Collisions for rubber roller

[mindThomas]

I am trying to simulate a rubber-coated roller and would like some suggestions on the collision modelling.
So far I have tried playing with the collider settings and the Physics material properties, but I simply cannot get the roller to "push" away any resting object on it as I would expect. Instead the object starts jumping until it comes to rest at a "floating" position above the colliders.

Take the following video as an example: https://drive.google.com/file/d/1FS63QZxDeDFEKAtiW53SZjCHlxQu-hQK/view?usp=sharing

I have deliberately used the Cylinder Shape instead of Cylinder Mesh such as to use the efficient cylinder collider.

Is what I am seeing a result of simulation of a non-compressible collider and hence a limitation I should expect and accept? If so, are there any parameters (for example collider ranges/zones) that could be adjusted to help improve the simulation and make it closer to reality?

I am using Isaac Sim 5.1.0 on Ubuntu 24.04 with an RTX 5090.

[PeterL-NV]

Hi, PhysX uses contact offset (distance where contact detection starts) and rest offset (distance where objects come to rest). When rest offset is too large or not set correctly, objects "float" above surfaces instead of touching.

Here're a few things you can try:

• Set rest_offset=0.0 to eliminate floating gap
• contact_offset should be > 0 (e.g., 0.02) for stable detection
• Increase friction (1.0-2.0 range) for rubber-like behavior
• Use surface velocity if the roller actively rotates
• Increase solver iterations if objects still jitter