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Diffstat (limited to 'extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp')
| -rw-r--r-- | extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp b/extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp new file mode 100644 index 00000000000..12a33d7851e --- /dev/null +++ b/extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp @@ -0,0 +1,286 @@ +/* +Bullet Continuous Collision Detection and Physics Library +btConeTwistConstraint is Copyright (c) 2007 Starbreeze Studios + +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: + +1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. + +Written by: Marcus Hennix +*/ + + +#include "btConeTwistConstraint.h" +#include "BulletDynamics/Dynamics/btRigidBody.h" +#include "LinearMath/btTransformUtil.h" +#include "LinearMath/btSimdMinMax.h" +#include <new> + +btConeTwistConstraint::btConeTwistConstraint() +{ +} + + +btConeTwistConstraint::btConeTwistConstraint(btRigidBody& rbA,btRigidBody& rbB, + const btTransform& rbAFrame,const btTransform& rbBFrame) + :btTypedConstraint(rbA,rbB),m_rbAFrame(rbAFrame),m_rbBFrame(rbBFrame), + m_angularOnly(false) +{ + // flip axis for correct angles + m_rbBFrame.getBasis()[1][0] *= btScalar(-1.); + m_rbBFrame.getBasis()[1][1] *= btScalar(-1.); + m_rbBFrame.getBasis()[1][2] *= btScalar(-1.); + + m_swingSpan1 = btScalar(1e30); + m_swingSpan2 = btScalar(1e30); + m_twistSpan = btScalar(1e30); + m_biasFactor = 0.3f; + m_relaxationFactor = 1.0f; + + m_solveTwistLimit = false; + m_solveSwingLimit = false; + +} + +btConeTwistConstraint::btConeTwistConstraint(btRigidBody& rbA,const btTransform& rbAFrame) + :btTypedConstraint(rbA),m_rbAFrame(rbAFrame), + m_angularOnly(false) +{ + m_rbBFrame = m_rbAFrame; + + // flip axis for correct angles + m_rbBFrame.getBasis()[1][0] *= btScalar(-1.); + m_rbBFrame.getBasis()[1][1] *= btScalar(-1.); + m_rbBFrame.getBasis()[1][2] *= btScalar(-1.); + + m_rbBFrame.getBasis()[2][0] *= btScalar(-1.); + m_rbBFrame.getBasis()[2][1] *= btScalar(-1.); + m_rbBFrame.getBasis()[2][2] *= btScalar(-1.); + + m_swingSpan1 = btScalar(1e30); + m_swingSpan2 = btScalar(1e30); + m_twistSpan = btScalar(1e30); + m_biasFactor = 0.3f; + m_relaxationFactor = 1.0f; + + m_solveTwistLimit = false; + m_solveSwingLimit = false; + +} + +void btConeTwistConstraint::buildJacobian() +{ + m_appliedImpulse = btScalar(0.); + + //set bias, sign, clear accumulator + m_swingCorrection = btScalar(0.); + m_twistLimitSign = btScalar(0.); + m_solveTwistLimit = false; + m_solveSwingLimit = false; + m_accTwistLimitImpulse = btScalar(0.); + m_accSwingLimitImpulse = btScalar(0.); + + if (!m_angularOnly) + { + btVector3 pivotAInW = m_rbA.getCenterOfMassTransform()*m_rbAFrame.getOrigin(); + btVector3 pivotBInW = m_rbB.getCenterOfMassTransform()*m_rbBFrame.getOrigin(); + btVector3 relPos = pivotBInW - pivotAInW; + + btVector3 normal[3]; + if (relPos.length2() > SIMD_EPSILON) + { + normal[0] = relPos.normalized(); + } + else + { + normal[0].setValue(btScalar(1.0),0,0); + } + + btPlaneSpace1(normal[0], normal[1], normal[2]); + + for (int i=0;i<3;i++) + { + new (&m_jac[i]) btJacobianEntry( + m_rbA.getCenterOfMassTransform().getBasis().transpose(), + m_rbB.getCenterOfMassTransform().getBasis().transpose(), + pivotAInW - m_rbA.getCenterOfMassPosition(), + pivotBInW - m_rbB.getCenterOfMassPosition(), + normal[i], + m_rbA.getInvInertiaDiagLocal(), + m_rbA.getInvMass(), + m_rbB.getInvInertiaDiagLocal(), + m_rbB.getInvMass()); + } + } + + btVector3 b1Axis1,b1Axis2,b1Axis3; + btVector3 b2Axis1,b2Axis2; + + b1Axis1 = getRigidBodyA().getCenterOfMassTransform().getBasis() * this->m_rbAFrame.getBasis().getColumn(0); + b2Axis1 = getRigidBodyB().getCenterOfMassTransform().getBasis() * this->m_rbBFrame.getBasis().getColumn(0); + + btScalar swing1=btScalar(0.),swing2 = btScalar(0.); + + // Get Frame into world space + if (m_swingSpan1 >= btScalar(0.05f)) + { + b1Axis2 = getRigidBodyA().getCenterOfMassTransform().getBasis() * this->m_rbAFrame.getBasis().getColumn(1); + swing1 = btAtan2Fast( b2Axis1.dot(b1Axis2),b2Axis1.dot(b1Axis1) ); + } + + if (m_swingSpan2 >= btScalar(0.05f)) + { + b1Axis3 = getRigidBodyA().getCenterOfMassTransform().getBasis() * this->m_rbAFrame.getBasis().getColumn(2); + swing2 = btAtan2Fast( b2Axis1.dot(b1Axis3),b2Axis1.dot(b1Axis1) ); + } + + btScalar RMaxAngle1Sq = 1.0f / (m_swingSpan1*m_swingSpan1); + btScalar RMaxAngle2Sq = 1.0f / (m_swingSpan2*m_swingSpan2); + btScalar EllipseAngle = btFabs(swing1)* RMaxAngle1Sq + btFabs(swing2) * RMaxAngle2Sq; + + if (EllipseAngle > 1.0f) + { + m_swingCorrection = EllipseAngle-1.0f; + m_solveSwingLimit = true; + + // Calculate necessary axis & factors + m_swingAxis = b2Axis1.cross(b1Axis2* b2Axis1.dot(b1Axis2) + b1Axis3* b2Axis1.dot(b1Axis3)); + m_swingAxis.normalize(); + + btScalar swingAxisSign = (b2Axis1.dot(b1Axis1) >= 0.0f) ? 1.0f : -1.0f; + m_swingAxis *= swingAxisSign; + + m_kSwing = btScalar(1.) / (getRigidBodyA().computeAngularImpulseDenominator(m_swingAxis) + + getRigidBodyB().computeAngularImpulseDenominator(m_swingAxis)); + + } + + // Twist limits + if (m_twistSpan >= btScalar(0.)) + { + btVector3 b2Axis2 = getRigidBodyB().getCenterOfMassTransform().getBasis() * this->m_rbBFrame.getBasis().getColumn(1); + btQuaternion rotationArc = shortestArcQuat(b2Axis1,b1Axis1); + btVector3 TwistRef = quatRotate(rotationArc,b2Axis2); + btScalar twist = btAtan2Fast( TwistRef.dot(b1Axis3), TwistRef.dot(b1Axis2) ); + + btScalar lockedFreeFactor = (m_twistSpan > btScalar(0.05f)) ? m_limitSoftness : btScalar(0.); + if (twist <= -m_twistSpan*lockedFreeFactor) + { + m_twistCorrection = -(twist + m_twistSpan); + m_solveTwistLimit = true; + + m_twistAxis = (b2Axis1 + b1Axis1) * 0.5f; + m_twistAxis.normalize(); + m_twistAxis *= -1.0f; + + m_kTwist = btScalar(1.) / (getRigidBodyA().computeAngularImpulseDenominator(m_twistAxis) + + getRigidBodyB().computeAngularImpulseDenominator(m_twistAxis)); + + } else + if (twist > m_twistSpan*lockedFreeFactor) + { + m_twistCorrection = (twist - m_twistSpan); + m_solveTwistLimit = true; + + m_twistAxis = (b2Axis1 + b1Axis1) * 0.5f; + m_twistAxis.normalize(); + + m_kTwist = btScalar(1.) / (getRigidBodyA().computeAngularImpulseDenominator(m_twistAxis) + + getRigidBodyB().computeAngularImpulseDenominator(m_twistAxis)); + + } + } +} + +void btConeTwistConstraint::solveConstraint(btScalar timeStep) +{ + + btVector3 pivotAInW = m_rbA.getCenterOfMassTransform()*m_rbAFrame.getOrigin(); + btVector3 pivotBInW = m_rbB.getCenterOfMassTransform()*m_rbBFrame.getOrigin(); + + btScalar tau = btScalar(0.3); + btScalar damping = btScalar(1.); + + //linear part + if (!m_angularOnly) + { + btVector3 rel_pos1 = pivotAInW - m_rbA.getCenterOfMassPosition(); + btVector3 rel_pos2 = pivotBInW - m_rbB.getCenterOfMassPosition(); + + btVector3 vel1 = m_rbA.getVelocityInLocalPoint(rel_pos1); + btVector3 vel2 = m_rbB.getVelocityInLocalPoint(rel_pos2); + btVector3 vel = vel1 - vel2; + + for (int i=0;i<3;i++) + { + const btVector3& normal = m_jac[i].m_linearJointAxis; + btScalar jacDiagABInv = btScalar(1.) / m_jac[i].getDiagonal(); + + btScalar rel_vel; + rel_vel = normal.dot(vel); + //positional error (zeroth order error) + btScalar depth = -(pivotAInW - pivotBInW).dot(normal); //this is the error projected on the normal + btScalar impulse = depth*tau/timeStep * jacDiagABInv - rel_vel * jacDiagABInv; + m_appliedImpulse += impulse; + btVector3 impulse_vector = normal * impulse; + m_rbA.applyImpulse(impulse_vector, pivotAInW - m_rbA.getCenterOfMassPosition()); + m_rbB.applyImpulse(-impulse_vector, pivotBInW - m_rbB.getCenterOfMassPosition()); + } + } + + { + ///solve angular part + const btVector3& angVelA = getRigidBodyA().getAngularVelocity(); + const btVector3& angVelB = getRigidBodyB().getAngularVelocity(); + + // solve swing limit + if (m_solveSwingLimit) + { + btScalar amplitude = ((angVelB - angVelA).dot( m_swingAxis )*m_relaxationFactor*m_relaxationFactor + m_swingCorrection*(btScalar(1.)/timeStep)*m_biasFactor); + btScalar impulseMag = amplitude * m_kSwing; + + // Clamp the accumulated impulse + btScalar temp = m_accSwingLimitImpulse; + m_accSwingLimitImpulse = btMax(m_accSwingLimitImpulse + impulseMag, 0.0f ); + impulseMag = m_accSwingLimitImpulse - temp; + + btVector3 impulse = m_swingAxis * impulseMag; + + m_rbA.applyTorqueImpulse(impulse); + m_rbB.applyTorqueImpulse(-impulse); + + } + + // solve twist limit + if (m_solveTwistLimit) + { + btScalar amplitude = ((angVelB - angVelA).dot( m_twistAxis )*m_relaxationFactor*m_relaxationFactor + m_twistCorrection*(btScalar(1.)/timeStep)*m_biasFactor ); + btScalar impulseMag = amplitude * m_kTwist; + + // Clamp the accumulated impulse + btScalar temp = m_accTwistLimitImpulse; + m_accTwistLimitImpulse = btMax(m_accTwistLimitImpulse + impulseMag, 0.0f ); + impulseMag = m_accTwistLimitImpulse - temp; + + btVector3 impulse = m_twistAxis * impulseMag; + + m_rbA.applyTorqueImpulse(impulse); + m_rbB.applyTorqueImpulse(-impulse); + + } + + } + +} + +void btConeTwistConstraint::updateRHS(btScalar timeStep) +{ + (void)timeStep; + +} |