Physics Simulation Forum

I have spent a lot of time over the last year working on two physics-based indie games and one of them (Invader Zurp) has finally gotten to 1.0 and is now selling on the App Store!



Invader Zurp is built completely around Bullet's physics simulation and that simulation is actually the core gameplay mechanic. You can check out a quick gameplay trailer to get a taste for what the game is like here: http://www.youtube.com/watch?v=X3JtlDrIFnE

Web Site: http://www.invaderzurp.com
App Store Link: http://bit.ly/invaderzurp

During the course of development I learned a ton about the internal workings of Bullet and physics simulation in general. As much as possible I tried to write about the things I learned on my blog.
Here are the articles I wrote that may be of interest to Bullet developers:

Determinism In Games - Basic rundown of determinism importance and issues with networking and serialization
Bullet Physics Optimization For iOS - The best compiler configurations I found for Bullet performance on iOS
When Bullets Move Too Fast - Basic rundown of tunneling and how to deal with it in Bullet
Application-Specific Bullet Physics Optimization - Milking that last few % of Bullet performance

Hopefully some of these articles might be of help to others experiencing similar issues. Let me know if you find anything incorrect in them or have anything else to add. Thanks!

Hey thanks for sharing your experiences



Did Bullets CCD system not help with dynamic objects vs dynamic objects? I've gotten it to work just fine for individual fast moving objects vs static collision meshes. I've found a problem with it with fast moving rag dolls vs static collision issues though.

I played around with it a while ago and couldn't get it to work. I didn't spend a ton of time on it and unfortunately I don't quite remember the particulars about the issues I had. If I understand Bullet's CCD correctly, the methods that I employed produce a fairly similar result and performance. I have high hopes that Bullet 3 might kick CCD support into high gear

The parameters and usuage are a little vague but with a little digging I was able to figure it out and got it working well for single RBs that aren't constrained to other ones.