Monday, January 8, 2007

Models and skeletons and formats....

This past weekend I unfortunately wasn't able to get much work done. Most of my time was spent on working through the Collada converter issue, and the rest working on getting the skeletal animation stuff up and running and some computer issues. The basics are now there, but I still haven't made any major decisions yet like whether I want a separate skeleton format (.arskel) or whether I want to inline them into all models and animation files (.arm and .aranim). The benefit to a separate skeleton file would be skeleton sharing (and decreased memory usage), while a unified model format (with built-in skeleton) would allow for more verbose error checking. I'm leaning towards skeleton sharing at this point since the model exporter should do most of the error checking anyways.

I've started implementing matrix palette skinning on the CPU but I plan to eventually use the GPU for the task. Before then I need a good plan in place for the shaders that will require variable bone indices. I'll probably only support 1, 2, and 4 bone indices, but that would require up to 4 versions of each vertex shader (that's including the 0-bone version). Something else I need to consider soon is adding pre-calculated silhouette edges to the model format since I plan on doing stencil shadows at some point. Sure I could calculate them at load time but it would be just as easy to pre-calculate them and directly load them from file (and much quicker as well).

As most people know, Microsoft OS's start to crap out and get flaky after about 6 months of heavy use. Well I've had the same install of Windows XP on my current machine for nearly 2 1/2 years now and I was well overdue for a clean sweep. It's not usually a painful process but I decided to do a very thorough wipe of my hard-drive using DBAN. This took quite a while but honestly not as long as it took to back up all of my critical data onto disk media and my backup hard-drives. So since most of the process entails waiting I had a lot of time to think about some design aspects for Star Trader. I think I've basically worked out all the details for ship-to-ship combat as well as planetary ground combat. I've got to run but I'll describe it in my next update.


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