Use cylinder inertia tensor, instead of box, by default.

See Issue 427

Expose some internal data for constraints,
Thanks to Francois Sugny, see Issue 420

src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp

@@ -1114,4 +1114,12 @@ btScalar btConeTwistConstraint::getParam(int num, int axis) const
 }
 
 
+void btConeTwistConstraint::setFrames(const btTransform & frameA, const btTransform & frameB)
+{
+	m_rbAFrame = frameA;
+	m_rbBFrame = frameB;
+	buildJacobian();
+	//calculateTransforms();
+}
+
 

src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h

@@ -144,6 +144,16 @@ public:
 
 	void	updateRHS(btScalar	timeStep);
 
+	const btTransform & getFrameOffsetA() const
+	{
+		return m_rbAFrame;
+	}
+
+	const btTransform & getFrameOffsetB() const
+	{
+		return m_rbBFrame;
+	}
+
 	const btRigidBody& getRigidBodyA() const
 	{
 		return m_rbA;
@@ -244,6 +254,7 @@ public:
 	}
 	bool isPastSwingLimit() { return m_solveSwingLimit; }
 
+	void setFrames(const btTransform & frameA, const btTransform & frameB);
 
 	void setDamping(btScalar damping) { m_damping = damping; }
 

src/BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.cpp

@@ -713,6 +713,15 @@ void	btGeneric6DofConstraint::updateRHS(btScalar	timeStep)
 }
 
 
+void btGeneric6DofConstraint::setFrames(const btTransform & frameA, const btTransform & frameB)
+{
+	m_frameInA = frameA;
+	m_frameInB = frameB;
+	buildJacobian();
+	calculateTransforms();
+}
+
+
 
 btVector3 btGeneric6DofConstraint::getAxis(int axis_index) const
 {

src/BulletDynamics/ConstraintSolver/btGeneric6DofConstraint.h

@@ -433,6 +433,7 @@ public:
 	*/
 	btScalar getRelativePivotPosition(int axis_index) const;
 
+	void setFrames(const btTransform & frameA, const btTransform & frameB);
 
 	//! Test angular limit.
 	/*!
@@ -446,23 +447,45 @@ public:
     	m_linearLimits.m_lowerLimit = linearLower;
     }
 
+	void	getLinearLowerLimit(btVector3& linearLower)
+	{
+		linearLower = m_linearLimits.m_lowerLimit;
+	}
+
     void	setLinearUpperLimit(const btVector3& linearUpper)
     {
     	m_linearLimits.m_upperLimit = linearUpper;
     }
 
+	void	getLinearUpperLimit(btVector3& linearUpper)
+	{
+		linearUpper = m_linearLimits.m_upperLimit;
+	}
+
     void	setAngularLowerLimit(const btVector3& angularLower)
     {
 		for(int i = 0; i < 3; i++) 
 			m_angularLimits[i].m_loLimit = btNormalizeAngle(angularLower[i]);
     }
 
+	void	getAngularLowerLimit(btVector3& angularLower)
+	{
+		for(int i = 0; i < 3; i++) 
+			angularLower[i] = m_angularLimits[i].m_loLimit;
+	}
+
     void	setAngularUpperLimit(const btVector3& angularUpper)
     {
 		for(int i = 0; i < 3; i++)
 			m_angularLimits[i].m_hiLimit = btNormalizeAngle(angularUpper[i]);
     }
 
+	void	getAngularUpperLimit(btVector3& angularUpper)
+	{
+		for(int i = 0; i < 3; i++)
+			angularUpper[i] = m_angularLimits[i].m_hiLimit;
+	}
+
 	//! Retrieves the angular limit informacion
     btRotationalLimitMotor * getRotationalLimitMotor(int index)
     {

src/BulletDynamics/ConstraintSolver/btHingeConstraint.cpp

@@ -550,8 +550,12 @@ void btHingeConstraint::getInfo2Internal(btConstraintInfo2* info, const btTransf
 }
 
 
-
-
+void btHingeConstraint::setFrames(const btTransform & frameA, const btTransform & frameB)
+{
+	m_rbAFrame = frameA;
+	m_rbBFrame = frameB;
+	buildJacobian();
+}
 
 
 void	btHingeConstraint::updateRHS(btScalar	timeStep)

src/BulletDynamics/ConstraintSolver/btHingeConstraint.h

@@ -132,7 +132,19 @@ public:
 	btRigidBody& getRigidBodyB()	
 	{		
 		return m_rbB;	
-	}	
+	}
+
+	btTransform & getFrameOffsetA()
+	{
+	return m_rbAFrame;
+	}
+
+	btTransform & getFrameOffsetB()
+	{
+		return m_rbBFrame;
+	}
+
+	void setFrames(const btTransform & frameA, const btTransform & frameB);
 	
 	void	setAngularOnly(bool angularOnly)
 	{
@@ -182,8 +194,7 @@ public:
 		btVector3 rbAxisB1 =  quatRotate(rotationArc,rbAxisA1);
 		btVector3 rbAxisB2 = axisInB.cross(rbAxisB1);
 
-
-		m_rbBFrame.getOrigin() = m_rbA.getCenterOfMassTransform()(pivotInA);
+	m_rbBFrame.getOrigin() = m_rbB.getCenterOfMassTransform().inverse()(m_rbA.getCenterOfMassTransform()(pivotInA));
 		m_rbBFrame.getBasis().setValue( rbAxisB1.getX(),rbAxisB2.getX(),axisInB.getX(),
 										rbAxisB1.getY(),rbAxisB2.getY(),axisInB.getY(),
 										rbAxisB1.getZ(),rbAxisB2.getZ(),axisInB.getZ() );