a few major issues (penetration/stuck etc.)

[mickey]

Hey guys

Here's my own contribution - a Bullet physics powered DirectX demo.



I used these Bullet features on my demo:

• Rigid bodies using most common shapes
• Kinematic character controller
• Heightfield Terrain shape
• BvhTriangleMeshShape3
• Raycast vehicle
• Ragdolls

I made a point to write formatted and easily readable code. You can download both source and executable here.

Unfortunately it suffers from a few major issues when colliding, which currently I'm trying to seek answers here in the forums:

1. Kinematic character controller would frequently stick / slide.
2. Rigid bodies would also frequently get stuck.
3. Fast moving rigid bodies will penetrate.

These all happen with the triangle mesh and the height field terrain shape. It does not happen when they collide with the dynamic rigid bodies.

[mickey]

Hi

I just released my Bullet powered DirectX demo - http://www.bulletphysics.com/Bullet/php ... =17&t=3219

Unfortunately, it (still) suffers from 3 major issues.

1. the penetration of fast moving rigid bodies with the triangle mesh shape - http://www.bulletphysics.com/Bullet/php ... f=9&t=3203

2. the kinematic character controller still - http://www.bulletphysics.com/Bullet/php ... f=9&t=2842

3. And then rigid bodies getting stuck on the height field / triangle mesh shapes.

I'm hoping that these could be resolve since I think these are some major issues.

Thanks!

[mickey]

Hi Erwin

I have released my Bullet powered DirectX demo and one of the major issues(there were 3) was (still) the character controller capsule shape sticking to a triangle mesh shapes.

I have screen shots and video over at my site showing these major issues and I have opened a thread about it here as well.

[Erwin Coumans]

Your 'demo' is a good reproduction case for your reported issues, so I merged them into this issue to track and discuss the problem.

There is one new issue for the character controller getting stuck
http://code.google.com/p/bullet/issues/detail?id=198
Issues 2 and 3 are related, we should try to avoid penetration/tunneling for fast objects:
http://code.google.com/p/bullet/issues/detail?id=22

Please wait until we have the chance to look at your demo to see what causes the issues, and resolve it. Until then, write your own character controller and for issue 2/3 avoid huge velocities (or use a smaller internal timestep).
Thanks for the report and reproduction case,
Erwin

[mickey]

Hi Erwin!

Thanks for noticing my app / issues. I can see that you have merged my threads, do you think its okay if I retain a copy of my demo show case thread over at the "Games or Demos using Bullet" forum? Or else this will get buried and I like to share my demo with the community.

Thanks.