Bullet C-API b3ChangeDynamicsInfoSetSpinningFriction/RollingFriction/Resitution b3PhysicsParamSetRestitutionVelocityThreshold, / pybullet.setPhysicsEngineParameter restitutionVelocityThreshold: if the velocity is below this threshhold, the restitution is zero (this prevents energy buildup at near-resting state) pybullet restitution.py example.