Added slider constraint class btSliderConstraint
This commit is contained in:
rponom
273
src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp
Executable file
273
src/BulletDynamics/ConstraintSolver/btSliderConstraint.cpp
Executable file
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/*
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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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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/*
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Added by Roman Ponomarev (rponom@gmail.com)
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April 04, 2008
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*/
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//-----------------------------------------------------------------------------
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#include "btSliderConstraint.h"
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#include "BulletDynamics/Dynamics/btRigidBody.h"
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#include "LinearMath/btTransformUtil.h"
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#include <new>
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//-----------------------------------------------------------------------------
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void btSliderConstraint::initParams()
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{
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m_lowerLinLimit = btScalar(1.0);
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m_upperLinLimit = btScalar(-1.0);
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m_lowerAngLimit = btScalar(0.);
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m_upperAngLimit = btScalar(0.);
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m_softnessDirLin = SLIDER_CONSTRAINT_DEF_SOFTNESS;
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m_restitutionDirLin = SLIDER_CONSTRAINT_DEF_RESTITUTION;
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m_dampingDirLin = btScalar(0.);
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m_softnessDirAng = SLIDER_CONSTRAINT_DEF_SOFTNESS;
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m_restitutionDirAng = SLIDER_CONSTRAINT_DEF_RESTITUTION;
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m_dampingDirAng = btScalar(0.);
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m_softnessOrthoLin = SLIDER_CONSTRAINT_DEF_SOFTNESS;
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m_restitutionOrthoLin = SLIDER_CONSTRAINT_DEF_RESTITUTION;
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m_dampingOrthoLin = SLIDER_CONSTRAINT_DEF_DAMPING;
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m_softnessOrthoAng = SLIDER_CONSTRAINT_DEF_SOFTNESS;
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m_restitutionOrthoAng = SLIDER_CONSTRAINT_DEF_RESTITUTION;
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m_dampingOrthoAng = SLIDER_CONSTRAINT_DEF_DAMPING;
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m_softnessLimLin = SLIDER_CONSTRAINT_DEF_SOFTNESS;
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m_restitutionLimLin = SLIDER_CONSTRAINT_DEF_RESTITUTION;
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m_dampingLimLin = SLIDER_CONSTRAINT_DEF_DAMPING;
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m_softnessLimAng = SLIDER_CONSTRAINT_DEF_SOFTNESS;
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m_restitutionLimAng = SLIDER_CONSTRAINT_DEF_RESTITUTION;
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m_dampingLimAng = SLIDER_CONSTRAINT_DEF_DAMPING;
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} // btSliderConstraint::initParams()
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//-----------------------------------------------------------------------------
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btSliderConstraint::btSliderConstraint()
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:btTypedConstraint(SLIDER_CONSTRAINT_TYPE),
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m_useLinearReferenceFrameA(true)
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{
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initParams();
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} // btSliderConstraint::btSliderConstraint()
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//-----------------------------------------------------------------------------
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btSliderConstraint::btSliderConstraint(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB, bool useLinearReferenceFrameA)
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: btTypedConstraint(SLIDER_CONSTRAINT_TYPE, rbA, rbB)
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, m_frameInA(frameInA)
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, m_frameInB(frameInB),
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m_useLinearReferenceFrameA(useLinearReferenceFrameA)
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{
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initParams();
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} // btSliderConstraint::btSliderConstraint()
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//-----------------------------------------------------------------------------
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void btSliderConstraint::buildJacobian()
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{
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if(m_useLinearReferenceFrameA)
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{
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buildJacobianInt(m_rbA, m_rbB, m_frameInA, m_frameInB);
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}
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else
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{
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buildJacobianInt(m_rbB, m_rbA, m_frameInB, m_frameInA);
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}
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} // btSliderConstraint::buildJacobian()
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//-----------------------------------------------------------------------------
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void btSliderConstraint::buildJacobianInt(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB)
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{
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//calculate transforms
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m_calculatedTransformA = rbA.getCenterOfMassTransform() * frameInA;
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m_calculatedTransformB = rbB.getCenterOfMassTransform() * frameInB;
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m_realPivotAInW = m_calculatedTransformA.getOrigin();
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m_realPivotBInW = m_calculatedTransformB.getOrigin();
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m_sliderAxis = m_calculatedTransformA.getBasis().getColumn(0); // along X
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m_delta = m_realPivotBInW - m_realPivotAInW;
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m_projPivotInW = m_realPivotAInW + m_sliderAxis.dot(m_delta) * m_sliderAxis;
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m_relPosA = m_projPivotInW - rbA.getCenterOfMassPosition();
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m_relPosB = m_realPivotBInW - rbB.getCenterOfMassPosition();
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btVector3 normalWorld;
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int i;
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//linear part
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for(i = 0; i < 3; i++)
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{
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normalWorld = m_calculatedTransformA.getBasis().getColumn(i);
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new (&m_jacLin[i]) btJacobianEntry(
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rbA.getCenterOfMassTransform().getBasis().transpose(),
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rbB.getCenterOfMassTransform().getBasis().transpose(),
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m_relPosA,
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m_relPosB,
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normalWorld,
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rbA.getInvInertiaDiagLocal(),
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rbA.getInvMass(),
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rbB.getInvInertiaDiagLocal(),
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rbB.getInvMass()
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);
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m_jacLinDiagABInv[i] = btScalar(1.) / m_jacLin[i].getDiagonal();
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m_depth[i] = m_delta.dot(normalWorld);
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}
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m_solveLinLim = false;
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if(m_lowerLinLimit <= m_upperLinLimit)
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{
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if(m_depth[0] > m_upperLinLimit)
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{
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m_depth[0] -= m_upperLinLimit;
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m_solveLinLim = true;
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}
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else if(m_depth[0] < m_lowerLinLimit)
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{
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m_depth[0] -= m_lowerLinLimit;
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m_solveLinLim = true;
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}
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else
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{
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m_depth[0] = btScalar(0.);
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}
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}
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else
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{
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m_depth[0] = btScalar(0.);
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}
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// angular part
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for(i = 0; i < 3; i++)
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{
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normalWorld = m_calculatedTransformA.getBasis().getColumn(i);
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new (&m_jacAng[i]) btJacobianEntry(
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normalWorld,
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rbA.getCenterOfMassTransform().getBasis().transpose(),
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rbB.getCenterOfMassTransform().getBasis().transpose(),
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rbA.getInvInertiaDiagLocal(),
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rbB.getInvInertiaDiagLocal()
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);
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}
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m_angDepth = btScalar(0.);
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m_solveAngLim = false;
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if(m_lowerAngLimit <= m_upperAngLimit)
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{
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const btVector3 axisA0 = m_calculatedTransformA.getBasis().getColumn(1);
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const btVector3 axisA1 = m_calculatedTransformA.getBasis().getColumn(2);
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const btVector3 axisB0 = m_calculatedTransformB.getBasis().getColumn(1);
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btScalar rot = btAtan2Fast(axisB0.dot(axisA1), axisB0.dot(axisA0));
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if(rot < m_lowerAngLimit)
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{
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m_angDepth = rot - m_lowerAngLimit;
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m_solveAngLim = true;
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}
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else if(rot > m_upperAngLimit)
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{
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m_angDepth = rot - m_upperAngLimit;
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m_solveAngLim = true;
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}
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}
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btVector3 axisA = m_calculatedTransformA.getBasis().getColumn(0);
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m_kAngle = btScalar(1.0 )/ (rbA.computeAngularImpulseDenominator(axisA) + rbB.computeAngularImpulseDenominator(axisA));
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} // btSliderConstraint::buildJacobianInt()
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//-----------------------------------------------------------------------------
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void btSliderConstraint::solveConstraint(btScalar timeStep)
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{
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m_timeStep = timeStep;
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if(m_useLinearReferenceFrameA)
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{
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solveConstraintInt(m_rbA, m_rbB);
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}
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else
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{
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solveConstraintInt(m_rbB, m_rbA);
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}
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} // btSliderConstraint::solveConstraint()
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//-----------------------------------------------------------------------------
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void btSliderConstraint::solveConstraintInt(btRigidBody& rbA, btRigidBody& rbB)
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{
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int i;
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// linear
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btVector3 velA = rbA.getVelocityInLocalPoint(m_relPosA);
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btVector3 velB = rbB.getVelocityInLocalPoint(m_relPosB);
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btVector3 vel = velA - velB;
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for(i = 0; i < 3; i++)
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{
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const btVector3& normal = m_jacLin[i].m_linearJointAxis;
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btScalar rel_vel = normal.dot(vel);
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// calculate positional error
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btScalar depth = m_depth[i];
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// get parameters
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btScalar softness = (i) ? m_softnessOrthoLin : (m_solveLinLim ? m_softnessLimLin : m_softnessDirLin);
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btScalar restitution = (i) ? m_restitutionOrthoLin : (m_solveLinLim ? m_restitutionLimLin : m_restitutionDirLin);
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btScalar damping = (i) ? m_dampingOrthoLin : (m_solveLinLim ? m_dampingLimLin : m_dampingDirLin);
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// calcutate and apply impulse
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btScalar normalImpulse = softness * (restitution * depth / m_timeStep - damping * rel_vel) * m_jacLinDiagABInv[i];
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btVector3 impulse_vector = normal * normalImpulse;
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rbA.applyImpulse( impulse_vector, m_relPosA);
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rbB.applyImpulse(-impulse_vector, m_relPosB);
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}
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// angular
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// get axes in world space
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btVector3 axisA = m_calculatedTransformA.getBasis().getColumn(0);
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btVector3 axisB = m_calculatedTransformB.getBasis().getColumn(0);
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const btVector3& angVelA = rbA.getAngularVelocity();
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const btVector3& angVelB = rbB.getAngularVelocity();
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btVector3 angVelAroundAxisA = axisA * axisA.dot(angVelA);
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btVector3 angVelAroundAxisB = axisB * axisB.dot(angVelB);
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btVector3 angAorthog = angVelA - angVelAroundAxisA;
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btVector3 angBorthog = angVelB - angVelAroundAxisB;
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btVector3 velrelOrthog = angAorthog-angBorthog;
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//solve orthogonal angular velocity correction
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btScalar len = velrelOrthog.length();
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if (len > btScalar(0.00001))
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{
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btVector3 normal = velrelOrthog.normalized();
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btScalar denom = rbA.computeAngularImpulseDenominator(normal) + rbB.computeAngularImpulseDenominator(normal);
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velrelOrthog *= (btScalar(1.)/denom) * m_dampingOrthoAng * m_softnessOrthoAng;
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}
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//solve angular positional correction
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btVector3 angularError = axisA.cross(axisB) *(btScalar(1.)/m_timeStep);
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btScalar len2 = angularError.length();
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if (len2>btScalar(0.00001))
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{
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btVector3 normal2 = angularError.normalized();
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btScalar denom2 = rbA.computeAngularImpulseDenominator(normal2) + rbB.computeAngularImpulseDenominator(normal2);
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angularError *= (btScalar(1.)/denom2) * m_restitutionOrthoAng * m_softnessOrthoAng;
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}
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// apply impulse
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rbA.applyTorqueImpulse(-velrelOrthog+angularError);
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rbB.applyTorqueImpulse(velrelOrthog-angularError);
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btScalar impulseMag;
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//solve angular limits
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if(m_solveAngLim)
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{
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impulseMag = (angVelB - angVelA).dot(axisA) * m_dampingLimAng + m_angDepth * m_restitutionLimAng / m_timeStep;
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impulseMag *= m_kAngle * m_softnessLimAng;
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}
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else
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{
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impulseMag = (angVelB - angVelA).dot(axisA) * m_dampingDirAng + m_angDepth * m_restitutionDirAng / m_timeStep;
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impulseMag *= m_kAngle * m_softnessDirAng;
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}
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btVector3 impulse = axisA * impulseMag;
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rbA.applyTorqueImpulse(impulse);
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rbB.applyTorqueImpulse(-impulse);
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} // btSliderConstraint::solveConstraint()
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//-----------------------------------------------------------------------------
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