mirror of https://github.com/axmolengine/axmol.git
390 lines
12 KiB
C++
390 lines
12 KiB
C++
#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, int type)
|
|
: m_bodyA(bodyA),
|
|
m_bodyB(bodyB),
|
|
m_linkA(linkA),
|
|
m_linkB(linkB),
|
|
m_type(type),
|
|
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,
|
|
btScalar damping)
|
|
{
|
|
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 = constraintNormalAng.dot(solverConstraint.m_angularComponentA);
|
|
}
|
|
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 = constraintNormalAng.dot(-solverConstraint.m_angularComponentB);
|
|
}
|
|
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->getLinearVelocity().dot(solverConstraint.m_contactNormal1);
|
|
rel_vel += rb0->getAngularVelocity().dot(solverConstraint.m_relpos1CrossNormal);
|
|
}
|
|
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->getLinearVelocity().dot(solverConstraint.m_contactNormal2);
|
|
rel_vel += rb1->getAngularVelocity().dot(solverConstraint.m_relpos2CrossNormal);
|
|
}
|
|
|
|
solverConstraint.m_friction = 0.f; //cp.m_combinedFriction;
|
|
}
|
|
|
|
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;
|
|
}
|