Constraints can override their own number of solver iterations (either more or less than the default) or leave it default (-1)

Bump version to 2.80

Demos/SerializeDemo/SerializeDemo.cpp

@@ -69,6 +69,87 @@ btSoftBodySolver*	fSoftBodySolver=0;
 #include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h"
 #endif
 
+void SerializeDemo::keyboardCallback(unsigned char key, int x, int y)
+{
+	btAlignedObjectArray<btRigidBody*> bodies;
+	if (key == 'g')
+	{
+		int numManifolds = getDynamicsWorld()->getDispatcher()->getNumManifolds();
+
+		for (int i=0;i<numManifolds;i++)
+		{
+			btPersistentManifold* manifold = getDynamicsWorld()->getDispatcher()->getManifoldByIndexInternal(i);
+			if (!manifold->getNumContacts())
+				continue;
+
+			btScalar minDist = 1e30f;
+			int minIndex = -1;
+			for (int v=0;v<manifold->getNumContacts();v++)
+			{
+				if (minDist >manifold->getContactPoint(v).getDistance())
+				{
+					minDist = manifold->getContactPoint(v).getDistance();
+					minIndex = v;
+				}
+			}
+			if (minDist>0.)
+				continue;
+		
+			btCollisionObject* colObj0 = (btCollisionObject*)manifold->getBody0();
+			btCollisionObject* colObj1 = (btCollisionObject*)manifold->getBody1();
+			int tag0 = (colObj0)->getIslandTag();
+			int tag1 = (colObj1)->getIslandTag();
+			btRigidBody* body0 = btRigidBody::upcast(colObj0);
+			btRigidBody* body1 = btRigidBody::upcast(colObj1);
+			if (bodies.findLinearSearch(body0)==bodies.size())
+				bodies.push_back(body0);
+			if (bodies.findLinearSearch(body1)==bodies.size())
+				bodies.push_back(body1);
+
+			if (body0 && body1)
+			{
+				if (!colObj0->isStaticOrKinematicObject() && !colObj1->isStaticOrKinematicObject())
+				{
+					if (body0->checkCollideWithOverride(body1))
+					{
+						{
+							btTransform trA,trB;
+							trA.setIdentity();
+							trB.setIdentity();
+							btVector3 contactPosWorld = manifold->getContactPoint(minIndex).m_positionWorldOnA;
+							btTransform globalFrame;
+							globalFrame.setIdentity();
+							globalFrame.setOrigin(contactPosWorld);
+
+							trA = body0->getWorldTransform().inverse()*globalFrame;
+							trB = body1->getWorldTransform().inverse()*globalFrame;
+
+							btGeneric6DofConstraint* dof6 = new btGeneric6DofConstraint(*body0,*body1,trA,trB,true);
+							dof6->setOverrideNumSolverIterations(100);
+
+							dof6->setBreakingImpulseThreshold(35);
+
+							for (int i=0;i<6;i++)
+								dof6->setLimit(i,0,0);
+							getDynamicsWorld()->addConstraint(dof6,true);
+							
+						}
+					}
+				}
+			}
+			
+		} 
+
+		for (int i=0;i<bodies.size();i++)
+		{
+			getDynamicsWorld()->removeRigidBody(bodies[i]);
+			getDynamicsWorld()->addRigidBody(bodies[i]);
+		}
+	}else
+	{
+		PlatformDemoApplication::keyboardCallback(key,x,y);
+	}
+}
 
 
 void SerializeDemo::clientMoveAndDisplay()
@@ -81,7 +162,6 @@ void SerializeDemo::clientMoveAndDisplay()
 	///step the simulation
 	if (m_dynamicsWorld)
 	{
-		
 		m_dynamicsWorld->stepSimulation(ms / 1000000.f);
 
 #ifdef DESERIALIZE_SOFT_BODIES
@@ -242,9 +322,13 @@ void	SerializeDemo::setupEmptyDynamicsWorld()
     btSoftRigidDynamicsWorld* world = new btSoftRigidDynamicsWorld(m_dispatcher, m_broadphase, m_solver,
                                           m_collisionConfiguration, fSoftBodySolver);
 	m_dynamicsWorld = world;
+
 	//world->setDrawFlags(world->getDrawFlags()^fDrawFlags::Clusters);
 #else
 	m_dynamicsWorld = new btDiscreteDynamicsWorld(m_dispatcher,m_broadphase,m_solver,m_collisionConfiguration);
+	//m_dynamicsWorld ->getSolverInfo().m_solverMode|=SOLVER_RANDMIZE_ORDER;
+	//m_dynamicsWorld->getDispatchInfo().m_enableSatConvex = true;
+	//m_dynamicsWorld->getSolverInfo().m_splitImpulse=true;
 #endif //DESERIALIZE_SOFT_BODIES
 
 	//btGImpactCollisionAlgorithm::registerAlgorithm((btCollisionDispatcher*)m_dynamicsWorld->getDispatcher());
@@ -731,7 +815,7 @@ void	SerializeDemo::initPhysics()
 						
 						body->setActivationState(ISLAND_SLEEPING);
 
-						m_dynamicsWorld->addRigidBody(body);
+						m_dynamicsWorld->addRigidBody(body,1,2);
 						body->setActivationState(ISLAND_SLEEPING);
 					}
 				}

Demos/SerializeDemo/SerializeDemo.h

@@ -64,6 +64,8 @@ class SerializeDemo : public PlatformDemoApplication
 
 	void	exitPhysics();
 
+	virtual void keyboardCallback(unsigned char key, int x, int y);
+
 	virtual void clientMoveAndDisplay();
 
 	virtual void displayCallback();

Extras/Serialize/BulletFileLoader/bFile.h

@@ -145,6 +145,10 @@ namespace bParse {
 
 		void	dumpChunks(bDNA* dna);
 		
+		int		getVersion() const
+		{
+			return mVersion;
+		}
 
 		
 	};

Extras/Serialize/BulletWorldImporter/btBulletWorldImporter.cpp

@@ -1164,6 +1164,14 @@ bool	btBulletWorldImporter::convertAllObjects(  bParse::btBulletFile* bulletFile
 		if (constraint)
 		{
 			constraint->setDbgDrawSize(constraintData->m_dbgDrawSize);
+			///those fields didn't exist and set to zero for pre-280 versions, so do a check here
+			if (bulletFile2->getVersion()>=280)
+			{
+				constraint->setBreakingImpulseThreshold(constraintData->m_breakingImpulseThreshold);
+				constraint->setEnabled(constraintData->m_isEnabled);
+				constraint->setOverrideNumSolverIterations(constraintData->m_overrideNumSolverIterations);
+			}
+
 			if (constraintData->m_name)
 			{
 				char* newname = duplicateName(constraintData->m_name);

VERSION

@@ -1 +1 @@
-2.79
+2.80

configure.ac

@@ -9,7 +9,7 @@ AC_PREREQ([2.54])
 #----------------------------------------------------------------------------
 AC_INIT(
     [bullet],
-    [2.79],
+    [2.80],
     [bullet@erwincoumans.com])
 AC_CANONICAL_HOST
 AC_CONFIG_SRCDIR([configure.ac])

src/BulletCollision/CollisionShapes/btTriangleInfoMap.h

@@ -85,12 +85,13 @@ struct	btTriangleInfoMap : public btInternalTriangleInfoMap
 
 };
 
+///those fields have to be float and not btScalar for the serialization to work properly
 struct	btTriangleInfoData
 {
 	int			m_flags;
-	btScalar	m_edgeV0V1Angle;
-	btScalar	m_edgeV1V2Angle;
-	btScalar	m_edgeV2V0Angle;
+	float	m_edgeV0V1Angle;
+	float	m_edgeV1V2Angle;
+	float	m_edgeV2V0Angle;
 };
 
 struct	btTriangleInfoMapData
@@ -100,11 +101,11 @@ struct	btTriangleInfoMapData
 	btTriangleInfoData	*m_valueArrayPtr;
 	int					*m_keyArrayPtr;
 
-	btScalar	m_convexEpsilon;
-	btScalar	m_planarEpsilon;
-	btScalar	m_equalVertexThreshold; 
-	btScalar	m_edgeDistanceThreshold;
-	btScalar	m_zeroAreaThreshold;
+	float	m_convexEpsilon;
+	float	m_planarEpsilon;
+	float	m_equalVertexThreshold; 
+	float	m_edgeDistanceThreshold;
+	float	m_zeroAreaThreshold;
 
 	int		m_nextSize;
 	int		m_hashTableSize;

src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp

@@ -740,13 +740,13 @@ void	btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 	}
 }
 
-
 btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySetup(btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer,btStackAlloc* stackAlloc)
 {
 	BT_PROFILE("solveGroupCacheFriendlySetup");
 	(void)stackAlloc;
 	(void)debugDrawer;
 
+	m_maxOverrideNumSolverIterations = 0;
 
 	if (!(numConstraints + numManifolds))
 	{
@@ -831,12 +831,15 @@ btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySetup(btCol
 
 					btSolverConstraint* currentConstraintRow = &m_tmpSolverNonContactConstraintPool[currentRow];
 					btTypedConstraint* constraint = constraints[i];
-
-
 					btRigidBody& rbA = constraint->getRigidBodyA();
 					btRigidBody& rbB = constraint->getRigidBodyB();
 
 
+					int overrideNumSolverIterations = constraint->getOverrideNumSolverIterations() > 0 ? constraint->getOverrideNumSolverIterations() : infoGlobal.m_numIterations;
+					if (overrideNumSolverIterations>m_maxOverrideNumSolverIterations)
+						m_maxOverrideNumSolverIterations = overrideNumSolverIterations;
+
+
 					int j;
 					for ( j=0;j<info1.m_numConstraintRows;j++)
 					{
@@ -847,6 +850,7 @@ btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySetup(btCol
 						currentConstraintRow[j].m_appliedPushImpulse = 0.f;
 						currentConstraintRow[j].m_solverBodyA = &rbA;
 						currentConstraintRow[j].m_solverBodyB = &rbB;
+						currentConstraintRow[j].m_overrideNumSolverIterations = overrideNumSolverIterations;
 					}
 
 					rbA.internalGetDeltaLinearVelocity().setValue(0.f,0.f,0.f);
@@ -1004,18 +1008,22 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 				m_orderNonContactConstraintPool[swapi] = tmp;
 			}
 
-			for (j=0; j<numConstraintPool; ++j) {
-				int tmp = m_orderTmpConstraintPool[j];
-				int swapi = btRandInt2(j+1);
-				m_orderTmpConstraintPool[j] = m_orderTmpConstraintPool[swapi];
-				m_orderTmpConstraintPool[swapi] = tmp;
-			}
+			//contact/friction constraints are not solved more than 
+			if (iteration< infoGlobal.m_numIterations)
+			{
+				for (j=0; j<numConstraintPool; ++j) {
+					int tmp = m_orderTmpConstraintPool[j];
+					int swapi = btRandInt2(j+1);
+					m_orderTmpConstraintPool[j] = m_orderTmpConstraintPool[swapi];
+					m_orderTmpConstraintPool[swapi] = tmp;
+				}
 
-			for (j=0; j<numFrictionPool; ++j) {
-				int tmp = m_orderFrictionConstraintPool[j];
-				int swapi = btRandInt2(j+1);
-				m_orderFrictionConstraintPool[j] = m_orderFrictionConstraintPool[swapi];
-				m_orderFrictionConstraintPool[swapi] = tmp;
+				for (j=0; j<numFrictionPool; ++j) {
+					int tmp = m_orderFrictionConstraintPool[j];
+					int swapi = btRandInt2(j+1);
+					m_orderFrictionConstraintPool[j] = m_orderFrictionConstraintPool[swapi];
+					m_orderFrictionConstraintPool[swapi] = tmp;
+				}
 			}
 		}
 	}
@@ -1026,35 +1034,40 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 		for (j=0;j<m_tmpSolverNonContactConstraintPool.size();j++)
 		{
 			btSolverConstraint& constraint = m_tmpSolverNonContactConstraintPool[m_orderNonContactConstraintPool[j]];
-			resolveSingleConstraintRowGenericSIMD(*constraint.m_solverBodyA,*constraint.m_solverBodyB,constraint);
+			if (iteration < constraint.m_overrideNumSolverIterations)
+				resolveSingleConstraintRowGenericSIMD(*constraint.m_solverBodyA,*constraint.m_solverBodyB,constraint);
 		}
 
-		for (j=0;j<numConstraints;j++)
+		if (iteration< infoGlobal.m_numIterations)
 		{
-			constraints[j]->solveConstraintObsolete(constraints[j]->getRigidBodyA(),constraints[j]->getRigidBodyB(),infoGlobal.m_timeStep);
-		}
-
-		///solve all contact constraints using SIMD, if available
-		int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
-		for (j=0;j<numPoolConstraints;j++)
-		{
-			const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[j]];
-			resolveSingleConstraintRowLowerLimitSIMD(*solveManifold.m_solverBodyA,*solveManifold.m_solverBodyB,solveManifold);
-
-		}
-		///solve all friction constraints, using SIMD, if available
-		int numFrictionPoolConstraints = m_tmpSolverContactFrictionConstraintPool.size();
-		for (j=0;j<numFrictionPoolConstraints;j++)
-		{
-			btSolverConstraint& solveManifold = m_tmpSolverContactFrictionConstraintPool[m_orderFrictionConstraintPool[j]];
-			btScalar totalImpulse = m_tmpSolverContactConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
-
-			if (totalImpulse>btScalar(0))
+			for (j=0;j<numConstraints;j++)
 			{
-				solveManifold.m_lowerLimit = -(solveManifold.m_friction*totalImpulse);
-				solveManifold.m_upperLimit = solveManifold.m_friction*totalImpulse;
+				constraints[j]->solveConstraintObsolete(constraints[j]->getRigidBodyA(),constraints[j]->getRigidBodyB(),infoGlobal.m_timeStep);
+			}
 
-				resolveSingleConstraintRowGenericSIMD(*solveManifold.m_solverBodyA,	*solveManifold.m_solverBodyB,solveManifold);
+			///solve all contact constraints using SIMD, if available
+			int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
+			for (j=0;j<numPoolConstraints;j++)
+			{
+				const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[j]];
+				resolveSingleConstraintRowLowerLimitSIMD(*solveManifold.m_solverBodyA,*solveManifold.m_solverBodyB,solveManifold);
+
+			}
+		
+			///solve all friction constraints, using SIMD, if available
+			int numFrictionPoolConstraints = m_tmpSolverContactFrictionConstraintPool.size();
+			for (j=0;j<numFrictionPoolConstraints;j++)
+			{
+				btSolverConstraint& solveManifold = m_tmpSolverContactFrictionConstraintPool[m_orderFrictionConstraintPool[j]];
+				btScalar totalImpulse = m_tmpSolverContactConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
+
+				if (totalImpulse>btScalar(0))
+				{
+					solveManifold.m_lowerLimit = -(solveManifold.m_friction*totalImpulse);
+					solveManifold.m_upperLimit = solveManifold.m_friction*totalImpulse;
+
+					resolveSingleConstraintRowGenericSIMD(*solveManifold.m_solverBodyA,	*solveManifold.m_solverBodyB,solveManifold);
+				}
 			}
 		}
 	} else
@@ -1064,33 +1077,37 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 		for (j=0;j<m_tmpSolverNonContactConstraintPool.size();j++)
 		{
 			btSolverConstraint& constraint = m_tmpSolverNonContactConstraintPool[m_orderNonContactConstraintPool[j]];
-			resolveSingleConstraintRowGeneric(*constraint.m_solverBodyA,*constraint.m_solverBodyB,constraint);
+			if (iteration < constraint.m_overrideNumSolverIterations)
+				resolveSingleConstraintRowGeneric(*constraint.m_solverBodyA,*constraint.m_solverBodyB,constraint);
 		}
 
-		for (j=0;j<numConstraints;j++)
+		if (iteration< infoGlobal.m_numIterations)
 		{
-			constraints[j]->solveConstraintObsolete(constraints[j]->getRigidBodyA(),constraints[j]->getRigidBodyB(),infoGlobal.m_timeStep);
-		}
-		///solve all contact constraints
-		int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
-		for (j=0;j<numPoolConstraints;j++)
-		{
-			const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[j]];
-			resolveSingleConstraintRowLowerLimit(*solveManifold.m_solverBodyA,*solveManifold.m_solverBodyB,solveManifold);
-		}
-		///solve all friction constraints
-		int numFrictionPoolConstraints = m_tmpSolverContactFrictionConstraintPool.size();
-		for (j=0;j<numFrictionPoolConstraints;j++)
-		{
-			btSolverConstraint& solveManifold = m_tmpSolverContactFrictionConstraintPool[m_orderFrictionConstraintPool[j]];
-			btScalar totalImpulse = m_tmpSolverContactConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
-
-			if (totalImpulse>btScalar(0))
+			for (j=0;j<numConstraints;j++)
 			{
-				solveManifold.m_lowerLimit = -(solveManifold.m_friction*totalImpulse);
-				solveManifold.m_upperLimit = solveManifold.m_friction*totalImpulse;
+				constraints[j]->solveConstraintObsolete(constraints[j]->getRigidBodyA(),constraints[j]->getRigidBodyB(),infoGlobal.m_timeStep);
+			}
+			///solve all contact constraints
+			int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
+			for (j=0;j<numPoolConstraints;j++)
+			{
+				const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[j]];
+				resolveSingleConstraintRowLowerLimit(*solveManifold.m_solverBodyA,*solveManifold.m_solverBodyB,solveManifold);
+			}
+			///solve all friction constraints
+			int numFrictionPoolConstraints = m_tmpSolverContactFrictionConstraintPool.size();
+			for (j=0;j<numFrictionPoolConstraints;j++)
+			{
+				btSolverConstraint& solveManifold = m_tmpSolverContactFrictionConstraintPool[m_orderFrictionConstraintPool[j]];
+				btScalar totalImpulse = m_tmpSolverContactConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
 
-				resolveSingleConstraintRowGeneric(*solveManifold.m_solverBodyA,*solveManifold.m_solverBodyB,solveManifold);
+				if (totalImpulse>btScalar(0))
+				{
+					solveManifold.m_lowerLimit = -(solveManifold.m_friction*totalImpulse);
+					solveManifold.m_upperLimit = solveManifold.m_friction*totalImpulse;
+
+					resolveSingleConstraintRowGeneric(*solveManifold.m_solverBodyA,*solveManifold.m_solverBodyB,solveManifold);
+				}
 			}
 		}
 	}
@@ -1142,13 +1159,14 @@ btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyIterations(
 {
 	BT_PROFILE("solveGroupCacheFriendlyIterations");
 
-	
-	//should traverse the contacts random order...
-	int iteration;
 	{
+		///this is a special step to resolve penetrations (just for contacts)
 		solveGroupCacheFriendlySplitImpulseIterations(bodies ,numBodies,manifoldPtr, numManifolds,constraints,numConstraints,infoGlobal,debugDrawer,stackAlloc);
 
-		for ( iteration = 0;iteration<infoGlobal.m_numIterations;iteration++)
+		int maxIterations = m_maxOverrideNumSolverIterations > infoGlobal.m_numIterations? m_maxOverrideNumSolverIterations : infoGlobal.m_numIterations;
+
+		for ( int iteration = 0 ; iteration< maxIterations ; iteration++)
+		//for ( int iteration = maxIterations-1  ; iteration >= 0;iteration--)
 		{			
 			solveSingleIteration(iteration, bodies ,numBodies,manifoldPtr, numManifolds,constraints,numConstraints,infoGlobal,debugDrawer,stackAlloc);
 		}

src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h

@@ -36,6 +36,7 @@ protected:
 	btAlignedObjectArray<int>	m_orderNonContactConstraintPool;
 	btAlignedObjectArray<int>	m_orderFrictionConstraintPool;
 	btAlignedObjectArray<btTypedConstraint::btConstraintInfo1> m_tmpConstraintSizesPool;
+	int							m_maxOverrideNumSolverIterations;
 
 	void setupFrictionConstraint(	btSolverConstraint& solverConstraint, const btVector3& normalAxis,btRigidBody* solverBodyA,btRigidBody* solverBodyIdB,
 									btManifoldPoint& cp,const btVector3& rel_pos1,const btVector3& rel_pos2,

src/BulletDynamics/ConstraintSolver/btSolverConstraint.h

@@ -51,6 +51,8 @@ ATTRIBUTE_ALIGNED64 (struct)	btSolverConstraint
 		btScalar	m_unusedPadding0;
 	};
 
+	int	m_overrideNumSolverIterations;
+
 	union
 	{
 		int			m_frictionIndex;

src/BulletDynamics/ConstraintSolver/btTypedConstraint.cpp

@@ -28,6 +28,7 @@ m_userConstraintId(-1),
 m_breakingImpulseThreshold(SIMD_INFINITY),
 m_isEnabled(true),
 m_needsFeedback(false),
+m_overrideNumSolverIterations(-1),
 m_rbA(rbA),
 m_rbB(getFixedBody()),
 m_appliedImpulse(btScalar(0.)),
@@ -43,6 +44,7 @@ m_userConstraintId(-1),
 m_breakingImpulseThreshold(SIMD_INFINITY),
 m_isEnabled(true),
 m_needsFeedback(false),
+m_overrideNumSolverIterations(-1),
 m_rbA(rbA),
 m_rbB(rbB),
 m_appliedImpulse(btScalar(0.)),
@@ -118,6 +120,10 @@ const char*	btTypedConstraint::serialize(void* dataBuffer, btSerializer* seriali
 
 	tcd->m_objectType = m_objectType;
 	tcd->m_needsFeedback = m_needsFeedback;
+	tcd->m_overrideNumSolverIterations = m_overrideNumSolverIterations;
+	tcd->m_breakingImpulseThreshold = float(m_breakingImpulseThreshold);
+	tcd->m_isEnabled = m_isEnabled? 1: 0;
+	
 	tcd->m_userConstraintId =m_userConstraintId;
 	tcd->m_userConstraintType =m_userConstraintType;
 

src/BulletDynamics/ConstraintSolver/btTypedConstraint.h

@@ -64,10 +64,10 @@ class btTypedConstraint : public btTypedObject
 
 	btScalar	m_breakingImpulseThreshold;
 	bool		m_isEnabled;
+	bool		m_needsFeedback;
+	int			m_overrideNumSolverIterations;
 
 
-	bool m_needsFeedback;
-
 	btTypedConstraint&	operator=(btTypedConstraint&	other)
 	{
 		btAssert(0);
@@ -131,6 +131,18 @@ public:
 		btScalar	m_damping;
 	};
 
+	int	getOverrideNumSolverIterations() const
+	{
+		return m_overrideNumSolverIterations;
+	}
+
+	///override the number of constraint solver iterations used to solve this constraint
+	///-1 will use the default number of iterations, as specified in SolverInfo.m_numIterations
+	void setOverrideNumSolverIterations(int overideNumIterations)
+	{
+		m_overrideNumSolverIterations = overideNumIterations;
+	}
+
 	///internal method used by the constraint solver, don't use them directly
 	virtual void	buildJacobian() {};
 
@@ -329,7 +341,10 @@ struct	btTypedConstraintData
 	float	m_dbgDrawSize;
 
 	int	m_disableCollisionsBetweenLinkedBodies;
-	char	m_pad4[4];
+	int	m_overrideNumSolverIterations;
+
+	float	m_breakingImpulseThreshold;
+	int		m_isEnabled;
 	
 };
 

src/LinearMath/btScalar.h

@@ -28,7 +28,7 @@ subject to the following restrictions:
 #include <float.h>
 
 /* SVN $Revision$ on $Date$ from http://bullet.googlecode.com*/
-#define BT_BULLET_VERSION 279
+#define BT_BULLET_VERSION 280
 
 inline int	btGetVersion()
 {

src/LinearMath/btSerializer.h

@@ -437,8 +437,8 @@ public:
 
 
 			buffer[9] = '2';
-			buffer[10] = '7';
-			buffer[11] = '8';
+			buffer[10] = '8';
+			buffer[11] = '0';
 
 		}