Introduce kF_UseGjkConvexCastRaytest, and make kF_UseSubSimplexConvexCastRaytest the default for btCollisionWorld::rayTest See https://github.com/bulletphysics/bullet3/issues/34

Add btCollisionObject::setIgnoreCollisionCheck to disable collisions between specific instances, without having a btTypedConstraint. See https://github.com/bulletphysics/bullet3/issues/165

Make btMultiBody and btMultiBodyJointMotor backwards compatible with Bullet 2.82 API (single-DOF API)

ObsoleteDemos/FeatherstoneMultiBodyDemo/FeatherstoneMultiBodyDemo.cpp

@@ -394,23 +394,16 @@ btMultiBody* FeatherstoneMultiBodyDemo::createFeatherstoneMultiBody(class btMult
 			if (1)
 			{
 				btCollisionShape* box = new btBoxShape(btVector3(halfExtents[0],halfExtents[1],halfExtents[2])*scaling);
-				btRigidBody* body = new btRigidBody(mass,0,box,inertia);
 				btMultiBodyLinkCollider* col= new btMultiBodyLinkCollider(bod,-1);
-
-				body->setCollisionShape(box);
 				col->setCollisionShape(box);
-								
 				btTransform tr;
 				tr.setIdentity();
 				tr.setOrigin(local_origin[0]);
 				tr.setRotation(btQuaternion(quat[0],quat[1],quat[2],quat[3]));
-				body->setWorldTransform(tr);
 				col->setWorldTransform(tr);
-				
 				world->addCollisionObject(col, 2,1+2);
 				col->setFriction(friction);
-				bod->setBaseCollider(col);
-				
+				bod->setBaseCollider(col);	
 			}
 		}
 

src/BulletCollision/CollisionDispatch/btCollisionDispatcher.cpp

@@ -189,7 +189,7 @@ bool	btCollisionDispatcher::needsCollision(const btCollisionObject* body0,const
 
 	if ((!body0->isActive()) && (!body1->isActive()))
 		needsCollision = false;
-	else if (!body0->checkCollideWith(body1))
+	else if ((!body0->checkCollideWith(body1)) || (!body1->checkCollideWith(body0)))
 		needsCollision = false;
 	
 	return needsCollision ;

src/BulletCollision/CollisionDispatch/btCollisionObject.h

@@ -110,13 +110,11 @@ protected:
 	/// If some object should have elaborate collision filtering by sub-classes
 	int			m_checkCollideWith;
 
+	btAlignedObjectArray<const btCollisionObject*> m_objectsWithoutCollisionCheck;
+
 	///internal update revision number. It will be increased when the object changes. This allows some subsystems to perform lazy evaluation.
 	int			m_updateRevision;
 
-	virtual bool	checkCollideWithOverride(const btCollisionObject* /* co */) const
-	{
-		return true;
-	}
 
 public:
 
@@ -225,7 +223,34 @@ public:
 		return m_collisionShape;
 	}
 
-	
+	void	setIgnoreCollisionCheck(const btCollisionObject* co, bool ignoreCollisionCheck)
+	{
+		if (ignoreCollisionCheck)
+		{
+			//We don't check for duplicates. Is it ok to leave that up to the user of this API?
+			//int index = m_objectsWithoutCollisionCheck.findLinearSearch(co);
+			//if (index == m_objectsWithoutCollisionCheck.size())
+			//{
+			m_objectsWithoutCollisionCheck.push_back(co);
+			//}
+		}
+		else
+		{
+			m_objectsWithoutCollisionCheck.remove(co);
+		}
+		m_checkCollideWith = m_objectsWithoutCollisionCheck.size() > 0;
+	}
+
+	virtual bool	checkCollideWithOverride(const btCollisionObject*  co) const
+	{
+		int index = m_objectsWithoutCollisionCheck.findLinearSearch(co);
+		if (index < m_objectsWithoutCollisionCheck.size())
+		{
+			return false;
+		}
+		return true;
+	}
+
 
 	
 

src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp

@@ -294,10 +294,11 @@ void	btCollisionWorld::rayTestSingleInternal(const btTransform& rayFromTrans,con
 		//btContinuousConvexCollision convexCaster(castShape,convexShape,&simplexSolver,0);
 		bool condition = true;
 		btConvexCast* convexCasterPtr = 0;
-		if (resultCallback.m_flags & btTriangleRaycastCallback::kF_UseSubSimplexConvexCastRaytest)
-			convexCasterPtr = &subSimplexConvexCaster;
-		else
+		//use kF_UseSubSimplexConvexCastRaytest by default
+		if (resultCallback.m_flags & btTriangleRaycastCallback::kF_UseGjkConvexCastRaytest)
 			convexCasterPtr = &gjkConvexCaster;
+		else
+			convexCasterPtr = &subSimplexConvexCaster;
 		
 		btConvexCast& convexCaster = *convexCasterPtr;
 

src/BulletCollision/NarrowPhaseCollision/btRaycastCallback.h

@@ -21,6 +21,7 @@ subject to the following restrictions:
 struct btBroadphaseProxy;
 class btConvexShape;
 
+
 class  btTriangleRaycastCallback: public btTriangleCallback
 {
 public:
@@ -32,10 +33,12 @@ public:
    //@BP Mod - allow backface filtering and unflipped normals
    enum EFlags
    {
-      kF_None                 = 0,
+	  kF_None = 0,
       kF_FilterBackfaces      = 1 << 0,
       kF_KeepUnflippedNormal  = 1 << 1,   // Prevents returned face normal getting flipped when a ray hits a back-facing triangle
-	  kF_UseSubSimplexConvexCastRaytest =  1 << 2,   // Uses an approximate but faster ray versus convex intersection algorithm
+		///SubSimplexConvexCastRaytest is the default, even if kF_None is set.
+	  kF_UseSubSimplexConvexCastRaytest = 1 << 2,   // Uses an approximate but faster ray versus convex intersection algorithm
+	  kF_UseGjkConvexCastRaytest = 1 << 3,
       kF_Terminator        = 0xFFFFFFFF
    };
    unsigned int m_flags;

src/BulletDynamics/Dynamics/btRigidBody.cpp

@@ -317,38 +317,48 @@ void btRigidBody::setCenterOfMassTransform(const btTransform& xform)
 }
 
 
-bool btRigidBody::checkCollideWithOverride(const  btCollisionObject* co) const
-{
-	const btRigidBody* otherRb = btRigidBody::upcast(co);
-	if (!otherRb)
-		return true;
-
-	for (int i = 0; i < m_constraintRefs.size(); ++i)
-	{
-		const btTypedConstraint* c = m_constraintRefs[i];
-		if (c->isEnabled())
-			if (&c->getRigidBodyA() == otherRb || &c->getRigidBodyB() == otherRb)
-				return false;
-	}
-
-	return true;
-}
 
 
 
 void btRigidBody::addConstraintRef(btTypedConstraint* c)
 {
-	int index = m_constraintRefs.findLinearSearch(c);
-	if (index == m_constraintRefs.size())
-		m_constraintRefs.push_back(c); 
+	///disable collision with the 'other' body
 
-	m_checkCollideWith = true;
+	int index = m_constraintRefs.findLinearSearch(c);
+	//don't add constraints that are already referenced
+	btAssert(index == m_constraintRefs.size());
+	if (index == m_constraintRefs.size())
+	{
+		m_constraintRefs.push_back(c);
+		btCollisionObject* colObjA = &c->getRigidBodyA();
+		btCollisionObject* colObjB = &c->getRigidBodyB();
+		if (colObjA == this)
+		{
+			colObjA->setIgnoreCollisionCheck(colObjB, true);
+		}
+		else
+		{
+			colObjB->setIgnoreCollisionCheck(colObjA, true);
+		}
+	}
 }
 
 void btRigidBody::removeConstraintRef(btTypedConstraint* c)
 {
+	int index = m_constraintRefs.findLinearSearch(c);
+	//don't remove constraints that are not referenced
+	btAssert(index < m_constraintRefs.size());
 	m_constraintRefs.remove(c);
-	m_checkCollideWith = m_constraintRefs.size() > 0;
+	btCollisionObject* colObjA = &c->getRigidBodyA();
+	btCollisionObject* colObjB = &c->getRigidBodyB();
+	if (colObjA == this)
+	{
+		colObjA->setIgnoreCollisionCheck(colObjB, false);
+	}
+	else
+	{
+		colObjB->setIgnoreCollisionCheck(colObjA, false);
+	}
 }
 
 int	btRigidBody::calculateSerializeBufferSize()	const

src/BulletDynamics/Dynamics/btRigidBody.h

@@ -87,7 +87,7 @@ class btRigidBody  : public btCollisionObject
 	//m_optionalMotionState allows to automatic synchronize the world transform for active objects
 	btMotionState*	m_optionalMotionState;
 
-	//keep track of typed constraints referencing this rigid body
+	//keep track of typed constraints referencing this rigid body, to disable collision between linked bodies
 	btAlignedObjectArray<btTypedConstraint*> m_constraintRefs;
 
 	int				m_rigidbodyFlags;
@@ -506,8 +506,6 @@ public:
 		return (getBroadphaseProxy() != 0);
 	}
 
-	virtual bool checkCollideWithOverride(const  btCollisionObject* co) const;
-
 	void addConstraintRef(btTypedConstraint* c);
 	void removeConstraintRef(btTypedConstraint* c);
 

src/BulletDynamics/Featherstone/btMultiBody.h

@@ -45,14 +45,15 @@ public:
     // initialization
     //
     
-    btMultiBody(int n_links,             // NOT including the base
-              btScalar mass,                // mass of base
-              const btVector3 &inertia,    // inertia of base, in base frame; assumed diagonal
-              bool fixedBase,           // whether the base is fixed (true) or can move (false)
-              bool canSleep,
-			  bool multiDof
+	btMultiBody(int n_links,             // NOT including the base
+		btScalar mass,                // mass of base
+		const btVector3 &inertia,    // inertia of base, in base frame; assumed diagonal
+		bool fixedBase,           // whether the base is fixed (true) or can move (false)
+		bool canSleep,
+		bool multiDof = false
 			  );
 
+
     ~btMultiBody();	
     
     void setupPrismatic(int i,             // 0 to num_links-1

src/BulletDynamics/Featherstone/btMultiBodyJointMotor.cpp

@@ -21,6 +21,12 @@ subject to the following restrictions:
 #include "BulletCollision/CollisionDispatch/btCollisionObject.h"
 
 
+btMultiBodyJointMotor::btMultiBodyJointMotor(btMultiBody* body, int link, btScalar desiredVelocity, btScalar maxMotorImpulse)
+:btMultiBodyJointMotor(body,link,0,desiredVelocity,maxMotorImpulse)
+{
+}
+
+
 btMultiBodyJointMotor::btMultiBodyJointMotor(btMultiBody* body, int link, int linkDoF, btScalar desiredVelocity, btScalar maxMotorImpulse)
 	//:btMultiBodyConstraint(body,0,link,-1,1,true),
 	:btMultiBodyConstraint(body,body,link,link,1,true),

src/BulletDynamics/Featherstone/btMultiBodyJointMotor.h

@@ -30,6 +30,7 @@ protected:
 
 public:
 
+	btMultiBodyJointMotor(btMultiBody* body, int link,btScalar desiredVelocity, btScalar maxMotorImpulse);
 	btMultiBodyJointMotor(btMultiBody* body, int link, int linkDoF, btScalar desiredVelocity, btScalar maxMotorImpulse);
 	virtual ~btMultiBodyJointMotor();