Expose the multi-point perturbation algorithm for btConvexPlaneCollisionAlgorithm

Usage:
	m_collisionConfiguration = new btDefaultCollisionConfiguration();
	m_collisionConfiguration->setPlaneConvexMultipointIterations();

It is only enabled for polyhedral convex shapes, because implicit/smooth surfaces such as spheres, cylinders, capsules and cones keep on rolling forever, due to the extra off-center contact points

1 files changed, 4 insertions, 1 deletions

diff --git a/src/BulletCollision/CollisionDispatch/btConvexPlaneCollisionAlgorithm.cpp b/src/BulletCollision/CollisionDispatch/btConvexPlaneCollisionAlgorithm.cpp
index 85a8a4e8f..b2e9bfaf5 100644
--- a/src/BulletCollision/CollisionDispatch/btConvexPlaneCollisionAlgorithm.cpp
+++ b/src/BulletCollision/CollisionDispatch/btConvexPlaneCollisionAlgorithm.cpp
@@ -127,7 +127,10 @@ void btConvexPlaneCollisionAlgorithm::processCollision (btCollisionObject* body0
 		resultOut->addContactPoint(normalOnSurfaceB,pOnB,distance);
 	}
 
-	if (resultOut->getPersistentManifold()->getNumContacts()<m_minimumPointsPerturbationThreshold)
+	//the perturbation algorithm doesn't work well with implicit surfaces such as spheres, cylinder and cones:
+	//they keep on rolling forever because of the additional off-center contact points
+	//so only enable the feature for polyhedral shapes (btBoxShape, btConvexHullShape etc)
+	if (convexShape->isPolyhedral() && resultOut->getPersistentManifold()->getNumContacts()<m_minimumPointsPerturbationThreshold)
 	{
 		btVector3 v0,v1;
 		btPlaneSpace1(planeNormal,v0,v1);