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Add support for target motion and slip/cfm for both friction directions.

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It can be handy for effects such as powered conveyor belt effect or sideways slipping tyre friction.
This commit is contained in:
erwin.coumans
2009-09-18 07:48:15 +00:00
parent 49474da938
commit da4a1b14b5
3 changed files with 19 additions and 6 deletions
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13
src/BulletCollision/NarrowPhaseCollision/btManifoldPoint.h
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@@ -34,6 +34,10 @@ class btManifoldPoint
m_lateralFrictionInitialized(false),
m_appliedImpulseLateral1(0.f),
m_appliedImpulseLateral2(0.f),
m_contactMotion1(0.f),
m_contactMotion2(0.f),
m_contactCFM1(0.f),
m_contactCFM2(0.f),
m_lifeTime(0)
{
}
@@ -52,6 +56,10 @@ class btManifoldPoint
m_lateralFrictionInitialized(false),
m_appliedImpulseLateral1(0.f),
m_appliedImpulseLateral2(0.f),
m_contactMotion1(0.f),
m_contactMotion2(0.f),
m_contactCFM1(0.f),
m_contactCFM2(0.f),
m_lifeTime(0)
{
@@ -83,6 +91,11 @@ class btManifoldPoint
bool m_lateralFrictionInitialized;
btScalar m_appliedImpulseLateral1;
btScalar m_appliedImpulseLateral2;
btScalar m_contactMotion1;
btScalar m_contactMotion2;
btScalar m_contactCFM1;
btScalar m_contactCFM2;
int m_lifeTime;//lifetime of the contactpoint in frames
btVector3 m_lateralFrictionDir1;

10
src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp
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@@ -329,7 +329,7 @@ void applyAnisotropicFriction(btCollisionObject* colObj,btVector3& frictionDirec
btSolverConstraint& btSequentialImpulseConstraintSolver::addFrictionConstraint(const btVector3& normalAxis,int solverBodyIdA,int solverBodyIdB,int frictionIndex,btManifoldPoint& cp,const btVector3& rel_pos1,const btVector3& rel_pos2,btCollisionObject* colObj0,btCollisionObject* colObj1, btScalar relaxation)
btSolverConstraint& btSequentialImpulseConstraintSolver::addFrictionConstraint(const btVector3& normalAxis,int solverBodyIdA,int solverBodyIdB,int frictionIndex,btManifoldPoint& cp,const btVector3& rel_pos1,const btVector3& rel_pos2,btCollisionObject* colObj0,btCollisionObject* colObj1, btScalar relaxation, btScalar desiredVelocity, btScalar cfmSlip)
{
@@ -405,10 +405,10 @@ btSolverConstraint& btSequentialImpulseConstraintSolver::addFrictionConstraint(c
// btScalar positionalError = 0.f;
btSimdScalar velocityError = - rel_vel;
btSimdScalar velocityError = desiredVelocity - rel_vel;
btSimdScalar velocityImpulse = velocityError * btSimdScalar(solverConstraint.m_jacDiagABInv);
solverConstraint.m_rhs = velocityImpulse;
solverConstraint.m_cfm = 0.f;
solverConstraint.m_cfm = cfmSlip;
solverConstraint.m_lowerLimit = 0;
solverConstraint.m_upperLimit = 1e10f;
}
@@ -652,9 +652,9 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
} else
{
addFrictionConstraint(cp.m_lateralFrictionDir1,solverBodyIdA,solverBodyIdB,frictionIndex,cp,rel_pos1,rel_pos2,colObj0,colObj1, relaxation);
addFrictionConstraint(cp.m_lateralFrictionDir1,solverBodyIdA,solverBodyIdB,frictionIndex,cp,rel_pos1,rel_pos2,colObj0,colObj1, relaxation,cp.m_contactMotion1, cp.m_contactCFM1);
if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
addFrictionConstraint(cp.m_lateralFrictionDir2,solverBodyIdA,solverBodyIdB,frictionIndex,cp,rel_pos1,rel_pos2,colObj0,colObj1, relaxation);
addFrictionConstraint(cp.m_lateralFrictionDir2,solverBodyIdA,solverBodyIdB,frictionIndex,cp,rel_pos1,rel_pos2,colObj0,colObj1, relaxation, cp.m_contactMotion2, cp.m_contactCFM2);
}
if (infoGlobal.m_solverMode & SOLVER_USE_FRICTION_WARMSTARTING)

2
src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h
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@@ -37,7 +37,7 @@ protected:
btAlignedObjectArray<int> m_orderFrictionConstraintPool;
btAlignedObjectArray<btTypedConstraint::btConstraintInfo1> m_tmpConstraintSizesPool;
btSolverConstraint& addFrictionConstraint(const btVector3& normalAxis,int solverBodyIdA,int solverBodyIdB,int frictionIndex,btManifoldPoint& cp,const btVector3& rel_pos1,const btVector3& rel_pos2,btCollisionObject* colObj0,btCollisionObject* colObj1, btScalar relaxation);
btSolverConstraint& addFrictionConstraint(const btVector3& normalAxis,int solverBodyIdA,int solverBodyIdB,int frictionIndex,btManifoldPoint& cp,const btVector3& rel_pos1,const btVector3& rel_pos2,btCollisionObject* colObj0,btCollisionObject* colObj1, btScalar relaxation, btScalar desiredVelocity=0., btScalar cfmSlip=0.);
///m_btSeed2 is used for re-arranging the constraint rows. improves convergence/quality of friction
unsigned long m_btSeed2;