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Diffstat (limited to 'thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyJointLimitConstraint.cpp')
| -rw-r--r-- | thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyJointLimitConstraint.cpp | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyJointLimitConstraint.cpp b/thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyJointLimitConstraint.cpp new file mode 100644 index 0000000000..6d173b66a1 --- /dev/null +++ b/thirdparty/bullet/BulletDynamics/Featherstone/btMultiBodyJointLimitConstraint.cpp @@ -0,0 +1,205 @@ +/* +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. +*/ + +///This file was written by Erwin Coumans + +#include "btMultiBodyJointLimitConstraint.h" +#include "btMultiBody.h" +#include "btMultiBodyLinkCollider.h" +#include "BulletCollision/CollisionDispatch/btCollisionObject.h" + + + +btMultiBodyJointLimitConstraint::btMultiBodyJointLimitConstraint(btMultiBody* body, int link, btScalar lower, btScalar upper) + //:btMultiBodyConstraint(body,0,link,-1,2,true), + :btMultiBodyConstraint(body,body,link,body->getLink(link).m_parent,2,true), + m_lowerBound(lower), + m_upperBound(upper) +{ + +} + +void btMultiBodyJointLimitConstraint::finalizeMultiDof() +{ + // the data.m_jacobians never change, so may as well + // initialize them here + + allocateJacobiansMultiDof(); + + unsigned int offset = 6 + m_bodyA->getLink(m_linkA).m_dofOffset; + + // row 0: the lower bound + jacobianA(0)[offset] = 1; + // row 1: the upper bound + //jacobianA(1)[offset] = -1; + jacobianB(1)[offset] = -1; + + m_numDofsFinalized = m_jacSizeBoth; +} + +btMultiBodyJointLimitConstraint::~btMultiBodyJointLimitConstraint() +{ +} + +int btMultiBodyJointLimitConstraint::getIslandIdA() const +{ + if(m_bodyA) + { + btMultiBodyLinkCollider* col = m_bodyA->getBaseCollider(); + if (col) + return col->getIslandTag(); + for (int i=0;i<m_bodyA->getNumLinks();i++) + { + if (m_bodyA->getLink(i).m_collider) + return m_bodyA->getLink(i).m_collider->getIslandTag(); + } + } + return -1; +} + +int btMultiBodyJointLimitConstraint::getIslandIdB() const +{ + if(m_bodyB) + { + btMultiBodyLinkCollider* col = m_bodyB->getBaseCollider(); + if (col) + return col->getIslandTag(); + + for (int i=0;i<m_bodyB->getNumLinks();i++) + { + col = m_bodyB->getLink(i).m_collider; + if (col) + return col->getIslandTag(); + } + } + return -1; +} + + +void btMultiBodyJointLimitConstraint::createConstraintRows(btMultiBodyConstraintArray& constraintRows, + btMultiBodyJacobianData& data, + const btContactSolverInfo& infoGlobal) +{ + + // only positions need to be updated -- data.m_jacobians and force + // directions were set in the ctor and never change. + + if (m_numDofsFinalized != m_jacSizeBoth) + { + finalizeMultiDof(); + } + + + // row 0: the lower bound + setPosition(0, m_bodyA->getJointPos(m_linkA) - m_lowerBound); //multidof: this is joint-type dependent + + // row 1: the upper bound + setPosition(1, m_upperBound - m_bodyA->getJointPos(m_linkA)); + + for (int row=0;row<getNumRows();row++) + { + btScalar penetration = getPosition(row); + + //todo: consider adding some safety threshold here + if (penetration>0) + { + continue; + } + btScalar direction = row? -1 : 1; + + btMultiBodySolverConstraint& constraintRow = constraintRows.expandNonInitializing(); + constraintRow.m_orgConstraint = this; + constraintRow.m_orgDofIndex = row; + + constraintRow.m_multiBodyA = m_bodyA; + constraintRow.m_multiBodyB = m_bodyB; + const btScalar posError = 0; //why assume it's zero? + const btVector3 dummy(0, 0, 0); + + btScalar rel_vel = fillMultiBodyConstraint(constraintRow,data,jacobianA(row),jacobianB(row),dummy,dummy,dummy,dummy,posError,infoGlobal,0,m_maxAppliedImpulse); + + { + //expect either prismatic or revolute joint type for now + btAssert((m_bodyA->getLink(m_linkA).m_jointType == btMultibodyLink::eRevolute)||(m_bodyA->getLink(m_linkA).m_jointType == btMultibodyLink::ePrismatic)); + switch (m_bodyA->getLink(m_linkA).m_jointType) + { + case btMultibodyLink::eRevolute: + { + constraintRow.m_contactNormal1.setZero(); + constraintRow.m_contactNormal2.setZero(); + btVector3 revoluteAxisInWorld = direction*quatRotate(m_bodyA->getLink(m_linkA).m_cachedWorldTransform.getRotation(),m_bodyA->getLink(m_linkA).m_axes[0].m_topVec); + constraintRow.m_relpos1CrossNormal=revoluteAxisInWorld; + constraintRow.m_relpos2CrossNormal=-revoluteAxisInWorld; + + break; + } + case btMultibodyLink::ePrismatic: + { + btVector3 prismaticAxisInWorld = direction* quatRotate(m_bodyA->getLink(m_linkA).m_cachedWorldTransform.getRotation(),m_bodyA->getLink(m_linkA).m_axes[0].m_bottomVec); + constraintRow.m_contactNormal1=prismaticAxisInWorld; + constraintRow.m_contactNormal2=-prismaticAxisInWorld; + constraintRow.m_relpos1CrossNormal.setZero(); + constraintRow.m_relpos2CrossNormal.setZero(); + + break; + } + default: + { + btAssert(0); + } + }; + + } + + { + + btScalar positionalError = 0.f; + btScalar velocityError = - rel_vel;// * damping; + btScalar erp = infoGlobal.m_erp2; + if (!infoGlobal.m_splitImpulse || (penetration > infoGlobal.m_splitImpulsePenetrationThreshold)) + { + erp = infoGlobal.m_erp; + } + if (penetration>0) + { + positionalError = 0; + velocityError = -penetration / infoGlobal.m_timeStep; + } else + { + positionalError = -penetration * erp/infoGlobal.m_timeStep; + } + + btScalar penetrationImpulse = positionalError*constraintRow.m_jacDiagABInv; + btScalar velocityImpulse = velocityError *constraintRow.m_jacDiagABInv; + if (!infoGlobal.m_splitImpulse || (penetration > infoGlobal.m_splitImpulsePenetrationThreshold)) + { + //combine position and velocity into rhs + constraintRow.m_rhs = penetrationImpulse+velocityImpulse; + constraintRow.m_rhsPenetration = 0.f; + + } else + { + //split position and velocity into rhs and m_rhsPenetration + constraintRow.m_rhs = velocityImpulse; + constraintRow.m_rhsPenetration = penetrationImpulse; + } + } + } + +} + + + + |