diff --git a/src/BulletDynamics/ConstraintSolver/btConstraintSolver.h b/src/BulletDynamics/ConstraintSolver/btConstraintSolver.h
index 39421c1fc..3a8e3c729 100644
--- a/src/BulletDynamics/ConstraintSolver/btConstraintSolver.h
+++ b/src/BulletDynamics/ConstraintSolver/btConstraintSolver.h
@@ -35,8 +35,12 @@ public:
 
 	virtual ~btConstraintSolver() {}
 	
+	///solve a group of constraints
 	virtual btScalar solveGroup(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifold,int numManifolds,btTypedConstraint** constraints,int numConstraints, const btContactSolverInfo& info,class btIDebugDraw* debugDrawer, btStackAlloc* stackAlloc) = 0;
 
+	///clear internal cached data and reset random seed
+	virtual	void	reset() = 0;
+
 };
 
 
diff --git a/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp b/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp
index 14b36ad44..285361b82 100644
--- a/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp
+++ b/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp
@@ -1156,3 +1156,10 @@ btScalar btSequentialImpulseConstraintSolver::solveFriction(btRigidBody* body0,b
 	}
 	return btScalar(0.);
 }
+
+
+void	btSequentialImpulseConstraintSolver::reset()
+{
+	m_btSeed2 = 0;
+}
+
diff --git a/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h b/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h
index 13e70c41b..5ee92e698 100644
--- a/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h
+++ b/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h
@@ -74,6 +74,9 @@ public:
 
 	virtual btScalar solveGroupCacheFriendly(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer,btStackAlloc* stackAlloc);
 
+	///clear internal cached data and reset random seed
+	virtual	void	reset();
+
 	btScalar solveCombinedContactFriction(btRigidBody* body0,btRigidBody* body1, btManifoldPoint& cp, const btContactSolverInfo& info,int iter,btIDebugDraw* debugDrawer);
 
 
diff --git a/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp b/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp
index 29719ec9a..fe0dddbb8 100644
--- a/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp
+++ b/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.cpp
@@ -940,6 +940,12 @@ void	btDiscreteDynamicsWorld::setConstraintSolver(btConstraintSolver* solver)
 	m_constraintSolver = solver;
 }
 
+btConstraintSolver* btDiscreteDynamicsWorld::getConstraintSolver()
+{
+	return m_constraintSolver;
+}
+
+
 int		btDiscreteDynamicsWorld::getNumConstraints() const
 {
 	return int(m_constraints.size());
diff --git a/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h b/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h
index e5c35fc96..733a47cbc 100644
--- a/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h
+++ b/src/BulletDynamics/Dynamics/btDiscreteDynamicsWorld.h
@@ -139,6 +139,8 @@ public:
 	void	debugDrawObject(const btTransform& worldTransform, const btCollisionShape* shape, const btVector3& color);
 
 	virtual void	setConstraintSolver(btConstraintSolver* solver);
+
+	virtual btConstraintSolver* getConstraintSolver();
 	
 	virtual	int		getNumConstraints() const;
 
diff --git a/src/BulletDynamics/Dynamics/btDynamicsWorld.h b/src/BulletDynamics/Dynamics/btDynamicsWorld.h
index ecc3009f3..cac0ef8e2 100644
--- a/src/BulletDynamics/Dynamics/btDynamicsWorld.h
+++ b/src/BulletDynamics/Dynamics/btDynamicsWorld.h
@@ -65,6 +65,8 @@ class btDynamicsWorld : public btCollisionWorld
 		virtual void	removeRigidBody(btRigidBody* body) = 0;
 
 		virtual void	setConstraintSolver(btConstraintSolver* solver) = 0;
+
+		virtual btConstraintSolver* getConstraintSolver() = 0;
 		
 		virtual	int		getNumConstraints() const {	return 0;		}
 		
diff --git a/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.cpp b/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.cpp
index 24e24d3f9..af6e6b5a4 100644
--- a/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.cpp
+++ b/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.cpp
@@ -209,3 +209,8 @@ void	btSimpleDynamicsWorld::setConstraintSolver(btConstraintSolver* solver)
 	m_ownsConstraintSolver = false;
 	m_constraintSolver = solver;
 }
+
+btConstraintSolver* btSimpleDynamicsWorld::getConstraintSolver()
+{
+	return m_constraintSolver;
+}
diff --git a/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.h b/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.h
index accef62ce..5b00173de 100644
--- a/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.h
+++ b/src/BulletDynamics/Dynamics/btSimpleDynamicsWorld.h
@@ -77,6 +77,8 @@ public:
 
 	virtual void	setConstraintSolver(btConstraintSolver* solver);
 
+	virtual btConstraintSolver* getConstraintSolver();
+
 };
 
 #endif //BT_SIMPLE_DYNAMICS_WORLD_H