#include "btMultiBodyConstraint.h"
#include "BulletDynamics/Dynamics/btRigidBody.h"
#include "btMultiBodyPoint2Point.h" //for testing (BTMBP2PCONSTRAINT_BLOCK_ANGULAR_MOTION_TEST macro)
btMultiBodyConstraint::btMultiBodyConstraint(btMultiBody* bodyA,btMultiBody* bodyB,int linkA, int linkB, int numRows, bool isUnilateral)
:m_bodyA(bodyA),
m_bodyB(bodyB),
m_linkA(linkA),
m_linkB(linkB),
m_numRows(numRows),
m_jacSizeA(0),
m_jacSizeBoth(0),
m_isUnilateral(isUnilateral),
m_numDofsFinalized(-1),
m_maxAppliedImpulse(100)
{
}
void btMultiBodyConstraint::updateJacobianSizes()
{
if(m_bodyA)
{
m_jacSizeA = (6 + m_bodyA->getNumDofs());
}
if(m_bodyB)
{
m_jacSizeBoth = m_jacSizeA + 6 + m_bodyB->getNumDofs();
}
else
m_jacSizeBoth = m_jacSizeA;
}
void btMultiBodyConstraint::allocateJacobiansMultiDof()
{
updateJacobianSizes();
m_posOffset = ((1 + m_jacSizeBoth)*m_numRows);
m_data.resize((2 + m_jacSizeBoth) * m_numRows);
}
btMultiBodyConstraint::~btMultiBodyConstraint()
{
}
void btMultiBodyConstraint::applyDeltaVee(btMultiBodyJacobianData& data, btScalar* delta_vee, btScalar impulse, int velocityIndex, int ndof)
{
for (int i = 0; i < ndof; ++i)
data.m_deltaVelocities[velocityIndex+i] += delta_vee[i] * impulse;
}
btScalar btMultiBodyConstraint::fillMultiBodyConstraint( btMultiBodySolverConstraint& solverConstraint,
btMultiBodyJacobianData& data,
btScalar* jacOrgA, btScalar* jacOrgB,
const btVector3& constraintNormalAng,
const btVector3& constraintNormalLin,
const btVector3& posAworld, const btVector3& posBworld,
btScalar posError,
const btContactSolverInfo& infoGlobal,
btScalar lowerLimit, btScalar upperLimit,
bool angConstraint,
btScalar relaxation,
bool isFriction, btScalar desiredVelocity, btScalar cfmSlip)
{
solverConstraint.m_multiBodyA = m_bodyA;
solverConstraint.m_multiBodyB = m_bodyB;
solverConstraint.m_linkA = m_linkA;
solverConstraint.m_linkB = m_linkB;
btMultiBody* multiBodyA = solverConstraint.m_multiBodyA;
btMultiBody* multiBodyB = solverConstraint.m_multiBodyB;
btSolverBody* bodyA = multiBodyA ? 0 : &data.m_solverBodyPool->at(solverConstraint.m_solverBodyIdA);
btSolverBody* bodyB = multiBodyB ? 0 : &data.m_solverBodyPool->at(solverConstraint.m_solverBodyIdB);
btRigidBody* rb0 = multiBodyA ? 0 : bodyA->m_originalBody;
btRigidBody* rb1 = multiBodyB ? 0 : bodyB->m_originalBody;
btVector3 rel_pos1, rel_pos2; //these two used to be inited to posAworld and posBworld (respectively) but it does not seem necessary
if (bodyA)
rel_pos1 = posAworld - bodyA->getWorldTransform().getOrigin();
if (bodyB)
rel_pos2 = posBworld - bodyB->getWorldTransform().getOrigin();
if (multiBodyA)
{
if (solverConstraint.m_linkA<0)
{
rel_pos1 = posAworld - multiBodyA->getBasePos();
} else
{
rel_pos1 = posAworld - 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 = data.m_deltaVelocities.size();
multiBodyA->setCompanionId(solverConstraint.m_deltaVelAindex);
data.m_deltaVelocities.resize(data.m_deltaVelocities.size()+ndofA);
} else
{
btAssert(data.m_deltaVelocities.size() >= solverConstraint.m_deltaVelAindex+ndofA);
}
//determine jacobian of this 1D constraint in terms of multibodyA's degrees of freedom
//resize..
solverConstraint.m_jacAindex = data.m_jacobians.size();
data.m_jacobians.resize(data.m_jacobians.size()+ndofA);
//copy/determine
if(jacOrgA)
{
for (int i=0;i<ndofA;i++)
data.m_jacobians[solverConstraint.m_jacAindex+i] = jacOrgA[i];
}
else
{
btScalar* jac1=&data.m_jacobians[solverConstraint.m_jacAindex];
//multiBodyA->fillContactJacobianMultiDof(solverConstraint.m_linkA, posAworld, constraintNormalLin, jac1, data.scratch_r, data.scratch_v, data.scratch_m);
multiBodyA->fillConstraintJacobianMultiDof(solverConstraint.m_linkA, posAworld, constraintNormalAng, constraintNormalLin, jac1, data.scratch_r, data.scratch_v, data.scratch_m);
}
//determine the velocity response of multibodyA to reaction impulses of this constraint (i.e. A[i,i] for i=1,...n_con: multibody's inverse inertia with respect to this 1D constraint)
//resize..
data.m_deltaVelocitiesUnitImpulse.resize(data.m_deltaVelocitiesUnitImpulse.size()+ndofA); //=> each constraint row has the constrained tree dofs allocated in m_deltaVelocitiesUnitImpulse
btAssert(data.m_jacobians.size() == data.m_deltaVelocitiesUnitImpulse.size());
btScalar* delta = &data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
//determine..
multiBodyA->calcAccelerationDeltasMultiDof(&data.m_jacobians[solverConstraint.m_jacAindex],delta,data.scratch_r, data.scratch_v);
btVector3 torqueAxis0;
if (angConstraint) {
torqueAxis0 = constraintNormalAng;
}
else {
torqueAxis0 = rel_pos1.cross(constraintNormalLin);
}
solverConstraint.m_relpos1CrossNormal = torqueAxis0;
solverConstraint.m_contactNormal1 = constraintNormalLin;
}
else //if(rb0)
{
btVector3 torqueAxis0;
if (angConstraint) {
torqueAxis0 = constraintNormalAng;
}
else {
torqueAxis0 = rel_pos1.cross(constraintNormalLin);
}
solverConstraint.m_angularComponentA = rb0 ? rb0->getInvInertiaTensorWorld()*torqueAxis0*rb0->getAngularFactor() : btVector3(0,0,0);
solverConstraint.m_relpos1CrossNormal = torqueAxis0;
solverConstraint.m_contactNormal1 = constraintNormalLin;
}
if (multiBodyB)
{
if (solverConstraint.m_linkB<0)
{
rel_pos2 = posBworld - multiBodyB->getBasePos();
} else
{
rel_pos2 = posBworld - 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 = data.m_deltaVelocities.size();
multiBodyB->setCompanionId(solverConstraint.m_deltaVelBindex);
data.m_deltaVelocities.resize(data.m_deltaVelocities.size()+ndofB);
}
//determine jacobian of this 1D constraint in terms of multibodyB's degrees of freedom
//resize..
solverConstraint.m_jacBindex = data.m_jacobians.size();
data.m_jacobians.resize(data.m_jacobians.size()+ndofB);
//copy/determine..
if(jacOrgB)
{
for (int i=0;i<ndofB;i++)
data.m_jacobians[solverConstraint.m_jacBindex+i] = jacOrgB[i];
}
else
{
//multiBodyB->fillContactJacobianMultiDof(solverConstraint.m_linkB, posBworld, -constraintNormalLin, &data.m_jacobians[solverConstraint.m_jacBindex], data.scratch_r, data.scratch_v, data.scratch_m);
multiBodyB->fillConstraintJacobianMultiDof(solverConstraint.m_linkB, posBworld, -constraintNormalAng, -constraintNormalLin, &data.m_jacobians[solverConstraint.m_jacBindex], data.scratch_r, data.scratch_v, data.scratch_m);
}
//determine velocity response of multibodyB to reaction impulses of this constraint (i.e. A[i,i] for i=1,...n_con: multibody's inverse inertia with respect to this 1D constraint)
//resize..
data.m_deltaVelocitiesUnitImpulse.resize(data.m_deltaVelocitiesUnitImpulse.size()+ndofB);
btAssert(data.m_jacobians.size() == data.m_deltaVelocitiesUnitImpulse.size());
btScalar* delta = &data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
//determine..
multiBodyB->calcAccelerationDeltasMultiDof(&data.m_jacobians[solverConstraint.m_jacBindex],delta,data.scratch_r, data.scratch_v);
btVector3 torqueAxis1;
if (angConstraint) {
torqueAxis1 = constraintNormalAng;
}
else {
torqueAxis1 = rel_pos2.cross(constraintNormalLin);
}
solverConstraint.m_relpos2CrossNormal = -torqueAxis1;
solverConstraint.m_contactNormal2 = -constraintNormalLin;
}
else //if(rb1)
{
btVector3 torqueAxis1;
if (angConstraint) {
torqueAxis1 = constraintNormalAng;
}
else {
torqueAxis1 = rel_pos2.cross(constraintNormalLin);
}
solverConstraint.m_angularComponentB = rb1 ? rb1->getInvInertiaTensorWorld()*-torqueAxis1*rb1->getAngularFactor() : btVector3(0,0,0);
solverConstraint.m_relpos2CrossNormal = -torqueAxis1;
solverConstraint.m_contactNormal2 = -constraintNormalLin;
}
{
btVector3 vec;
btScalar denom0 = 0.f;
btScalar denom1 = 0.f;
btScalar* jacB = 0;
btScalar* jacA = 0;
btScalar* deltaVelA = 0;
btScalar* deltaVelB = 0;
int ndofA = 0;
//determine the "effective mass" of the constrained multibodyA with respect to this 1D constraint (i.e. 1/A[i,i])
if (multiBodyA)
{
ndofA = multiBodyA->getNumDofs() + 6;
jacA = &data.m_jacobians[solverConstraint.m_jacAindex];
deltaVelA = &data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
for (int i = 0; i < ndofA; ++i)
{
btScalar j = jacA[i] ;
btScalar l = deltaVelA[i];
denom0 += j*l;
}
}
else if(rb0)
{
vec = ( solverConstraint.m_angularComponentA).cross(rel_pos1);
if (angConstraint) {
denom0 = rb0->getInvMass() + constraintNormalAng.dot(vec);
}
else {
denom0 = rb0->getInvMass() + constraintNormalLin.dot(vec);
}
}
//
if (multiBodyB)
{
const int ndofB = multiBodyB->getNumDofs() + 6;
jacB = &data.m_jacobians[solverConstraint.m_jacBindex];
deltaVelB = &data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
for (int i = 0; i < ndofB; ++i)
{
btScalar j = jacB[i] ;
btScalar l = deltaVelB[i];
denom1 += j*l;
}
}
else if(rb1)
{
vec = ( -solverConstraint.m_angularComponentB).cross(rel_pos2);
if (angConstraint) {
denom1 = rb1->getInvMass() + constraintNormalAng.dot(vec);
}
else {
denom1 = rb1->getInvMass() + constraintNormalLin.dot(vec);
}
}
//
btScalar d = denom0+denom1;
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 penetration = isFriction? 0 : posError;
btScalar rel_vel = 0.f;
int ndofA = 0;
int ndofB = 0;
{
btVector3 vel1,vel2;
if (multiBodyA)
{
ndofA = multiBodyA->getNumDofs() + 6;
btScalar* jacA = &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).dot(solverConstraint.m_contactNormal1);
}
if (multiBodyB)
{
ndofB = multiBodyB->getNumDofs() + 6;
btScalar* jacB = &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).dot(solverConstraint.m_contactNormal2);
}
solverConstraint.m_friction = 0.f;//cp.m_combinedFriction;
}
///warm starting (or zero if disabled)
/*
if (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 = &data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacAindex];
multiBodyA->applyDeltaVee(deltaV,impulse);
applyDeltaVee(data,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 = &data.m_deltaVelocitiesUnitImpulse[solverConstraint.m_jacBindex];
multiBodyB->applyDeltaVee(deltaV,impulse);
applyDeltaVee(data,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 = desiredVelocity - rel_vel;// * damping;
btScalar erp = infoGlobal.m_erp2;
//split impulse is not implemented yet for btMultiBody*
//if (!infoGlobal.m_splitImpulse || (penetration > infoGlobal.m_splitImpulsePenetrationThreshold))
{
erp = infoGlobal.m_erp;
}
positionalError = -penetration * erp/infoGlobal.m_timeStep;
btScalar penetrationImpulse = positionalError*solverConstraint.m_jacDiagABInv;
btScalar velocityImpulse = velocityError *solverConstraint.m_jacDiagABInv;
//split impulse is not implemented yet for btMultiBody*
// 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_cfm = 0.f;
solverConstraint.m_lowerLimit = lowerLimit;
solverConstraint.m_upperLimit = upperLimit;
}
return rel_vel;
}