CCD to be enabled, underwater like "slowdown" (beginner)

Post Reply
And1
Posts: 1
Joined: Mon Mar 11, 2013 11:03 am

CCD to be enabled, underwater like "slowdown" (beginner)

Post by And1 » Mon Mar 11, 2013 11:21 am

I tried to search in the faq and there were good information on collision detection in general, but what I couldn't find is how to enable CCD in bullet, even to consider angular motion?
The only thing I found was setCcdMotionThreshold(), but I think that's not quite what I need.
What I have is a couple of triangles on top of a plane (constructed with convexhull) that start to fall down and they hit the ground + maybe bounce off of each other and finally settle. What the problem is that sometimes they 1 triangle just goes right through another one and sometimes they interpret each other which looks bad. I tried setting the simulation step's dt to very low but even like that the problems occured.
My biggest problem is I couldn't find a documentation on how to setup the world and the solver, all I found was the typical default config that most people seem to use (btDefaultCollisionConfiguration, btDbvtBroadphase, btSequentialImpulseConstraintSolver, btDiscreteDynamicsWorld) and I'm having a hard time learning about other options and how to use them.

The other issue I have, is more like a general physics question. In this same scenario (1 ground, a few triangles) my aim is to have them float like if they were underwater. The way I tried to achieve this was that I lowered the dt for the step, lowered gravity, added linear and angular damping on the bodies...and it looks quite close what I want to do, but I was wondering if there was anything aimed specifically for this in bullet?
This can be in connection with the first question, since ultimately I want to have an underwater like feeling of the simulation, where every movement is slower than usually -> probably this can be a helpful thing for implementing non interpenetrating objects.

thanks a lot!

Post Reply