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-rw-r--r--thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyConstraintSolver.cpp1429
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diff --git a/thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyConstraintSolver.cpp b/thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyConstraintSolver.cpp
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+++ b/thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyConstraintSolver.cpp
@@ -0,0 +1,1429 @@
+/*
+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.
+*/
+
+
+#include "btMultiBodyConstraintSolver.h"
+#include "BulletCollision/NarrowPhaseCollision/btPersistentManifold.h"
+#include "btMultiBodyLinkCollider.h"
+
+#include "BulletDynamics/ConstraintSolver/btSolverBody.h"
+#include "btMultiBodyConstraint.h"
+#include "BulletDynamics/ConstraintSolver/btContactSolverInfo.h"
+
+#include "LinearMath/btQuickprof.h"
+
+btScalar btMultiBodyConstraintSolver::solveSingleIteration(int iteration, btCollisionObject** bodies ,int numBodies,btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer)
+{
+ btScalar leastSquaredResidual = btSequentialImpulseConstraintSolver::solveSingleIteration(iteration, bodies ,numBodies,manifoldPtr, numManifolds,constraints,numConstraints,infoGlobal,debugDrawer);
+
+ //solve featherstone non-contact constraints
+
+ //printf("m_multiBodyNonContactConstraints = %d\n",m_multiBodyNonContactConstraints.size());
+
+ for (int j=0;j<m_multiBodyNonContactConstraints.size();j++)
+ {
+ int index = iteration&1? j : m_multiBodyNonContactConstraints.size()-1-j;
+
+ btMultiBodySolverConstraint& constraint = m_multiBodyNonContactConstraints[index];
+
+ btScalar residual = resolveSingleConstraintRowGeneric(constraint);
+ leastSquaredResidual += residual*residual;
+
+ if(constraint.m_multiBodyA)
+ constraint.m_multiBodyA->setPosUpdated(false);
+ if(constraint.m_multiBodyB)
+ constraint.m_multiBodyB->setPosUpdated(false);
+ }
+
+ //solve featherstone normal contact
+ for (int j0=0;j0<m_multiBodyNormalContactConstraints.size();j0++)
+ {
+ int index = j0;//iteration&1? j0 : m_multiBodyNormalContactConstraints.size()-1-j0;
+
+ btMultiBodySolverConstraint& constraint = m_multiBodyNormalContactConstraints[index];
+ btScalar residual = 0.f;
+
+ if (iteration < infoGlobal.m_numIterations)
+ {
+ residual = resolveSingleConstraintRowGeneric(constraint);
+ }
+
+ leastSquaredResidual += residual*residual;
+
+ if(constraint.m_multiBodyA)
+ constraint.m_multiBodyA->setPosUpdated(false);
+ if(constraint.m_multiBodyB)
+ constraint.m_multiBodyB->setPosUpdated(false);
+ }
+
+ //solve featherstone frictional contact
+
+ for (int j1=0;j1<this->m_multiBodyFrictionContactConstraints.size();j1++)
+ {
+ if (iteration < infoGlobal.m_numIterations)
+ {
+ int index = j1;//iteration&1? j1 : m_multiBodyFrictionContactConstraints.size()-1-j1;
+
+ btMultiBodySolverConstraint& frictionConstraint = m_multiBodyFrictionContactConstraints[index];
+ btScalar totalImpulse = m_multiBodyNormalContactConstraints[frictionConstraint.m_frictionIndex].m_appliedImpulse;
+ //adjust friction limits here
+ if (totalImpulse>btScalar(0))
+ {
+ frictionConstraint.m_lowerLimit = -(frictionConstraint.m_friction*totalImpulse);
+ frictionConstraint.m_upperLimit = frictionConstraint.m_friction*totalImpulse;
+ btScalar residual = resolveSingleConstraintRowGeneric(frictionConstraint);
+ leastSquaredResidual += residual*residual;
+
+ if(frictionConstraint.m_multiBodyA)
+ frictionConstraint.m_multiBodyA->setPosUpdated(false);
+ if(frictionConstraint.m_multiBodyB)
+ frictionConstraint.m_multiBodyB->setPosUpdated(false);
+ }
+ }
+ }
+ return leastSquaredResidual;
+}
+
+btScalar btMultiBodyConstraintSolver::solveGroupCacheFriendlySetup(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer)
+{
+ m_multiBodyNonContactConstraints.resize(0);
+ m_multiBodyNormalContactConstraints.resize(0);
+ m_multiBodyFrictionContactConstraints.resize(0);
+ m_data.m_jacobians.resize(0);
+ m_data.m_deltaVelocitiesUnitImpulse.resize(0);
+ m_data.m_deltaVelocities.resize(0);
+
+ for (int i=0;i<numBodies;i++)
+ {
+ const btMultiBodyLinkCollider* fcA = btMultiBodyLinkCollider::upcast(bodies[i]);
+ if (fcA)
+ {
+ fcA->m_multiBody->setCompanionId(-1);
+ }
+ }
+
+ btScalar val = btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySetup( bodies,numBodies,manifoldPtr, numManifolds, constraints,numConstraints,infoGlobal,debugDrawer);
+
+ return val;
+}
+
+void btMultiBodyConstraintSolver::applyDeltaVee(btScalar* delta_vee, btScalar impulse, int velocityIndex, int ndof)
+{
+ for (int i = 0; i < ndof; ++i)
+ m_data.m_deltaVelocities[velocityIndex+i] += delta_vee[i] * impulse;
+}
+
+btScalar btMultiBodyConstraintSolver::resolveSingleConstraintRowGeneric(const btMultiBodySolverConstraint& c)
+{
+
+ btScalar deltaImpulse = c.m_rhs-btScalar(c.m_appliedImpulse)*c.m_cfm;
+ btScalar deltaVelADotn=0;
+ btScalar deltaVelBDotn=0;
+ btSolverBody* bodyA = 0;
+ btSolverBody* bodyB = 0;
+ int ndofA=0;
+ int ndofB=0;
+
+ if (c.m_multiBodyA)
+ {
+ ndofA = c.m_multiBodyA->getNumDofs() + 6;
+ for (int i = 0; i < ndofA; ++i)
+ deltaVelADotn += m_data.m_jacobians[c.m_jacAindex+i] * m_data.m_deltaVelocities[c.m_deltaVelAindex+i];
+ } else if(c.m_solverBodyIdA >= 0)
+ {
+ bodyA = &m_tmpSolverBodyPool[c.m_solverBodyIdA];
+ deltaVelADotn += c.m_contactNormal1.dot(bodyA->internalGetDeltaLinearVelocity()) + c.m_relpos1CrossNormal.dot(bodyA->internalGetDeltaAngularVelocity());
+ }
+
+ if (c.m_multiBodyB)
+ {
+ ndofB = c.m_multiBodyB->getNumDofs() + 6;
+ for (int i = 0; i < ndofB; ++i)
+ deltaVelBDotn += m_data.m_jacobians[c.m_jacBindex+i] * m_data.m_deltaVelocities[c.m_deltaVelBindex+i];
+ } else if(c.m_solverBodyIdB >= 0)
+ {
+ bodyB = &m_tmpSolverBodyPool[c.m_solverBodyIdB];
+ deltaVelBDotn += c.m_contactNormal2.dot(bodyB->internalGetDeltaLinearVelocity()) + c.m_relpos2CrossNormal.dot(bodyB->internalGetDeltaAngularVelocity());
+ }
+
+
+ deltaImpulse -= deltaVelADotn*c.m_jacDiagABInv;//m_jacDiagABInv = 1./denom
+ deltaImpulse -= deltaVelBDotn*c.m_jacDiagABInv;
+ const btScalar sum = btScalar(c.m_appliedImpulse) + deltaImpulse;
+
+ if (sum < c.m_lowerLimit)
+ {
+ deltaImpulse = c.m_lowerLimit-c.m_appliedImpulse;
+ c.m_appliedImpulse = c.m_lowerLimit;
+ }
+ else if (sum > c.m_upperLimit)
+ {
+ deltaImpulse = c.m_upperLimit-c.m_appliedImpulse;
+ c.m_appliedImpulse = c.m_upperLimit;
+ }
+ else
+ {
+ c.m_appliedImpulse = sum;
+ }
+
+ if (c.m_multiBodyA)
+ {
+ applyDeltaVee(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacAindex],deltaImpulse,c.m_deltaVelAindex,ndofA);
+#ifdef DIRECTLY_UPDATE_VELOCITY_DURING_SOLVER_ITERATIONS
+ //note: update of the actual velocities (below) in the multibody does not have to happen now since m_deltaVelocities can be applied after all iterations
+ //it would make the multibody solver more like the regular one with m_deltaVelocities being equivalent to btSolverBody::m_deltaLinearVelocity/m_deltaAngularVelocity
+ c.m_multiBodyA->applyDeltaVeeMultiDof2(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacAindex],deltaImpulse);
+#endif //DIRECTLY_UPDATE_VELOCITY_DURING_SOLVER_ITERATIONS
+ } else if(c.m_solverBodyIdA >= 0)
+ {
+ bodyA->internalApplyImpulse(c.m_contactNormal1*bodyA->internalGetInvMass(),c.m_angularComponentA,deltaImpulse);
+
+ }
+ if (c.m_multiBodyB)
+ {
+ applyDeltaVee(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacBindex],deltaImpulse,c.m_deltaVelBindex,ndofB);
+#ifdef DIRECTLY_UPDATE_VELOCITY_DURING_SOLVER_ITERATIONS
+ //note: update of the actual velocities (below) in the multibody does not have to happen now since m_deltaVelocities can be applied after all iterations
+ //it would make the multibody solver more like the regular one with m_deltaVelocities being equivalent to btSolverBody::m_deltaLinearVelocity/m_deltaAngularVelocity
+ c.m_multiBodyB->applyDeltaVeeMultiDof2(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacBindex],deltaImpulse);
+#endif //DIRECTLY_UPDATE_VELOCITY_DURING_SOLVER_ITERATIONS
+ } else if(c.m_solverBodyIdB >= 0)
+ {
+ bodyB->internalApplyImpulse(c.m_contactNormal2*bodyB->internalGetInvMass(),c.m_angularComponentB,deltaImpulse);
+ }
+ return deltaImpulse;
+}
+
+
+
+
+void btMultiBodyConstraintSolver::setupMultiBodyContactConstraint(btMultiBodySolverConstraint& solverConstraint,
+ const btVector3& contactNormal,
+ btManifoldPoint& cp, const btContactSolverInfo& infoGlobal,
+ btScalar& relaxation,
+ bool isFriction, btScalar desiredVelocity, btScalar cfmSlip)
+{
+
+ BT_PROFILE("setupMultiBodyContactConstraint");
+ btVector3 rel_pos1;
+ btVector3 rel_pos2;
+
+ btMultiBody* multiBodyA = solverConstraint.m_multiBodyA;
+ btMultiBody* multiBodyB = solverConstraint.m_multiBodyB;
+
+ const btVector3& pos1 = cp.getPositionWorldOnA();
+ const btVector3& pos2 = cp.getPositionWorldOnB();
+
+ btSolverBody* bodyA = multiBodyA ? 0 : &m_tmpSolverBodyPool[solverConstraint.m_solverBodyIdA];
+ btSolverBody* bodyB = multiBodyB ? 0 : &m_tmpSolverBodyPool[solverConstraint.m_solverBodyIdB];
+
+ btRigidBody* rb0 = multiBodyA ? 0 : bodyA->m_originalBody;
+ btRigidBody* rb1 = multiBodyB ? 0 : bodyB->m_originalBody;
+
+ if (bodyA)
+ rel_pos1 = pos1 - bodyA->getWorldTransform().getOrigin();
+ if (bodyB)
+ rel_pos2 = pos2 - bodyB->getWorldTransform().getOrigin();
+
+ relaxation = infoGlobal.m_sor;
+
+ btScalar invTimeStep = btScalar(1)/infoGlobal.m_timeStep;
+
+ //cfm = 1 / ( dt * kp + kd )
+ //erp = dt * kp / ( dt * kp + kd )
+
+ btScalar cfm;
+ btScalar erp;
+ if (isFriction)
+ {
+ cfm = infoGlobal.m_frictionCFM;
+ erp = infoGlobal.m_frictionERP;
+ } else
+ {
+ cfm = infoGlobal.m_globalCfm;
+ erp = infoGlobal.m_erp2;
+
+ if ((cp.m_contactPointFlags&BT_CONTACT_FLAG_HAS_CONTACT_CFM) || (cp.m_contactPointFlags&BT_CONTACT_FLAG_HAS_CONTACT_ERP))
+ {
+ if (cp.m_contactPointFlags&BT_CONTACT_FLAG_HAS_CONTACT_CFM)
+ cfm = cp.m_contactCFM;
+ if (cp.m_contactPointFlags&BT_CONTACT_FLAG_HAS_CONTACT_ERP)
+ erp = cp.m_contactERP;
+ } else
+ {
+ if (cp.m_contactPointFlags & BT_CONTACT_FLAG_CONTACT_STIFFNESS_DAMPING)
+ {
+ btScalar denom = ( infoGlobal.m_timeStep * cp.m_combinedContactStiffness1 + cp.m_combinedContactDamping1 );
+ if (denom < SIMD_EPSILON)
+ {
+ denom = SIMD_EPSILON;
+ }
+ cfm = btScalar(1) / denom;
+ erp = (infoGlobal.m_timeStep * cp.m_combinedContactStiffness1) / denom;
+ }
+ }
+ }
+
+ cfm *= invTimeStep;
+
+ if (multiBodyA)
+ {
+ if (solverConstraint.m_linkA<0)
+ {
+ rel_pos1 = pos1 - multiBodyA->getBasePos();
+ } else
+ {
+ rel_pos1 = pos1 - multiBodyA->getLink(solverConstraint.m_linkA).m_cachedWorldTransform.getOrigin();
+ }
+ const int ndofA = multiBodyA->getNumDofs() + 6;
+
+ solverConstraint.m_deltaVelAindex = multiBodyA->getCompanionId();
+
+ if (solverConstraint.m_deltaVelAindex <0)
+ {
+ solverConstraint.m_deltaVelAindex = m_data.m_deltaVelocities.size();
+ multiBodyA->setCompanionId(solverConstraint.m_deltaVelAindex);
+ m_data.m_deltaVelocities.resize(m_data.m_deltaVelocities.size()+ndofA);
+ } else
+ {
+ btAssert(m_data.m_deltaVelocities.size() >= solverConstraint.m_deltaVelAindex+ndofA);
+ }
+
+ solverConstraint.m_jacAindex = m_data.m_jacobians.size();
+ m_data.m_jacobians.resize(m_data.m_jacobians.size()+ndofA);
+ m_data.m_deltaVelocitiesUnitImpulse.resize(m_data.m_deltaVelocitiesUnitImpulse.size()+ndofA);
+ btAssert(m_data.m_jacobians.size() == m_data.m_deltaVelocitiesUnitImpulse.size());
+
+ btScalar* jac1=&m_data.m_jacobians[solverConstraint.m_jacAindex];
+ multiBodyA->fillContactJacobianMultiDof(solverConstraint.m_linkA, cp.getPositionWorldOnA(), contactNormal, jac1, m_data.scratch_r, m_data.scratch_v, m_data.scratch_m);
+ btScalar* delta = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
+ multiBodyA->calcAccelerationDeltasMultiDof(&m_data.m_jacobians[solverConstraint.m_jacAindex],delta,m_data.scratch_r, m_data.scratch_v);
+
+ btVector3 torqueAxis0 = rel_pos1.cross(contactNormal);
+ solverConstraint.m_relpos1CrossNormal = torqueAxis0;
+ solverConstraint.m_contactNormal1 = contactNormal;
+ } else
+ {
+ btVector3 torqueAxis0 = rel_pos1.cross(contactNormal);
+ solverConstraint.m_relpos1CrossNormal = torqueAxis0;
+ solverConstraint.m_contactNormal1 = contactNormal;
+ solverConstraint.m_angularComponentA = rb0 ? rb0->getInvInertiaTensorWorld()*torqueAxis0*rb0->getAngularFactor() : btVector3(0,0,0);
+ }
+
+
+
+ if (multiBodyB)
+ {
+ if (solverConstraint.m_linkB<0)
+ {
+ rel_pos2 = pos2 - multiBodyB->getBasePos();
+ } else
+ {
+ rel_pos2 = pos2 - multiBodyB->getLink(solverConstraint.m_linkB).m_cachedWorldTransform.getOrigin();
+ }
+
+ const int ndofB = multiBodyB->getNumDofs() + 6;
+
+ solverConstraint.m_deltaVelBindex = multiBodyB->getCompanionId();
+ if (solverConstraint.m_deltaVelBindex <0)
+ {
+ solverConstraint.m_deltaVelBindex = m_data.m_deltaVelocities.size();
+ multiBodyB->setCompanionId(solverConstraint.m_deltaVelBindex);
+ m_data.m_deltaVelocities.resize(m_data.m_deltaVelocities.size()+ndofB);
+ }
+
+ solverConstraint.m_jacBindex = m_data.m_jacobians.size();
+
+ m_data.m_jacobians.resize(m_data.m_jacobians.size()+ndofB);
+ m_data.m_deltaVelocitiesUnitImpulse.resize(m_data.m_deltaVelocitiesUnitImpulse.size()+ndofB);
+ btAssert(m_data.m_jacobians.size() == m_data.m_deltaVelocitiesUnitImpulse.size());
+
+ multiBodyB->fillContactJacobianMultiDof(solverConstraint.m_linkB, cp.getPositionWorldOnB(), -contactNormal, &m_data.m_jacobians[solverConstraint.m_jacBindex], m_data.scratch_r, m_data.scratch_v, m_data.scratch_m);
+ multiBodyB->calcAccelerationDeltasMultiDof(&m_data.m_jacobians[solverConstraint.m_jacBindex],&m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex],m_data.scratch_r, m_data.scratch_v);
+
+ btVector3 torqueAxis1 = rel_pos2.cross(contactNormal);
+ solverConstraint.m_relpos2CrossNormal = -torqueAxis1;
+ solverConstraint.m_contactNormal2 = -contactNormal;
+
+ } else
+ {
+ btVector3 torqueAxis1 = rel_pos2.cross(contactNormal);
+ solverConstraint.m_relpos2CrossNormal = -torqueAxis1;
+ solverConstraint.m_contactNormal2 = -contactNormal;
+
+ solverConstraint.m_angularComponentB = rb1 ? rb1->getInvInertiaTensorWorld()*-torqueAxis1*rb1->getAngularFactor() : btVector3(0,0,0);
+ }
+
+ {
+
+ 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)
+ {
+ ndofA = multiBodyA->getNumDofs() + 6;
+ jacA = &m_data.m_jacobians[solverConstraint.m_jacAindex];
+ lambdaA = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
+ for (int i = 0; i < ndofA; ++i)
+ {
+ btScalar j = jacA[i] ;
+ btScalar l =lambdaA[i];
+ denom0 += j*l;
+ }
+ } else
+ {
+ if (rb0)
+ {
+ vec = ( solverConstraint.m_angularComponentA).cross(rel_pos1);
+ denom0 = rb0->getInvMass() + contactNormal.dot(vec);
+ }
+ }
+ if (multiBodyB)
+ {
+ const int ndofB = multiBodyB->getNumDofs() + 6;
+ jacB = &m_data.m_jacobians[solverConstraint.m_jacBindex];
+ lambdaB = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
+ for (int i = 0; i < ndofB; ++i)
+ {
+ btScalar j = jacB[i] ;
+ btScalar l =lambdaB[i];
+ denom1 += j*l;
+ }
+
+ } else
+ {
+ if (rb1)
+ {
+ vec = ( -solverConstraint.m_angularComponentB).cross(rel_pos2);
+ denom1 = rb1->getInvMass() + contactNormal.dot(vec);
+ }
+ }
+
+
+
+ btScalar d = denom0+denom1+cfm;
+ if (d>SIMD_EPSILON)
+ {
+ solverConstraint.m_jacDiagABInv = relaxation/(d);
+ } else
+ {
+ //disable the constraint row to handle singularity/redundant constraint
+ solverConstraint.m_jacDiagABInv = 0.f;
+ }
+
+ }
+
+
+ //compute rhs and remaining solverConstraint fields
+
+
+
+ btScalar restitution = 0.f;
+ btScalar distance = 0;
+ if (!isFriction)
+ {
+ distance = cp.getDistance()+infoGlobal.m_linearSlop;
+ } else
+ {
+ if (cp.m_contactPointFlags & BT_CONTACT_FLAG_FRICTION_ANCHOR)
+ {
+ distance = (cp.getPositionWorldOnA() - cp.getPositionWorldOnB()).dot(contactNormal);
+ }
+ }
+
+
+ btScalar rel_vel = 0.f;
+ int ndofA = 0;
+ int ndofB = 0;
+ {
+
+ btVector3 vel1,vel2;
+ if (multiBodyA)
+ {
+ ndofA = multiBodyA->getNumDofs() + 6;
+ btScalar* jacA = &m_data.m_jacobians[solverConstraint.m_jacAindex];
+ for (int i = 0; i < ndofA ; ++i)
+ rel_vel += multiBodyA->getVelocityVector()[i] * jacA[i];
+ } else
+ {
+ if (rb0)
+ {
+ rel_vel += (rb0->getVelocityInLocalPoint(rel_pos1) +
+ (rb0->getTotalTorque()*rb0->getInvInertiaTensorWorld()*infoGlobal.m_timeStep).cross(rel_pos1)+
+ rb0->getTotalForce()*rb0->getInvMass()*infoGlobal.m_timeStep).dot(solverConstraint.m_contactNormal1);
+ }
+ }
+ if (multiBodyB)
+ {
+ ndofB = multiBodyB->getNumDofs() + 6;
+ btScalar* jacB = &m_data.m_jacobians[solverConstraint.m_jacBindex];
+ for (int i = 0; i < ndofB ; ++i)
+ rel_vel += multiBodyB->getVelocityVector()[i] * jacB[i];
+
+ } else
+ {
+ if (rb1)
+ {
+ rel_vel += (rb1->getVelocityInLocalPoint(rel_pos2)+
+ (rb1->getTotalTorque()*rb1->getInvInertiaTensorWorld()*infoGlobal.m_timeStep).cross(rel_pos2) +
+ rb1->getTotalForce()*rb1->getInvMass()*infoGlobal.m_timeStep).dot(solverConstraint.m_contactNormal2);
+ }
+ }
+
+ solverConstraint.m_friction = cp.m_combinedFriction;
+
+ if(!isFriction)
+ {
+ restitution = restitutionCurve(rel_vel, cp.m_combinedRestitution, infoGlobal.m_restitutionVelocityThreshold);
+ if (restitution <= btScalar(0.))
+ {
+ restitution = 0.f;
+ }
+ }
+ }
+
+
+ ///warm starting (or zero if disabled)
+ //disable warmstarting for btMultiBody, it has issues gaining energy (==explosion)
+ if (0)//infoGlobal.m_solverMode & SOLVER_USE_WARMSTARTING)
+ {
+ solverConstraint.m_appliedImpulse = isFriction ? 0 : cp.m_appliedImpulse * infoGlobal.m_warmstartingFactor;
+
+ if (solverConstraint.m_appliedImpulse)
+ {
+ if (multiBodyA)
+ {
+ btScalar impulse = solverConstraint.m_appliedImpulse;
+ btScalar* deltaV = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
+ multiBodyA->applyDeltaVeeMultiDof(deltaV,impulse);
+
+ applyDeltaVee(deltaV,impulse,solverConstraint.m_deltaVelAindex,ndofA);
+ } else
+ {
+ if (rb0)
+ bodyA->internalApplyImpulse(solverConstraint.m_contactNormal1*bodyA->internalGetInvMass()*rb0->getLinearFactor(),solverConstraint.m_angularComponentA,solverConstraint.m_appliedImpulse);
+ }
+ if (multiBodyB)
+ {
+ btScalar impulse = solverConstraint.m_appliedImpulse;
+ btScalar* deltaV = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
+ multiBodyB->applyDeltaVeeMultiDof(deltaV,impulse);
+ applyDeltaVee(deltaV,impulse,solverConstraint.m_deltaVelBindex,ndofB);
+ } else
+ {
+ if (rb1)
+ bodyB->internalApplyImpulse(-solverConstraint.m_contactNormal2*bodyB->internalGetInvMass()*rb1->getLinearFactor(),-solverConstraint.m_angularComponentB,-(btScalar)solverConstraint.m_appliedImpulse);
+ }
+ }
+ } else
+ {
+ solverConstraint.m_appliedImpulse = 0.f;
+ }
+
+ solverConstraint.m_appliedPushImpulse = 0.f;
+
+ {
+
+ btScalar positionalError = 0.f;
+ btScalar velocityError = restitution - rel_vel;// * damping; //note for friction restitution is always set to 0 (check above) so it is acutally velocityError = -rel_vel for friction
+ if (isFriction)
+ {
+ positionalError = -distance * erp/infoGlobal.m_timeStep;
+ } else
+ {
+ if (distance>0)
+ {
+ positionalError = 0;
+ velocityError -= distance / infoGlobal.m_timeStep;
+
+ } else
+ {
+ positionalError = -distance * erp/infoGlobal.m_timeStep;
+ }
+ }
+
+ btScalar penetrationImpulse = positionalError*solverConstraint.m_jacDiagABInv;
+ btScalar velocityImpulse = velocityError *solverConstraint.m_jacDiagABInv;
+
+ if(!isFriction)
+ {
+ // if (!infoGlobal.m_splitImpulse || (penetration > infoGlobal.m_splitImpulsePenetrationThreshold))
+ {
+ //combine position and velocity into rhs
+ solverConstraint.m_rhs = penetrationImpulse+velocityImpulse;
+ solverConstraint.m_rhsPenetration = 0.f;
+
+ }
+ /*else
+ {
+ //split position and velocity into rhs and m_rhsPenetration
+ solverConstraint.m_rhs = velocityImpulse;
+ solverConstraint.m_rhsPenetration = penetrationImpulse;
+ }
+ */
+ solverConstraint.m_lowerLimit = 0;
+ solverConstraint.m_upperLimit = 1e10f;
+ }
+ else
+ {
+ solverConstraint.m_rhs = penetrationImpulse+velocityImpulse;
+ solverConstraint.m_rhsPenetration = 0.f;
+ solverConstraint.m_lowerLimit = -solverConstraint.m_friction;
+ solverConstraint.m_upperLimit = solverConstraint.m_friction;
+ }
+
+ solverConstraint.m_cfm = cfm*solverConstraint.m_jacDiagABInv;
+
+
+
+ }
+
+}
+
+void btMultiBodyConstraintSolver::setupMultiBodyTorsionalFrictionConstraint(btMultiBodySolverConstraint& solverConstraint,
+ const btVector3& constraintNormal,
+ btManifoldPoint& cp,
+ btScalar combinedTorsionalFriction,
+ const btContactSolverInfo& infoGlobal,
+ btScalar& relaxation,
+ bool isFriction, btScalar desiredVelocity, btScalar cfmSlip)
+{
+
+ BT_PROFILE("setupMultiBodyRollingFrictionConstraint");
+ btVector3 rel_pos1;
+ btVector3 rel_pos2;
+
+ btMultiBody* multiBodyA = solverConstraint.m_multiBodyA;
+ btMultiBody* multiBodyB = solverConstraint.m_multiBodyB;
+
+ const btVector3& pos1 = cp.getPositionWorldOnA();
+ const btVector3& pos2 = cp.getPositionWorldOnB();
+
+ btSolverBody* bodyA = multiBodyA ? 0 : &m_tmpSolverBodyPool[solverConstraint.m_solverBodyIdA];
+ btSolverBody* bodyB = multiBodyB ? 0 : &m_tmpSolverBodyPool[solverConstraint.m_solverBodyIdB];
+
+ btRigidBody* rb0 = multiBodyA ? 0 : bodyA->m_originalBody;
+ btRigidBody* rb1 = multiBodyB ? 0 : bodyB->m_originalBody;
+
+ if (bodyA)
+ rel_pos1 = pos1 - bodyA->getWorldTransform().getOrigin();
+ if (bodyB)
+ rel_pos2 = pos2 - bodyB->getWorldTransform().getOrigin();
+
+ relaxation = infoGlobal.m_sor;
+
+ // btScalar invTimeStep = btScalar(1)/infoGlobal.m_timeStep;
+
+
+ if (multiBodyA)
+ {
+ if (solverConstraint.m_linkA<0)
+ {
+ rel_pos1 = pos1 - multiBodyA->getBasePos();
+ } else
+ {
+ rel_pos1 = pos1 - multiBodyA->getLink(solverConstraint.m_linkA).m_cachedWorldTransform.getOrigin();
+ }
+ const int ndofA = multiBodyA->getNumDofs() + 6;
+
+ solverConstraint.m_deltaVelAindex = multiBodyA->getCompanionId();
+
+ if (solverConstraint.m_deltaVelAindex <0)
+ {
+ solverConstraint.m_deltaVelAindex = m_data.m_deltaVelocities.size();
+ multiBodyA->setCompanionId(solverConstraint.m_deltaVelAindex);
+ m_data.m_deltaVelocities.resize(m_data.m_deltaVelocities.size()+ndofA);
+ } else
+ {
+ btAssert(m_data.m_deltaVelocities.size() >= solverConstraint.m_deltaVelAindex+ndofA);
+ }
+
+ solverConstraint.m_jacAindex = m_data.m_jacobians.size();
+ m_data.m_jacobians.resize(m_data.m_jacobians.size()+ndofA);
+ m_data.m_deltaVelocitiesUnitImpulse.resize(m_data.m_deltaVelocitiesUnitImpulse.size()+ndofA);
+ btAssert(m_data.m_jacobians.size() == m_data.m_deltaVelocitiesUnitImpulse.size());
+
+ btScalar* jac1=&m_data.m_jacobians[solverConstraint.m_jacAindex];
+ multiBodyA->fillConstraintJacobianMultiDof(solverConstraint.m_linkA, cp.getPositionWorldOnA(), constraintNormal, btVector3(0,0,0), jac1, m_data.scratch_r, m_data.scratch_v, m_data.scratch_m);
+ btScalar* delta = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
+ multiBodyA->calcAccelerationDeltasMultiDof(&m_data.m_jacobians[solverConstraint.m_jacAindex],delta,m_data.scratch_r, m_data.scratch_v);
+
+ btVector3 torqueAxis0 = -constraintNormal;
+ solverConstraint.m_relpos1CrossNormal = torqueAxis0;
+ solverConstraint.m_contactNormal1 = btVector3(0,0,0);
+ } else
+ {
+ btVector3 torqueAxis0 = -constraintNormal;
+ solverConstraint.m_relpos1CrossNormal = torqueAxis0;
+ solverConstraint.m_contactNormal1 = btVector3(0,0,0);
+ solverConstraint.m_angularComponentA = rb0 ? rb0->getInvInertiaTensorWorld()*torqueAxis0*rb0->getAngularFactor() : btVector3(0,0,0);
+ }
+
+
+
+ if (multiBodyB)
+ {
+ if (solverConstraint.m_linkB<0)
+ {
+ rel_pos2 = pos2 - multiBodyB->getBasePos();
+ } else
+ {
+ rel_pos2 = pos2 - multiBodyB->getLink(solverConstraint.m_linkB).m_cachedWorldTransform.getOrigin();
+ }
+
+ const int ndofB = multiBodyB->getNumDofs() + 6;
+
+ solverConstraint.m_deltaVelBindex = multiBodyB->getCompanionId();
+ if (solverConstraint.m_deltaVelBindex <0)
+ {
+ solverConstraint.m_deltaVelBindex = m_data.m_deltaVelocities.size();
+ multiBodyB->setCompanionId(solverConstraint.m_deltaVelBindex);
+ m_data.m_deltaVelocities.resize(m_data.m_deltaVelocities.size()+ndofB);
+ }
+
+ solverConstraint.m_jacBindex = m_data.m_jacobians.size();
+
+ m_data.m_jacobians.resize(m_data.m_jacobians.size()+ndofB);
+ m_data.m_deltaVelocitiesUnitImpulse.resize(m_data.m_deltaVelocitiesUnitImpulse.size()+ndofB);
+ btAssert(m_data.m_jacobians.size() == m_data.m_deltaVelocitiesUnitImpulse.size());
+
+ multiBodyB->fillConstraintJacobianMultiDof(solverConstraint.m_linkB, cp.getPositionWorldOnB(), -constraintNormal, btVector3(0,0,0), &m_data.m_jacobians[solverConstraint.m_jacBindex], m_data.scratch_r, m_data.scratch_v, m_data.scratch_m);
+ multiBodyB->calcAccelerationDeltasMultiDof(&m_data.m_jacobians[solverConstraint.m_jacBindex],&m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex],m_data.scratch_r, m_data.scratch_v);
+
+ btVector3 torqueAxis1 = constraintNormal;
+ solverConstraint.m_relpos2CrossNormal = torqueAxis1;
+ solverConstraint.m_contactNormal2 = -btVector3(0,0,0);
+
+ } else
+ {
+ btVector3 torqueAxis1 = constraintNormal;
+ solverConstraint.m_relpos2CrossNormal = torqueAxis1;
+ solverConstraint.m_contactNormal2 = -btVector3(0,0,0);
+
+ solverConstraint.m_angularComponentB = rb1 ? rb1->getInvInertiaTensorWorld()*torqueAxis1*rb1->getAngularFactor() : btVector3(0,0,0);
+ }
+
+ {
+
+ 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)
+ {
+ ndofA = multiBodyA->getNumDofs() + 6;
+ jacA = &m_data.m_jacobians[solverConstraint.m_jacAindex];
+ lambdaA = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
+ for (int i = 0; i < ndofA; ++i)
+ {
+ btScalar j = jacA[i] ;
+ btScalar l =lambdaA[i];
+ denom0 += j*l;
+ }
+ } else
+ {
+ if (rb0)
+ {
+ btVector3 iMJaA = rb0?rb0->getInvInertiaTensorWorld()*solverConstraint.m_relpos1CrossNormal:btVector3(0,0,0);
+ denom0 = iMJaA.dot(solverConstraint.m_relpos1CrossNormal);
+ }
+ }
+ if (multiBodyB)
+ {
+ const int ndofB = multiBodyB->getNumDofs() + 6;
+ jacB = &m_data.m_jacobians[solverConstraint.m_jacBindex];
+ lambdaB = &m_data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
+ for (int i = 0; i < ndofB; ++i)
+ {
+ btScalar j = jacB[i] ;
+ btScalar l =lambdaB[i];
+ denom1 += j*l;
+ }
+
+ } else
+ {
+ if (rb1)
+ {
+ btVector3 iMJaB = rb1?rb1->getInvInertiaTensorWorld()*solverConstraint.m_relpos2CrossNormal:btVector3(0,0,0);
+ denom1 = iMJaB.dot(solverConstraint.m_relpos2CrossNormal);
+ }
+ }
+
+
+
+ btScalar d = denom0+denom1+infoGlobal.m_globalCfm;
+ if (d>SIMD_EPSILON)
+ {
+ solverConstraint.m_jacDiagABInv = relaxation/(d);
+ } else
+ {
+ //disable the constraint row to handle singularity/redundant constraint
+ solverConstraint.m_jacDiagABInv = 0.f;
+ }
+
+ }
+
+
+ //compute rhs and remaining solverConstraint fields
+
+
+
+ btScalar restitution = 0.f;
+ btScalar penetration = isFriction? 0 : cp.getDistance();
+
+ btScalar rel_vel = 0.f;
+ int ndofA = 0;
+ int ndofB = 0;
+ {
+
+ btVector3 vel1,vel2;
+ if (multiBodyA)
+ {
+ ndofA = multiBodyA->getNumDofs() + 6;
+ btScalar* jacA = &m_data.m_jacobians[solverConstraint.m_jacAindex];
+ for (int i = 0; i < ndofA ; ++i)
+ rel_vel += multiBodyA->getVelocityVector()[i] * jacA[i];
+ } else
+ {
+ if (rb0)
+ {
+ btSolverBody* solverBodyA = &m_tmpSolverBodyPool[solverConstraint.m_solverBodyIdA];
+ rel_vel += solverConstraint.m_contactNormal1.dot(rb0?solverBodyA->m_linearVelocity+solverBodyA->m_externalForceImpulse:btVector3(0,0,0))
+ + solverConstraint.m_relpos1CrossNormal.dot(rb0?solverBodyA->m_angularVelocity:btVector3(0,0,0));
+
+ }
+ }
+ if (multiBodyB)
+ {
+ ndofB = multiBodyB->getNumDofs() + 6;
+ btScalar* jacB = &m_data.m_jacobians[solverConstraint.m_jacBindex];
+ for (int i = 0; i < ndofB ; ++i)
+ rel_vel += multiBodyB->getVelocityVector()[i] * jacB[i];
+
+ } else
+ {
+ if (rb1)
+ {
+ btSolverBody* solverBodyB = &m_tmpSolverBodyPool[solverConstraint.m_solverBodyIdB];
+ rel_vel += solverConstraint.m_contactNormal2.dot(rb1?solverBodyB->m_linearVelocity+solverBodyB->m_externalForceImpulse:btVector3(0,0,0))
+ + solverConstraint.m_relpos2CrossNormal.dot(rb1?solverBodyB->m_angularVelocity:btVector3(0,0,0));
+
+ }
+ }
+
+ solverConstraint.m_friction =combinedTorsionalFriction;
+
+ if(!isFriction)
+ {
+ restitution = restitutionCurve(rel_vel, cp.m_combinedRestitution, infoGlobal.m_restitutionVelocityThreshold);
+ if (restitution <= btScalar(0.))
+ {
+ restitution = 0.f;
+ }
+ }
+ }
+
+
+ solverConstraint.m_appliedImpulse = 0.f;
+ solverConstraint.m_appliedPushImpulse = 0.f;
+
+ {
+
+ btScalar velocityError = 0 - rel_vel;// * damping; //note for friction restitution is always set to 0 (check above) so it is acutally velocityError = -rel_vel for friction
+
+
+
+ btScalar velocityImpulse = velocityError*solverConstraint.m_jacDiagABInv;
+
+ solverConstraint.m_rhs = velocityImpulse;
+ solverConstraint.m_rhsPenetration = 0.f;
+ solverConstraint.m_lowerLimit = -solverConstraint.m_friction;
+ solverConstraint.m_upperLimit = solverConstraint.m_friction;
+
+ solverConstraint.m_cfm = infoGlobal.m_globalCfm*solverConstraint.m_jacDiagABInv;
+
+
+
+ }
+
+}
+
+btMultiBodySolverConstraint& btMultiBodyConstraintSolver::addMultiBodyFrictionConstraint(const btVector3& normalAxis,btPersistentManifold* manifold,int frictionIndex,btManifoldPoint& cp,btCollisionObject* colObj0,btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip)
+{
+ BT_PROFILE("addMultiBodyFrictionConstraint");
+ btMultiBodySolverConstraint& solverConstraint = m_multiBodyFrictionContactConstraints.expandNonInitializing();
+ solverConstraint.m_orgConstraint = 0;
+ solverConstraint.m_orgDofIndex = -1;
+
+ solverConstraint.m_frictionIndex = frictionIndex;
+ bool isFriction = true;
+
+ const btMultiBodyLinkCollider* fcA = btMultiBodyLinkCollider::upcast(manifold->getBody0());
+ const btMultiBodyLinkCollider* fcB = btMultiBodyLinkCollider::upcast(manifold->getBody1());
+
+ btMultiBody* mbA = fcA? fcA->m_multiBody : 0;
+ btMultiBody* mbB = fcB? fcB->m_multiBody : 0;
+
+ int solverBodyIdA = mbA? -1 : getOrInitSolverBody(*colObj0,infoGlobal.m_timeStep);
+ int solverBodyIdB = mbB ? -1 : getOrInitSolverBody(*colObj1,infoGlobal.m_timeStep);
+
+ solverConstraint.m_solverBodyIdA = solverBodyIdA;
+ solverConstraint.m_solverBodyIdB = solverBodyIdB;
+ solverConstraint.m_multiBodyA = mbA;
+ if (mbA)
+ solverConstraint.m_linkA = fcA->m_link;
+
+ solverConstraint.m_multiBodyB = mbB;
+ if (mbB)
+ solverConstraint.m_linkB = fcB->m_link;
+
+ solverConstraint.m_originalContactPoint = &cp;
+
+ setupMultiBodyContactConstraint(solverConstraint, normalAxis, cp, infoGlobal,relaxation,isFriction, desiredVelocity, cfmSlip);
+ return solverConstraint;
+}
+
+btMultiBodySolverConstraint& btMultiBodyConstraintSolver::addMultiBodyTorsionalFrictionConstraint(const btVector3& normalAxis,btPersistentManifold* manifold,int frictionIndex,btManifoldPoint& cp,
+ btScalar combinedTorsionalFriction,
+ btCollisionObject* colObj0,btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip)
+{
+ BT_PROFILE("addMultiBodyRollingFrictionConstraint");
+ btMultiBodySolverConstraint& solverConstraint = m_multiBodyFrictionContactConstraints.expandNonInitializing();
+ solverConstraint.m_orgConstraint = 0;
+ solverConstraint.m_orgDofIndex = -1;
+
+ solverConstraint.m_frictionIndex = frictionIndex;
+ bool isFriction = true;
+
+ const btMultiBodyLinkCollider* fcA = btMultiBodyLinkCollider::upcast(manifold->getBody0());
+ const btMultiBodyLinkCollider* fcB = btMultiBodyLinkCollider::upcast(manifold->getBody1());
+
+ btMultiBody* mbA = fcA? fcA->m_multiBody : 0;
+ btMultiBody* mbB = fcB? fcB->m_multiBody : 0;
+
+ int solverBodyIdA = mbA? -1 : getOrInitSolverBody(*colObj0,infoGlobal.m_timeStep);
+ int solverBodyIdB = mbB ? -1 : getOrInitSolverBody(*colObj1,infoGlobal.m_timeStep);
+
+ solverConstraint.m_solverBodyIdA = solverBodyIdA;
+ solverConstraint.m_solverBodyIdB = solverBodyIdB;
+ solverConstraint.m_multiBodyA = mbA;
+ if (mbA)
+ solverConstraint.m_linkA = fcA->m_link;
+
+ solverConstraint.m_multiBodyB = mbB;
+ if (mbB)
+ solverConstraint.m_linkB = fcB->m_link;
+
+ solverConstraint.m_originalContactPoint = &cp;
+
+ setupMultiBodyTorsionalFrictionConstraint(solverConstraint, normalAxis, cp, combinedTorsionalFriction,infoGlobal,relaxation,isFriction, desiredVelocity, cfmSlip);
+ return solverConstraint;
+}
+
+void btMultiBodyConstraintSolver::convertMultiBodyContact(btPersistentManifold* manifold,const btContactSolverInfo& infoGlobal)
+{
+ const btMultiBodyLinkCollider* fcA = btMultiBodyLinkCollider::upcast(manifold->getBody0());
+ const btMultiBodyLinkCollider* fcB = btMultiBodyLinkCollider::upcast(manifold->getBody1());
+
+ btMultiBody* mbA = fcA? fcA->m_multiBody : 0;
+ btMultiBody* mbB = fcB? fcB->m_multiBody : 0;
+
+ btCollisionObject* colObj0=0,*colObj1=0;
+
+ colObj0 = (btCollisionObject*)manifold->getBody0();
+ colObj1 = (btCollisionObject*)manifold->getBody1();
+
+ int solverBodyIdA = mbA? -1 : getOrInitSolverBody(*colObj0,infoGlobal.m_timeStep);
+ int solverBodyIdB = mbB ? -1 : getOrInitSolverBody(*colObj1,infoGlobal.m_timeStep);
+
+// btSolverBody* solverBodyA = mbA ? 0 : &m_tmpSolverBodyPool[solverBodyIdA];
+// btSolverBody* solverBodyB = mbB ? 0 : &m_tmpSolverBodyPool[solverBodyIdB];
+
+
+ ///avoid collision response between two static objects
+// if (!solverBodyA || (solverBodyA->m_invMass.isZero() && (!solverBodyB || solverBodyB->m_invMass.isZero())))
+ // return;
+
+ //only a single rollingFriction per manifold
+ int rollingFriction=1;
+
+ for (int j=0;j<manifold->getNumContacts();j++)
+ {
+
+ btManifoldPoint& cp = manifold->getContactPoint(j);
+
+ if (cp.getDistance() <= manifold->getContactProcessingThreshold())
+ {
+
+ btScalar relaxation;
+
+ int frictionIndex = m_multiBodyNormalContactConstraints.size();
+
+ btMultiBodySolverConstraint& solverConstraint = m_multiBodyNormalContactConstraints.expandNonInitializing();
+
+ // btRigidBody* rb0 = btRigidBody::upcast(colObj0);
+ // btRigidBody* rb1 = btRigidBody::upcast(colObj1);
+ solverConstraint.m_orgConstraint = 0;
+ solverConstraint.m_orgDofIndex = -1;
+ solverConstraint.m_solverBodyIdA = solverBodyIdA;
+ solverConstraint.m_solverBodyIdB = solverBodyIdB;
+ solverConstraint.m_multiBodyA = mbA;
+ if (mbA)
+ solverConstraint.m_linkA = fcA->m_link;
+
+ solverConstraint.m_multiBodyB = mbB;
+ if (mbB)
+ solverConstraint.m_linkB = fcB->m_link;
+
+ solverConstraint.m_originalContactPoint = &cp;
+
+ bool isFriction = false;
+ setupMultiBodyContactConstraint(solverConstraint, cp.m_normalWorldOnB,cp, infoGlobal, relaxation, isFriction);
+
+// const btVector3& pos1 = cp.getPositionWorldOnA();
+// const btVector3& pos2 = cp.getPositionWorldOnB();
+
+ /////setup the friction constraints
+#define ENABLE_FRICTION
+#ifdef ENABLE_FRICTION
+ solverConstraint.m_frictionIndex = frictionIndex;
+
+ ///Bullet has several options to set the friction directions
+ ///By default, each contact has only a single friction direction that is recomputed automatically every frame
+ ///based on the relative linear velocity.
+ ///If the relative velocity is zero, it will automatically compute a friction direction.
+
+ ///You can also enable two friction directions, using the SOLVER_USE_2_FRICTION_DIRECTIONS.
+ ///In that case, the second friction direction will be orthogonal to both contact normal and first friction direction.
+ ///
+ ///If you choose SOLVER_DISABLE_VELOCITY_DEPENDENT_FRICTION_DIRECTION, then the friction will be independent from the relative projected velocity.
+ ///
+ ///The user can manually override the friction directions for certain contacts using a contact callback,
+ ///and set the cp.m_lateralFrictionInitialized to true
+ ///In that case, you can set the target relative motion in each friction direction (cp.m_contactMotion1 and cp.m_contactMotion2)
+ ///this will give a conveyor belt effect
+ ///
+
+ btPlaneSpace1(cp.m_normalWorldOnB,cp.m_lateralFrictionDir1,cp.m_lateralFrictionDir2);
+ cp.m_lateralFrictionDir1.normalize();
+ cp.m_lateralFrictionDir2.normalize();
+
+ if (rollingFriction > 0 )
+ {
+ if (cp.m_combinedSpinningFriction>0)
+ {
+ addMultiBodyTorsionalFrictionConstraint(cp.m_normalWorldOnB,manifold,frictionIndex,cp,cp.m_combinedSpinningFriction, colObj0,colObj1, relaxation,infoGlobal);
+ }
+ if (cp.m_combinedRollingFriction>0)
+ {
+
+ applyAnisotropicFriction(colObj0,cp.m_lateralFrictionDir1,btCollisionObject::CF_ANISOTROPIC_ROLLING_FRICTION);
+ applyAnisotropicFriction(colObj1,cp.m_lateralFrictionDir1,btCollisionObject::CF_ANISOTROPIC_ROLLING_FRICTION);
+ applyAnisotropicFriction(colObj0,cp.m_lateralFrictionDir2,btCollisionObject::CF_ANISOTROPIC_ROLLING_FRICTION);
+ applyAnisotropicFriction(colObj1,cp.m_lateralFrictionDir2,btCollisionObject::CF_ANISOTROPIC_ROLLING_FRICTION);
+
+ if (cp.m_lateralFrictionDir1.length()>0.001)
+ addMultiBodyTorsionalFrictionConstraint(cp.m_lateralFrictionDir1,manifold,frictionIndex,cp,cp.m_combinedRollingFriction, colObj0,colObj1, relaxation,infoGlobal);
+
+ if (cp.m_lateralFrictionDir2.length()>0.001)
+ addMultiBodyTorsionalFrictionConstraint(cp.m_lateralFrictionDir2,manifold,frictionIndex,cp,cp.m_combinedRollingFriction, colObj0,colObj1, relaxation,infoGlobal);
+ }
+ rollingFriction--;
+ }
+ if (!(infoGlobal.m_solverMode & SOLVER_ENABLE_FRICTION_DIRECTION_CACHING) || !(cp.m_contactPointFlags&BT_CONTACT_FLAG_LATERAL_FRICTION_INITIALIZED))
+ {/*
+ cp.m_lateralFrictionDir1 = vel - cp.m_normalWorldOnB * rel_vel;
+ btScalar lat_rel_vel = cp.m_lateralFrictionDir1.length2();
+ if (!(infoGlobal.m_solverMode & SOLVER_DISABLE_VELOCITY_DEPENDENT_FRICTION_DIRECTION) && lat_rel_vel > SIMD_EPSILON)
+ {
+ cp.m_lateralFrictionDir1 *= 1.f/btSqrt(lat_rel_vel);
+ if((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
+ {
+ cp.m_lateralFrictionDir2 = cp.m_lateralFrictionDir1.cross(cp.m_normalWorldOnB);
+ cp.m_lateralFrictionDir2.normalize();//??
+ applyAnisotropicFriction(colObj0,cp.m_lateralFrictionDir2,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ applyAnisotropicFriction(colObj1,cp.m_lateralFrictionDir2,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ addMultiBodyFrictionConstraint(cp.m_lateralFrictionDir2,solverBodyIdA,solverBodyIdB,frictionIndex,cp,rel_pos1,rel_pos2,colObj0,colObj1, relaxation);
+
+ }
+
+ applyAnisotropicFriction(colObj0,cp.m_lateralFrictionDir1,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ applyAnisotropicFriction(colObj1,cp.m_lateralFrictionDir1,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ addMultiBodyFrictionConstraint(cp.m_lateralFrictionDir1,solverBodyIdA,solverBodyIdB,frictionIndex,cp,rel_pos1,rel_pos2,colObj0,colObj1, relaxation);
+
+ } else
+ */
+ {
+
+
+ applyAnisotropicFriction(colObj0,cp.m_lateralFrictionDir1,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ applyAnisotropicFriction(colObj1,cp.m_lateralFrictionDir1,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ addMultiBodyFrictionConstraint(cp.m_lateralFrictionDir1,manifold,frictionIndex,cp,colObj0,colObj1, relaxation,infoGlobal);
+
+
+ if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
+ {
+ applyAnisotropicFriction(colObj0,cp.m_lateralFrictionDir2,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ applyAnisotropicFriction(colObj1,cp.m_lateralFrictionDir2,btCollisionObject::CF_ANISOTROPIC_FRICTION);
+ addMultiBodyFrictionConstraint(cp.m_lateralFrictionDir2,manifold,frictionIndex,cp,colObj0,colObj1, relaxation,infoGlobal);
+ }
+
+ if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS) && (infoGlobal.m_solverMode & SOLVER_DISABLE_VELOCITY_DEPENDENT_FRICTION_DIRECTION))
+ {
+ cp.m_contactPointFlags|=BT_CONTACT_FLAG_LATERAL_FRICTION_INITIALIZED;
+ }
+ }
+
+ } else
+ {
+ addMultiBodyFrictionConstraint(cp.m_lateralFrictionDir1,manifold,frictionIndex,cp,colObj0,colObj1, relaxation,infoGlobal,cp.m_contactMotion1, cp.m_frictionCFM);
+
+ if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
+ addMultiBodyFrictionConstraint(cp.m_lateralFrictionDir2,manifold,frictionIndex,cp,colObj0,colObj1, relaxation, infoGlobal,cp.m_contactMotion2, cp.m_frictionCFM);
+
+ //setMultiBodyFrictionConstraintImpulse( solverConstraint, solverBodyIdA, solverBodyIdB, cp, infoGlobal);
+ //todo:
+ solverConstraint.m_appliedImpulse = 0.f;
+ solverConstraint.m_appliedPushImpulse = 0.f;
+ }
+
+
+#endif //ENABLE_FRICTION
+
+ }
+ }
+}
+
+void btMultiBodyConstraintSolver::convertContacts(btPersistentManifold** manifoldPtr,int numManifolds, const btContactSolverInfo& infoGlobal)
+{
+ //btPersistentManifold* manifold = 0;
+
+ for (int i=0;i<numManifolds;i++)
+ {
+ btPersistentManifold* manifold= manifoldPtr[i];
+ const btMultiBodyLinkCollider* fcA = btMultiBodyLinkCollider::upcast(manifold->getBody0());
+ const btMultiBodyLinkCollider* fcB = btMultiBodyLinkCollider::upcast(manifold->getBody1());
+ if (!fcA && !fcB)
+ {
+ //the contact doesn't involve any Featherstone btMultiBody, so deal with the regular btRigidBody/btCollisionObject case
+ convertContact(manifold,infoGlobal);
+ } else
+ {
+ convertMultiBodyContact(manifold,infoGlobal);
+ }
+ }
+
+ //also convert the multibody constraints, if any
+
+
+ for (int i=0;i<m_tmpNumMultiBodyConstraints;i++)
+ {
+ btMultiBodyConstraint* c = m_tmpMultiBodyConstraints[i];
+ m_data.m_solverBodyPool = &m_tmpSolverBodyPool;
+ m_data.m_fixedBodyId = m_fixedBodyId;
+
+ c->createConstraintRows(m_multiBodyNonContactConstraints,m_data, infoGlobal);
+ }
+
+}
+
+
+
+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);
+}
+
+#if 0
+static void applyJointFeedback(btMultiBodyJacobianData& data, const btMultiBodySolverConstraint& solverConstraint, int jacIndex, btMultiBody* mb, btScalar appliedImpulse)
+{
+ if (appliedImpulse!=0 && mb->internalNeedsJointFeedback())
+ {
+ //todo: get rid of those temporary memory allocations for the joint feedback
+ btAlignedObjectArray<btScalar> forceVector;
+ int numDofsPlusBase = 6+mb->getNumDofs();
+ forceVector.resize(numDofsPlusBase);
+ for (int i=0;i<numDofsPlusBase;i++)
+ {
+ forceVector[i] = data.m_jacobians[jacIndex+i]*appliedImpulse;
+ }
+ btAlignedObjectArray<btScalar> output;
+ output.resize(numDofsPlusBase);
+ bool applyJointFeedback = true;
+ mb->calcAccelerationDeltasMultiDof(&forceVector[0],&output[0],data.scratch_r,data.scratch_v,applyJointFeedback);
+ }
+}
+#endif
+
+
+void btMultiBodyConstraintSolver::writeBackSolverBodyToMultiBody(btMultiBodySolverConstraint& c, btScalar deltaTime)
+{
+#if 1
+
+ //bod->addBaseForce(m_gravity * bod->getBaseMass());
+ //bod->addLinkForce(j, m_gravity * bod->getLinkMass(j));
+
+ if (c.m_orgConstraint)
+ {
+ c.m_orgConstraint->internalSetAppliedImpulse(c.m_orgDofIndex,c.m_appliedImpulse);
+ }
+
+
+ if (c.m_multiBodyA)
+ {
+
+ c.m_multiBodyA->setCompanionId(-1);
+ btVector3 force = c.m_contactNormal1*(c.m_appliedImpulse/deltaTime);
+ btVector3 torque = c.m_relpos1CrossNormal*(c.m_appliedImpulse/deltaTime);
+ if (c.m_linkA<0)
+ {
+ c.m_multiBodyA->addBaseConstraintForce(force);
+ c.m_multiBodyA->addBaseConstraintTorque(torque);
+ } else
+ {
+ c.m_multiBodyA->addLinkConstraintForce(c.m_linkA,force);
+ //b3Printf("force = %f,%f,%f\n",force[0],force[1],force[2]);//[0],torque[1],torque[2]);
+ c.m_multiBodyA->addLinkConstraintTorque(c.m_linkA,torque);
+ }
+ }
+
+ if (c.m_multiBodyB)
+ {
+ {
+ c.m_multiBodyB->setCompanionId(-1);
+ btVector3 force = c.m_contactNormal2*(c.m_appliedImpulse/deltaTime);
+ btVector3 torque = c.m_relpos2CrossNormal*(c.m_appliedImpulse/deltaTime);
+ if (c.m_linkB<0)
+ {
+ c.m_multiBodyB->addBaseConstraintForce(force);
+ c.m_multiBodyB->addBaseConstraintTorque(torque);
+ } else
+ {
+ {
+ c.m_multiBodyB->addLinkConstraintForce(c.m_linkB,force);
+ //b3Printf("t = %f,%f,%f\n",force[0],force[1],force[2]);//[0],torque[1],torque[2]);
+ c.m_multiBodyB->addLinkConstraintTorque(c.m_linkB,torque);
+ }
+
+ }
+ }
+ }
+#endif
+
+#ifndef DIRECTLY_UPDATE_VELOCITY_DURING_SOLVER_ITERATIONS
+
+ if (c.m_multiBodyA)
+ {
+
+ if(c.m_multiBodyA->isMultiDof())
+ {
+ c.m_multiBodyA->applyDeltaVeeMultiDof(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacAindex],c.m_appliedImpulse);
+ }
+ else
+ {
+ c.m_multiBodyA->applyDeltaVee(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacAindex],c.m_appliedImpulse);
+ }
+ }
+
+ if (c.m_multiBodyB)
+ {
+ if(c.m_multiBodyB->isMultiDof())
+ {
+ c.m_multiBodyB->applyDeltaVeeMultiDof(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacBindex],c.m_appliedImpulse);
+ }
+ else
+ {
+ c.m_multiBodyB->applyDeltaVee(&m_data.m_deltaVelocitiesUnitImpulse[c.m_jacBindex],c.m_appliedImpulse);
+ }
+ }
+#endif
+
+
+
+}
+
+btScalar btMultiBodyConstraintSolver::solveGroupCacheFriendlyFinish(btCollisionObject** bodies,int numBodies,const btContactSolverInfo& infoGlobal)
+{
+ BT_PROFILE("btMultiBodyConstraintSolver::solveGroupCacheFriendlyFinish");
+ int numPoolConstraints = m_multiBodyNormalContactConstraints.size();
+
+
+ //write back the delta v to the multi bodies, either as applied impulse (direct velocity change)
+ //or as applied force, so we can measure the joint reaction forces easier
+ for (int i=0;i<numPoolConstraints;i++)
+ {
+ btMultiBodySolverConstraint& solverConstraint = m_multiBodyNormalContactConstraints[i];
+ writeBackSolverBodyToMultiBody(solverConstraint,infoGlobal.m_timeStep);
+
+ writeBackSolverBodyToMultiBody(m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex],infoGlobal.m_timeStep);
+
+ if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
+ {
+ writeBackSolverBodyToMultiBody(m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1],infoGlobal.m_timeStep);
+ }
+ }
+
+
+ for (int i=0;i<m_multiBodyNonContactConstraints.size();i++)
+ {
+ btMultiBodySolverConstraint& solverConstraint = m_multiBodyNonContactConstraints[i];
+ writeBackSolverBodyToMultiBody(solverConstraint,infoGlobal.m_timeStep);
+ }
+
+
+ if (infoGlobal.m_solverMode & SOLVER_USE_WARMSTARTING)
+ {
+ BT_PROFILE("warm starting write back");
+ for (int j=0;j<numPoolConstraints;j++)
+ {
+ const btMultiBodySolverConstraint& solverConstraint = m_multiBodyNormalContactConstraints[j];
+ btManifoldPoint* pt = (btManifoldPoint*) solverConstraint.m_originalContactPoint;
+ btAssert(pt);
+ pt->m_appliedImpulse = solverConstraint.m_appliedImpulse;
+ pt->m_appliedImpulseLateral1 = m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_appliedImpulse;
+
+ //printf("pt->m_appliedImpulseLateral1 = %f\n", pt->m_appliedImpulseLateral1);
+ if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
+ {
+ pt->m_appliedImpulseLateral2 = m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_appliedImpulse;
+ }
+ //do a callback here?
+ }
+ }
+#if 0
+ //multibody joint feedback
+ {
+ BT_PROFILE("multi body joint feedback");
+ for (int j=0;j<numPoolConstraints;j++)
+ {
+ const btMultiBodySolverConstraint& solverConstraint = m_multiBodyNormalContactConstraints[j];
+
+ //apply the joint feedback into all links of the btMultiBody
+ //todo: double-check the signs of the applied impulse
+
+ if(solverConstraint.m_multiBodyA && solverConstraint.m_multiBodyA->isMultiDof())
+ {
+ applyJointFeedback(m_data,solverConstraint, solverConstraint.m_jacAindex,solverConstraint.m_multiBodyA, solverConstraint.m_appliedImpulse*btSimdScalar(1./infoGlobal.m_timeStep));
+ }
+ if(solverConstraint.m_multiBodyB && solverConstraint.m_multiBodyB->isMultiDof())
+ {
+ applyJointFeedback(m_data,solverConstraint, solverConstraint.m_jacBindex,solverConstraint.m_multiBodyB,solverConstraint.m_appliedImpulse*btSimdScalar(-1./infoGlobal.m_timeStep));
+ }
+#if 0
+ if (m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_multiBodyA && m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_multiBodyA->isMultiDof())
+ {
+ applyJointFeedback(m_data,m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex],
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_jacAindex,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_multiBodyA,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_appliedImpulse*btSimdScalar(1./infoGlobal.m_timeStep));
+
+ }
+ if (m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_multiBodyB && m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_multiBodyB->isMultiDof())
+ {
+ applyJointFeedback(m_data,m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex],
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_jacBindex,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_multiBodyB,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex].m_appliedImpulse*btSimdScalar(-1./infoGlobal.m_timeStep));
+ }
+
+ if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
+ {
+ if (m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_multiBodyA && m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_multiBodyA->isMultiDof())
+ {
+ applyJointFeedback(m_data,m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1],
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_jacAindex,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_multiBodyA,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_appliedImpulse*btSimdScalar(1./infoGlobal.m_timeStep));
+ }
+
+ if (m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_multiBodyB && m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_multiBodyB->isMultiDof())
+ {
+ applyJointFeedback(m_data,m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1],
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_jacBindex,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_multiBodyB,
+ m_multiBodyFrictionContactConstraints[solverConstraint.m_frictionIndex+1].m_appliedImpulse*btSimdScalar(-1./infoGlobal.m_timeStep));
+ }
+ }
+#endif
+ }
+
+ for (int i=0;i<m_multiBodyNonContactConstraints.size();i++)
+ {
+ const btMultiBodySolverConstraint& solverConstraint = m_multiBodyNonContactConstraints[i];
+ if(solverConstraint.m_multiBodyA && solverConstraint.m_multiBodyA->isMultiDof())
+ {
+ applyJointFeedback(m_data,solverConstraint, solverConstraint.m_jacAindex,solverConstraint.m_multiBodyA, solverConstraint.m_appliedImpulse*btSimdScalar(1./infoGlobal.m_timeStep));
+ }
+ if(solverConstraint.m_multiBodyB && solverConstraint.m_multiBodyB->isMultiDof())
+ {
+ applyJointFeedback(m_data,solverConstraint, solverConstraint.m_jacBindex,solverConstraint.m_multiBodyB,solverConstraint.m_appliedImpulse*btSimdScalar(1./infoGlobal.m_timeStep));
+ }
+ }
+ }
+
+ numPoolConstraints = m_multiBodyNonContactConstraints.size();
+
+#if 0
+ //@todo: m_originalContactPoint is not initialized for btMultiBodySolverConstraint
+ for (int i=0;i<numPoolConstraints;i++)
+ {
+ const btMultiBodySolverConstraint& c = m_multiBodyNonContactConstraints[i];
+
+ btTypedConstraint* constr = (btTypedConstraint*)c.m_originalContactPoint;
+ btJointFeedback* fb = constr->getJointFeedback();
+ if (fb)
+ {
+ fb->m_appliedForceBodyA += c.m_contactNormal1*c.m_appliedImpulse*constr->getRigidBodyA().getLinearFactor()/infoGlobal.m_timeStep;
+ fb->m_appliedForceBodyB += c.m_contactNormal2*c.m_appliedImpulse*constr->getRigidBodyB().getLinearFactor()/infoGlobal.m_timeStep;
+ fb->m_appliedTorqueBodyA += c.m_relpos1CrossNormal* constr->getRigidBodyA().getAngularFactor()*c.m_appliedImpulse/infoGlobal.m_timeStep;
+ fb->m_appliedTorqueBodyB += c.m_relpos2CrossNormal* constr->getRigidBodyB().getAngularFactor()*c.m_appliedImpulse/infoGlobal.m_timeStep; /*RGM ???? */
+
+ }
+
+ constr->internalSetAppliedImpulse(c.m_appliedImpulse);
+ if (btFabs(c.m_appliedImpulse)>=constr->getBreakingImpulseThreshold())
+ {
+ constr->setEnabled(false);
+ }
+
+ }
+#endif
+#endif
+
+ return btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyFinish(bodies,numBodies,infoGlobal);
+}
+
+
+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)
+{
+ //printf("solveMultiBodyGroup start\n");
+ m_tmpMultiBodyConstraints = multiBodyConstraints;
+ m_tmpNumMultiBodyConstraints = numMultiBodyConstraints;
+
+ btSequentialImpulseConstraintSolver::solveGroup(bodies,numBodies,manifold,numManifolds,constraints,numConstraints,info,debugDrawer,dispatcher);
+
+ m_tmpMultiBodyConstraints = 0;
+ m_tmpNumMultiBodyConstraints = 0;
+
+
+}