Is there still life in the "Old Dog"

Sep 27, 2007 at 4:58 PM
Not that I'm saying your old Jon, : o )
Just a quick prompt to see if yor still working on stuff here or what your up to.

(apart from writing tutorials for The tutorial contest)
Oct 9, 2007 at 7:10 PM
Hey there,

Absolutely - Since June or so I've decided I ought to learn more about collision detection and physics, because, well, the current 3D physics engines for XNA simply will not work with the Xbox 360. I know that sounds like a lot to pick up, especially if you're not that good at math, and let me tell you it is.

I haven't checked in much code lately because it's not actually ready; neither was my knowledge. I believe that I'm actually getting very, very close to being ready with the GameDynamics stuff, however. I don't want to claim that I've devised a GJK-based algorithm that works in O(1) constant time, for instance, even though I've got a simplified problem statement - because things just aren't bouncing/crashing into each other yet.

When things do start crashing/bouncing/deforming I plan on moving back to deferred rendering, which I see many people seem to have tutorials about lately. I didn't understand it a couple months ago, but I really want to so I can make some neato lighting effects.

As far as my current efforts, I'm hoping there is less than a month till I can release a beta of my GameDyanmics physics engine with the following features:
- 95% of codebase should be reentrant for multi threading/coring
- O(n log n) Broadphase with an O(n2) patological case
- O(1) Narrowphase
- Bodies and particles in the same simulation
- Constraints
- No heap garbage
- Non-penetration constraints to a certain extent, enough for decent object stacking yet configurable for speed/accuracy
- Highly interactive framerates without GC-hit on both PC and 360

If you're not into physics, in short, 'Really cool bouncy/crash effects at low-to-linear cost'. I hope to then go back and integrate this code with the 3D World Studio code and be able to drive a car down a road, and, upon impact with a lamp post leave a lamp post shaped dent in the hood.

Super Grand Theft Halo 2 here I come!
Oct 10, 2007 at 9:50 AM
ooohhh, I see you've updated the logo on your site now, V.Nice.

So are you planning to do a project to integrate the 3DWS importer and the physics engine together.
A good robust 3D physics engine completely in XNA would be fantastic, most of the rest are only 2D which is a pain.
Most of the Physics I've enabled is only placeholders to mimic proper physics until I could come back to it later, so this will be a big boost.

Would be interesting to try and do a quick Physics puzzle type thing to test it out, sorta like the Half-Life barrel demo (forget the name of it, but to do with one small effect which causes others to happen and cascade, like a domino effect)