144 lines
8.2 KiB
C++
144 lines
8.2 KiB
C++
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/*
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Written by Xuchen Han <xuchenhan2015@u.northwestern.edu>
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2019 Google Inc. http://bulletphysics.org
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This software is provided 'as-is', without any express or implied warranty.
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In no event will the authors be held liable for any damages arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it freely,
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subject to the following restrictions:
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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.
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2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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#include "btDeformableMultiBodyConstraintSolver.h"
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#include <iostream>
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// override the iterations method to include deformable/multibody contact
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btScalar btDeformableMultiBodyConstraintSolver::solveDeformableGroupIterations(btCollisionObject** bodies,int numBodies,btCollisionObject** deformableBodies,int numDeformableBodies,btPersistentManifold** manifoldPtr, int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& infoGlobal,btIDebugDraw* debugDrawer)
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{
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{
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///this is a special step to resolve penetrations (just for contacts)
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solveGroupCacheFriendlySplitImpulseIterations(bodies, numBodies, manifoldPtr, numManifolds, constraints, numConstraints, infoGlobal, debugDrawer);
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int maxIterations = m_maxOverrideNumSolverIterations > infoGlobal.m_numIterations ? m_maxOverrideNumSolverIterations : infoGlobal.m_numIterations;
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for (int iteration = 0; iteration < maxIterations; iteration++)
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{
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// rigid bodies are solved using solver body velocity, but rigid/deformable contact directly uses the velocity of the actual rigid body. So we have to do the following: Solve one iteration of the rigid/rigid contact, get the updated velocity in the solver body and update the velocity of the underlying rigid body. Then solve the rigid/deformable contact. Finally, grab the (once again) updated rigid velocity and update the velocity of the wrapping solver body
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// solve rigid/rigid in solver body
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m_leastSquaresResidual = solveSingleIteration(iteration, bodies, numBodies, manifoldPtr, numManifolds, constraints, numConstraints, infoGlobal, debugDrawer);
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// solver body velocity -> rigid body velocity
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solverBodyWriteBack(infoGlobal);
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btScalar deformableResidual = m_deformableSolver->solveContactConstraints(deformableBodies,numDeformableBodies);
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// update rigid body velocity in rigid/deformable contact
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m_leastSquaresResidual = btMax(m_leastSquaresResidual, deformableResidual);
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// solver body velocity <- rigid body velocity
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writeToSolverBody(bodies, numBodies, infoGlobal);
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if (m_leastSquaresResidual <= infoGlobal.m_leastSquaresResidualThreshold || (iteration >= (maxIterations - 1)))
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{
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#ifdef VERBOSE_RESIDUAL_PRINTF
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printf("residual = %f at iteration #%d\n", m_leastSquaresResidual, iteration);
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#endif
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m_analyticsData.m_numSolverCalls++;
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m_analyticsData.m_numIterationsUsed = iteration+1;
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m_analyticsData.m_islandId = -2;
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if (numBodies>0)
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m_analyticsData.m_islandId = bodies[0]->getCompanionId();
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m_analyticsData.m_numBodies = numBodies;
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m_analyticsData.m_numContactManifolds = numManifolds;
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m_analyticsData.m_remainingLeastSquaresResidual = m_leastSquaresResidual;
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break;
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}
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}
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}
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return 0.f;
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}
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void btDeformableMultiBodyConstraintSolver::solveDeformableBodyGroup(btCollisionObject * *bodies, int numBodies, btCollisionObject * *deformableBodies, int numDeformableBodies, btPersistentManifold** manifold, int numManifolds, btTypedConstraint** constraints, int numConstraints, btMultiBodyConstraint** multiBodyConstraints, int numMultiBodyConstraints, const btContactSolverInfo& info, btIDebugDraw* debugDrawer, btDispatcher* dispatcher)
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{
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m_tmpMultiBodyConstraints = multiBodyConstraints;
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m_tmpNumMultiBodyConstraints = numMultiBodyConstraints;
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// inherited from MultiBodyConstraintSolver
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solveGroupCacheFriendlySetup(bodies, numBodies, manifold, numManifolds, constraints, numConstraints, info, debugDrawer);
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// overriden
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solveDeformableGroupIterations(bodies, numBodies, deformableBodies, numDeformableBodies, manifold, numManifolds, constraints, numConstraints, info, debugDrawer);
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// inherited from MultiBodyConstraintSolver
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solveGroupCacheFriendlyFinish(bodies, numBodies, info);
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m_tmpMultiBodyConstraints = 0;
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m_tmpNumMultiBodyConstraints = 0;
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}
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void btDeformableMultiBodyConstraintSolver::writeToSolverBody(btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal)
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{
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for (int i = 0; i < numBodies; i++)
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{
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int bodyId = getOrInitSolverBody(*bodies[i], infoGlobal.m_timeStep);
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btRigidBody* body = btRigidBody::upcast(bodies[i]);
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if (body && body->getInvMass())
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{
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btSolverBody& solverBody = m_tmpSolverBodyPool[bodyId];
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solverBody.m_linearVelocity = body->getLinearVelocity() - solverBody.m_deltaLinearVelocity;
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solverBody.m_angularVelocity = body->getAngularVelocity() - solverBody.m_deltaAngularVelocity;
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}
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}
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}
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void btDeformableMultiBodyConstraintSolver::solverBodyWriteBack(const btContactSolverInfo& infoGlobal)
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{
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for (int i = 0; i < m_tmpSolverBodyPool.size(); i++)
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{
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btRigidBody* body = m_tmpSolverBodyPool[i].m_originalBody;
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if (body)
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{
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m_tmpSolverBodyPool[i].m_originalBody->setLinearVelocity(m_tmpSolverBodyPool[i].m_linearVelocity + m_tmpSolverBodyPool[i].m_deltaLinearVelocity);
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m_tmpSolverBodyPool[i].m_originalBody->setAngularVelocity(m_tmpSolverBodyPool[i].m_angularVelocity+m_tmpSolverBodyPool[i].m_deltaAngularVelocity);
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}
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}
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}
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void btDeformableMultiBodyConstraintSolver::solveGroupCacheFriendlySplitImpulseIterations(btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer)
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{
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BT_PROFILE("solveGroupCacheFriendlySplitImpulseIterations");
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int iteration;
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if (infoGlobal.m_splitImpulse)
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{
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{
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m_deformableSolver->splitImpulseSetup(infoGlobal);
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for (iteration = 0; iteration < infoGlobal.m_numIterations; iteration++)
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{
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btScalar leastSquaresResidual = 0.f;
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{
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int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
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int j;
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for (j = 0; j < numPoolConstraints; j++)
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{
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const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[j]];
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btScalar residual = resolveSplitPenetrationImpulse(m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
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leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
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}
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// solve the position correction between deformable and rigid/multibody
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btScalar residual = m_deformableSolver->solveSplitImpulse(infoGlobal);
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leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
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}
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if (leastSquaresResidual <= infoGlobal.m_leastSquaresResidualThreshold || iteration >= (infoGlobal.m_numIterations - 1))
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{
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#ifdef VERBOSE_RESIDUAL_PRINTF
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printf("residual = %f at iteration #%d\n", leastSquaresResidual, iteration);
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#endif
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break;
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}
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}
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}
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}
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}
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