498 lines
16 KiB
C++
498 lines
16 KiB
C++
/*
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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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#include "btRigidBody.h"
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#include "BulletCollision/CollisionShapes/btConvexShape.h"
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#include "LinearMath/btMinMax.h"
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#include "LinearMath/btTransformUtil.h"
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#include "LinearMath/btMotionState.h"
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#include "BulletDynamics/ConstraintSolver/btTypedConstraint.h"
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#include "LinearMath/btSerializer.h"
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//'temporarily' global variables
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btScalar gDeactivationTime = btScalar(2.);
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bool gDisableDeactivation = false;
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static int uniqueId = 0;
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btRigidBody::btRigidBody(const btRigidBody::btRigidBodyConstructionInfo& constructionInfo)
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{
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setupRigidBody(constructionInfo);
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}
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btRigidBody::btRigidBody(btScalar mass, btMotionState* motionState, btCollisionShape* collisionShape, const btVector3& localInertia)
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{
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btRigidBodyConstructionInfo cinfo(mass, motionState, collisionShape, localInertia);
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setupRigidBody(cinfo);
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}
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void btRigidBody::setupRigidBody(const btRigidBody::btRigidBodyConstructionInfo& constructionInfo)
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{
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m_internalType = CO_RIGID_BODY;
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m_linearVelocity.setValue(btScalar(0.0), btScalar(0.0), btScalar(0.0));
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m_angularVelocity.setValue(btScalar(0.), btScalar(0.), btScalar(0.));
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m_angularFactor.setValue(1, 1, 1);
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m_linearFactor.setValue(1, 1, 1);
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m_gravity.setValue(btScalar(0.0), btScalar(0.0), btScalar(0.0));
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m_gravity_acceleration.setValue(btScalar(0.0), btScalar(0.0), btScalar(0.0));
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m_totalForce.setValue(btScalar(0.0), btScalar(0.0), btScalar(0.0));
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m_totalTorque.setValue(btScalar(0.0), btScalar(0.0), btScalar(0.0)),
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setDamping(constructionInfo.m_linearDamping, constructionInfo.m_angularDamping);
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m_linearSleepingThreshold = constructionInfo.m_linearSleepingThreshold;
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m_angularSleepingThreshold = constructionInfo.m_angularSleepingThreshold;
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m_optionalMotionState = constructionInfo.m_motionState;
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m_contactSolverType = 0;
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m_frictionSolverType = 0;
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m_additionalDamping = constructionInfo.m_additionalDamping;
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m_additionalDampingFactor = constructionInfo.m_additionalDampingFactor;
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m_additionalLinearDampingThresholdSqr = constructionInfo.m_additionalLinearDampingThresholdSqr;
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m_additionalAngularDampingThresholdSqr = constructionInfo.m_additionalAngularDampingThresholdSqr;
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m_additionalAngularDampingFactor = constructionInfo.m_additionalAngularDampingFactor;
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if (m_optionalMotionState)
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{
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m_optionalMotionState->getWorldTransform(m_worldTransform);
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}
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else
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{
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m_worldTransform = constructionInfo.m_startWorldTransform;
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}
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m_interpolationWorldTransform = m_worldTransform;
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m_interpolationLinearVelocity.setValue(0, 0, 0);
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m_interpolationAngularVelocity.setValue(0, 0, 0);
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//moved to btCollisionObject
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m_friction = constructionInfo.m_friction;
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m_rollingFriction = constructionInfo.m_rollingFriction;
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m_spinningFriction = constructionInfo.m_spinningFriction;
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m_restitution = constructionInfo.m_restitution;
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setCollisionShape(constructionInfo.m_collisionShape);
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m_debugBodyId = uniqueId++;
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setMassProps(constructionInfo.m_mass, constructionInfo.m_localInertia);
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updateInertiaTensor();
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m_rigidbodyFlags = BT_ENABLE_GYROSCOPIC_FORCE_IMPLICIT_BODY;
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m_deltaLinearVelocity.setZero();
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m_deltaAngularVelocity.setZero();
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m_invMass = m_inverseMass * m_linearFactor;
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m_pushVelocity.setZero();
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m_turnVelocity.setZero();
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}
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void btRigidBody::predictIntegratedTransform(btScalar timeStep, btTransform& predictedTransform)
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{
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btTransformUtil::integrateTransform(m_worldTransform, m_linearVelocity, m_angularVelocity, timeStep, predictedTransform);
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}
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void btRigidBody::saveKinematicState(btScalar timeStep)
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{
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//todo: clamp to some (user definable) safe minimum timestep, to limit maximum angular/linear velocities
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if (timeStep != btScalar(0.))
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{
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//if we use motionstate to synchronize world transforms, get the new kinematic/animated world transform
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if (getMotionState())
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getMotionState()->getWorldTransform(m_worldTransform);
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btVector3 linVel, angVel;
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btTransformUtil::calculateVelocity(m_interpolationWorldTransform, m_worldTransform, timeStep, m_linearVelocity, m_angularVelocity);
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m_interpolationLinearVelocity = m_linearVelocity;
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m_interpolationAngularVelocity = m_angularVelocity;
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m_interpolationWorldTransform = m_worldTransform;
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//printf("angular = %f %f %f\n",m_angularVelocity.getX(),m_angularVelocity.getY(),m_angularVelocity.getZ());
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}
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}
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void btRigidBody::getAabb(btVector3& aabbMin, btVector3& aabbMax) const
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{
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getCollisionShape()->getAabb(m_worldTransform, aabbMin, aabbMax);
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}
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void btRigidBody::setGravity(const btVector3& acceleration)
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{
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if (m_inverseMass != btScalar(0.0))
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{
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m_gravity = acceleration * (btScalar(1.0) / m_inverseMass);
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}
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m_gravity_acceleration = acceleration;
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}
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void btRigidBody::setDamping(btScalar lin_damping, btScalar ang_damping)
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{
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m_linearDamping = btClamped(lin_damping, (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
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m_angularDamping = btClamped(ang_damping, (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
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}
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///applyDamping damps the velocity, using the given m_linearDamping and m_angularDamping
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void btRigidBody::applyDamping(btScalar timeStep)
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{
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//On new damping: see discussion/issue report here: http://code.google.com/p/bullet/issues/detail?id=74
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//todo: do some performance comparisons (but other parts of the engine are probably bottleneck anyway
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//#define USE_OLD_DAMPING_METHOD 1
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#ifdef USE_OLD_DAMPING_METHOD
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m_linearVelocity *= GEN_clamped((btScalar(1.) - timeStep * m_linearDamping), (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
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m_angularVelocity *= GEN_clamped((btScalar(1.) - timeStep * m_angularDamping), (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
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#else
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m_linearVelocity *= btPow(btScalar(1) - m_linearDamping, timeStep);
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m_angularVelocity *= btPow(btScalar(1) - m_angularDamping, timeStep);
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#endif
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if (m_additionalDamping)
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{
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//Additional damping can help avoiding lowpass jitter motion, help stability for ragdolls etc.
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//Such damping is undesirable, so once the overall simulation quality of the rigid body dynamics system has improved, this should become obsolete
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if ((m_angularVelocity.length2() < m_additionalAngularDampingThresholdSqr) &&
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(m_linearVelocity.length2() < m_additionalLinearDampingThresholdSqr))
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{
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m_angularVelocity *= m_additionalDampingFactor;
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m_linearVelocity *= m_additionalDampingFactor;
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}
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btScalar speed = m_linearVelocity.length();
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if (speed < m_linearDamping)
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{
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btScalar dampVel = btScalar(0.005);
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if (speed > dampVel)
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{
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btVector3 dir = m_linearVelocity.normalized();
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m_linearVelocity -= dir * dampVel;
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}
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else
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{
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m_linearVelocity.setValue(btScalar(0.), btScalar(0.), btScalar(0.));
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}
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}
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btScalar angSpeed = m_angularVelocity.length();
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if (angSpeed < m_angularDamping)
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{
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btScalar angDampVel = btScalar(0.005);
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if (angSpeed > angDampVel)
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{
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btVector3 dir = m_angularVelocity.normalized();
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m_angularVelocity -= dir * angDampVel;
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}
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else
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{
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m_angularVelocity.setValue(btScalar(0.), btScalar(0.), btScalar(0.));
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}
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}
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}
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}
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void btRigidBody::applyGravity()
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{
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if (isStaticOrKinematicObject())
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return;
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applyCentralForce(m_gravity);
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}
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void btRigidBody::clearGravity()
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{
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if (isStaticOrKinematicObject())
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return;
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applyCentralForce(-m_gravity);
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}
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void btRigidBody::proceedToTransform(const btTransform& newTrans)
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{
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setCenterOfMassTransform(newTrans);
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}
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void btRigidBody::setMassProps(btScalar mass, const btVector3& inertia)
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{
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if (mass == btScalar(0.))
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{
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m_collisionFlags |= btCollisionObject::CF_STATIC_OBJECT;
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m_inverseMass = btScalar(0.);
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}
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else
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{
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m_collisionFlags &= (~btCollisionObject::CF_STATIC_OBJECT);
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m_inverseMass = btScalar(1.0) / mass;
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}
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//Fg = m * a
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m_gravity = mass * m_gravity_acceleration;
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m_invInertiaLocal.setValue(inertia.x() != btScalar(0.0) ? btScalar(1.0) / inertia.x() : btScalar(0.0),
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inertia.y() != btScalar(0.0) ? btScalar(1.0) / inertia.y() : btScalar(0.0),
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inertia.z() != btScalar(0.0) ? btScalar(1.0) / inertia.z() : btScalar(0.0));
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m_invMass = m_linearFactor * m_inverseMass;
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}
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void btRigidBody::updateInertiaTensor()
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{
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m_invInertiaTensorWorld = m_worldTransform.getBasis().scaled(m_invInertiaLocal) * m_worldTransform.getBasis().transpose();
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}
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btVector3 btRigidBody::getLocalInertia() const
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{
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btVector3 inertiaLocal;
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const btVector3 inertia = m_invInertiaLocal;
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inertiaLocal.setValue(inertia.x() != btScalar(0.0) ? btScalar(1.0) / inertia.x() : btScalar(0.0),
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inertia.y() != btScalar(0.0) ? btScalar(1.0) / inertia.y() : btScalar(0.0),
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inertia.z() != btScalar(0.0) ? btScalar(1.0) / inertia.z() : btScalar(0.0));
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return inertiaLocal;
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}
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inline btVector3 evalEulerEqn(const btVector3& w1, const btVector3& w0, const btVector3& T, const btScalar dt,
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const btMatrix3x3& I)
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{
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const btVector3 w2 = I * w1 + w1.cross(I * w1) * dt - (T * dt + I * w0);
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return w2;
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}
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inline btMatrix3x3 evalEulerEqnDeriv(const btVector3& w1, const btVector3& w0, const btScalar dt,
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const btMatrix3x3& I)
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{
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btMatrix3x3 w1x, Iw1x;
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const btVector3 Iwi = (I * w1);
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w1.getSkewSymmetricMatrix(&w1x[0], &w1x[1], &w1x[2]);
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Iwi.getSkewSymmetricMatrix(&Iw1x[0], &Iw1x[1], &Iw1x[2]);
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const btMatrix3x3 dfw1 = I + (w1x * I - Iw1x) * dt;
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return dfw1;
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}
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btVector3 btRigidBody::computeGyroscopicForceExplicit(btScalar maxGyroscopicForce) const
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{
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btVector3 inertiaLocal = getLocalInertia();
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btMatrix3x3 inertiaTensorWorld = getWorldTransform().getBasis().scaled(inertiaLocal) * getWorldTransform().getBasis().transpose();
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btVector3 tmp = inertiaTensorWorld * getAngularVelocity();
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btVector3 gf = getAngularVelocity().cross(tmp);
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btScalar l2 = gf.length2();
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if (l2 > maxGyroscopicForce * maxGyroscopicForce)
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{
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gf *= btScalar(1.) / btSqrt(l2) * maxGyroscopicForce;
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}
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return gf;
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}
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btVector3 btRigidBody::computeGyroscopicImpulseImplicit_Body(btScalar step) const
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{
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btVector3 idl = getLocalInertia();
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btVector3 omega1 = getAngularVelocity();
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btQuaternion q = getWorldTransform().getRotation();
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// Convert to body coordinates
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btVector3 omegab = quatRotate(q.inverse(), omega1);
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btMatrix3x3 Ib;
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Ib.setValue(idl.x(), 0, 0,
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0, idl.y(), 0,
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0, 0, idl.z());
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btVector3 ibo = Ib * omegab;
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// Residual vector
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btVector3 f = step * omegab.cross(ibo);
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btMatrix3x3 skew0;
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omegab.getSkewSymmetricMatrix(&skew0[0], &skew0[1], &skew0[2]);
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btVector3 om = Ib * omegab;
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btMatrix3x3 skew1;
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om.getSkewSymmetricMatrix(&skew1[0], &skew1[1], &skew1[2]);
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// Jacobian
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btMatrix3x3 J = Ib + (skew0 * Ib - skew1) * step;
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// btMatrix3x3 Jinv = J.inverse();
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// btVector3 omega_div = Jinv*f;
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btVector3 omega_div = J.solve33(f);
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// Single Newton-Raphson update
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omegab = omegab - omega_div; //Solve33(J, f);
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// Back to world coordinates
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btVector3 omega2 = quatRotate(q, omegab);
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btVector3 gf = omega2 - omega1;
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return gf;
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}
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btVector3 btRigidBody::computeGyroscopicImpulseImplicit_World(btScalar step) const
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{
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// use full newton-euler equations. common practice to drop the wxIw term. want it for better tumbling behavior.
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// calculate using implicit euler step so it's stable.
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const btVector3 inertiaLocal = getLocalInertia();
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const btVector3 w0 = getAngularVelocity();
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btMatrix3x3 I;
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I = m_worldTransform.getBasis().scaled(inertiaLocal) *
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m_worldTransform.getBasis().transpose();
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// use newtons method to find implicit solution for new angular velocity (w')
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// f(w') = -(T*step + Iw) + Iw' + w' + w'xIw'*step = 0
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// df/dw' = I + 1xIw'*step + w'xI*step
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btVector3 w1 = w0;
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// one step of newton's method
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{
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const btVector3 fw = evalEulerEqn(w1, w0, btVector3(0, 0, 0), step, I);
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const btMatrix3x3 dfw = evalEulerEqnDeriv(w1, w0, step, I);
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btVector3 dw;
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dw = dfw.solve33(fw);
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//const btMatrix3x3 dfw_inv = dfw.inverse();
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//dw = dfw_inv*fw;
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w1 -= dw;
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}
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btVector3 gf = (w1 - w0);
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return gf;
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}
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void btRigidBody::integrateVelocities(btScalar step)
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{
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if (isStaticOrKinematicObject())
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return;
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m_linearVelocity += m_totalForce * (m_inverseMass * step);
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m_angularVelocity += m_invInertiaTensorWorld * m_totalTorque * step;
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#define MAX_ANGVEL SIMD_HALF_PI
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/// clamp angular velocity. collision calculations will fail on higher angular velocities
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btScalar angvel = m_angularVelocity.length();
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if (angvel * step > MAX_ANGVEL)
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{
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m_angularVelocity *= (MAX_ANGVEL / step) / angvel;
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}
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}
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btQuaternion btRigidBody::getOrientation() const
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{
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btQuaternion orn;
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m_worldTransform.getBasis().getRotation(orn);
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return orn;
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}
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void btRigidBody::setCenterOfMassTransform(const btTransform& xform)
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{
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if (isKinematicObject())
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{
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m_interpolationWorldTransform = m_worldTransform;
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}
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else
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{
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m_interpolationWorldTransform = xform;
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}
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m_interpolationLinearVelocity = getLinearVelocity();
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m_interpolationAngularVelocity = getAngularVelocity();
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m_worldTransform = xform;
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updateInertiaTensor();
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}
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void btRigidBody::addConstraintRef(btTypedConstraint* c)
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{
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///disable collision with the 'other' body
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int index = m_constraintRefs.findLinearSearch(c);
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//don't add constraints that are already referenced
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//btAssert(index == m_constraintRefs.size());
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if (index == m_constraintRefs.size())
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{
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m_constraintRefs.push_back(c);
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btCollisionObject* colObjA = &c->getRigidBodyA();
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btCollisionObject* colObjB = &c->getRigidBodyB();
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if (colObjA == this)
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{
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colObjA->setIgnoreCollisionCheck(colObjB, true);
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}
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else
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{
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colObjB->setIgnoreCollisionCheck(colObjA, true);
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}
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}
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}
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void btRigidBody::removeConstraintRef(btTypedConstraint* c)
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{
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int index = m_constraintRefs.findLinearSearch(c);
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//don't remove constraints that are not referenced
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if (index < m_constraintRefs.size())
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{
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m_constraintRefs.remove(c);
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btCollisionObject* colObjA = &c->getRigidBodyA();
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btCollisionObject* colObjB = &c->getRigidBodyB();
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if (colObjA == this)
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{
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colObjA->setIgnoreCollisionCheck(colObjB, false);
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}
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else
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{
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colObjB->setIgnoreCollisionCheck(colObjA, false);
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}
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}
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}
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int btRigidBody::calculateSerializeBufferSize() const
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{
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int sz = sizeof(btRigidBodyData);
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return sz;
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}
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///fills the dataBuffer and returns the struct name (and 0 on failure)
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const char* btRigidBody::serialize(void* dataBuffer, class btSerializer* serializer) const
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{
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btRigidBodyData* rbd = (btRigidBodyData*)dataBuffer;
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btCollisionObject::serialize(&rbd->m_collisionObjectData, serializer);
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m_invInertiaTensorWorld.serialize(rbd->m_invInertiaTensorWorld);
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m_linearVelocity.serialize(rbd->m_linearVelocity);
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m_angularVelocity.serialize(rbd->m_angularVelocity);
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rbd->m_inverseMass = m_inverseMass;
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m_angularFactor.serialize(rbd->m_angularFactor);
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m_linearFactor.serialize(rbd->m_linearFactor);
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m_gravity.serialize(rbd->m_gravity);
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m_gravity_acceleration.serialize(rbd->m_gravity_acceleration);
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m_invInertiaLocal.serialize(rbd->m_invInertiaLocal);
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m_totalForce.serialize(rbd->m_totalForce);
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m_totalTorque.serialize(rbd->m_totalTorque);
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rbd->m_linearDamping = m_linearDamping;
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rbd->m_angularDamping = m_angularDamping;
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rbd->m_additionalDamping = m_additionalDamping;
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rbd->m_additionalDampingFactor = m_additionalDampingFactor;
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rbd->m_additionalLinearDampingThresholdSqr = m_additionalLinearDampingThresholdSqr;
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rbd->m_additionalAngularDampingThresholdSqr = m_additionalAngularDampingThresholdSqr;
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rbd->m_additionalAngularDampingFactor = m_additionalAngularDampingFactor;
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rbd->m_linearSleepingThreshold = m_linearSleepingThreshold;
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rbd->m_angularSleepingThreshold = m_angularSleepingThreshold;
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// Fill padding with zeros to appease msan.
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#ifdef BT_USE_DOUBLE_PRECISION
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memset(rbd->m_padding, 0, sizeof(rbd->m_padding));
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#endif
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return btRigidBodyDataName;
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}
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void btRigidBody::serializeSingleObject(class btSerializer* serializer) const
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{
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btChunk* chunk = serializer->allocate(calculateSerializeBufferSize(), 1);
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const char* structType = serialize(chunk->m_oldPtr, serializer);
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serializer->finalizeChunk(chunk, structType, BT_RIGIDBODY_CODE, (void*)this);
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}
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