| /* |
| Bullet Continuous Collision Detection and Physics Library |
| Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ |
| |
| 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 "BulletDynamics/ConstraintSolver/btPoint2PointConstraint.h" |
| #include "BulletDynamics/Dynamics/btRigidBody.h" |
| #include <new> |
| |
| |
| |
| btPoint2PointConstraint::btPoint2PointConstraint() |
| :btTypedConstraint(POINT2POINT_CONSTRAINT_TYPE), |
| m_useSolveConstraintObsolete(false) |
| { |
| } |
| |
| btPoint2PointConstraint::btPoint2PointConstraint(btRigidBody& rbA,btRigidBody& rbB, const btVector3& pivotInA,const btVector3& pivotInB) |
| :btTypedConstraint(POINT2POINT_CONSTRAINT_TYPE,rbA,rbB),m_pivotInA(pivotInA),m_pivotInB(pivotInB), |
| m_useSolveConstraintObsolete(false) |
| { |
| |
| } |
| |
| |
| btPoint2PointConstraint::btPoint2PointConstraint(btRigidBody& rbA,const btVector3& pivotInA) |
| :btTypedConstraint(POINT2POINT_CONSTRAINT_TYPE,rbA),m_pivotInA(pivotInA),m_pivotInB(rbA.getCenterOfMassTransform()(pivotInA)), |
| m_useSolveConstraintObsolete(false) |
| { |
| |
| } |
| |
| void btPoint2PointConstraint::buildJacobian() |
| { |
| |
| ///we need it for both methods |
| { |
| m_appliedImpulse = btScalar(0.); |
| |
| btVector3 normal(0,0,0); |
| |
| for (int i=0;i<3;i++) |
| { |
| normal[i] = 1; |
| new (&m_jac[i]) btJacobianEntry( |
| m_rbA.getCenterOfMassTransform().getBasis().transpose(), |
| m_rbB.getCenterOfMassTransform().getBasis().transpose(), |
| m_rbA.getCenterOfMassTransform()*m_pivotInA - m_rbA.getCenterOfMassPosition(), |
| m_rbB.getCenterOfMassTransform()*m_pivotInB - m_rbB.getCenterOfMassPosition(), |
| normal, |
| m_rbA.getInvInertiaDiagLocal(), |
| m_rbA.getInvMass(), |
| m_rbB.getInvInertiaDiagLocal(), |
| m_rbB.getInvMass()); |
| normal[i] = 0; |
| } |
| } |
| |
| |
| } |
| |
| void btPoint2PointConstraint::getInfo1 (btConstraintInfo1* info) |
| { |
| getInfo1NonVirtual(info); |
| } |
| |
| void btPoint2PointConstraint::getInfo1NonVirtual (btConstraintInfo1* info) |
| { |
| if (m_useSolveConstraintObsolete) |
| { |
| info->m_numConstraintRows = 0; |
| info->nub = 0; |
| } else |
| { |
| info->m_numConstraintRows = 3; |
| info->nub = 3; |
| } |
| } |
| |
| |
| |
| |
| void btPoint2PointConstraint::getInfo2 (btConstraintInfo2* info) |
| { |
| getInfo2NonVirtual(info, m_rbA.getCenterOfMassTransform(),m_rbB.getCenterOfMassTransform()); |
| } |
| |
| void btPoint2PointConstraint::getInfo2NonVirtual (btConstraintInfo2* info, const btTransform& body0_trans, const btTransform& body1_trans) |
| { |
| btAssert(!m_useSolveConstraintObsolete); |
| |
| //retrieve matrices |
| |
| // anchor points in global coordinates with respect to body PORs. |
| |
| // set jacobian |
| info->m_J1linearAxis[0] = 1; |
| info->m_J1linearAxis[info->rowskip+1] = 1; |
| info->m_J1linearAxis[2*info->rowskip+2] = 1; |
| |
| btVector3 a1 = body0_trans.getBasis()*getPivotInA(); |
| { |
| btVector3* angular0 = (btVector3*)(info->m_J1angularAxis); |
| btVector3* angular1 = (btVector3*)(info->m_J1angularAxis+info->rowskip); |
| btVector3* angular2 = (btVector3*)(info->m_J1angularAxis+2*info->rowskip); |
| btVector3 a1neg = -a1; |
| a1neg.getSkewSymmetricMatrix(angular0,angular1,angular2); |
| } |
| |
| /*info->m_J2linearAxis[0] = -1; |
| info->m_J2linearAxis[s+1] = -1; |
| info->m_J2linearAxis[2*s+2] = -1; |
| */ |
| |
| btVector3 a2 = body1_trans.getBasis()*getPivotInB(); |
| |
| { |
| btVector3 a2n = -a2; |
| btVector3* angular0 = (btVector3*)(info->m_J2angularAxis); |
| btVector3* angular1 = (btVector3*)(info->m_J2angularAxis+info->rowskip); |
| btVector3* angular2 = (btVector3*)(info->m_J2angularAxis+2*info->rowskip); |
| a2.getSkewSymmetricMatrix(angular0,angular1,angular2); |
| } |
| |
| |
| |
| // set right hand side |
| btScalar k = info->fps * info->erp; |
| int j; |
| |
| for (j=0; j<3; j++) |
| { |
| info->m_constraintError[j*info->rowskip] = k * (a2[j] + body1_trans.getOrigin()[j] - a1[j] - body0_trans.getOrigin()[j]); |
| //printf("info->m_constraintError[%d]=%f\n",j,info->m_constraintError[j]); |
| } |
| |
| btScalar impulseClamp = m_setting.m_impulseClamp;// |
| for (j=0; j<3; j++) |
| { |
| if (m_setting.m_impulseClamp > 0) |
| { |
| info->m_lowerLimit[j*info->rowskip] = -impulseClamp; |
| info->m_upperLimit[j*info->rowskip] = impulseClamp; |
| } |
| } |
| |
| } |
| |
| |
| void btPoint2PointConstraint::solveConstraintObsolete(btSolverBody& bodyA,btSolverBody& bodyB,btScalar timeStep) |
| { |
| |
| if (m_useSolveConstraintObsolete) |
| { |
| btVector3 pivotAInW = m_rbA.getCenterOfMassTransform()*m_pivotInA; |
| btVector3 pivotBInW = m_rbB.getCenterOfMassTransform()*m_pivotInB; |
| |
| |
| btVector3 normal(0,0,0); |
| |
| |
| // btVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity(); |
| // btVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity(); |
| |
| for (int i=0;i<3;i++) |
| { |
| normal[i] = 1; |
| btScalar jacDiagABInv = btScalar(1.) / m_jac[i].getDiagonal(); |
| |
| btVector3 rel_pos1 = pivotAInW - m_rbA.getCenterOfMassPosition(); |
| btVector3 rel_pos2 = pivotBInW - m_rbB.getCenterOfMassPosition(); |
| //this jacobian entry could be re-used for all iterations |
| |
| btVector3 vel1,vel2; |
| bodyA.getVelocityInLocalPointObsolete(rel_pos1,vel1); |
| bodyB.getVelocityInLocalPointObsolete(rel_pos2,vel2); |
| btVector3 vel = vel1 - vel2; |
| |
| btScalar rel_vel; |
| rel_vel = normal.dot(vel); |
| |
| /* |
| //velocity error (first order error) |
| btScalar rel_vel = m_jac[i].getRelativeVelocity(m_rbA.getLinearVelocity(),angvelA, |
| m_rbB.getLinearVelocity(),angvelB); |
| */ |
| |
| //positional error (zeroth order error) |
| btScalar depth = -(pivotAInW - pivotBInW).dot(normal); //this is the error projected on the normal |
| |
| btScalar deltaImpulse = depth*m_setting.m_tau/timeStep * jacDiagABInv - m_setting.m_damping * rel_vel * jacDiagABInv; |
| |
| btScalar impulseClamp = m_setting.m_impulseClamp; |
| |
| const btScalar sum = btScalar(m_appliedImpulse) + deltaImpulse; |
| if (sum < -impulseClamp) |
| { |
| deltaImpulse = -impulseClamp-m_appliedImpulse; |
| m_appliedImpulse = -impulseClamp; |
| } |
| else if (sum > impulseClamp) |
| { |
| deltaImpulse = impulseClamp-m_appliedImpulse; |
| m_appliedImpulse = impulseClamp; |
| } |
| else |
| { |
| m_appliedImpulse = sum; |
| } |
| |
| |
| btVector3 impulse_vector = normal * deltaImpulse; |
| |
| btVector3 ftorqueAxis1 = rel_pos1.cross(normal); |
| btVector3 ftorqueAxis2 = rel_pos2.cross(normal); |
| bodyA.applyImpulse(normal*m_rbA.getInvMass(), m_rbA.getInvInertiaTensorWorld()*ftorqueAxis1,deltaImpulse); |
| bodyB.applyImpulse(normal*m_rbB.getInvMass(), m_rbB.getInvInertiaTensorWorld()*ftorqueAxis2,-deltaImpulse); |
| |
| |
| normal[i] = 0; |
| } |
| } |
| |
| } |
| |
| void btPoint2PointConstraint::updateRHS(btScalar timeStep) |
| { |
| (void)timeStep; |
| |
| } |
| |