Collision detection and contact generation for triangle mesh geometries

[SumantBagri]

Hi,

Context:
I am trying to leverage the GPU acceleration for collision detection provided by PhysX for robotic manipulator motion planning tasks. In a specific test, I am trying to load a particular arm link with a triangle mesh geometry as a kinematic actor (create RigidDynamic and set PxRigidBodyFlag::eKINEMATIC flag).

Then I will create an RigidDynamic environment object with a triangle mesh geometry as well and perform a collision by moving the arm link using setKinematicTarget() (triangle mesh <> triangle mesh collision)

I have been able to perform the same test using primitive objects:

• Box: setup as a kinematic actor
• Spheres and Capsules setup as dynamic actors

physx_primitive_test_nv_render.mp4

Background:
I am trying to do the same for mesh geometries and evaluate the performance gains from the acceleration. During my research, I came across this post: https://forums.developer.nvidia.com/t/physx-3-3-1-loading-obj-and-creating-a-dynamic-actor/34122/2. From what I understand, in PhysX 3.3.1, mesh geometries attached to dynamic actors participates in scene queries (such as PxScene::overlap()) but does not participate in contact generation (i.e it is not possible to get contact information from sceneDesc.simulationEventCallback for such geometries).

Questions

1. Is my understanding accurate or does the phrase "but does not participate in rigid body or particle contact" in the post mean something else ?
2. Is this limitation still present in PhysX 5.2.1 ?
3. Do you recommend converting the triangle meshes into convex hulls before performing collisions ? If yes, could you point me to a sample / snippet that provides some guidelines for such a conversion ?
4. Finally, do you have any other recommendations / suggestions when performing collisions / contact generations, on the GPU, with triangle mesh geometries ?