Deformable meshes don't collide with kinematics objects with surface velocity

Omniverse Isaac Sim
1

Isaac Sim Version

4.5.0

Operating System

Ubuntu 22.04

GPU Information

  • Model: RTX 4090
  • Driver Version: 570

Topic Description

Detailed Description

If you create:
1- A deformable object with collision
2- A rigid body, either kinematic with velocity, or rigid body with the SurfaceVelocityApi

Then the models don’t collide with each other. The moment the rigid body adds velocity (to act as a conveyor belt, for example) the deformable body goes down through it.

Attached a video and a super simple sample
deformable_body_collision_test.zip (79.2 KB)

3

Hi @christianbarcelo, thank you for posting your issue. Unfortunately, contact interactions between deformables and surface velocity objects are not currently supported in PhysX/Isaac Sim. Eventually, we may be releasing this feature through Newton, but there are no concrete plans for this yet. I apologize for the inconvenience.

If this helps, one proxy you could do is to make a pseudo-deformable object by instantiating many cubes in a grid and creating your own 6 DOF joints between them (almost like a manual FEM). In that case, the individual cubes at the vertices will have collision support with the velocity surface.

Sorry for the inconvenience!

4

Understood. At least I know it’s not supported and not something I’m not doing right.

The idea of creating it manually does not work for my use case since I’m willing to have the visuals as well, but you made me think adding a solid attachment of a similar size to the deformable body may help, so the deformable body can act when in contact to solid pieces, and it will sink a little on surface velocities until the solid attachment catches the contact.

BTW and sorry for the off-topic, any news regarding Newton’s release date?

Thanks!

1 Like
5

Thanks for the understanding! Newton release date is still TBD, there is only the prerelease code for now: GitHub - newton-physics/newton: An open-source, GPU-accelerated physics simulation engine built upon NVIDIA Warp, specifically targeting roboticists and simulation researchers.
I’ll close this topic for now, but feel free to follow-up on a different thread if you have further questions.