MuJoCo's soft friction constraints trade slip for force, so at the default
impratio of 1 a box resting below its friction limit still creeps and a grasped
object slides out of the grip. frictionImpedanceRatio makes friction as stiff as
the normal constraints; the slide limit itself is unchanged, so contacts that
should slide still slide at the same rate.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>