Current State of Bullet on 360

Topics: Developer Forum, Project Management Forum, User Forum
Nov 20, 2007 at 4:02 AM
Hey, I'm itching to write a 3D physics based game on the 360 and Bullet looks to be the best engine currently available. However, I grabbed the latest snapshot from the source tree and I'm having some trouble.

First off, none of the .csproj files target the 360, so I had to manually edit the xml before I could get them to build and deploy to my xbox. Next, once I actually got it running on the xbox, it was running painfully slowly, like less than a frame a second for the Basic demo. It's clear that I must be doing something wrong, as most of the videos I've watched of Bullet show it running very fluidly. Likewise, the demos run great on my housemates machine even though they run god awful on mine.

To direct my questions:
  • Why aren't there .sln/.csproj files targetting the 360 in the source tree by default?
  • Which part of the source tree should I be building, I see three folders that all seem like they could be the correct one. Should I be using XnaDevRu.Bullet, XnaDevRu.Engine, XnaDevRu.Physics, or some combination?

-rez
Coordinator
Nov 20, 2007 at 7:38 AM
Bullet project is temporary freezed. sorry..
Nov 20, 2007 at 5:21 PM
For what reason has the project been frozen? And what state was Bullet in at the time it was frozen? Are there any sort of organizational documents anywhere where I can see what is in working order and what isn't working/implemented?
Coordinator
Nov 21, 2007 at 7:26 PM
The main reason is that our lead project coordinator (Klemix) is busy with his own stuff. He has no spare time for this project.
Take a look at Bullet Files To Be Ported ...
Nov 29, 2007 at 12:30 PM
Pity about the freeze, it would be great to see more work done on this promising API. But, it's open source so I guess we can all pitch in :)

I've started porting the Raycast Vehicle class: http://www.bulletphysics.com/Bullet/phpBB3/viewtopic.php?p=6473#p6473

The biggest bug I have found (and not yet fixed) is in the raycast code against rotated boxes, more info here: http://www.bulletphysics.com/Bullet/phpBB3/viewtopic.php?f=9&t=1247

Cheers,
Will
Coordinator
Nov 30, 2007 at 4:07 AM
this is very good news. i can add you to the project team if you want.
Dec 5, 2007 at 4:49 AM
I just got my project files updated for the 360 as well (http://xnaengine.com/) and it does seem to run slow on the 360. I'm not sure why, but i suspect it could be garbage collection issues. The XBOX version of .net doesn't have generational GC like the PC does, so creating new objects every frame can hurt performance. I'm not too knowledgeable on the subject, but there are some articles out there that explain the issues. Perhaps BulletX can be optimized to avoid GC and to take advantage of the 360's 3 cores.s