Applied patch/contribution to improve btGeneric6DofConstraint. See also GenericJointDemo/Ragdoll.cpp
Thanks Francisco Leon/projectileman.
This commit is contained in:
ejcoumans
@@ -4,14 +4,20 @@ 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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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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2007-09-09
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Refactored by Francisco Le<4C>n
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email: projectileman@yahoo.com
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http://gimpact.sf.net
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*/
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#include "btGeneric6DofConstraint.h"
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@@ -19,372 +25,473 @@ subject to the following restrictions:
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#include "LinearMath/btTransformUtil.h"
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#include <new>
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static const btScalar kSign[] = { btScalar(1.0), btScalar(-1.0), btScalar(1.0) };
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static const int kAxisA[] = { 1, 0, 0 };
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static const int kAxisB[] = { 2, 2, 1 };
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#define GENERIC_D6_DISABLE_WARMSTARTING 1
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btGeneric6DofConstraint::btGeneric6DofConstraint()
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:btTypedConstraint(D6_CONSTRAINT_TYPE)
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btScalar btGetMatrixElem(const btMatrix3x3& mat, int index)
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{
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}
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btGeneric6DofConstraint::btGeneric6DofConstraint(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB)
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: btTypedConstraint(D6_CONSTRAINT_TYPE, rbA, rbB)
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, m_frameInA(frameInA)
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, m_frameInB(frameInB)
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{
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//free means upper < lower,
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//locked means upper == lower
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//limited means upper > lower
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//so start all locked
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for (int i=0; i<6;++i)
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{
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m_lowerLimit[i] = btScalar(0.0);
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m_upperLimit[i] = btScalar(0.0);
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m_accumulatedImpulse[i] = btScalar(0.0);
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}
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}
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void btGeneric6DofConstraint::buildJacobian()
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{
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btVector3 localNormalInA(0,0,0);
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const btVector3& pivotInA = m_frameInA.getOrigin();
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const btVector3& pivotInB = m_frameInB.getOrigin();
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btVector3 pivotAInW = m_rbA.getCenterOfMassTransform() * m_frameInA.getOrigin();
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btVector3 pivotBInW = m_rbB.getCenterOfMassTransform() * m_frameInB.getOrigin();
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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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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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if (isLimited(i))
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{
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localNormalInA[i] = 1;
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btVector3 normalWorld = m_rbA.getCenterOfMassTransform().getBasis() * localNormalInA;
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// Create linear atom
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new (&m_jacLinear[i]) btJacobianEntry(
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m_rbA.getCenterOfMassTransform().getBasis().transpose(),
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m_rbB.getCenterOfMassTransform().getBasis().transpose(),
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m_rbA.getCenterOfMassTransform()*pivotInA - m_rbA.getCenterOfMassPosition(),
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m_rbB.getCenterOfMassTransform()*pivotInB - m_rbB.getCenterOfMassPosition(),
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normalWorld,
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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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//optionally disable warmstarting
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#ifdef GENERIC_D6_DISABLE_WARMSTARTING
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m_accumulatedImpulse[i] = btScalar(0.);
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#endif //GENERIC_D6_DISABLE_WARMSTARTING
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// Apply accumulated impulse
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btVector3 impulse_vector = m_accumulatedImpulse[i] * normalWorld;
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m_rbA.applyImpulse( impulse_vector, rel_pos1);
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m_rbB.applyImpulse(-impulse_vector, rel_pos2);
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localNormalInA[i] = 0;
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}
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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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if (isLimited(i+3))
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{
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btVector3 axisA = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn( kAxisA[i] );
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btVector3 axisB = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn( kAxisB[i] );
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// Dirk: This is IMO mathematically the correct way, but we should consider axisA and axisB being near parallel maybe
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btVector3 axis = kSign[i] * axisA.cross(axisB);
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// Create angular atom
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new (&m_jacAng[i]) btJacobianEntry(axis,
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m_rbA.getCenterOfMassTransform().getBasis().transpose(),
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m_rbB.getCenterOfMassTransform().getBasis().transpose(),
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m_rbA.getInvInertiaDiagLocal(),
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m_rbB.getInvInertiaDiagLocal());
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#ifdef GENERIC_D6_DISABLE_WARMSTARTING
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m_accumulatedImpulse[i + 3] = btScalar(0.);
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#endif //GENERIC_D6_DISABLE_WARMSTARTING
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// Apply accumulated impulse
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btVector3 impulse_vector = m_accumulatedImpulse[i + 3] * axis;
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m_rbA.applyTorqueImpulse( impulse_vector);
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m_rbB.applyTorqueImpulse(-impulse_vector);
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}
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}
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}
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btScalar getMatrixElem(const btMatrix3x3& mat,int index)
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{
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int row = index%3;
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int col = index / 3;
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return mat[row][col];
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int i = index%3;
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int j = index/3;
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return mat[i][j];
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}
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///MatrixToEulerXYZ from http://www.geometrictools.com/LibFoundation/Mathematics/Wm4Matrix3.inl.html
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bool MatrixToEulerXYZ(const btMatrix3x3& mat,btVector3& xyz)
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bool matrixToEulerXYZ(const btMatrix3x3& mat,btVector3& xyz)
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{
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// rot = cy*cz -cy*sz sy
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// cz*sx*sy+cx*sz cx*cz-sx*sy*sz -cy*sx
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// -cx*cz*sy+sx*sz cz*sx+cx*sy*sz cx*cy
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// // rot = cy*cz -cy*sz sy
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// // cz*sx*sy+cx*sz cx*cz-sx*sy*sz -cy*sx
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// // -cx*cz*sy+sx*sz cz*sx+cx*sy*sz cx*cy
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//
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if (btGetMatrixElem(mat,2) < btScalar(1.0))
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{
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if (btGetMatrixElem(mat,2) > btScalar(-1.0))
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{
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xyz[0] = btAtan2(-btGetMatrixElem(mat,5),btGetMatrixElem(mat,8));
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xyz[1] = btAsin(btGetMatrixElem(mat,2));
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xyz[2] = btAtan2(-btGetMatrixElem(mat,1),btGetMatrixElem(mat,0));
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return true;
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}
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else
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{
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// WARNING. Not unique. XA - ZA = -atan2(r10,r11)
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xyz[0] = -btAtan2(btGetMatrixElem(mat,3),btGetMatrixElem(mat,4));
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xyz[1] = -SIMD_HALF_PI;
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xyz[2] = btScalar(0.0);
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return false;
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}
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}
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else
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{
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// WARNING. Not unique. XAngle + ZAngle = atan2(r10,r11)
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xyz[0] = btAtan2(btGetMatrixElem(mat,3),btGetMatrixElem(mat,4));
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xyz[1] = SIMD_HALF_PI;
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xyz[2] = 0.0;
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}
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/// 0..8
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if (getMatrixElem(mat,2) < btScalar(1.0))
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{
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if (getMatrixElem(mat,2) > btScalar(-1.0))
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{
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xyz[0] = btAtan2(-getMatrixElem(mat,5),getMatrixElem(mat,8));
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xyz[1] = btAsin(getMatrixElem(mat,2));
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xyz[2] = btAtan2(-getMatrixElem(mat,1),getMatrixElem(mat,0));
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return true;
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}
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else
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{
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// WARNING. Not unique. XA - ZA = -atan2(r10,r11)
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xyz[0] = -btAtan2(getMatrixElem(mat,3),getMatrixElem(mat,4));
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xyz[1] = -SIMD_HALF_PI;
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xyz[2] = btScalar(0.0);
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return false;
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}
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}
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else
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{
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// WARNING. Not unique. XAngle + ZAngle = atan2(r10,r11)
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xyz[0] = btAtan2(getMatrixElem(mat,3),getMatrixElem(mat,4));
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xyz[1] = SIMD_HALF_PI;
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xyz[2] = 0.0;
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}
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return false;
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}
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void btGeneric6DofConstraint::solveConstraint(btScalar timeStep)
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//////////////////////////// btRotationalLimitMotor ////////////////////////////////////
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int btRotationalLimitMotor::testLimitValue(btScalar test_value)
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{
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btScalar tau = btScalar(0.1);
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btScalar damping = btScalar(1.0);
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btVector3 pivotAInW = m_rbA.getCenterOfMassTransform() * m_frameInA.getOrigin();
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btVector3 pivotBInW = m_rbB.getCenterOfMassTransform() * m_frameInB.getOrigin();
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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 localNormalInA(0,0,0);
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int i;
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// linear
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for (i=0;i<3;i++)
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{
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if (isLimited(i))
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{
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btVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity();
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btVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity();
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localNormalInA.setValue(0,0,0);
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localNormalInA[i] = 1;
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btVector3 normalWorld = m_rbA.getCenterOfMassTransform().getBasis() * localNormalInA;
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btScalar jacDiagABInv = btScalar(1.) / m_jacLinear[i].getDiagonal();
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//velocity error (first order error)
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btScalar rel_vel = m_jacLinear[i].getRelativeVelocity(m_rbA.getLinearVelocity(),angvelA,
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m_rbB.getLinearVelocity(),angvelB);
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//positional error (zeroth order error)
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btScalar depth = -(pivotAInW - pivotBInW).dot(normalWorld);
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btScalar lo = btScalar(-1e30);
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btScalar hi = btScalar(1e30);
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//handle the limits
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if (m_lowerLimit[i] < m_upperLimit[i])
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{
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{
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if (depth > m_upperLimit[i])
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{
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depth -= m_upperLimit[i];
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lo = btScalar(0.);
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} else
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{
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if (depth < m_lowerLimit[i])
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{
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depth -= m_lowerLimit[i];
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hi = btScalar(0.);
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} else
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{
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continue;
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}
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}
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}
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}
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btScalar normalImpulse= (tau*depth/timeStep - damping*rel_vel) * jacDiagABInv;
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btScalar oldNormalImpulse = m_accumulatedImpulse[i];
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btScalar sum = oldNormalImpulse + normalImpulse;
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m_accumulatedImpulse[i] = sum > hi ? btScalar(0.) : sum < lo ? btScalar(0.) : sum;
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normalImpulse = m_accumulatedImpulse[i] - oldNormalImpulse;
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btVector3 impulse_vector = normalWorld * normalImpulse;
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m_rbA.applyImpulse( impulse_vector, rel_pos1);
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m_rbB.applyImpulse(-impulse_vector, rel_pos2);
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localNormalInA[i] = 0;
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}
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}
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btVector3 axis;
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btScalar angle;
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btTransform frameAWorld = m_rbA.getCenterOfMassTransform() * m_frameInA;
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btTransform frameBWorld = m_rbB.getCenterOfMassTransform() * m_frameInB;
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btTransformUtil::calculateDiffAxisAngle(frameAWorld,frameBWorld,axis,angle);
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btQuaternion diff(axis,angle);
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btMatrix3x3 diffMat (diff);
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btVector3 xyz;
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///this is not perfect, we can first check which axis are limited, and choose a more appropriate order
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MatrixToEulerXYZ(diffMat,xyz);
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// angular
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for (i=0;i<3;i++)
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if(m_loLimit>m_hiLimit)
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{
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if (isLimited(i+3))
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{
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btVector3 angvelA = m_rbA.getCenterOfMassTransform().getBasis().transpose() * m_rbA.getAngularVelocity();
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btVector3 angvelB = m_rbB.getCenterOfMassTransform().getBasis().transpose() * m_rbB.getAngularVelocity();
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btScalar jacDiagABInv = btScalar(1.) / m_jacAng[i].getDiagonal();
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//velocity error (first order error)
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btScalar rel_vel = m_jacAng[i].getRelativeVelocity(m_rbA.getLinearVelocity(),angvelA,
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m_rbB.getLinearVelocity(),angvelB);
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//positional error (zeroth order error)
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btVector3 axisA = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn( kAxisA[i] );
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btVector3 axisB = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn( kAxisB[i] );
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btScalar rel_pos = kSign[i] * axisA.dot(axisB);
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btScalar lo = btScalar(-1e30);
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btScalar hi = btScalar(1e30);
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//handle the twist limit
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if (m_lowerLimit[i+3] < m_upperLimit[i+3])
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{
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//clamp the values
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btScalar loLimit = m_lowerLimit[i+3] > -3.1415 ? m_lowerLimit[i+3] : btScalar(-1e30);
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btScalar hiLimit = m_upperLimit[i+3] < 3.1415 ? m_upperLimit[i+3] : btScalar(1e30);
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btScalar projAngle = btScalar(-1.)*xyz[i];
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if (projAngle < loLimit)
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{
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hi = btScalar(0.);
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rel_pos = (loLimit - projAngle);
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} else
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{
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if (projAngle > hiLimit)
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{
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lo = btScalar(0.);
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rel_pos = (hiLimit - projAngle);
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} else
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{
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continue;
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}
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}
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}
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//impulse
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btScalar normalImpulse= -(tau*rel_pos/timeStep + damping*rel_vel) * jacDiagABInv;
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btScalar oldNormalImpulse = m_accumulatedImpulse[i+3];
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btScalar sum = oldNormalImpulse + normalImpulse;
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m_accumulatedImpulse[i+3] = sum > hi ? btScalar(0.) : sum < lo ? btScalar(0.) : sum;
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normalImpulse = m_accumulatedImpulse[i+3] - oldNormalImpulse;
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// Dirk: Not needed - we could actually project onto Jacobian entry here (same as above)
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btVector3 axis = kSign[i] * axisA.cross(axisB);
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btVector3 impulse_vector = axis * normalImpulse;
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m_rbA.applyTorqueImpulse( impulse_vector);
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m_rbB.applyTorqueImpulse(-impulse_vector);
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}
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m_currentLimit = 0;//Free from violation
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return 0;
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}
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if (test_value < m_loLimit)
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{
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m_currentLimit = 1;//low limit violation
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m_currentLimitError = test_value - m_loLimit;
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return 1;
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}
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else if (test_value> m_hiLimit)
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{
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m_currentLimit = 2;//High limit violation
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m_currentLimitError = test_value - m_hiLimit;
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return 2;
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}
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else
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{
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m_currentLimit = 0;//Free from violation
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return 0;
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}
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return 0;
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}
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btScalar btRotationalLimitMotor::solveAngularLimits(
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btScalar timeStep,btVector3 axis,btScalar jacDiagABInv,
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btRigidBody * body0, btRigidBody * body1)
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{
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if (needApplyTorques()==false) return 0.0f;
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btScalar target_velocity = m_targetVelocity;
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btScalar maxMotorForce = m_maxMotorForce;
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//current error correction
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if (m_currentLimit!=0)
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{
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target_velocity = -m_ERP*m_currentLimitError/(timeStep);
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maxMotorForce = m_maxLimitForce;
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}
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maxMotorForce *= timeStep;
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// current velocity difference
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btVector3 vel_diff = body0->getAngularVelocity();
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if (body1)
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{
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vel_diff -= body1->getAngularVelocity();
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}
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||||
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||||
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btScalar rel_vel = axis.dot(vel_diff);
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// correction velocity
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btScalar motor_relvel = m_limitSoftness*(target_velocity - m_damping*rel_vel);
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if ( motor_relvel < SIMD_EPSILON && motor_relvel > -SIMD_EPSILON )
|
||||
{
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return 0.0f;//no need for applying force
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}
|
||||
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||||
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// correction impulse
|
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btScalar unclippedMotorImpulse = (1+m_bounce)*motor_relvel*jacDiagABInv;
|
||||
|
||||
// clip correction impulse
|
||||
btScalar clippedMotorImpulse;
|
||||
|
||||
//todo: should clip against accumulated impulse
|
||||
if (unclippedMotorImpulse>0.0f)
|
||||
{
|
||||
clippedMotorImpulse = unclippedMotorImpulse > maxMotorForce? maxMotorForce: unclippedMotorImpulse;
|
||||
}
|
||||
else
|
||||
{
|
||||
clippedMotorImpulse = unclippedMotorImpulse < -maxMotorForce ? -maxMotorForce: unclippedMotorImpulse;
|
||||
}
|
||||
|
||||
|
||||
// sort with accumulated impulses
|
||||
btScalar lo = btScalar(-1e30);
|
||||
btScalar hi = btScalar(1e30);
|
||||
|
||||
btScalar oldaccumImpulse = m_accumulatedImpulse;
|
||||
btScalar sum = oldaccumImpulse + clippedMotorImpulse;
|
||||
m_accumulatedImpulse = sum > hi ? btScalar(0.) : sum < lo ? btScalar(0.) : sum;
|
||||
|
||||
clippedMotorImpulse = m_accumulatedImpulse - oldaccumImpulse;
|
||||
|
||||
|
||||
|
||||
btVector3 motorImp = clippedMotorImpulse * axis;
|
||||
|
||||
|
||||
body0->applyTorqueImpulse(motorImp);
|
||||
if (body1) body1->applyTorqueImpulse(-motorImp);
|
||||
|
||||
return clippedMotorImpulse;
|
||||
|
||||
|
||||
}
|
||||
|
||||
//////////////////////////// End btRotationalLimitMotor ////////////////////////////////////
|
||||
|
||||
//////////////////////////// btTranslationalLimitMotor ////////////////////////////////////
|
||||
btScalar btTranslationalLimitMotor::solveLinearAxis(
|
||||
btScalar timeStep,
|
||||
btScalar jacDiagABInv,
|
||||
btRigidBody& body1,const btVector3 &pointInA,
|
||||
btRigidBody& body2,const btVector3 &pointInB,
|
||||
int limit_index,
|
||||
const btVector3 & axis_normal_on_a)
|
||||
{
|
||||
|
||||
///find relative velocity
|
||||
btVector3 rel_pos1 = pointInA - body1.getCenterOfMassPosition();
|
||||
btVector3 rel_pos2 = pointInB - body2.getCenterOfMassPosition();
|
||||
|
||||
btVector3 vel1 = body1.getVelocityInLocalPoint(rel_pos1);
|
||||
btVector3 vel2 = body2.getVelocityInLocalPoint(rel_pos2);
|
||||
btVector3 vel = vel1 - vel2;
|
||||
|
||||
btScalar rel_vel = axis_normal_on_a.dot(vel);
|
||||
|
||||
|
||||
|
||||
/// apply displacement correction
|
||||
|
||||
//positional error (zeroth order error)
|
||||
btScalar depth = -(pointInA - pointInB).dot(axis_normal_on_a);
|
||||
btScalar lo = btScalar(-1e30);
|
||||
btScalar hi = btScalar(1e30);
|
||||
|
||||
btScalar minLimit = m_lowerLimit[limit_index];
|
||||
btScalar maxLimit = m_upperLimit[limit_index];
|
||||
|
||||
//handle the limits
|
||||
if (minLimit < maxLimit)
|
||||
{
|
||||
{
|
||||
if (depth > maxLimit)
|
||||
{
|
||||
depth -= maxLimit;
|
||||
lo = btScalar(0.);
|
||||
|
||||
}
|
||||
else
|
||||
{
|
||||
if (depth < minLimit)
|
||||
{
|
||||
depth -= minLimit;
|
||||
hi = btScalar(0.);
|
||||
}
|
||||
else
|
||||
{
|
||||
return 0.0f;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
btScalar normalImpulse= m_limitSoftness*(m_restitution*depth/timeStep - m_damping*rel_vel) * jacDiagABInv;
|
||||
|
||||
|
||||
|
||||
|
||||
btScalar oldNormalImpulse = m_accumulatedImpulse[limit_index];
|
||||
btScalar sum = oldNormalImpulse + normalImpulse;
|
||||
m_accumulatedImpulse[limit_index] = sum > hi ? btScalar(0.) : sum < lo ? btScalar(0.) : sum;
|
||||
normalImpulse = m_accumulatedImpulse[limit_index] - oldNormalImpulse;
|
||||
|
||||
btVector3 impulse_vector = axis_normal_on_a * normalImpulse;
|
||||
body1.applyImpulse( impulse_vector, rel_pos1);
|
||||
body2.applyImpulse(-impulse_vector, rel_pos2);
|
||||
return normalImpulse;
|
||||
}
|
||||
|
||||
//////////////////////////// btTranslationalLimitMotor ////////////////////////////////////
|
||||
|
||||
|
||||
btGeneric6DofConstraint::btGeneric6DofConstraint()
|
||||
:btTypedConstraint(D6_CONSTRAINT_TYPE),
|
||||
m_useLinearReferenceFrameA(true)
|
||||
{
|
||||
}
|
||||
|
||||
btGeneric6DofConstraint::btGeneric6DofConstraint(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB, bool useLinearReferenceFrameA)
|
||||
: btTypedConstraint(D6_CONSTRAINT_TYPE, rbA, rbB)
|
||||
, m_frameInA(frameInA)
|
||||
, m_frameInB(frameInB),
|
||||
m_useLinearReferenceFrameA(useLinearReferenceFrameA)
|
||||
{
|
||||
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
void btGeneric6DofConstraint::calculateAngleInfo()
|
||||
{
|
||||
btMatrix3x3 relative_frame = m_calculatedTransformA.getBasis().inverse()*m_calculatedTransformB.getBasis();
|
||||
|
||||
matrixToEulerXYZ(relative_frame,m_calculatedAxisAngleDiff);
|
||||
|
||||
|
||||
|
||||
// in euler angle mode we do not actually constrain the angular velocity
|
||||
// along the axes axis[0] and axis[2] (although we do use axis[1]) :
|
||||
//
|
||||
// to get constrain w2-w1 along ...not
|
||||
// ------ --------------------- ------
|
||||
// d(angle[0])/dt = 0 ax[1] x ax[2] ax[0]
|
||||
// d(angle[1])/dt = 0 ax[1]
|
||||
// d(angle[2])/dt = 0 ax[0] x ax[1] ax[2]
|
||||
//
|
||||
// constraining w2-w1 along an axis 'a' means that a'*(w2-w1)=0.
|
||||
// to prove the result for angle[0], write the expression for angle[0] from
|
||||
// GetInfo1 then take the derivative. to prove this for angle[2] it is
|
||||
// easier to take the euler rate expression for d(angle[2])/dt with respect
|
||||
// to the components of w and set that to 0.
|
||||
|
||||
btVector3 axis0 = m_calculatedTransformB.getBasis().getColumn(0);
|
||||
btVector3 axis2 = m_calculatedTransformA.getBasis().getColumn(2);
|
||||
|
||||
m_calculatedAxis[1] = axis2.cross(axis0);
|
||||
m_calculatedAxis[0] = m_calculatedAxis[1].cross(axis2);
|
||||
m_calculatedAxis[2] = axis0.cross(m_calculatedAxis[1]);
|
||||
|
||||
|
||||
// if(m_debugDrawer)
|
||||
// {
|
||||
//
|
||||
// char buff[300];
|
||||
// sprintf(buff,"\n X: %.2f ; Y: %.2f ; Z: %.2f ",
|
||||
// m_calculatedAxisAngleDiff[0],
|
||||
// m_calculatedAxisAngleDiff[1],
|
||||
// m_calculatedAxisAngleDiff[2]);
|
||||
// m_debugDrawer->reportErrorWarning(buff);
|
||||
// }
|
||||
|
||||
}
|
||||
|
||||
void btGeneric6DofConstraint::calculateTransforms()
|
||||
{
|
||||
m_calculatedTransformA = m_rbA.getCenterOfMassTransform() * m_frameInA;
|
||||
m_calculatedTransformB = m_rbB.getCenterOfMassTransform() * m_frameInB;
|
||||
|
||||
calculateAngleInfo();
|
||||
}
|
||||
|
||||
|
||||
void btGeneric6DofConstraint::buildLinearJacobian(
|
||||
btJacobianEntry & jacLinear,const btVector3 & normalWorld,
|
||||
const btVector3 & pivotAInW,const btVector3 & pivotBInW)
|
||||
{
|
||||
new (&jacLinear) btJacobianEntry(
|
||||
m_rbA.getCenterOfMassTransform().getBasis().transpose(),
|
||||
m_rbB.getCenterOfMassTransform().getBasis().transpose(),
|
||||
pivotAInW - m_rbA.getCenterOfMassPosition(),
|
||||
pivotBInW - m_rbB.getCenterOfMassPosition(),
|
||||
normalWorld,
|
||||
m_rbA.getInvInertiaDiagLocal(),
|
||||
m_rbA.getInvMass(),
|
||||
m_rbB.getInvInertiaDiagLocal(),
|
||||
m_rbB.getInvMass());
|
||||
|
||||
}
|
||||
|
||||
void btGeneric6DofConstraint::buildAngularJacobian(
|
||||
btJacobianEntry & jacAngular,const btVector3 & jointAxisW)
|
||||
{
|
||||
new (&jacAngular) btJacobianEntry(jointAxisW,
|
||||
m_rbA.getCenterOfMassTransform().getBasis().transpose(),
|
||||
m_rbB.getCenterOfMassTransform().getBasis().transpose(),
|
||||
m_rbA.getInvInertiaDiagLocal(),
|
||||
m_rbB.getInvInertiaDiagLocal());
|
||||
|
||||
}
|
||||
|
||||
bool btGeneric6DofConstraint::testAngularLimitMotor(int axis_index)
|
||||
{
|
||||
btScalar angle = m_calculatedAxisAngleDiff[axis_index];
|
||||
|
||||
//test limits
|
||||
m_angularLimits[axis_index].testLimitValue(angle);
|
||||
return m_angularLimits[axis_index].needApplyTorques();
|
||||
}
|
||||
|
||||
void btGeneric6DofConstraint::buildJacobian()
|
||||
{
|
||||
//calculates transform
|
||||
calculateTransforms();
|
||||
|
||||
const btVector3& pivotAInW = m_calculatedTransformA.getOrigin();
|
||||
const btVector3& pivotBInW = m_calculatedTransformB.getOrigin();
|
||||
|
||||
|
||||
btVector3 rel_pos1 = pivotAInW - m_rbA.getCenterOfMassPosition();
|
||||
btVector3 rel_pos2 = pivotBInW - m_rbB.getCenterOfMassPosition();
|
||||
|
||||
btVector3 normalWorld;
|
||||
int i;
|
||||
//linear part
|
||||
for (i=0;i<3;i++)
|
||||
{
|
||||
if (m_linearLimits.isLimited(i))
|
||||
{
|
||||
if (m_useLinearReferenceFrameA)
|
||||
normalWorld = m_calculatedTransformA.getBasis().getColumn(i);
|
||||
else
|
||||
normalWorld = m_calculatedTransformB.getBasis().getColumn(i);
|
||||
|
||||
buildLinearJacobian(
|
||||
m_jacLinear[i],normalWorld ,
|
||||
pivotAInW,pivotBInW);
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
// angular part
|
||||
for (i=0;i<3;i++)
|
||||
{
|
||||
//calculates error angle
|
||||
if (testAngularLimitMotor(i))
|
||||
{
|
||||
normalWorld = this->getAxis(i);
|
||||
// Create angular atom
|
||||
buildAngularJacobian(m_jacAng[i],normalWorld);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
|
||||
|
||||
void btGeneric6DofConstraint::solveConstraint(btScalar timeStep)
|
||||
{
|
||||
m_timeStep = timeStep;
|
||||
|
||||
//calculateTransforms();
|
||||
|
||||
int i;
|
||||
|
||||
// linear
|
||||
|
||||
btVector3 pointInA = m_calculatedTransformA.getOrigin();
|
||||
btVector3 pointInB = m_calculatedTransformB.getOrigin();
|
||||
|
||||
btScalar jacDiagABInv;
|
||||
btVector3 linear_axis;
|
||||
for (i=0;i<3;i++)
|
||||
{
|
||||
if (m_linearLimits.isLimited(i))
|
||||
{
|
||||
jacDiagABInv = btScalar(1.) / m_jacLinear[i].getDiagonal();
|
||||
|
||||
if (m_useLinearReferenceFrameA)
|
||||
linear_axis = m_calculatedTransformA.getBasis().getColumn(i);
|
||||
else
|
||||
linear_axis = m_calculatedTransformB.getBasis().getColumn(i);
|
||||
|
||||
m_linearLimits.solveLinearAxis(
|
||||
m_timeStep,
|
||||
jacDiagABInv,
|
||||
m_rbA,pointInA,
|
||||
m_rbB,pointInB,
|
||||
i,linear_axis);
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
// angular
|
||||
btVector3 angular_axis;
|
||||
btScalar angularJacDiagABInv;
|
||||
for (i=0;i<3;i++)
|
||||
{
|
||||
if (m_angularLimits[i].needApplyTorques())
|
||||
{
|
||||
|
||||
// get axis
|
||||
angular_axis = getAxis(i);
|
||||
|
||||
angularJacDiagABInv = btScalar(1.) / m_jacAng[i].getDiagonal();
|
||||
|
||||
m_angularLimits[i].solveAngularLimits(m_timeStep,angular_axis,angularJacDiagABInv, &m_rbA,&m_rbB);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void btGeneric6DofConstraint::updateRHS(btScalar timeStep)
|
||||
{
|
||||
(void)timeStep;
|
||||
(void)timeStep;
|
||||
|
||||
}
|
||||
|
||||
btScalar btGeneric6DofConstraint::computeAngle(int axis) const
|
||||
{
|
||||
btScalar angle = btScalar(0.f);
|
||||
btVector3 btGeneric6DofConstraint::getAxis(int axis_index) const
|
||||
{
|
||||
return m_calculatedAxis[axis_index];
|
||||
}
|
||||
|
||||
switch (axis)
|
||||
{
|
||||
case 0:
|
||||
{
|
||||
btVector3 v1 = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn(1);
|
||||
btVector3 v2 = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn(1);
|
||||
btVector3 w2 = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn(2);
|
||||
btScalar btGeneric6DofConstraint::getAngle(int axis_index) const
|
||||
{
|
||||
return m_calculatedAxisAngleDiff[axis_index];
|
||||
}
|
||||
|
||||
btScalar s = v1.dot(w2);
|
||||
btScalar c = v1.dot(v2);
|
||||
|
||||
angle = btAtan2( s, c );
|
||||
}
|
||||
break;
|
||||
|
||||
case 1:
|
||||
{
|
||||
btVector3 w1 = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn(2);
|
||||
btVector3 w2 = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn(2);
|
||||
btVector3 u2 = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn(0);
|
||||
|
||||
btScalar s = w1.dot(u2);
|
||||
btScalar c = w1.dot(w2);
|
||||
|
||||
angle = btAtan2( s, c );
|
||||
}
|
||||
break;
|
||||
|
||||
case 2:
|
||||
{
|
||||
btVector3 u1 = m_rbA.getCenterOfMassTransform().getBasis() * m_frameInA.getBasis().getColumn(0);
|
||||
btVector3 u2 = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn(0);
|
||||
btVector3 v2 = m_rbB.getCenterOfMassTransform().getBasis() * m_frameInB.getBasis().getColumn(1);
|
||||
|
||||
btScalar s = u1.dot(v2);
|
||||
btScalar c = u1.dot(u2);
|
||||
|
||||
angle = btAtan2( s, c );
|
||||
}
|
||||
break;
|
||||
default:
|
||||
btAssert ( 0 ) ;
|
||||
|
||||
break ;
|
||||
}
|
||||
|
||||
return angle;
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user