Matt's Dev Blog

So, it turns out that I didn't use Criterium for the video game competition at Stanford.  I actually met a partner and went with another concept instead -- Warp.  It's kind of like Starfox and it's inspired by Rez, one of the first PS2 games.  Explosions and missiles fire in time with the music; we used ChucK , an audio processing language, to achieve this. We also made some destructible objects using rigid bodies, and I added some particle explosion effects.  We used Lua to for enemy AI, and wrote a small TCL-like script parser that reads in data for the level layout.  The buildings in the background are procedurally generated.  We used OGRE for the graphics (this was a loose requirement of the project) and Bullet for the physics.  I had a lot of fun with this project, and I've posted a video capture below.

I finally got around to making the road tool for Criterium.  The tool has two parts: a Java application that lets you paint roads on the 2D heightmap texture, and a Ogre-based tool that automatically converts a 2D path into a 3D mesh.  The Ogre-tool queries the heightmap to get the height of the road, and performs smoothing so there are no discontinuous road segments.  I've posted a screenshot below.  Also, I've got my GIMP terrain shown in the screenshot.  I generated it using random noise and the GIMP lightmap filter.

Lua is a big name in game scripting.  I chose it for my engine because it is simple, easy to integrate and has excellent performance. Anyway, I just read an article about LuaJIT , which is a just-in-time compiler for Lua that is partially sponsored by Google.  It's supposed to have even more amazing performance than the standard implementation.  It's also binary-compatible with the standard Lua library and interpreter, which means I'm going to try it out with my game engine ASAP.

Here's a screen capture of my game engine in action. The video quality isn't great, but hopefully it shows off the engine well enough. While you're at it, check out a screenshot  (better quality).

Today I was working on animating my cyclist/bike mesh for Criterium. I just wanted to give kudos to the folks who developed Blender , because it is a great tool and the documentation keeps getting better and better. The inverse kinematics feature for animation is particularly awesome.  However, using Blender is not for the faint-hearted. It is extremely well designed, but also extremely complicated. In fact, when I first used Blender I thought it was buggy; strange unexplained things would sometimes happen to my models. Now I know that the "bugs" were all my fault. I simply didn't understand the software. Thankfully, I think I've progressed past that state of ignorance. When I finish my animations with the cyclist (hopefully this week) I'll post a video. P.S. Here is a link to a render of the bike model .

I'm considering game mechanics related to cycling.  First up is gearing: should the player control the gears, or should this be automatic?  Gearing would definitely give more realism, but might be clunky for the player. A mechanic I definitely want to use is drafting.  I figure it's relatively easy to do this: draw a ray along the bike's velocity vector.  If it doesn't hit another bike in front within a certain distance (say, 2 meters) then apply a small aerodynamic friction force in the opposite direction of the velocity vector.  Did you know the drag coefficient of a bicycle + rider is about 0.9 ? Finally, the user has to have some control over power the cyclist is expending.  I'll probably display some kind of heart rate counter as an indicator of effort, and possibly a stamina indicator that's proportional to lactic acid buildup.  This will keep the player from sprinting through the whole race!

Today, I was thinking about the "advanced" effects that would most benefit the realism of the game: Motion blur , to give the illusion of speed.  Ogre compositors are most likely the best solution. Dust particles , which would be thrown up occasionally when the bikes cross sandy portions of road.  Dust, IMO, is one of the easiest particle systems to implement well.  My Asteroids demo has some dust particle systems and textures. Rain , which is also easy to implement, given Ogre's built-in particle scripts . Bloom effect , one of my favorite effects, and definitely necessary for a setting sun.  I plan to use bloom to boost glare from specular highlights on the bike frame.  I used this affect in the Asteroids demo as well, and it looks quite good for highly reflective surfaces.  This can be easily done using HDR + high pass filter + Gaussian blur, and Ogre might have a compositor plugin for it. Shadows , which are completely trivial with Ogre.  Aw...