Contact Restitution with PhysX in IsaacGym

I try to change the contact restitution between one object and the ground plane.

I set restitution = 1.0 for both object and plane. I find that the simulation is still inelastic.

I am wondering what is the mechanism behind the contact?


same question here…

Hi there,

here is a step by step setup for testing the restitution:

  • in an empty stage add a Plane, two Cubes (Create->Mesh->Plane/Cube) and a Physics Material (Create->Physics->Rigid Body Material)
  • select the Plane and the two Cubes and add Physics->Colliders and for the two Cubes add [Physics->Rigid Body]
  • for the PhysicsMaterial set the Restitution value to 1.0, and the Restitution Combine Mode to average or max
  • apply the PhysicsMaterial to the second Cube physics material (in the Materials on selected models TAB)

Here is an example screenshot with the second cube’s elastic collision:


Hi, I use python to load the object from urdf file to IsaacGym.
Is it possible to modify the urdf file or the python script to achieve this elastic behavior?

My bad, I overlooked that the question is for Isaac Gym. I will forward this to the Isaac Gym team.

Hi, is there any feedback from IsaacGym team?

Hi @HarryYang, @zhuceyonghu123,

I’ll try to repro your case and take a look into the issue.


Are there any news regarding this matter?


I guess changing the restitution coefficient before creating the actor might solve it

I think I also observed weird restitution settings behavior, are you using gpu or cpu physX?