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Code Issues Releases Wiki Activity

Fix some crashes in FeatherstoneMultiBodyDemo, when using a fixed base

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Create two btMultiBody, one fixed and one free base
Preparation towards btMultiBodyConstraint
This commit is contained in:
erwin.coumans 2013-10-02 03:07:52 +00:00
parent f02dd51597
commit d8b6a02a7a
8 changed files with 397 additions and 35 deletions
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22
Demos/FeatherstoneMultiBodyDemo/FeatherstoneMultiBodyDemo.cpp
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@ -209,18 +209,27 @@ void FeatherstoneMultiBodyDemo::initPhysics()
}
createFeatherstoneMultiBody(world, 10, btVector3 (20,29.5,-2), true);
createFeatherstoneMultiBody(world, 5, btVector3 (0,29.5,-2), false);
}
void FeatherstoneMultiBodyDemo::createFeatherstoneMultiBody(class btMultiBodyDynamicsWorld* world, int numLinks, const btVector3& basePosition,bool isFixedBase)
{
{
int n_links = 5;
int n_links = numLinks;
float mass = 13.5;
btVector3 inertia(91,344,253);
bool isFixedBase = false;
bool canSleep = true;//false;
btMultiBody * bod = new btMultiBody(n_links, mass, inertia, isFixedBase, canSleep);
btVector3 pos(0,9.5,-2);
//btQuaternion orn(btVector3(0,0,1),-0.25*SIMD_HALF_PI);//0,0,0,1);
btQuaternion orn(0,0,0,1);
bod->setBasePos(pos);
bod->setBasePos(basePosition);
bod->setWorldToBaseRot(orn);
btVector3 vel(0,0,0);
bod->setBaseVel(vel);
@ -342,10 +351,9 @@ void FeatherstoneMultiBodyDemo::initPhysics()
world->addMultiBody(bod);
}
}
void FeatherstoneMultiBodyDemo::clientResetScene()
{
exitPhysics();

3
Demos/FeatherstoneMultiBodyDemo/FeatherstoneMultiBodyDemo.h
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@ -52,6 +52,9 @@ class FeatherstoneMultiBodyDemo : public PlatformDemoApplication
btDefaultCollisionConfiguration* m_collisionConfiguration;
void createFeatherstoneMultiBody(class btMultiBodyDynamicsWorld* world, int numLinks, const btVector3& basePosition,bool isFixedBase);
public:
FeatherstoneMultiBodyDemo()

35
src/BulletDynamics/Featherstone/btMultiBodyConstraint.h Normal file
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@ -0,0 +1,35 @@
/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2013 Erwin Coumans http://bulletphysics.org
This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it freely,
subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#ifndef BT_MULTIBODY_CONSTRAINT_H
#define BT_MULTIBODY_CONSTRAINT_H
class btMultiBodyConstraint
{
public:
int getIslandIdA() const
{
return 0;
}
int getIslandIdB() const
{
return 0;
}
};
#endif //BT_MULTIBODY_CONSTRAINT_H

57
src/BulletDynamics/Featherstone/btMultiBodyConstraintSolver.cpp
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@ -203,11 +203,15 @@ void btMultiBodyConstraintSolver::setupMultiBodyContactConstraint(btMultiBodySol
const int ndofA = multiBodyA->getNumLinks() + 6;
solverConstraint.m_deltaVelAindex = multiBodyA->getCompanionId();
if (solverConstraint.m_deltaVelAindex <0)
{
solverConstraint.m_deltaVelAindex = m_deltaVelocities.size();
multiBodyA->setCompanionId(solverConstraint.m_deltaVelAindex);
m_deltaVelocities.resize(m_deltaVelocities.size()+ndofA);
} else
{
btAssert(m_deltaVelocities.size() >= solverConstraint.m_deltaVelAindex+ndofA);
}
solverConstraint.m_jacAindex = m_jacobians.size();
@ -260,11 +264,16 @@ void btMultiBodyConstraintSolver::setupMultiBodyContactConstraint(btMultiBodySol
btVector3 vec;
btScalar denom0 = 0.f;
btScalar denom1 = 0.f;
btScalar* jacB = 0;
btScalar* jacA = 0;
btScalar* lambdaA =0;
btScalar* lambdaB =0;
int ndofA = 0;
if (multiBodyA)
{
const int ndofA = multiBodyA->getNumLinks() + 6;
btScalar* jacA = &m_jacobians[solverConstraint.m_jacAindex];
btScalar* lambdaA = &m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
ndofA = multiBodyA->getNumLinks() + 6;
jacA = &m_jacobians[solverConstraint.m_jacAindex];
lambdaA = &m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
for (int i = 0; i < ndofA; ++i)
{
float j = jacA[i] ;
@ -282,8 +291,8 @@ void btMultiBodyConstraintSolver::setupMultiBodyContactConstraint(btMultiBodySol
if (multiBodyB)
{
const int ndofB = multiBodyB->getNumLinks() + 6;
btScalar* jacB = &m_jacobians[solverConstraint.m_jacBindex];
btScalar* lambdaB = &m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
jacB = &m_jacobians[solverConstraint.m_jacBindex];
lambdaB = &m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
for (int i = 0; i < ndofB; ++i)
{
float j = jacB[i] ;
@ -300,8 +309,26 @@ void btMultiBodyConstraintSolver::setupMultiBodyContactConstraint(btMultiBodySol
}
}
btScalar denom = relaxation/(denom0+denom1);
solverConstraint.m_jacDiagABInv = denom;
if (multiBodyA && (multiBodyA==multiBodyB))
{
// ndof1 == ndof2 in this case
for (int i = 0; i < ndofA; ++i)
{
denom1 += jacB[i] * lambdaA[i];
denom1 += jacA[i] * lambdaB[i];
}
}
float d = denom0+denom1;
if (btFabs(d)>SIMD_EPSILON)
{
solverConstraint.m_jacDiagABInv = relaxation/(d);
} else
{
solverConstraint.m_jacDiagABInv = 1.f;
}
}
@ -691,4 +718,18 @@ void btMultiBodyConstraintSolver::convertContacts(btPersistentManifold** manifol
btScalar btMultiBodyConstraintSolver::solveGroup(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifold,int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& info, btIDebugDraw* debugDrawer,btDispatcher* dispatcher)
{
return btSequentialImpulseConstraintSolver::solveGroup(bodies,numBodies,manifold,numManifolds,constraints,numConstraints,info,debugDrawer,dispatcher);
}
}
void btMultiBodyConstraintSolver::solveMultiBodyGroup(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifold,int numManifolds,btTypedConstraint** constraints,int numConstraints,btMultiBodyConstraint** multiBodyConstraints, int numMultiBodyConstraints, const btContactSolverInfo& info, btIDebugDraw* debugDrawer,btDispatcher* dispatcher)
{
m_tmpMultiBodyConstraints = multiBodyConstraints;
m_tmpNumMultiBodyConstraints = numMultiBodyConstraints;
btSequentialImpulseConstraintSolver::solveGroup(bodies,numBodies,manifold,numManifolds,constraints,numConstraints,info,debugDrawer,dispatcher);
m_tmpMultiBodyConstraints = 0;
m_tmpNumMultiBodyConstraints = 0;
}

12
src/BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h
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@ -21,7 +21,7 @@ subject to the following restrictions:
class btMultiBody;
class btMultiBodyConstraint;
ATTRIBUTE_ALIGNED16(class) btMultiBodyConstraintSolver : public btSequentialImpulseConstraintSolver
{
@ -42,10 +42,11 @@ protected:
btAlignedObjectArray<btScalar> scratch_r;
btAlignedObjectArray<btVector3> scratch_v;
btAlignedObjectArray<btMatrix3x3> scratch_m;
// virtual void solveGroupCacheFriendlySplitImpulseIterations(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer);
// virtual btScalar solveGroupCacheFriendlyFinish(btCollisionObject** bodies,int numBodies,const btContactSolverInfo& infoGlobal);
//temp storage for multi body constraints for a specific island/group called by 'solveGroup'
btMultiBodyConstraint** m_tmpMultiBodyConstraints;
int m_tmpNumMultiBodyConstraints;
void resolveSingleConstraintRowGeneric(const btMultiBodySolverConstraint& c);
void convertContacts(btPersistentManifold** manifoldPtr,int numManifolds, const btContactSolverInfo& infoGlobal);
btMultiBodySolverConstraint& addMultiBodyFrictionConstraint(const btVector3& normalAxis,btPersistentManifold* manifold,int frictionIndex,btManifoldPoint& cp,btCollisionObject* colObj0,btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity=0, btScalar cfmSlip=0);
@ -68,7 +69,10 @@ public:
BT_DECLARE_ALIGNED_ALLOCATOR();
///this method should not be called, it was just used during porting/integration of Featherstone btMultiBody, providing backwards compatibility but no support for btMultiBodyConstraint (only contact constraints)
virtual btScalar solveGroup(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifold,int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& info, btIDebugDraw* debugDrawer,btDispatcher* dispatcher);
virtual void solveMultiBodyGroup(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifold,int numManifolds,btTypedConstraint** constraints,int numConstraints,btMultiBodyConstraint** multiBodyConstraints, int numMultiBodyConstraints, const btContactSolverInfo& info, btIDebugDraw* debugDrawer,btDispatcher* dispatcher);
};

284
src/BulletDynamics/Featherstone/btMultiBodyDynamicsWorld.cpp
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@ -19,19 +19,9 @@ subject to the following restrictions:
#include "btMultiBodyLinkCollider.h"
#include "BulletCollision/CollisionDispatch/btSimulationIslandManager.h"
#include "LinearMath/btQuickprof.h"
#include "btMultiBodyConstraint.h"
btMultiBodyDynamicsWorld::btMultiBodyDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache,btMultiBodyConstraintSolver* constraintSolver,btCollisionConfiguration* collisionConfiguration)
:btDiscreteDynamicsWorld(dispatcher,pairCache,constraintSolver,collisionConfiguration)
{
//split impulse is not yet supported for Featherstone hierarchies
getSolverInfo().m_splitImpulse = false;
getSolverInfo().m_solverMode |=SOLVER_USE_2_FRICTION_DIRECTIONS;
}
btMultiBodyDynamicsWorld::~btMultiBodyDynamicsWorld ()
{
}
void btMultiBodyDynamicsWorld::addMultiBody(btMultiBody* body, short group, short mask)
@ -156,14 +146,268 @@ void btMultiBodyDynamicsWorld::updateActivationState(btScalar timeStep)
btDiscreteDynamicsWorld::updateActivationState(timeStep);
}
SIMD_FORCE_INLINE int btGetConstraintIslandId2(const btTypedConstraint* lhs)
{
int islandId;
const btCollisionObject& rcolObj0 = lhs->getRigidBodyA();
const btCollisionObject& rcolObj1 = lhs->getRigidBodyB();
islandId= rcolObj0.getIslandTag()>=0?rcolObj0.getIslandTag():rcolObj1.getIslandTag();
return islandId;
}
class btSortConstraintOnIslandPredicate2
{
public:
bool operator() ( const btTypedConstraint* lhs, const btTypedConstraint* rhs ) const
{
int rIslandId0,lIslandId0;
rIslandId0 = btGetConstraintIslandId2(rhs);
lIslandId0 = btGetConstraintIslandId2(lhs);
return lIslandId0 < rIslandId0;
}
};
SIMD_FORCE_INLINE int btGetMultiBodyConstraintIslandId(const btMultiBodyConstraint* lhs)
{
int islandId;
int islandTagA = lhs->getIslandIdA();
int islandTagB = lhs->getIslandIdB();
islandId= islandTagA>=0?islandTagA:islandTagB;
return islandId;
}
class btSortMultiBodyConstraintOnIslandPredicate
{
public:
bool operator() ( const btMultiBodyConstraint* lhs, const btMultiBodyConstraint* rhs ) const
{
int rIslandId0,lIslandId0;
rIslandId0 = btGetMultiBodyConstraintIslandId(rhs);
lIslandId0 = btGetMultiBodyConstraintIslandId(lhs);
return lIslandId0 < rIslandId0;
}
};
struct MultiBodyInplaceSolverIslandCallback : public btSimulationIslandManager::IslandCallback
{
btContactSolverInfo* m_solverInfo;
btMultiBodyConstraintSolver* m_solver;
btMultiBodyConstraint** m_multiBodySortedConstraints;
int m_numMultiBodyConstraints;
btTypedConstraint** m_sortedConstraints;
int m_numConstraints;
btIDebugDraw* m_debugDrawer;
btDispatcher* m_dispatcher;
btAlignedObjectArray<btCollisionObject*> m_bodies;
btAlignedObjectArray<btPersistentManifold*> m_manifolds;
btAlignedObjectArray<btTypedConstraint*> m_constraints;
btAlignedObjectArray<btMultiBodyConstraint*> m_multiBodyConstraints;
MultiBodyInplaceSolverIslandCallback( btMultiBodyConstraintSolver* solver,
btDispatcher* dispatcher)
:m_solverInfo(NULL),
m_solver(solver),
m_multiBodySortedConstraints(NULL),
m_numConstraints(0),
m_debugDrawer(NULL),
m_dispatcher(dispatcher)
{
}
MultiBodyInplaceSolverIslandCallback& operator=(MultiBodyInplaceSolverIslandCallback& other)
{
btAssert(0);
(void)other;
return *this;
}
SIMD_FORCE_INLINE void setup ( btContactSolverInfo* solverInfo, btTypedConstraint** sortedConstraints, int numConstraints, btMultiBodyConstraint** sortedMultiBodyConstraints, int numMultiBodyConstraints, btIDebugDraw* debugDrawer)
{
btAssert(solverInfo);
m_solverInfo = solverInfo;
m_multiBodySortedConstraints = sortedMultiBodyConstraints;
m_numMultiBodyConstraints = numMultiBodyConstraints;
m_sortedConstraints = sortedConstraints;
m_numConstraints = numConstraints;
m_debugDrawer = debugDrawer;
m_bodies.resize (0);
m_manifolds.resize (0);
m_constraints.resize (0);
m_multiBodyConstraints.resize(0);
}
virtual void processIsland(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifolds,int numManifolds, int islandId)
{
if (islandId<0)
{
///we don't split islands, so all constraints/contact manifolds/bodies are passed into the solver regardless the island id
m_solver->solveMultiBodyGroup( bodies,numBodies,manifolds, numManifolds,m_sortedConstraints, m_numConstraints, &m_multiBodySortedConstraints[0],m_numConstraints,*m_solverInfo,m_debugDrawer,m_dispatcher);
} else
{
//also add all non-contact constraints/joints for this island
btTypedConstraint** startConstraint = 0;
btMultiBodyConstraint** startMultiBodyConstraint = 0;
int numCurConstraints = 0;
int numCurMultiBodyConstraints = 0;
int i;
//find the first constraint for this island
for (i=0;i<m_numMultiBodyConstraints;i++)
{
if (btGetMultiBodyConstraintIslandId(m_multiBodySortedConstraints[i]) == islandId)
{
startMultiBodyConstraint = &m_multiBodySortedConstraints[i];
break;
}
}
for (i=0;i<m_numConstraints;i++)
{
if (btGetConstraintIslandId2(m_sortedConstraints[i]) == islandId)
{
startConstraint = &m_sortedConstraints[i];
break;
}
}
//count the number of constraints in this island
for (;i<m_numConstraints;i++)
{
if (btGetConstraintIslandId2(m_sortedConstraints[i]) == islandId)
{
numCurConstraints++;
}
}
//count the number of multi body constraints in this island
for (;i<m_numMultiBodyConstraints;i++)
{
if (btGetMultiBodyConstraintIslandId(m_multiBodySortedConstraints[i]) == islandId)
{
numCurMultiBodyConstraints++;
}
}
if (m_solverInfo->m_minimumSolverBatchSize<=1)
{
m_solver->solveGroup( bodies,numBodies,manifolds, numManifolds,startConstraint,numCurConstraints,*m_solverInfo,m_debugDrawer,m_dispatcher);
} else
{
for (i=0;i<numBodies;i++)
m_bodies.push_back(bodies[i]);
for (i=0;i<numManifolds;i++)
m_manifolds.push_back(manifolds[i]);
for (i=0;i<numCurConstraints;i++)
m_constraints.push_back(startConstraint[i]);
for (i=0;i<numCurMultiBodyConstraints;i++)
m_multiBodyConstraints.push_back(startMultiBodyConstraint[i]);
if ((m_constraints.size()+m_manifolds.size())>m_solverInfo->m_minimumSolverBatchSize)
{
processConstraints();
} else
{
//printf("deferred\n");
}
}
}
}
void processConstraints()
{
btCollisionObject** bodies = m_bodies.size()? &m_bodies[0]:0;
btPersistentManifold** manifold = m_manifolds.size()?&m_manifolds[0]:0;
btTypedConstraint** constraints = m_constraints.size()?&m_constraints[0]:0;
btMultiBodyConstraint** multiBodyConstraints = m_multiBodyConstraints.size() ? &m_multiBodyConstraints[0] : 0;
m_solver->solveMultiBodyGroup( bodies,m_bodies.size(),manifold, m_manifolds.size(),constraints, m_constraints.size() ,multiBodyConstraints, m_multiBodyConstraints.size(), *m_solverInfo,m_debugDrawer,m_dispatcher);
m_bodies.resize(0);
m_manifolds.resize(0);
m_constraints.resize(0);
}
};
btMultiBodyDynamicsWorld::btMultiBodyDynamicsWorld(btDispatcher* dispatcher,btBroadphaseInterface* pairCache,btMultiBodyConstraintSolver* constraintSolver,btCollisionConfiguration* collisionConfiguration)
:btDiscreteDynamicsWorld(dispatcher,pairCache,constraintSolver,collisionConfiguration),
m_multiBodyConstraintSolver(constraintSolver)
{
//split impulse is not yet supported for Featherstone hierarchies
getSolverInfo().m_splitImpulse = false;
getSolverInfo().m_solverMode |=SOLVER_USE_2_FRICTION_DIRECTIONS;
m_solverMultiBodyIslandCallback = new MultiBodyInplaceSolverIslandCallback(constraintSolver,dispatcher);
}
btMultiBodyDynamicsWorld::~btMultiBodyDynamicsWorld ()
{
delete m_solverMultiBodyIslandCallback;
}
void btMultiBodyDynamicsWorld::solveConstraints(btContactSolverInfo& solverInfo)
{
btVector3 g = m_gravity;
btAlignedObjectArray<btScalar> scratch_r;
btAlignedObjectArray<btVector3> scratch_v;
btAlignedObjectArray<btMatrix3x3> scratch_m;
BT_PROFILE("solveConstraints");
m_sortedConstraints.resize( m_constraints.size());
int i;
for (i=0;i<getNumConstraints();i++)
{
m_sortedConstraints[i] = m_constraints[i];
}
m_sortedConstraints.quickSort(btSortConstraintOnIslandPredicate2());
btTypedConstraint** constraintsPtr = getNumConstraints() ? &m_sortedConstraints[0] : 0;
for (i=0;i<m_multiBodyConstraints.size();i++)
{
m_sortedMultiBodyConstraints[i] = m_multiBodyConstraints[i];
}
btMultiBodyConstraint** sortedMultiBodyConstraints = m_sortedMultiBodyConstraints.size() ? &m_sortedMultiBodyConstraints[0] : 0;
m_solverMultiBodyIslandCallback->setup(&solverInfo,constraintsPtr,m_sortedConstraints.size(),sortedMultiBodyConstraints,m_sortedMultiBodyConstraints.size(), getDebugDrawer());
m_constraintSolver->prepareSolve(getCollisionWorld()->getNumCollisionObjects(), getCollisionWorld()->getDispatcher()->getNumManifolds());
/// solve all the constraints for this island
m_islandManager->buildAndProcessIslands(getCollisionWorld()->getDispatcher(),getCollisionWorld(),m_solverMultiBodyIslandCallback);
{
BT_PROFILE("btMultiBody addForce and stepVelocities");
for (int i=0;i<this->m_multiBodies.size();i++)
@ -193,7 +437,11 @@ void btMultiBodyDynamicsWorld::solveConstraints(btContactSolverInfo& solverInfo)
}
}
}
btDiscreteDynamicsWorld::solveConstraints(solverInfo);
m_solverMultiBodyIslandCallback->processConstraints();
m_constraintSolver->allSolved(solverInfo, m_debugDrawer);
}
void btMultiBodyDynamicsWorld::integrateTransforms(btScalar timeStep)
@ -263,3 +511,15 @@ void btMultiBodyDynamicsWorld::integrateTransforms(btScalar timeStep)
}
}
}
void btMultiBodyDynamicsWorld::addMultiBodyConstraint( btMultiBodyConstraint* constraint)
{
m_multiBodyConstraints.push_back(constraint);
}
void btMultiBodyDynamicsWorld::removeMultiBodyConstraint( btMultiBodyConstraint* constraint)
{
m_multiBodyConstraints.remove(constraint);
}

8
src/BulletDynamics/Featherstone/btMultiBodyDynamicsWorld.h
View File

@ -20,7 +20,9 @@ subject to the following restrictions:
class btMultiBody;
class btMultiBodyConstraint;
class btMultiBodyConstraintSolver;
struct MultiBodyInplaceSolverIslandCallback;
///The btMultiBodyDynamicsWorld adds Featherstone multi body dynamics to Bullet
///This implementation is still preliminary/experimental.
@ -28,6 +30,10 @@ class btMultiBodyDynamicsWorld : public btDiscreteDynamicsWorld
{
protected:
btAlignedObjectArray<btMultiBody*> m_multiBodies;
btAlignedObjectArray<btMultiBodyConstraint*> m_multiBodyConstraints;
btAlignedObjectArray<btMultiBodyConstraint*> m_sortedMultiBodyConstraints;
btMultiBodyConstraintSolver* m_multiBodyConstraintSolver;
MultiBodyInplaceSolverIslandCallback* m_solverMultiBodyIslandCallback;
virtual void calculateSimulationIslands();
virtual void updateActivationState(btScalar timeStep);
@ -43,6 +49,8 @@ public:
virtual void removeMultiBody(btMultiBody* body);
virtual void addMultiBodyConstraint( btMultiBodyConstraint* constraint);
virtual void removeMultiBodyConstraint( btMultiBodyConstraint* constraint);
};
#endif //BT_MULTIBODY_DYNAMICS_WORLD_H

11
src/BulletDynamics/Featherstone/btMultiBodyLinkCollider.h
View File

@ -33,13 +33,16 @@ public:
:m_multiBody(multiBody),
m_link(link)
{
if (link>=0 || (multiBody && !multiBody->hasFixedBase()))
//we need to remove the 'CF_STATIC_OBJECT' flag, otherwise links/base doesn't merge islands
//this means that some constraints might point to bodies that are not in the islands, causing crashes
//if (link>=0 || (multiBody && !multiBody->hasFixedBase()))
{
m_collisionFlags &= (~btCollisionObject::CF_STATIC_OBJECT);
} else
{
m_collisionFlags |= (btCollisionObject::CF_STATIC_OBJECT);
}
// else
//{
// m_collisionFlags |= (btCollisionObject::CF_STATIC_OBJECT);
//}
m_internalType = CO_FEATHERSTONE_LINK;
}