Real-Time Physics Simulation Forum

I checked with debug drawing and the 5-can stack sometimes deactivates while the 10-can pyramid does not deactivate. After some time the active stack tends to fall apart. So if I could increase the deactivation conditions I could improve these cases. Personally I think for a game it is better to hav...

I'm trying to improve the physics simulation of bullet. I have a simple test case: https://upload.wikimedia.org/wikipedia/commons/thumb/2/2b/Dosenwerfen_2008_035.jpg/330px-Dosenwerfen_2008_035.jpg Furthermore I have 5 cans on the ground stacked on top of each other in a straight pillar each exactly ...

It seems to use rolling friction you need to also enable anisotropic rolling friction. Doing so makes the rolling friction work without objects standing on the edges that much. There is still some angles at which they stand still but I'll go through the bullet examples and collect the parameters use...

I've done some more experimenting and disabled this and that rigid body option until I got a change. It looks like the rolling friction cause the problem. I used the value from the RollingFrictionDemo which is 0.1f . Using this value the cylinder does not roll but can even stand on its edge at 80 de...

Ok that debpMotionState looks fine: I don't see any misbehaving logic there. Any ideas where I could put a lever to debug this problem? I tried examining the contact constraint generated but I did not get the impression something is wrong. That said I'm not much into physics coding so I don't know ...

The beer can... when it lands on the ground does it get deactivated? or does it remain active? Are you using a custom MotionState in your game? If so, what does its getWorldTransform() and setWorldTransform() implementations look like? Yes, a motion state is used. The code is here: https://github.c...

The box and cylinder shapes are not unstable. I've seen them work fine. I don't know what is wrong with your beer can. It behaves as if... the moment it hits the ground its world-frame inverse inertia tensor gets zero elements in the two axes perpendicular to the UP direction. That is: it is constr...

I've added a small video showing the problem.

I'm trying to tackler issues in the bullet integration. I've got two main issues I can't find a solution for. Maybe somebody has seen them before and knows in what direction to look for the problem? The first is a strange behavior of cylinder and box shapes. For example I've got a can (beer can, pic...

I'm reading things up for a release soon and one problem started to show up when I used convexSweepTest instead if my own collision tests. This is for kinematic collision hence no physics involved (think human actor movement). If actors hit a wall bullet runs into a getting-stuck situation. The firs...

I've setup another example with the kinematic joint friction case. Bullet is definitely bugged since it is unable to counter gravity using a motor even if the force is set ridiculously high. The atteched example shows the problem. If nobody is going to take a look at this problem I'm going to throw ...

I tried putting together a test case in ExampleBrowser (getting this to work is a real pain). The attached file is the first part of the problem, the one with the constraint doing strange things right at the start. In my real test case this also leads to strange jittering but I could not directly re...

I did some more testings and after running into a strange problem where the first step produces a linear velocity that should not be there I have the suspicion Bullet is bugged. Can somebody confirm this behavior to be wrong? // before doing simulation step (showing state after last simulation step)...

That's not the final goal. This is just a step in between to get it working. What I want in the end is inner joint friction, hence the joint resisting to be moved along the limited degree of freedom, like a rusty hinge on a door.

I try to setup a linear motor on a generic 6dof constraint subclass with the simple task of cancelling all forces to keep a platform (no angular movement, only linear up-down movement possible) at a steady altitude. It's a preparation for more but I can't even get this simple problem working. I do t...