Real-Time Physics Simulation Forum

We did an Openvdb integration to bullet for a project. It uses an abstraction layer, so it probably wouldn't directly help you, but what we ended up doing to collide was generate triangles for outer edges of the voxel data, and made it work as a custom concave shape. You can find the code for it her...

IresomPCH, are you saying before or after the change I made? If you step into the code, you can see where it will limit the spring value. If that if triggers, the value of the spring drops way down because of the math error, but it would drop it to a consistent value regardless of your spring value ...

Around line 788 of btGeneric6DofSpring2Constraint is the following code. //limit stiffness (the spring should not be sampled faster that the quarter of its angular frequency) if( 0.25 < angularfreq * dt) { ks = BT_ONE / dt / dt / btScalar(16.0) / m; } I believe this is incorrect, but I still have pr...

Have you tried to run with doubles? I had a very large world using PhysX years ago, and I had to use doubles in Bullet.

I did see that when I was diffing, but I hadn't tried it. Unfortunately, it didn't work. I appreciate the help.

I'm not sure what your background is, so forgive me if you are a vehicle dynamics expert, but making a decently driving vehicle is a lot more complex than jointing rolling wheels to body. That said, I'm not sure why it's hard to apply torque to the wheels. You should be able to just apply a torque d...

I'm looking for some suggestions of what to try... I'm working on a mature driving simulation that has been using bullet since much earlier versions. It used 2.79 in its most recent last release. The vehicles in this simulation use spheres as wheels that a jointed using a combination of revolute and...

I'm building on 2.79, 2.81, 2.82, and the 2.83/3.0 alpha on OS X 10.9 both 32bit and 64bit. I'm not seeing that error, though I do get some compile errors in the demos when building with doubles on the 2.83/3.0 alpha. I use the following bash script. rm -rf bulletBuild rm -rf installPath mkdir bulle...

Yes, that works, but it's a bug that it slides down the hill regardless of whether you can fix it by modifying that variable. And it certainly should "work" with the default settings. That also affects everything else that uses the ccd sweeps, and I may not want to change the default for e...

The more I think about it, the more I think that the version where it moves the current position back up by the interpenetration amount is better because that would allow the volume to interpenetrate along the sides as well, giving the body some fuzz, but at the same time, if the body ends up interp...

btKinematicCharacterController character can't stand on a hill of any incline in 2.78. This was not an issue in 2.77. While there were not changes in the btKinematicCharacterController code aside from a one liner that is irrelevant, the sweep test seems to work a bit differently. The sweep in stepDo...

The patch fixes the linux build, but the multi threading doesn't work. The multi-threaded demo won't startup even though all the other demos do, and my applications that use it don't get any collisions when running with the multi threaded using the SpuGatheringCollisionDispatcher. Anyone seen this? ...

Look at issue 198 in the bug tracker. There is an updated character controller in there with lots of bugs fixed and jump support added. Try that one out and see if it does what you want. If you have some better code for that, great.

For your latter question, to make bullets work, we essentially turned off collision detection on them, then just did a ray cast between their position the last frame and the current frame. then we would see what was hit in the middle. That was the only way to get accuracy with something moving reall...

It won't be kinematic if you want to apply a force. Actually, you would apply a torque, but you need to slow it down. You can either apply a an angular damping or have it sit on something with friction, but the latter will be harder to bend to your will .