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1) Add fast branchless SIMD support for constraint solver (Windows only until we get other contributions). See resolveSingleConstraintRowGenericSIMD in Bullet/src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp resolveSingleConstraintRowGenericSIMD can be used for all constraints, including contact, point 2 point, hinge, generic etc. 2) During this refactoring, all constraints support the obsolete 'solveConstraintObsolete' while we add 'getInfo1' and 'getInfo2' support. This interface is almost identical interface to Open Dynamics Engine, to make it easier to port Dantzig LCP solver. 3) Some minor refactoring to reduce huge constructor overhead in math classes.
321 lines
10 KiB
C++
321 lines
10 KiB
C++
/*
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Bullet Continuous Collision Detection and Physics Library
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btConeTwistConstraint is Copyright (c) 2007 Starbreeze Studios
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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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Written by: Marcus Hennix
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*/
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#include "btConeTwistConstraint.h"
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#include "BulletDynamics/Dynamics/btRigidBody.h"
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#include "LinearMath/btTransformUtil.h"
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#include "LinearMath/btMinMax.h"
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#include <new>
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btConeTwistConstraint::btConeTwistConstraint()
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:btTypedConstraint(CONETWIST_CONSTRAINT_TYPE),
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m_useSolveConstraintObsolete(true)
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{
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}
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btConeTwistConstraint::btConeTwistConstraint(btRigidBody& rbA,btRigidBody& rbB,
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const btTransform& rbAFrame,const btTransform& rbBFrame)
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:btTypedConstraint(CONETWIST_CONSTRAINT_TYPE, rbA,rbB),m_rbAFrame(rbAFrame),m_rbBFrame(rbBFrame),
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m_angularOnly(false),
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m_useSolveConstraintObsolete(true)
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{
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m_swingSpan1 = btScalar(1e30);
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m_swingSpan2 = btScalar(1e30);
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m_twistSpan = btScalar(1e30);
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m_biasFactor = 0.3f;
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m_relaxationFactor = 1.0f;
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m_solveTwistLimit = false;
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m_solveSwingLimit = false;
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}
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btConeTwistConstraint::btConeTwistConstraint(btRigidBody& rbA,const btTransform& rbAFrame)
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:btTypedConstraint(CONETWIST_CONSTRAINT_TYPE,rbA),m_rbAFrame(rbAFrame),
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m_angularOnly(false),
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m_useSolveConstraintObsolete(true)
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{
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m_rbBFrame = m_rbAFrame;
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m_swingSpan1 = btScalar(1e30);
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m_swingSpan2 = btScalar(1e30);
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m_twistSpan = btScalar(1e30);
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m_biasFactor = 0.3f;
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m_relaxationFactor = 1.0f;
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m_solveTwistLimit = false;
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m_solveSwingLimit = false;
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}
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void btConeTwistConstraint::getInfo1 (btConstraintInfo1* info)
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{
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if (m_useSolveConstraintObsolete)
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{
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info->m_numConstraintRows = 0;
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info->nub = 0;
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} else
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{
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btAssert(0);
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}
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}
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void btConeTwistConstraint::getInfo2 (btConstraintInfo2* info)
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{
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btAssert(0);
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}
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void btConeTwistConstraint::buildJacobian()
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{
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if (m_useSolveConstraintObsolete)
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{
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m_appliedImpulse = btScalar(0.);
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//set bias, sign, clear accumulator
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m_swingCorrection = btScalar(0.);
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m_twistLimitSign = btScalar(0.);
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m_solveTwistLimit = false;
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m_solveSwingLimit = false;
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m_accTwistLimitImpulse = btScalar(0.);
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m_accSwingLimitImpulse = btScalar(0.);
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if (!m_angularOnly)
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{
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btVector3 pivotAInW = m_rbA.getCenterOfMassTransform()*m_rbAFrame.getOrigin();
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btVector3 pivotBInW = m_rbB.getCenterOfMassTransform()*m_rbBFrame.getOrigin();
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btVector3 relPos = pivotBInW - pivotAInW;
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btVector3 normal[3];
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if (relPos.length2() > SIMD_EPSILON)
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{
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normal[0] = relPos.normalized();
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}
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else
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{
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normal[0].setValue(btScalar(1.0),0,0);
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}
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btPlaneSpace1(normal[0], normal[1], normal[2]);
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for (int i=0;i<3;i++)
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{
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new (&m_jac[i]) btJacobianEntry(
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pivotAInW - m_rbA.getCenterOfMassPosition(),
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pivotBInW - m_rbB.getCenterOfMassPosition(),
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normal[i],
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m_rbA.getInvInertiaDiagLocal(),
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m_rbA.getInvMass(),
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m_rbB.getInvInertiaDiagLocal(),
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m_rbB.getInvMass());
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}
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}
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btVector3 b1Axis1,b1Axis2,b1Axis3;
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btVector3 b2Axis1,b2Axis2;
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b1Axis1 = getRigidBodyA().getCenterOfMassTransform().getBasis() * this->m_rbAFrame.getBasis().getColumn(0);
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b2Axis1 = getRigidBodyB().getCenterOfMassTransform().getBasis() * this->m_rbBFrame.getBasis().getColumn(0);
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btScalar swing1=btScalar(0.),swing2 = btScalar(0.);
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btScalar swx=btScalar(0.),swy = btScalar(0.);
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btScalar thresh = btScalar(10.);
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btScalar fact;
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// Get Frame into world space
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if (m_swingSpan1 >= btScalar(0.05f))
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{
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b1Axis2 = getRigidBodyA().getCenterOfMassTransform().getBasis() * this->m_rbAFrame.getBasis().getColumn(1);
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// swing1 = btAtan2Fast( b2Axis1.dot(b1Axis2),b2Axis1.dot(b1Axis1) );
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swx = b2Axis1.dot(b1Axis1);
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swy = b2Axis1.dot(b1Axis2);
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swing1 = btAtan2Fast(swy, swx);
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fact = (swy*swy + swx*swx) * thresh * thresh;
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fact = fact / (fact + btScalar(1.0));
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swing1 *= fact;
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}
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if (m_swingSpan2 >= btScalar(0.05f))
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{
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b1Axis3 = getRigidBodyA().getCenterOfMassTransform().getBasis() * this->m_rbAFrame.getBasis().getColumn(2);
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// swing2 = btAtan2Fast( b2Axis1.dot(b1Axis3),b2Axis1.dot(b1Axis1) );
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swx = b2Axis1.dot(b1Axis1);
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swy = b2Axis1.dot(b1Axis3);
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swing2 = btAtan2Fast(swy, swx);
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fact = (swy*swy + swx*swx) * thresh * thresh;
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fact = fact / (fact + btScalar(1.0));
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swing2 *= fact;
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}
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btScalar RMaxAngle1Sq = 1.0f / (m_swingSpan1*m_swingSpan1);
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btScalar RMaxAngle2Sq = 1.0f / (m_swingSpan2*m_swingSpan2);
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btScalar EllipseAngle = btFabs(swing1*swing1)* RMaxAngle1Sq + btFabs(swing2*swing2) * RMaxAngle2Sq;
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if (EllipseAngle > 1.0f)
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{
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m_swingCorrection = EllipseAngle-1.0f;
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m_solveSwingLimit = true;
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// Calculate necessary axis & factors
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m_swingAxis = b2Axis1.cross(b1Axis2* b2Axis1.dot(b1Axis2) + b1Axis3* b2Axis1.dot(b1Axis3));
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m_swingAxis.normalize();
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btScalar swingAxisSign = (b2Axis1.dot(b1Axis1) >= 0.0f) ? 1.0f : -1.0f;
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m_swingAxis *= swingAxisSign;
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m_kSwing = btScalar(1.) / (getRigidBodyA().computeAngularImpulseDenominator(m_swingAxis) +
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getRigidBodyB().computeAngularImpulseDenominator(m_swingAxis));
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}
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// Twist limits
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if (m_twistSpan >= btScalar(0.))
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{
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btVector3 b2Axis2 = getRigidBodyB().getCenterOfMassTransform().getBasis() * this->m_rbBFrame.getBasis().getColumn(1);
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btQuaternion rotationArc = shortestArcQuat(b2Axis1,b1Axis1);
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btVector3 TwistRef = quatRotate(rotationArc,b2Axis2);
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btScalar twist = btAtan2Fast( TwistRef.dot(b1Axis3), TwistRef.dot(b1Axis2) );
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btScalar lockedFreeFactor = (m_twistSpan > btScalar(0.05f)) ? m_limitSoftness : btScalar(0.);
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if (twist <= -m_twistSpan*lockedFreeFactor)
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{
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m_twistCorrection = -(twist + m_twistSpan);
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m_solveTwistLimit = true;
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m_twistAxis = (b2Axis1 + b1Axis1) * 0.5f;
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m_twistAxis.normalize();
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m_twistAxis *= -1.0f;
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m_kTwist = btScalar(1.) / (getRigidBodyA().computeAngularImpulseDenominator(m_twistAxis) +
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getRigidBodyB().computeAngularImpulseDenominator(m_twistAxis));
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} else
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if (twist > m_twistSpan*lockedFreeFactor)
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{
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m_twistCorrection = (twist - m_twistSpan);
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m_solveTwistLimit = true;
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m_twistAxis = (b2Axis1 + b1Axis1) * 0.5f;
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m_twistAxis.normalize();
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m_kTwist = btScalar(1.) / (getRigidBodyA().computeAngularImpulseDenominator(m_twistAxis) +
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getRigidBodyB().computeAngularImpulseDenominator(m_twistAxis));
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}
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}
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}
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}
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void btConeTwistConstraint::solveConstraintObsolete(btSolverBody& bodyA,btSolverBody& bodyB,btScalar timeStep)
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{
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if (m_useSolveConstraintObsolete)
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{
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btVector3 pivotAInW = m_rbA.getCenterOfMassTransform()*m_rbAFrame.getOrigin();
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btVector3 pivotBInW = m_rbB.getCenterOfMassTransform()*m_rbBFrame.getOrigin();
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btScalar tau = btScalar(0.3);
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//linear part
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if (!m_angularOnly)
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{
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btVector3 rel_pos1 = pivotAInW - m_rbA.getCenterOfMassPosition();
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btVector3 rel_pos2 = pivotBInW - m_rbB.getCenterOfMassPosition();
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btVector3 vel1;
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bodyA.getVelocityInLocalPointObsolete(rel_pos1,vel1);
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btVector3 vel2;
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bodyB.getVelocityInLocalPointObsolete(rel_pos2,vel2);
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btVector3 vel = vel1 - vel2;
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for (int i=0;i<3;i++)
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{
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const btVector3& normal = m_jac[i].m_linearJointAxis;
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btScalar jacDiagABInv = btScalar(1.) / m_jac[i].getDiagonal();
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btScalar rel_vel;
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rel_vel = normal.dot(vel);
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//positional error (zeroth order error)
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btScalar depth = -(pivotAInW - pivotBInW).dot(normal); //this is the error projected on the normal
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btScalar impulse = depth*tau/timeStep * jacDiagABInv - rel_vel * jacDiagABInv;
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m_appliedImpulse += impulse;
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btVector3 ftorqueAxis1 = rel_pos1.cross(normal);
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btVector3 ftorqueAxis2 = rel_pos2.cross(normal);
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bodyA.applyImpulse(normal*m_rbA.getInvMass(), m_rbA.getInvInertiaTensorWorld()*ftorqueAxis1,impulse);
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bodyB.applyImpulse(normal*m_rbB.getInvMass(), m_rbB.getInvInertiaTensorWorld()*ftorqueAxis2,-impulse);
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}
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}
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{
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///solve angular part
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btVector3 angVelA;
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bodyA.getAngularVelocity(angVelA);
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btVector3 angVelB;
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bodyB.getAngularVelocity(angVelB);
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// solve swing limit
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if (m_solveSwingLimit)
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{
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btScalar amplitude = ((angVelB - angVelA).dot( m_swingAxis )*m_relaxationFactor*m_relaxationFactor + m_swingCorrection*(btScalar(1.)/timeStep)*m_biasFactor);
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btScalar impulseMag = amplitude * m_kSwing;
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// Clamp the accumulated impulse
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btScalar temp = m_accSwingLimitImpulse;
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m_accSwingLimitImpulse = btMax(m_accSwingLimitImpulse + impulseMag, btScalar(0.0) );
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impulseMag = m_accSwingLimitImpulse - temp;
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btVector3 impulse = m_swingAxis * impulseMag;
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bodyA.applyImpulse(btVector3(0,0,0), m_rbA.getInvInertiaTensorWorld()*m_swingAxis,impulseMag);
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bodyB.applyImpulse(btVector3(0,0,0), m_rbB.getInvInertiaTensorWorld()*m_swingAxis,-impulseMag);
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}
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// solve twist limit
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if (m_solveTwistLimit)
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{
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btScalar amplitude = ((angVelB - angVelA).dot( m_twistAxis )*m_relaxationFactor*m_relaxationFactor + m_twistCorrection*(btScalar(1.)/timeStep)*m_biasFactor );
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btScalar impulseMag = amplitude * m_kTwist;
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// Clamp the accumulated impulse
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btScalar temp = m_accTwistLimitImpulse;
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m_accTwistLimitImpulse = btMax(m_accTwistLimitImpulse + impulseMag, btScalar(0.0) );
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impulseMag = m_accTwistLimitImpulse - temp;
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btVector3 impulse = m_twistAxis * impulseMag;
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bodyA.applyImpulse(btVector3(0,0,0), m_rbA.getInvInertiaTensorWorld()*m_twistAxis,impulseMag);
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bodyB.applyImpulse(btVector3(0,0,0), m_rbB.getInvInertiaTensorWorld()*m_twistAxis,-impulseMag);
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}
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}
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}
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}
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void btConeTwistConstraint::updateRHS(btScalar timeStep)
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{
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(void)timeStep;
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}
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