A midphase for a particle pair where one or both have a large number of collisions shapes, or a non-flat hierarchy of shapes. This is the general-purpose collision path and does not cache as much data as theFShapePairParticlePairMidPhaseand must visit the geometry hierarchy on both shapes every time we detect collisions. It must also rerun the collision filters on overlapping pairs, among other things. It does, howver, take advantage of the BVH held in the root ImplicitObjectUnion if there is one, so it can be much faster the theFShapePairParticlePairMidPhasewhen the set of potentially colliding pairs is very large.