Rigid Body Dynamics

Hi, I asked this question in the Gym subforum, but I really meant to ask it here for Issac sim(maybe answers will be the same).

  1. I read nvidia physics engine doesn’t use true rigid body dynamics as it doesn’t include coriolis forces. Is this true?

  2. Can I use some other physics engine underneath Issaic sim?

Hi lowellm,

The physics engine for both Isaac Sim and Isaac Gym are the same, which is NVIDIA PhysX.
But as far as I know ( but I might be wrong) coriolis forces are included in reduced coordinates articulations:
https://gameworksdocs.nvidia.com/PhysX/4.0/documentation/PhysXGuide/Manual/Articulations.html?highlight=coriolis.

About using other physics engines, I need to ask and get back to you, but my guess is that is doable but not easily, you probably need to write the extension. This link might be useful:

Kindly,
Liila

I am referring to this paper which says PhysX doesn’t include some forces.

That is an old paper. PhysX has added reduced coordination and articulation specifically for robotics applications since then.