Hello,
I am working on a tabletop contact-rich soft body manipulation scenario on Isaac Gym, Preview 4. As a soft body dynamics model, I am using Isaac Gym’s FleX.
For reducing my simulated environment’s reality gap, it is important to understand how friction is computed in IG4’s FleX. I have not found any concrete answer in the documentation or anywhere else. This matter has also been touched in other discussions in this forum (e.g., How to eliminate slippage when grasping soft objects with Flex backend?), however it was done from the perspective of reducing contact errors intrinsic to the simulation.
Looking into DefGraspSim repo (GitHub - NVlabs/DefGraspSim: This package provides a framework to automatically perform grasp tests on an arbitrary object model of choice.), I observe that soft body friction is parameterised through FleX dynamic_friction contact parameter (DefGraspSim/grasp_evaluator/grasp_evaluator.py at main · NVlabs/DefGraspSim · GitHub).
My own experiments suggest a parameterisation in line with this. More specifically, the outcome of dragging a soft body along a rigid surface seems to be affected mainly by the flex.dynamic_friction value. In such contacts, toggling the rigid surface friction seems to have negligible to non-existent effects.
What is the community’s experience in this topic?
Can a member of the development team elaborate on this technical detail?
Thanks.