Real-Time Physics Simulation Forum

Thanks for the reply. Unfortunately, it makes no difference. I think velocity is ignored for kinematic objects. Edit: I finally figured it out. I was directly updating the WorldTransform, without updating the MotionState. I changed this to update both and now it works great: btTransform& t = m_p...

Kinematic objects do not seem to interact very well with dynamic objects. When you call m_pRigidBody->getWorldTransform().setOrigin() it caterpults any dynamic objects in it's way with enormous force. Is this normal?

I downloaded the latest version and now it seems to be ok. I no longer get the crash.

I wrote a blog entry detailing how I solved various problems I had with Bullet physics. I post it here in case it might prove useful to some one https://www.gamedev.net/blogs/entry/227 ... t-physics/

I discovered some bizzarre behaviour of a btRigidBody (with CF_KINEMATIC_OBJECT flag) when you try to set the position of the object. If set activation state to ISLAND_SLEEPING, then the position can be modified with this code: btTransform& t = m_pRigidBody->getWorldTransform(); t.setOrigin(btVe...

ah, thanks for the answer. I don't use btStaticPlaneShape, so it must be something else in my case.
My solution is to keep using the old version

I think I have solved the problem for most cases. Actually, I think changing the default values was what actually caused the problem. Mucking around with m_rollingFriction, m_spinningFriction, SleepingThresholds, Damping and DeactivationTime made everything worse. You should leave these at defaults....

Thanks for you answer drleviathan. I am using normal value for gravity. I tried messing around with the different parameters, but it does not seem to make any difference. I tried modifying m_friction, m_spinningFriction, m_restitution, m_rollingFriction to various values I set setAngularVelocity to ...

When I drop objects on the ground I always get objects landing on the thin edge of the object, when it should topple over onto the flat edge. About 30% of the time this happens. Does anyone know a solution to this problem?

I tried upgrading my project which was using an old version of bullet (2.88) to the lastest version (3.24) and now I get a crash at btConvexHullShape::localGetSupportingVertexWithoutMargin()

Anyone know what change could have happened to cause this crash?

Thanks for your answer, drleviathan. Adding small amount of angular velocity seemed to do the trick

Try setting a small amount of margin on both objects:
pCollisionShape->setMargin(0.05f);

I have a problem if a capsule shape object it dropped on to the ground on it's top or bottom side, it comes to rest on the same edge, which is round (because it's a capsule). It should fall over onto its longer edge. I also notice the same problem with btConvexHullShape - the object come to standsti...

A quick question: does bullet include inverse kinematics that could be used to control a skinned mesh?
I.e. it would allow me to enter the joints and constraints of a human skeleton and when I fix the feet to the floor and push down the root node, the knees would bend.

Quick question: Anyone know how to query if a btRigidBody object is already in btDynamicsWorld?