough to kill me. They don't look very big or strong. But I'm no jackass going into the water to find out :)

Some very colorful fishes.

And some more colorful plants. At least I'm not the only one taking pictures. But I guess I'm the only one blogging about it and taking pictures of other people taking pictures.

Enough of that aquarium. Let's check out this "Ye Olde Curiosity Shop".

3 Chinese Girls testing out crazy hats. But there was nothing useful in the shop for me. I just got a couple of postcards.

Wait a second? After leaving the shop and walking along the bay there is another shop with the same name on it? Deja vu. The 2 shops are actually the same and for some reason it is "normal" here to put up the same buildings right beside each other. For example Seattle has build 2 new sport stadiums right beside each other instead of improving the roads or even think of a better way to do public transportation.

Time to leave the bay area and head to the city.

Lets take the underground tour, so many people told me I had to do that.

After an introduction and some history about Seattle the tour began. Hey look over there, a sky scraper.

This is actually the Smith Tower and it was once the biggest building in the US. It was build by the Lyman C. Smith, which was one of the first manufacturer of typewriters. Good thing I got my own layout and don't have to live with same same layout that was invented over 100 years ago to prevent the keys of the typewriters to get stuck when typing nearby keys too fast.

Finally underground, which was once the ground level for this area of Seattle. It was elevated to move everything up and make the city more secure and save against floodings. But why am I looking at a toilet? Ohh well, toilets with the flush ability were inveted here too ..

This was the nice lady touring us through the underground. She made a lot of jokes and we didn't get very much of them, but she kept going, which was funny again. In the background you see a pic of time before the great fire in Seattle that destroyed all these newly build wodden houses.

Some junk down here from the time they build the new elevated street level.

An old rusty tank.

I also took a lot more pictures, but it was way too dark down there. And when I got up it was dark too, but still kinda early (I sometimes stay up at this time ^^). Well, my camera could not take any decent pictures and it has a long length of exposure (which means I had to stay still for few seconds to get a steady image).

Anyway, here are some random pictures from Seattle.

This is the bottom of the pretty tall Rainier Square building with a nice laser showing some figures.

A glowing christmas tree made out of light tubes.

This is how taxis look in Seattle.

The monorail, a pretty cool train to drive you from the center of the city to the Seattle Center (where the Space Needle is) in just a couple of minutes. It also doesn't cost anything, but it just drives back and forth between these 2 points on a 3 stores high railway.

This is the Seattle Space Needle tower from below. But it was already very dark and it would not make much sense to take pictures from above with this crappy camera. I will probably come back here tomorrow and then waste the 14 dollars it takes just to get up there.

Before going back to my hotel I checked out the park a little bit and saw this cool taffy machine.

Well, this is actually a nice sign for me as the last pedestrian standing. I was just a few hundred meters from my hotel, but this crazy 6 lane road was separating me from the way to my hotel.

Finally home I can now to some coding, my hands are shaking, I have to do something. But maybe it is just all that coffee finally kicking in

Well, Day 3 was very interesting. There are still a couple of things I could tweak in my code. I talked with a lot of guys today, had lunch with Mitch Walker, then talked to a couple of guys and girls. In the afternoon the XNA Team did a little presentation of all their internal games they did. It is pretty amazing and coming from the outside you would never think that they do so much cool stuff there. Where do they even get the time to develop their own games beside their job.

I'm not sure if these games get ever released, I guess most of them will not be in the final XNA Studio Express version coming out next month. Instead they will probably published on several blogs, MSDN, Coding4Fun and sites like that.

My little stater kit XNA Racer is now almost complete, I fixed all graphic issues this week and it runs now at a very good frame rate on the Xbox 360. Little fine tuning and I'm done. More on that in the next weeks.

My cell phone went dead and I forgot to get my Usb cable to work today. Sorry, no photos today, I just saw a lot people today and I guess most of them are glad I couldn't take any pictures. Tomorrow I will be a tourist and check out Seattle a little bit more and make more photos. There are some interesting attractions here.

In the evening I meet with Andy Dunn (ZMan) and Jason Olson (Managed World blog) and had something to eat in a nice traditional diner (Ruby's diner, seems popular here, never heard of it). We talked a lot about XNA, Microsoft, DirectX and everything on our mind. It was very nice meeting up with Andy again (we meet at the PDC before) and it was a pleasure to meet Jason it person.

There was a lot more going on today, but I'm way too tired right now to remember anything more .. and its also kinda boring not posting any pics ^^

Welcome back to my little photo diary of my experiences here in Seattle.

Today I worked a lot with the Xbox 360 side of XNA. In the earlier builds I had a lot of problems with testing my starter kit on the Xbox 360, but most of these issues are resolved now. About 99% works the same on the Windows and Xbox 360 platforms, but if you hit that 1% it does still get you angry and pushing your head into the wall. For example a couple of the more advanced shadow mapping shaders work fine on the windows platform, but all kinds of crazy things happen on the Xbox 360, the game crashes, you see black bars all over the screen or the output is just not right.

If you are like me and have not worked with the Xbox 360 before, I can tell you that it is not easy getting used to the way the console uses render targets. You have to resolve them with a little helper method in XNA (or in the Xbox 360 SDK) to get the contents copied over to your texture. This is not required on windows. But even if you take care of that the shaders might behave a little different. For example most of my post screen shaders use the background buffer to mix results and sometimes mix them together several times. This works fine on the windows platform and behaves the same way as it does in DirectX.

But after some discussion with Tom Miller, Matt and Mitch Walker from the XNA Team and debugging a little, it was clear that the background buffer can have garbage data after rendering into render targets. This was very bad for one of the shaders because it requires 2 separate images over several passes and then blend them together at the last pass. I used the back buffer to hold one of them and a render target for the other, but that had to be changed in order to run correctly on the Xbox 360. Good thing this was just one shader, in my bigger game engine I have over 100 shaders and it would not be fun to rethink all of the post screen shaders ^^

Anyway, this was just one of the many things today, I will talk about all this stuff in the near future on my blog. Let's go to the pics ..

Traffic was especially bad today, it took over an hour to get from Seattle to the XNA Team Building (somewhere in that greater Microsoft Campus area, don't ask me, I'm glad still knowing where the sky and ground are). I took a few pictures of the building today, it is called Millennium Building or something ...

And this is the entrance for some of the Xbox teams and XNA. I'm not sure why this image is so wobbly. The building is straight. Maybe there is a post screen shader in my camera, that would also explain the extremly blurry pictures I get out of it most of the time. Btw: Really crazy street numbers, unimaginable in Germany where every street that is longer than a few meters is renamed 7 times.

Okay, this is how an office looks like at Microsoft. Usually everyone, no matter in what position, gets his own office. But the XNA team is pretty big and they had to put 2 people in some of the offices. I was staying in Matt's office most of the time and he was really nice to me answering all kinds of questions.

Still in the same office. Now thats how a bookshelf should look like. Lots of Game Programming Gems Books (yeah, all of them). Feels like at home in my office. Ok, my books are just piling up on my desk and it looks a bit more chaotic

Later that day I checked out one of the malls and I was not very impressed. Well, I'm no big shopper anyways and the prices are too high for me, doesn't matter what I was looking at. But I saw the WII console from Nintendo in one of the game shops and played it for a bit, some fun racer. It looks really crazy holding the controller like a wheel and controlling it like a maniac in the air.

Hi there .. uh, not real?

And finally my little list of pro/cons of living in the USA (from my limited knowledge of course, and I rant a bit here):
Pro:

• People are very nice, last year in Los Angeles I also noticed that, but even here in Seattle cars break for people and bikes. It doesn't seem like everyone is cursing behind the wheel. And in general everyone was so nice to me and a pleasure to speak with.
• Coffee makes you crazy, especially the amount in Seattle. Coffee everywhere ^^ Hey wait? Shouldn't that be on the cons list?
• The cites look very bright and colorful at night. Like in the movies, just more real. We in Germany don't waste that much energy and the stars are too far away to be THAT bright.
• Yeah, the democrats won the last election here. Dunno what this has to do with my blog, but yeah.
• You can pay everything with credit cards and it really makes you life more easy. In Germany you can't pay with a credit card anywhere. And even our own sucky EC-Cards are not accepted if the price is too low. It is just stupid that we Germans have our own system, the rest of the world is using credit cards. Just for online transactions a better system than just credit cards should be invented (ok, there is paypal, but why should ebay become richer, banks themself should come up with something and compete).

Cons:

• Transportation really sucks here, trains were not invented here yet and the streets are so incredible overfilled with cars it is not funny. And even if there is a clear road ahead you can't drive faster than the speed limit of 55 mph (90 kmh) or similar. In germany there is no speed limit at most of the highways and it really seems slow, especially because the roads are usually filled to the max. And public transportation sucks even more, it is either non existent or so far away that you still need 3 times longer than driving slowly with a car.
• Dunno, but everything seems more expensive here. Well, everyone earns more, so that could be ok.
• TV is better here, a lot of good and funny shows. But it is hard for me to compare since I never watch TV in Germany anymore. Now why is this on the bad list? Well, commercials ever 5 minutes? Are you guys crazy? It is even too annoying every 15-20 minutes like in Germany ... Whatever, TV is boring anyway.
• Some food tastes kinda boring. Most of this stuff was told me by other ppl who moved over from Europe and they miss the taste of good beer, chocolate, cheese, dark bread, etc. I would probably don't care and have forgotten about all of this in a short time.
• So much to do, so few time.

Random things:

• My freaking Simyo cell phone provider doesn't work at all here. I can receive some calls and call to Germany, but not call any number here, which is really stupid and it if it would work the prices are insane (costs like 30 times as much).
• Console games are much more important here. In Germany maybe 30% of a game shop is used for console games, here it seem to be 70-80%.
• Internet is slow, Wireless LAN sucks and "high speed internet" at hotels is a bad joke. At Microsoft most of the downloads I made were from Microsoft servers anyway and that was pretty fast, but the Americans live with good cable connections for a long time now and do not think the same way as we in Germany to go faster faster faster :) This is just on the cons list because of my bad WiFi experiences, even Microsoft can't figure this out for their internal network. Sorry guys, check out the Freifunk project to see how to do WiFi internet with more than 1 Kb per sec :) Man, how much longer until someone brings out useful wifi technology, all this bluetooth and wifi stuff just sucks and is too slow and error prone.

Link for me to not forget about, pretty cool new project to allow converting HLSL shaders to GLSL:
http://sourceforge.net/projects/hlsl2glsl/

This was my first day working at Microsoft. Pretty interesting people work there and a lot of them. Good thing no one noticed that I'm not able to remember 500 names per second. I was installing stuff half of the day, but I found out more about XNA and already fixed some issues. Before talking more about my day, here are some News:

The XNA Team did a little 2 minute video of a couple of XNA games, my starter kit XNA Racer (which I hadn't talked about yet in detail, but that will come soon) can be seen at the end of the video. I got a lot of nice comments about that already :)

Here is the link to the video (Major Nelson has a nice blog btw):
http://www.majornelson.com/archive/2006/11/08/zune-video-xna-video-montage.aspx
And this is David Weller talking about it:
http://letskilldave.com/archive/2006/11/08/XNA-Video-Montage-_2300_1-is-ready-for-you_2100_.aspx

A nice guy from France with the name "Marc Guevremont" made yet another Rocket Commander Mod and this one just looks impressive. He managed to implement a landscape engine with shadow mapping (I guess precalculated). It looks very much like Rebel Assault. The game itself is still similar to Rocket Commander, but it looks so much different and he also made 3 cool levels. The game is called Canyon Commander and will hopefully be available soon.

More information, screenshots and a video can be found in the Rocket Commander Forums and here: http://www.webs7.com/Canyon/

I did not make many pictures today and it was to dark when we drove back to make any useful pictures with my phone camera.

Driving through Seattle.

And going over the long Evergreen Point Floating Bridge between Seattle and Redmond. It goes over the lake Washington and I couldn't get an answer if a Russian atom u-boot could fit under the bridge.

I was told that Bill Gates has his house somewhere on the right here, but you can't see it, too much leaves.

More pictures tomorrow.

I arrived in Seattle :) But that was a long journey, it took over 15 hours and in Seattle it was just 3pm when I arrived. At least I got some sleep in the plane.

I made some photos, but the quality is not very good. Next time I should use a better camera than the one in my cell.

This is the ceiling at Hannover Airport. I was very tired and watched it for quite a while. Has a pretty good shadow mapping algorithm if you ask me. Maybe they use already Direct3D 10 and render into cubemaps Btw: I am excited about the new NVidia Geforce 8800 GPUs, will check them out next week when I am back.

The second security control I had go through, in total it were at least 7 controlls and a lot of time waiting between them at every airport.

Guess what, waiting again. This time in Amsterdam. It was not even a security check, just the passport control checkpoint. The people of Holland speak a really funny language, at least it was fun to listen to it while being in Amsterdam. With knowledge of English and German it is possible to guess most words and unterstanding at least what the people are talking about.

After sleeping a while in the plane and watching the shitty movie "My super ex girlfriend" (wft, it was boring, unfunny and not exciting at all), I watched outside the window for a bit. We had almost reached seattle. I guess this is already the Washington state, some islands and a lot of water, looks nice from above. A few minutes later, everything was foggy again.

And finally after ariving and going through a bunch much security checks and questions I took this photo at the first bargage drop point. Well, I was not really supposed to take photos here as you can see on the warning signs there, I guess this is a top secret area .. whatever ..

After ariving at my hotel I checked out Seattle and walked around for a while searching for power adapter for my laptop (I knew I forgot something home). Well, not fun without a car .. I found a grocery store, but neither they nor my hotel had an adapter. Well, the laptop sucks anyway, XNA does not work because for some reason it cannot use any pixel or vertex shaders. NVidia says that the Geforce 4 Go fully supports DirectX 8, which would include ps1.1 and vs1.1, but I guess there is something missing.

Anyway, after I have now almost depleted both my laptop batteries. I just made one last photo and quickly wrote this post. Here is a view from my hotel room to the Seattle Space Needle Tower at night. With a less crappy camera this would look nice, hehe.

See ya tomorrow.

Microsoft has just released the new Beta 2 version of the XNA Game Studio Express IDE, which allows you to create great games for the windows and Xbox 360 platforms. It contains all the stuff from the beta 1 (like the SpaceWar starter kit, which was a improved a little bit). Additionally it now looks a lot more polished and you can check out the new content pipeline, which allows you to import 3d models from .x and .fbx files to do some cool 3d graphics. Btw: Check out the new logo of XNA. I first was a little bit confused since I was used to the old XNA logo, which has been around for several years now. But after a while you will get used to the new logo and start to like it

While you can compile games for the XBox 360, the XNA Creators Club membership is not yet available and theirfore you cannot test on the Xbox 360 yet. The XNA Creators Club membership stuff will be available later this year and then it is time to play your games on your Xbox 360.

You can find more information about XNA and download XNA Game Studio Express here:
http://msdn.microsoft.com/xna/

Also be sure to check out the boards, there is a lot of stuff to read and a ton of games (mostly 2d) came out in the last couple of months.

I will try to blog little bit more about XNA as it gets closer to the release. I got some great stories to tell :D

• Download XNA Beta1

• XNA Framework Forum and XNA Game Studio Express Forum

• Getting Started: Open C# Express (which is XNA Game Studio), Help->Content->Select XNA and navigate to Getting Started with XNA and read through Your First XNA Game

• Next you could try out the Space War Starter Kit Game. If you can't control the game read this tutorial from xnaspot.com about changing it to support keyboard input.

• x64 Bit platform support: Read this blog entry for an easy fix. Basically just add <PlatformTarget>x86</PlatformTarget> to your csproj file.
  Or download and extract this file (Xna64BitSupport.zip 14 KB) into:
  C:\Program Files (x86)\Microsoft Visual Studio 8\Common7\IDE\VCSExpress\

• Blogs:
  
  • http://blogs.msdn.com/xna/ XNA Team blog to get news from the makers
  • http://xbox360homebrew.com/ XBOX 360 Homebrew, quite good
  • http://thezbuffer.com/ Always a good resource, biggest MDX site ever
  • http://letskilldave.com/ Let's Kill Dave! Davil Weller about XNA. He posts a lot of interessting things.
  • http://blogs.msdn.com/tmiller/ Tom Millers Blog, yeah, this is the MDX father of all things :)
  • http://blogs.msdn.com/mitchw/ Mitch Walker, one of the XNA guys
  • http://blogs.msdn.com/al_msft/ Albert Ho, XNA Redux, another XNA guy
  • http://blogs.msdn.com/mklucher/default.aspx Michael Klucher's XNA Blog, guess what, another XNA guy
  • http://blogs.msdn.com/shawnhar/default.aspx Shawn Hargreaves Blog, Game programming, C#, and the XNA Framework Content Pipeline
  • http://blogs.msdn.com/rickhos/default.aspx Rick Hoskinson's Blog about XNA
  • And there are many more, but who's got the time ^^

• Tutorials:
  
  • http://www.xnadevelopment.com/ XNA Development, Tutorials and Co
  • http://learn-xna.com/default.aspx Learn XNA I guess, not much there yet
  • http://www.xnaspot.com/ XNA Spot, got already a nice tutorial about Getting started with the Space War Starter Kit

• Interessting reads:
  
  • http://msdn.microsoft.com/directx/XNA/default.aspx XNA Info and FAQ
  • http://forums.microsoft.com/msdn/default.aspx?forumgroupid=20&siteid=1 XNA Forums
  • http://makeitbigingames.com/blog/?p=34 XNA Game Studio Express Doubters Get It Wrong
  • http://xbox360homebrew.com/blogs/homebrew360/archive/2006/08/24/75.aspx Hearing some Audio from the Games Convention in Leipzig (scroll to 48:00 minutes). It demonstrates basically a Torque X game with XNA, but its quite interessting.
  • http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=634578&SiteID=1 Forum post about Xbox 360 Official Dev Kit vs. "the XNA thing"
  • http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=684005&SiteID=1 Pretty negative post about XNA, he wants to stay with c++ and DX (ever heard of MDX?)
  
  

• And now finally my own thoughts and tips:
  
  
  • How to render fonts like with Direct3D.Font?

    Well, thats not possible, there are not Font classes in XNA at all yet! You have to create your own font code by rendering bitmap fonts. If you want to see some code about that check out the SpaceWar Starter Kit and look inside the Font.cs class. The fonts in SpaceWar just contain numbers, but the game contains some text. How did they do that? Well, they just put most of the text in the game directly onto the textures, buttons, etc.
    Here is also a forum post about this issue and some source code, which might help.

  • How to play sounds?

    Thats quite easy, create sounds with XAct, load them in your game and then use the SoundBank class to play your sounds. Some tutorials can be found in the help and a simple example is in the Sound.cs file in SpaceWar Starter Kit.

  • Okay, where do I add my mp3 for some music playback?

    Could you stop asking this questions? Arg, I'm asking myself this, oh no. But I guess sooner or later this would come up anyway. Well the solution? There is none. No, I'm not kidding. There is no support for mp3, wma or CD playback of music in XNA. On the windows platform you could use some external stuff (DirectShow, MCI, external libraries, etc.), but on the XBox360 you are stuck with XAct, which does just support sound effect files.

    Ok, then just let add the .mp3 as a .wav file there. Yup, thats possible, but consider your game size. If your binaries are maybe 1MB, textures 5-10MB and sounds 2MB you don't want to add 3*50MB for 3 music files. I had quite a long discussion with some music artist about this issue and we agreed that it would be best to do try out some 22kHz mono sounds for the music for a smaller game size. Don't even try to think about any compression, the only format that XAct eats is PCM .Wav files. Sample them down or live with mega-files, your choice ...

  • How to add Controller (Mouse, Keyboard, XBox360 Controller) support?

    Again, this is not hard stuff. If you have worked with XInput before, this will be easy for you. Otherwise just read the XNA Programming Guide->Input pages, which all contain easy to work with code samples.

  • How to show a mouse cursor?

    You might notice that there is no mouse cursor in the samples, starter kit or any new project you create. The reason for this is that by default the Game.IsMouseVisible is set to false. If you set it to true (e.g. in your game constructor) you will see the mouse cursor again (write: this.IsMouseVisible = true;). Another way would be to display your own custom mouse cursor as a sprite at the current mouse position (see help to get mouse position, it is quit easy).

  • How to capture keyboard text?

    Well, thats not that easy. You can only check the state of each button (mouse, keyboard, whatever), but you can't get the text directly like with the OnKeyPress event in window forms. One way would be to write your own custom text handling, like this:
    
    string chatText = "";
List keysLastFrame = new List();

...

Keys[] keysNow = Keyboard.GetState().GetPressedKeys();
foreach (Keys key in keysNow)
    if (keysLastFrame.Contains(key) == false)
        chatText += key.ToString();
keysLastFrame = new List (keysNow);

    But this has the disadvantage if you run low on frames or the user types very fast you might miss some keys (test this by adding Thread.Sleep(50)), which really sucks. It is also a bit of work to get all the special keys, shift combinations, backspace, etc. working. For windows apps it might be wise to think about capuring the keyboard directly with some dummy form (very easy to get text then with OnKeyPress). Another approach would be to create an extra thread just for handling the keyboard at a high rate to make sure you catch all the keys. More about this solution can be found in this post.

  • What about drawing lines, boxes or other simple 2d stuff?

    Oh no, this is one of the parts that is really annoying and this does require some rethinking because all this kind of rendering was done with help of the fixed function pipeline (hello DirectX 7), which is no longer supported in XNA. It was never easy in DirectX to draw lines or filled boxes, you had to create your own vertex buffer or just draw some primitives and set all kinds of renderstages, but with XNA this gets even more complicated. Better not tell anyone how simple this is in OpenGL (glLine anyone ^^).

    So how can we draw some lines in 3d?

    Again: It is very important to know that you have to do EVERYTHING with shaders! The Sprite classes are just some helpers, but for 3d you need shaders, nothing else will work! I say this that often because many people in the XNA Forum already having problems rendering data and do not understand that if you don't have a shader around your rendering code, nothing will happen! Additionally you have to make sure you pass all the required data to your shader, there is a lot more work involved that just rendering some primitives in DirectX using the fixed function pipeline.

    I will try to keep this as short as possible, but you will see this is quite a lot of code for just rendering a single line. Here we go. We start with the variables we need (add to your Game class):

    Matrix Projection = Matrix.Identity,
View = Matrix.Identity;
Vector3 pos1 = new Vector3(0, 0, 0),
pos2 = new Vector3(100, 100, 100);
VertexPositionColor[] lineVertices =
new VertexPositionColor[2];
lineVertices[0] = new VertexPositionColor(pos1, Color.Red);
lineVertices[1] = new VertexPositionColor(pos2, Color.Yellow);

Effect effect = null;
EffectParameter worldViewProj = null;


    We will use the Projection and View to calculate the worldViewProj matrix for our shader to convert the 3d coordinates to 2d (yep, I told you, we have to do everything ourself). If you want some camera control, always update the View matrix, which again you have to manage yourself (hello XNA team, some help with this basic stuff plz). Ok, lets continue before I explode, here is the initialization code (copy to your Game constructor):

    float aspectRatio = (float)TestGame.Width / (float)TestGame.Height;
Projection = Matrix.CreatePerspectiveFieldOfView(
    (float)Math.PI / 2, aspectRatio, 0.1f, 1000.0f);
View = Matrix.CreateLookAt(
    new Vector3(0, 0, -50), Vector3.Zero, Vector3.Up);

CompiledEffect compiledEffect = Effect.CompileEffectFromFile(
    "Shaders\\LineRendering.fx", null, null, CompilerOptions.None,
    TargetPlatform.Windows);
effect = new Effect(TestGame.Device,
    compiledEffect.GetShaderCode(), CompilerOptions.None, null);

worldViewProj = effect.Parameters["worldViewProj"];


    Ok, what happens here? First of all we calculate our aspect ratio, nothing special. Then we have to calculate our projection and view matrices (please read the DirectX documentation if you have no idea what I'm talking about). Basically we have a field of view of 90 degrees (PI/2), we use our aspect ratio and we have a view range from 0.1 (near) to 1000.0 units (far). Then we create our camera at the position (0, 0, -50) looking at the center of our scene.

    Next we have to load our shader effect file. Yes, I told you about that earlier, we need a freaking shader to draw our simple line. We will get into that in a little bit, but ALWAYS make sure the .fx file is correct (test with FX Composer first). If the .fx file contains compiler errors you get unfunny NullReferenceExceptions, which won't help you (see below). Finally we are getting the worldViewProj parameter. This is the only line of this whole line code I really appreciate. Getting shader parameters is now a lot easier and cleaner, good work here! Also working with shaders is very easy now.

    Time to continue with our code, we need the rendering code (add to Draw()) now:

    // Start line shader
effect.Begin(EffectStateOptions.Default);
effect.Techniques[0].Passes[0].Begin();

// Render line
worldViewProj.SetValue(View * Projection);
TestGame.device.VertexDeclaration = new VertexDeclaration(
TestGame.device, VertexPositionColor.VertexElements);

TestGame.device.DrawUserPrimitives (
PrimitiveType.LineList, 1, lineVertices);

// End shader
effect.Techniques[0].Passes[0].End();
effect.End();


    This code is pretty straight forward. We start our shader and select the first technique (the only one we got). Then we calculate our worldViewProj matrix from the View and Projection matrices we calculated in the constructor. After setting the VertexDeclaration we can draw our primitives, which are lines in our case. Just one to be more specific. Adding more lines is quite easy at this point. Finally we have to close the rendering pass (we just got 1 pass, else we would have to make a foreach loop around this code) and we also close the shader.

    So far so good, but how does the rendering now happen? 100% in the shader, the code we just wrote will do nothing more than calling the shader with the data we set, the line point positions and colors. So lets take a look at the shader, which does all the rendering. The shader itself is quite simple:

    // File: LineRendering.fx, Author: Abi
// Code lines: 52, Size of file: 1,18 KB
// Creation date: 31.08.2006 05:36
// Last modified: 31.08.2006 06:44
// Generated with Commenter by abi.exDream.com
// Note: To test this use FX Composer from NVIDIA!

string description = "Line rendering helper shader for XNA";

// Default variables, supported by the engine
float4x4 worldViewProj : WorldViewProjection;

struct VertexInput
{
    float3 pos : POSITION;
    float4 color : COLOR;
};

struct VertexOutput
{
    float4 pos : POSITION;
    float4 color : COLOR;
};

VertexOutput LineRenderingVS(VertexInput In)
{
    VertexOutput Out;

    // Transform position
    Out.pos = mul(float4(In.pos, 1), worldViewProj);
    Out.color = In.color;

    // And pass everything to the pixel shader
    return Out;
} // LineRenderingVS(VertexInput In)

float4 LineRenderingPS(VertexOutput In) : Color
{
    return In.color;
} // LineRenderingPS(VertexOutput In)

// Techniques
technique LineRendering
{
    pass Pass0
    {
        VertexShader = compile vs_1_1 LineRenderingVS();
        PixelShader = compile ps_1_1 LineRenderingPS();
    } // Pass0
} // LineRendering


    And thats it. As you can see we just take the input position, transform it and then output the color we interpolated through the vertex shader. The pixel shader has just to output the color. Working with other primitive types can be done in a similar way, so I hope this code helps.

    And what about 2d lines?

    2D lines can be done quite similary. In DirectX you would never think about rendering 2D lines with shaders, when it is so much easier with the fixed function pipeline. But this is not possible in XNA, so we have to use shaders again. Lets go quickly through the code that is required:

    Matrix Projection = Matrix.Identity,
View = Matrix.Identity;
Point pos1 = new Point(0, 0),
pos2 = new Point(500, 250);
VertexPositionColor[] lineVertices =
new VertexPositionColor[2];
Effect effect = null;
EffectParameter worldViewProj = null;


    Very similar to what we had above, only our positions are now Points and not Vector3. Also note we don't calculate the lineVertices here because the data is resolution dependant and we have to grab the resolution from the graphics object first. Lets take a look at the initialization code:

    float aspectRatio = (float)TestGame.Width / (float)TestGame.Height;
Projection = Matrix.CreatePerspectiveFieldOfView(
    (float)Math.PI / 2, aspectRatio, 0.1f, 1000.0f);
View = Matrix.CreateLookAt(
    new Vector3(0, 0, -50), Vector3.Zero, Vector3.Up);

lineVertices[0] = new VertexPositionColor(
    new Vector3(
    -1.0f + 2.0f * pos1.X / TestGame.Width,
    -(-1.0f + 2.0f * pos1.Y / TestGame.Height), 0), Color.Red);
lineVertices[1] = new VertexPositionColor(
    new Vector3(
    -1.0f + 2.0f * pos2.X / TestGame.Width,
    -(-1.0f + 2.0f * pos2.Y / TestGame.Height), 0), Color.Green);

CompiledEffect compiledEffect = Effect.CompileEffectFromFile(
    "Shaders\\LineRendering2D.fx", null, null, CompilerOptions.None,
    TargetPlatform.Windows);
effect = new Effect(TestGame.Device,
    compiledEffect.GetShaderCode(), CompilerOptions.None, null);

worldViewProj = effect.Parameters["worldViewProj"];


    This looks slightly more complex. The reason for that is the conversation from pixel coordinates to screen space, which goes from -1 to +1 and has y inverted. We could also do this calculation in the vertex shader, but I like C# more ^^ Please also note that we don't need the z coordinate, but it is way easier to just use the VertexPositionColor struct instead of creating our own struct. Lets continue with the rendering.

    // Start line shader
effect.Begin(EffectStateOptions.Default);
effect.Techniques[0].Passes[0].Begin();

// Render line
worldViewProj.SetValue(View * Projection);
TestGame.device.VertexDeclaration = new VertexDeclaration(
TestGame.device, VertexPositionColor.VertexElements);

TestGame.device.DrawUserPrimitives (
PrimitiveType.LineList, 1, lineVertices);

// End shader
effect.Techniques[0].Passes[0].End();
effect.End();


    Nothing changed here, nothing we have to discuss. Everything works just the same. lets take a look at the shader!

    // File: LineRendering2D.fx, Author: Abi
// Code lines: 52, Size of file: 1,18 KB
// Creation date: 31.08.2006 05:36
// Last modified: 31.08.2006 06:55
// Generated with Commenter by abi.exDream.com
// Note: To test this use FX Composer from NVIDIA!

string description = "Line rendering in 2D space shader for XNA";

// Default variables, supported by the engine
float4x4 worldViewProj : WorldViewProjection;

struct VertexInput
{
    float3 pos : POSITION;
    float4 color : COLOR;
};

struct VertexOutput
{
    float4 pos : POSITION;
    float4 color : COLOR;
};

VertexOutput LineRendering2DVS(VertexInput In)
{
    VertexOutput Out;

    // Transform position
    Out.pos = float4(In.pos, 1);
    Out.color = In.color;

    // And pass everything to the pixel shader
    return Out;
} // LineRendering2DVS(VertexInput In)

float4 LineRendering2DPS(VertexOutput In) : Color
{
    return In.color;
} // LineRendering2DPS(VertexOutput In)

// Techniques
technique LineRendering2D
{
    pass Pass0
    {
        VertexShader = compile vs_1_1 LineRendering2DVS();
        PixelShader = compile ps_1_1 LineRendering2DPS();
    } // Pass0
} // LineRendering2D


    Not much changed here either. Only the vertex shader is changed, we don't have to use our worldViewProj matrix anymore. We are just copying the data over to the pixel shader for rendering the screen stuff directly.

    Thats it for rendering 2D data. I guess most 2D stuff will be covered by the Sprite class, but if you need some custom 2d stuff (lines, boxes, etc.) this code should help you out. Have fun writing more complex stuff.

  • Ok, if the line stuff is that hard, lets do some simple mesh rendering, right?

    Wrong again. While this was planed for the XNA Beta release, it didn't make it into the beta and you have to do your own mesh loading, handling and rendering. In the SpaceWar Starter Kit game you can find some code to load swm model files (wtf is this format?), but you can't render .x or .fbx files that easily yet. In the future no problem, but right know you are f .. erm, not able to ^^. When I got some code for mesh loading and rendering, I will show it

  • Content Management, what about that?

    Well, its quite cool to just drop your content files into your project and then you can directly access them in your code. But since this feature is not supported yet, there is no point discussing it ... If you want to read stuff anyway, check this blog posts about the content pipeline out: http://blogs.msdn.com/xna/archive/2006/08/29/730168.aspx and http://blogs.msdn.com/shawnhar/archive/2006/08/26/725954.aspx.

  • Why are there so few help topics in the most important namespace Microsoft.XNA.Graphics, especially for 3d rendering?

    Well, since most of the line rendering, mesh or even the content pipeline is not supported, it is no wonder some important topics are missing. The help basically just tells you how to create a textured cube yet, nothing else. But this is also an early beta release, expect more help topics in the future. The many new XNA pages that are created these days (like 10 new ones each day ^^) will also provide a lot of resources. I bet XNA will have a really big community after a while. XNA has already interessted a lot of people about this new technology.

    Please also try to use the DirectX documentation as backup help in case you need more tutorials, samples and documentation.

  • Shaders?

    Yap, everything except Sprites has to be done with shaders. I guess this will be reason enough for most XNA games to never have any 3d content. Working with sprites is quite easy, but having to write custom shader code, declaring vertex types and having crazy random exceptions is nothing easy.

    For example if your shader fails to compile you get just a System.NullReferenceException: Object reference not set to an instance of an object. There is no explanation what did went wrong, which is pretty bad IMO. Shaders are really a pain in the ass because they are not managed in any way. Its just some script that gets compiled for the GPU and if anything went wrong you can hope your tools tell you exactly what to do. MDX did already suck in this regard, but from my quick early preview XNA is way worse. I really hope this part gets improved. What does nice and clean sprite, sound and controller programming help me if the 3d code is ugly as hell and as hard to write as c++ minus the debugging benefits from DirectX.

    Debugging DirectX? Yes, lets do that. First you need VS 2005 (see below how to get that to work with XNA). Now activate unmanaged Debugging and make sure DirectX is running in Debug mode (either go to your control panel and open up DirectX or use Start->Programs->DirectX->Utilities->Control Panel (which is the only available choice on x64 bit), now select debug mode and also set the Managed DirectX dlls to debug for better debugging support. Now when crazy NullReferenceExceptions happen and you are lucky you might see some helpful explanation.

    Scroll above to see some simple shaders for the line rendering stuff. There is also another shader example in the documentation, work with that code and change it with help of tools like FX Composer to find out about compiling errors beforehand.

  • Do I have to dispose textures, models, etc. like in MDX?

    Not really. I didn't notice any problems yet. I guess XNA has some mechanisms to collect all resources when disposing itself (game component and device). As you can see in the SpaceWar Starter Kit they didn't had to implement any disposing for their MeshCache or TextureCache lists in SpacewarGame.cs.

    This is quite cool IMO, it makes coding even easier than it was in MDX.

  • Why does my game crash with a NullReferenceException when I drag it over to another screen when using SpriteBatches?

    I guess this is some bug in the SpriteBatch class, which does not handle the device lost event correctly or something. It always crashes in the Begin() method when dragging the window out of my first screen. Since the SpriteBatch class does not have any events other than disposing, the best and simplest solution is just to add a event handler for the OnCreateDevice event and put your SpriteBatch creation code there too. This way it gets re-created when you need it. Would be nice if you didn't have to do this yourself ... XNA team reading this? Who knows ^^

  • Occlusion quering for example for lens flare effects?

    Not supported, check out this post.

  • What about Physics, AI, Collision, Particles, etc.?

    Not supported right now, check out this post. Since XNA is mainly a graphic engine with sound and controller support, it is not very likely you get advanced engine features soon.

  • How to get XNA working in VS 2005 (with all the plugins you might have, which do not work in Express)?

    Thats not supported or even possible out of the box! Read more about this here (Forum) and in the FAQ.

    But since I'm such a clever guy I modified the XNA templates quite a bit and added support opening the project in VS 2005. Read the full story here. Basically just download this: Xna64BitSupport.zip (14 KB) and extract it to:
    C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\VCSExpress\
    Now you can open your created XNA Game Studio Express projects in VS 2005 and continue working on them there.

  • Unit Testing in XNA?

    Quite simple, just add NUnit.Framework.dll, which is fully managed and should even work on the XBox360 (not that you need unit testing there). If you use VS Express, TestDriven.NET will not work (unless you have a version from last year, which still supported it). If you use VS 2005 use TestDriven.NET or TestRunner (tested it few weeks ago, very nice, but does not support static unit tests, big nono for me).

    I also suggest using a TestGame class and do many static unit tests to play around with XNA (I already wrote 5 static unit tests today). Thats much faster than to create a new project everytime. And each test looks much easier and shorter than a complete new project.

  • Performance of XNA compared to MDX or native DirectX.

    I couldn't detect any performance penalities yet, someone in the XNA forums had some problems archiving 800 fps when using bitmap fonts, dunno what that was about. But it is very hard to say how XNA performs in relation to MDX because there is not much code or games we can compare yet.

    But in my opinion it does not even matter, the XBox360 is fast enough even if you write really shitty code and the windows platform is also quite fast with all this dual core around. For most simpler or casual games this will never matter much. However I do strongly believe that XNA will perform on the same level as MDX and DirectX.

  • But I want to play my XNA game on my XBox 360?

    Me too, but we have to wait for the next drop of XNA ^^ Not supported yet.

  • What about Rocket Commander for the XBox 360?

    Well, I thought about that, but since many of the classes used in Rocket Commander are not supported yet in XNA and the actual XBox360 execution is not yet possible, why even bother? As soon as XBox360 XNA'ing is possible, I will consider a Rocket Commander port again.

  • Btw: Why is the SpaceWar Starter Kit so big (155 MB uncompressed)? There is not even music in it.

    Most textures are uncompressed as .tga files, not good ... Rocket Commander has more graphics, music and I guess more sound files too, but is less than 10 MB.

  • Need more help? Then ask in the XNA Forums and not here, I got stuff to do :D

Hope this helps. I will post more about XNA Trick & Tips soon

Yes, I'm writing a XNA game too. It will even be a Starter Kit for the next XNA Game Studio Release, more about that next week, I will post weekly screenshots like in the Rocket Commander Development time.

Microsoft has released their XNA Framework and the XNA Game Studio Express (which is based on Visual Studio C# Express). You can now start developing your own games using the XNA Framework.

The download includes some documentation (not much on 3d graphics I have to say) and a pretty cool and interessting Starter Kit "SpaceWar", which is an Asteroids clone with both retro and modern graphics. More content, more help and more starter kits will come in the future.

Sadly there is no direct XBox360 support yet, so you cannot plugin your XBox360 and play your XNA games right now. As stated in the XNA FAQ this will be possible in the near future (next drop in a few months maybe).

Anyways, download the XNA Game Studio out and check it out:
http://msdn.microsoft.com/directx/xna/gse/

There are many questions in the XNA Boards, a lot of stuff to read ^^ If you are searching for some early XNA Tutorials, Samples and Blog, check out the links in this thread:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=682393&SiteID=1

Great stuff ahead, but be aware, this is still beta and might not be complete enough for every need. I guess some of the helper classes and 3d graphic classes will be extended and there will be much more help available in the future

I will also blog alot about XNA in the near future, but first of all I need to do more XNA coding and find stuff out.