CD issue in btBvhTriangleMeshShape vs btStaticPlaneShape

[roozbehg]

Hi all,

I've been trying to simulate terrain using btBvhTriangleMeshShape and in order to check the response of btBvhTriangleMeshShape in high speed impact I simply modified the BasicDemo example and replaced the btStaticPlaneShape shape with 5 flat btBvhTriangleMeshShape shapes and also increased the elevation of boxes. long story short, couple of boxes are passing through the ground (collision detection did not work perfectly) I tried to decreasing the time step and also changed the setCcdMotionThreshold value but none of them worked. btStaticPlaneShape is working perfectly fine for the same setup.

have any of you faced the same issue?

BTW, the source codes have been attached.
add/remove "#define Plane" at BasicDemo.cpp file to switch between plane/triangle.


thank you in advance.

[frogdog]

I am having a similar issue:

http://www.bulletphysics.org/Bullet/php ... =9&t=10814

It appears that Bullet is unreliable when using btBvhTriangleShape which is one triangle thin. In my example a single capsule without any force from any other rigid bodies falls through.

In your example if you add thickness by using a box shape, no cubes fall through, though this might be less to do with thickness and more to do with the way TriangleMeshShape is handled?

Code: Select all

groundShape = new btBoxShape( btVector3( 50.0f, 0.1f, 50.0f ));
btTransform groundTransform;
groundTransform.setIdentity();
groundTransform.setOrigin( btVector3( 0.0f, -50.0f, 0.0f ));

Edit: Just realised this post is a few months old Issue still exists however.

[roozbehg]

thanks for emphasizing this issue and yes it still exists.