Should I find another 3d physics library?

Newbie & Debugging Questions
#1

I’ve been using JBullet in my engine for quite awhile now and It’s always seemed to have a few issues with me. The main issue is that smaller objects seem to fall right through the ground almost always.
Here’s a gif

The main problem here is that this should not be happening. The game is running the physics at 120 tps.

I feel like 120 tps should be fast enough to get rid of these kinds of issues. Obviously I know that with any physics engine if a body is going too fast it will go right through an object, but this speed with 120 tps doesn’t feel right…

#2

Hi

I’m not sure that you’re right, it depends on the algorithms used in those engines, it shouldn’t happen with continuous collision detection, it can happen when the discretization step is too coarse.

#3 

myRigidBody.setCcdMotionThreshold((float) 1e-7);
myRigidBody.setCcdSweptSphereRadius(0.1f);

Put this on any btRigidBody and it greatly improves collision accuracy by activating CCD on a moving object
http://www.bulletphysics.org/mediawiki-1.5.8/index.php?title=Anti_tunneling_by_Motion_Clamping
(I think, but I could have read the doc wrong)

Check out this article on CCD too
https://www.aorensoftware.com/blog/2011/06/01/when-bullets-move-too-fast/

To answer your question, Bullet is super powerful if it’s configured correctly. Don’t try and switch it with some lib from 2009 and hope it’ll act the same (I’ve been there, it just creates more issues ! )

#4

I’ll give it a try :slight_smile: Thanks Ecumene.