Things learned the hard way

Decided to write a post. And possibly a helpful one! What a day!

I present – lessons learned the hard way in game programming:

Do not write your own physics for games.

Use http://farseerphysics.codeplex.com/ for 2D and http://physxdotnet.codeplex.com/ for 3D physics. Do not write you’re own just because you need a simple physics engine in your game – even if you do have the neccessary knowledge. It’s too big to finish in a reasonable time and there are far better engines out there.

Learn to use some paint software and a 3d modelling package

You will need art for your game. Lots and lots of art if you’re making anything bigger than puzzle games. Learn how to use Photoshop, Gimp or whatever to create basic game 2D game art. Also learn a 3D modelling package like Maya or Blender because – if you can handle the math – you will want to do something in 3 dimensions. Also learn Mudbox or some other free sculpting package if you don’t want to totally devote to 3D with learning how to uv map / texture. Also to touch UV mapping: Do not UV map a model manually using plane, sphere, … projections. Use something called LSCM mapping. Blender has it by default and most packages have a plugin that handles that (Maya has RoadKill)

Learn about view and projection transforms and object, view, world coordinate systems

Not knowing how to handle transformations between different coordinate systems turns out to be quite a bummer when trying to do anything a bit more complex with graphics. You need to know the maths so you can do a whole lot of cool stuff like shadow mapping and camera effects… Start with Vector math, and go on with Matrix math and View, Projection, Transformation matrices. It’s really practical math, ready-to-use math, not something abstract with a lot of theory behind.

Well, that’s it for now. What did you learn the hard way in game programming?

Export Maya’s custom attributes to XNA

If I only knew it was this easy…

I’m doing a spaceship shooter game, and I encountered a situation where the only solution was to write a custom xml file next to every one of my models. So I started a content pipeline extension project and began twiddling. I inherited the ModelProcessor to load info from my custom xml file, and I saw a OpaqueData dictionary in the NodeContents so I decided to google it.

With some help from http://blogs.msdn.com/b/etayrien/archive/2007/03/22/opaque-data-from-max-and-maya.aspx I got exactly what I wanted without the xml info file – getting extra information from Maya to XNA.

As the link says, soo

• 1. Add a custom attribute to a mesh in Maya
• 2. Read it in the OpaqueData
• 3. ???
• 4. Profit!

Simple as that! What you actually want to do in step 3 is pass on that extra information in a Model.Tag, or Mesh.Tag from the content pipeline to your game.

Spaceships and news

Been doing some really simple geometry in Maya, spaceships mostly.

As you can see none of them still textured, and I probably won’t be spending much time texturing any of them as I feel so helpless doing that. I’m really not an artistic guy (I couldn’t draw a bicycle on a piece of paper), as I ventured into 3D for my own personal needs , and I feel that texturing non-organics is my limit.

So yeah, now I’m stuck with a couple of untextured spaceship models so I decided to do a little 3D top-down space arcade / roguelike kinda action RPG where the textures won’t stand out as totally bad. And I said I’d finish it by the end of summer. We’ll see…

In other news:

• XNA 4.0 Beta – If you got the CTP version installed you have to uninstall it, but do uninstall the whole product (not piece by piece) as you’re quickly going to find a lot of problems if you try uninstalling piece by piece. I fixed my problems using the MSI Cleanup Utility.
• Goblin Camp v001 is out. You can call it a Dwarf Fortress killer, I call it cool. Anyhow it’s anonuncing the next generation of ascii graphics city builders. If you’re so confused right now, check http://www.goblincamp.com/ and Dwarf fortress. Only for hardcore people who play hardcore games.