Object Release Behavior Issue in CoppeliaSim with Bullet Engine

[ubless607]

I'm experiencing unexpected object behavior when attempting to release a grasped object in CoppeliaSim v4.1.0 using the Bullet physics engine on Ubuntu. When I execute the release method `self.env._scene.robot.gripper.release()`, the object occasionally exhibits unpredictable position and orientation changes.

Specific Observations:
- Release method sometimes causes object to move or rotate unexpectedly
- Occurs consistently enough to be a potential simulation/physics engine issue
- Currently using Python with Bullet engine

I'm seeking alternative strategies to reliably release objects while maintaining their original spatial configuration. Could you provide guidance on:
- Potential physics engine configuration adjustments
- Alternative object release techniques
- Debugging approaches to understand the object displacement

Environment Details:
- CoppeliaSim Version: v4.1.0
- Physics Engine: Bullet
- Operating System: Ubuntu

Thank you for your assistance.

[coppelia]

Hello,

first of all, make sure that all of the involved objects have their Bullet stickyContact value set to false.

Then, you could try several approaches, e.g.:

• Play with the frictionOld/friction, restitution, linearDamping and angularDamping parameters
• Try to increase the mass and/or inertias of the involved objects
• You could cheat a bit by setting the object to be released to static for a few simulation steps: sim.setBoolProperty(objectHandle, 'dynamic', false)
• You could try to call sim.resetDynamicObject(objectHandle) for a few simulation steps

Cheers