btMultiBody* MultiDofDemo::createFeatherstoneMultiBody_testMultiDof(btMultiBodyDynamicsWorld *pWorld, int numLinks, const btVector3 &basePosition, const btVector3 &baseHalfExtents, const btVector3 &linkHalfExtents, bool spherical, bool floating) { //init the base btVector3 baseInertiaDiag(0.f, 0.f, 0.f); float baseMass = 1.f; if(baseMass) { btCollisionShape *pTempBox = new btBoxShape(btVector3(baseHalfExtents[0], baseHalfExtents[1], baseHalfExtents[2])); pTempBox->calculateLocalInertia(baseMass, baseInertiaDiag); delete pTempBox; } bool canSleep = false; btMultiBody *pMultiBody = new btMultiBody(numLinks, baseMass, baseInertiaDiag, !floating, canSleep); btQuaternion baseOriQuat(0.f, 0.f, 0.f, 1.f); pMultiBody->setBasePos(basePosition); pMultiBody->setWorldToBaseRot(baseOriQuat); btVector3 vel(0, 0, 0); // pMultiBody->setBaseVel(vel); //init the links btVector3 hingeJointAxis(1, 0, 0); float linkMass = 1.f; btVector3 linkInertiaDiag(0.f, 0.f, 0.f); btCollisionShape *pTempBox = new btBoxShape(btVector3(linkHalfExtents[0], linkHalfExtents[1], linkHalfExtents[2])); pTempBox->calculateLocalInertia(linkMass, linkInertiaDiag); delete pTempBox; //y-axis assumed up btVector3 parentComToCurrentCom(0, -linkHalfExtents[1] * 2.f, 0); //par body's COM to cur body's COM offset btVector3 currentPivotToCurrentCom(0, -linkHalfExtents[1], 0); //cur body's COM to cur body's PIV offset btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; //par body's COM to cur body's PIV offset ////// btScalar q0 = 0.f * SIMD_PI/ 180.f; btQuaternion quat0(btVector3(0, 1, 0).normalized(), q0); quat0.normalize(); ///// for(int i = 0; i < numLinks; ++i) { if(!spherical) pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), hingeJointAxis, parentComToCurrentPivot, currentPivotToCurrentCom, true); else //pMultiBody->setupPlanar(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f)/*quat0*/, btVector3(1, 0, 0), parentComToCurrentPivot*2, false); pMultiBody->setupSpherical(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), parentComToCurrentPivot, currentPivotToCurrentCom, true); } pMultiBody->finalizeMultiDof(); /// pWorld->addMultiBody(pMultiBody); /// return pMultiBody; }
void TestJointTorqueSetup::initPhysics() { int upAxis = 1; gJointFeedbackInWorldSpace = true; gJointFeedbackInJointFrame = true; m_guiHelper->setUpAxis(upAxis); btVector4 colors[4] = { btVector4(1,0,0,1), btVector4(0,1,0,1), btVector4(0,1,1,1), btVector4(1,1,0,1), }; int curColor = 0; this->createEmptyDynamicsWorld(); m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld); m_dynamicsWorld->getDebugDrawer()->setDebugMode( //btIDebugDraw::DBG_DrawConstraints +btIDebugDraw::DBG_DrawWireframe +btIDebugDraw::DBG_DrawContactPoints +btIDebugDraw::DBG_DrawAabb );//+btIDebugDraw::DBG_DrawConstraintLimits); //create a static ground object if (1) { btVector3 groundHalfExtents(1,1,0.2); groundHalfExtents[upAxis]=1.f; btBoxShape* box = new btBoxShape(groundHalfExtents); box->initializePolyhedralFeatures(); m_guiHelper->createCollisionShapeGraphicsObject(box); btTransform start; start.setIdentity(); btVector3 groundOrigin(-0.4f, 3.f, 0.f); groundOrigin[upAxis] -=.5; groundOrigin[2]-=0.6; start.setOrigin(groundOrigin); btQuaternion groundOrn(btVector3(0,1,0),0.25*SIMD_PI); // start.setRotation(groundOrn); btRigidBody* body = createRigidBody(0,start,box); body->setFriction(0); btVector4 color = colors[curColor]; curColor++; curColor&=3; m_guiHelper->createRigidBodyGraphicsObject(body,color); } { bool floating = false; bool damping = false; bool gyro = false; int numLinks = 2; bool spherical = false; //set it ot false -to use 1DoF hinges instead of 3DoF sphericals bool canSleep = false; bool selfCollide = false; btVector3 linkHalfExtents(0.05, 0.37, 0.1); btVector3 baseHalfExtents(0.05, 0.37, 0.1); btVector3 basePosition = btVector3(-0.4f, 3.f, 0.f); //mbC->forceMultiDof(); //if !spherical, you can comment this line to check the 1DoF algorithm //init the base btVector3 baseInertiaDiag(0.f, 0.f, 0.f); float baseMass = 1.f; if(baseMass) { //btCollisionShape *shape = new btSphereShape(baseHalfExtents[0]);// btBoxShape(btVector3(baseHalfExtents[0], baseHalfExtents[1], baseHalfExtents[2])); btCollisionShape *shape = new btBoxShape(btVector3(baseHalfExtents[0], baseHalfExtents[1], baseHalfExtents[2])); shape->calculateLocalInertia(baseMass, baseInertiaDiag); delete shape; } bool isMultiDof = true; btMultiBody *pMultiBody = new btMultiBody(numLinks, baseMass, baseInertiaDiag, !floating, canSleep, isMultiDof); m_multiBody = pMultiBody; btQuaternion baseOriQuat(0.f, 0.f, 0.f, 1.f); // baseOriQuat.setEulerZYX(-.25*SIMD_PI,0,-1.75*SIMD_PI); pMultiBody->setBasePos(basePosition); pMultiBody->setWorldToBaseRot(baseOriQuat); btVector3 vel(0, 0, 0); // pMultiBody->setBaseVel(vel); //init the links btVector3 hingeJointAxis(1, 0, 0); //y-axis assumed up btVector3 parentComToCurrentCom(0, -linkHalfExtents[1] * 2.f, 0); //par body's COM to cur body's COM offset btVector3 currentPivotToCurrentCom(0, -linkHalfExtents[1], 0); //cur body's COM to cur body's PIV offset btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; //par body's COM to cur body's PIV offset ////// btScalar q0 = 0.f * SIMD_PI/ 180.f; btQuaternion quat0(btVector3(0, 1, 0).normalized(), q0); quat0.normalize(); ///// for(int i = 0; i < numLinks; ++i) { float linkMass = 1.f; //if (i==3 || i==2) // linkMass= 1000; btVector3 linkInertiaDiag(0.f, 0.f, 0.f); btCollisionShape* shape = 0; if (i==0) { shape = new btBoxShape(btVector3(linkHalfExtents[0], linkHalfExtents[1], linkHalfExtents[2]));// } else { shape = new btSphereShape(radius); } shape->calculateLocalInertia(linkMass, linkInertiaDiag); delete shape; if(!spherical) { //pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), hingeJointAxis, parentComToCurrentPivot, currentPivotToCurrentCom, false); if (i==0) { pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), hingeJointAxis, parentComToCurrentPivot, currentPivotToCurrentCom, false); } else { btVector3 parentComToCurrentCom(0, -radius * 2.f, 0); //par body's COM to cur body's COM offset btVector3 currentPivotToCurrentCom(0, -radius, 0); //cur body's COM to cur body's PIV offset btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; //par body's COM to cur body's PIV offset pMultiBody->setupFixed(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), parentComToCurrentPivot, currentPivotToCurrentCom, false); } //pMultiBody->setupFixed(i,linkMass,linkInertiaDiag,i-1,btQuaternion(0,0,0,1),parentComToCurrentPivot,currentPivotToCurrentCom,false); } else { //pMultiBody->setupPlanar(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f)/*quat0*/, btVector3(1, 0, 0), parentComToCurrentPivot*2, false); pMultiBody->setupSpherical(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), parentComToCurrentPivot, currentPivotToCurrentCom, false); } } pMultiBody->finalizeMultiDof(); //for (int i=pMultiBody->getNumLinks()-1;i>=0;i--)// for (int i=0;i<pMultiBody->getNumLinks();i++) { btMultiBodyJointFeedback* fb = new btMultiBodyJointFeedback(); pMultiBody->getLink(i).m_jointFeedback = fb; m_jointFeedbacks.push_back(fb); //break; } btMultiBodyDynamicsWorld* world = m_dynamicsWorld; /// world->addMultiBody(pMultiBody); btMultiBody* mbC = pMultiBody; mbC->setCanSleep(canSleep); mbC->setHasSelfCollision(selfCollide); mbC->setUseGyroTerm(gyro); // if(!damping) { mbC->setLinearDamping(0.f); mbC->setAngularDamping(0.f); }else { mbC->setLinearDamping(0.1f); mbC->setAngularDamping(0.9f); } // m_dynamicsWorld->setGravity(btVector3(0,0,-10)); ////////////////////////////////////////////// if(0)//numLinks > 0) { btScalar q0 = 45.f * SIMD_PI/ 180.f; if(!spherical) if(mbC->isMultiDof()) mbC->setJointPosMultiDof(0, &q0); else mbC->setJointPos(0, q0); else { btQuaternion quat0(btVector3(1, 1, 0).normalized(), q0); quat0.normalize(); mbC->setJointPosMultiDof(0, quat0); } } /// btAlignedObjectArray<btQuaternion> world_to_local; world_to_local.resize(pMultiBody->getNumLinks() + 1); btAlignedObjectArray<btVector3> local_origin; local_origin.resize(pMultiBody->getNumLinks() + 1); world_to_local[0] = pMultiBody->getWorldToBaseRot(); local_origin[0] = pMultiBody->getBasePos(); // double friction = 1; { // float pos[4]={local_origin[0].x(),local_origin[0].y(),local_origin[0].z(),1}; // btScalar quat[4]={-world_to_local[0].x(),-world_to_local[0].y(),-world_to_local[0].z(),world_to_local[0].w()}; if (1) { btCollisionShape* shape = new btBoxShape(btVector3(baseHalfExtents[0],baseHalfExtents[1],baseHalfExtents[2]));//new btSphereShape(baseHalfExtents[0]); m_guiHelper->createCollisionShapeGraphicsObject(shape); btMultiBodyLinkCollider* col= new btMultiBodyLinkCollider(pMultiBody, -1); col->setCollisionShape(shape); btTransform tr; tr.setIdentity(); //if we don't set the initial pose of the btCollisionObject, the simulator will do this //when syncing the btMultiBody link transforms to the btMultiBodyLinkCollider tr.setOrigin(local_origin[0]); btQuaternion orn(btVector3(0,0,1),0.25*3.1415926538); tr.setRotation(orn); col->setWorldTransform(tr); bool isDynamic = (baseMass > 0 && floating); short collisionFilterGroup = isDynamic? short(btBroadphaseProxy::DefaultFilter) : short(btBroadphaseProxy::StaticFilter); short collisionFilterMask = isDynamic? short(btBroadphaseProxy::AllFilter) : short(btBroadphaseProxy::AllFilter ^ btBroadphaseProxy::StaticFilter); world->addCollisionObject(col,collisionFilterGroup,collisionFilterMask);//, 2,1+2); btVector3 color(0.0,0.0,0.5); m_guiHelper->createCollisionObjectGraphicsObject(col,color); // col->setFriction(friction); pMultiBody->setBaseCollider(col); } } for (int i=0; i < pMultiBody->getNumLinks(); ++i) { const int parent = pMultiBody->getParent(i); world_to_local[i+1] = pMultiBody->getParentToLocalRot(i) * world_to_local[parent+1]; local_origin[i+1] = local_origin[parent+1] + (quatRotate(world_to_local[i+1].inverse() , pMultiBody->getRVector(i))); } for (int i=0; i < pMultiBody->getNumLinks(); ++i) { btVector3 posr = local_origin[i+1]; // float pos[4]={posr.x(),posr.y(),posr.z(),1}; btScalar quat[4]={-world_to_local[i+1].x(),-world_to_local[i+1].y(),-world_to_local[i+1].z(),world_to_local[i+1].w()}; btCollisionShape* shape =0; if (i==0) { shape = new btBoxShape(btVector3(linkHalfExtents[0],linkHalfExtents[1],linkHalfExtents[2]));//btSphereShape(linkHalfExtents[0]); } else { shape = new btSphereShape(radius); } m_guiHelper->createCollisionShapeGraphicsObject(shape); btMultiBodyLinkCollider* col = new btMultiBodyLinkCollider(pMultiBody, i); col->setCollisionShape(shape); btTransform tr; tr.setIdentity(); tr.setOrigin(posr); tr.setRotation(btQuaternion(quat[0],quat[1],quat[2],quat[3])); col->setWorldTransform(tr); // col->setFriction(friction); bool isDynamic = 1;//(linkMass > 0); short collisionFilterGroup = isDynamic? short(btBroadphaseProxy::DefaultFilter) : short(btBroadphaseProxy::StaticFilter); short collisionFilterMask = isDynamic? short(btBroadphaseProxy::AllFilter) : short(btBroadphaseProxy::AllFilter ^ btBroadphaseProxy::StaticFilter); //if (i==0||i>numLinks-2) { world->addCollisionObject(col,collisionFilterGroup,collisionFilterMask);//,2,1+2); btVector4 color = colors[curColor]; curColor++; curColor&=3; m_guiHelper->createCollisionObjectGraphicsObject(col,color); pMultiBody->getLink(i).m_collider=col; } } } btSerializer* s = new btDefaultSerializer; m_dynamicsWorld->serialize(s); b3ResourcePath p; char resourcePath[1024]; if (p.findResourcePath("multibody.bullet",resourcePath,1024)) { FILE* f = fopen(resourcePath,"wb"); fwrite(s->getBufferPointer(),s->getCurrentBufferSize(),1,f); fclose(f); } }
void Pendulum::initPhysics() { int upAxis = 1; m_guiHelper->setUpAxis(upAxis); this->createEmptyDynamicsWorld(); m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld); if (m_dynamicsWorld->getDebugDrawer()) { m_dynamicsWorld->getDebugDrawer()->setDebugMode( //btIDebugDraw::DBG_DrawConstraints +btIDebugDraw::DBG_DrawWireframe +btIDebugDraw::DBG_DrawContactPoints +btIDebugDraw::DBG_DrawAabb );//+btIDebugDraw::DBG_DrawConstraintLimits); } { bool floating = false; bool damping = false; bool gyro = false; int numLinks = 1; bool canSleep = false; bool selfCollide = false; btVector3 linkHalfExtents(0.05, 0.5, 0.1); btVector3 baseHalfExtents(0.05, 0.5, 0.1); btVector3 baseInertiaDiag(0.f, 0.f, 0.f); float baseMass = 0.f; btMultiBody *pMultiBody = new btMultiBody(numLinks, baseMass, baseInertiaDiag, !floating, canSleep); //pMultiBody->useRK4Integration(true); m_multiBody = pMultiBody; pMultiBody->setBaseWorldTransform(btTransform::getIdentity()); //init the links btVector3 hingeJointAxis(1, 0, 0); //y-axis assumed up btVector3 parentComToCurrentCom(0, -linkHalfExtents[1] , 0); btVector3 currentPivotToCurrentCom(0, -linkHalfExtents[1], 0); btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; for(int i = 0; i < numLinks; ++i) { float linkMass = 10.f; btVector3 linkInertiaDiag(0.f, 0.f, 0.f); btCollisionShape* shape = 0; { shape = new btSphereShape(radius); } shape->calculateLocalInertia(linkMass, linkInertiaDiag); delete shape; pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), hingeJointAxis, parentComToCurrentPivot, currentPivotToCurrentCom, false); } pMultiBody->finalizeMultiDof(); btMultiBodyDynamicsWorld* world = m_dynamicsWorld; world->addMultiBody(pMultiBody); pMultiBody->setCanSleep(canSleep); pMultiBody->setHasSelfCollision(selfCollide); pMultiBody->setUseGyroTerm(gyro); // if(!damping) { pMultiBody->setLinearDamping(0.f); pMultiBody->setAngularDamping(0.f); } else { pMultiBody->setLinearDamping(0.1f); pMultiBody->setAngularDamping(0.9f); } m_dynamicsWorld->setGravity(btVector3(0,-9.81,0)); for (int i=0; i < pMultiBody->getNumLinks(); ++i) { btCollisionShape* shape =new btSphereShape(radius); m_guiHelper->createCollisionShapeGraphicsObject(shape); btMultiBodyLinkCollider* col = new btMultiBodyLinkCollider(pMultiBody, i); col->setCollisionShape(shape); bool isDynamic = 1; short collisionFilterGroup = isDynamic? short(btBroadphaseProxy::DefaultFilter) : short(btBroadphaseProxy::StaticFilter); short collisionFilterMask = isDynamic? short(btBroadphaseProxy::AllFilter) : short(btBroadphaseProxy::AllFilter ^ btBroadphaseProxy::StaticFilter); world->addCollisionObject(col,collisionFilterGroup,collisionFilterMask);//,2,1+2); btVector4 color(1,0,0,1); m_guiHelper->createCollisionObjectGraphicsObject(col,color); pMultiBody->getLink(i).m_collider=col; } btAlignedObjectArray<btQuaternion> scratch_q; btAlignedObjectArray<btVector3> scratch_m; pMultiBody->forwardKinematics(scratch_q,scratch_m); btAlignedObjectArray<btQuaternion> world_to_local; btAlignedObjectArray<btVector3> local_origin; pMultiBody->updateCollisionObjectWorldTransforms(world_to_local,local_origin); } }
void TestJointTorqueSetup::initPhysics() { int upAxis = 2; m_guiHelper->setUpAxis(upAxis); btVector4 colors[4] = { btVector4(1,0,0,1), btVector4(0,1,0,1), btVector4(0,1,1,1), btVector4(1,1,0,1), }; int curColor = 0; this->createEmptyDynamicsWorld(); m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld); m_dynamicsWorld->getDebugDrawer()->setDebugMode( //btIDebugDraw::DBG_DrawConstraints +btIDebugDraw::DBG_DrawWireframe +btIDebugDraw::DBG_DrawContactPoints +btIDebugDraw::DBG_DrawAabb );//+btIDebugDraw::DBG_DrawConstraintLimits); //create a static ground object if (0) { btVector3 groundHalfExtents(20,20,20); groundHalfExtents[upAxis]=1.f; btBoxShape* box = new btBoxShape(groundHalfExtents); box->initializePolyhedralFeatures(); m_guiHelper->createCollisionShapeGraphicsObject(box); btTransform start; start.setIdentity(); btVector3 groundOrigin(0,0,0); groundOrigin[upAxis]=-1.5; start.setOrigin(groundOrigin); btRigidBody* body = createRigidBody(0,start,box); btVector4 color = colors[curColor]; curColor++; curColor&=3; m_guiHelper->createRigidBodyGraphicsObject(body,color); } { bool floating = false; bool damping = true; bool gyro = true; int numLinks = 5; bool spherical = false; //set it ot false -to use 1DoF hinges instead of 3DoF sphericals bool canSleep = false; bool selfCollide = false; btVector3 linkHalfExtents(0.05, 0.37, 0.1); btVector3 baseHalfExtents(0.05, 0.37, 0.1); btVector3 basePosition = btVector3(-0.4f, 3.f, 0.f); //mbC->forceMultiDof(); //if !spherical, you can comment this line to check the 1DoF algorithm //init the base btVector3 baseInertiaDiag(0.f, 0.f, 0.f); float baseMass = 1.f; if(baseMass) { btCollisionShape *pTempBox = new btBoxShape(btVector3(baseHalfExtents[0], baseHalfExtents[1], baseHalfExtents[2])); pTempBox->calculateLocalInertia(baseMass, baseInertiaDiag); delete pTempBox; } bool isMultiDof = false; btMultiBody *pMultiBody = new btMultiBody(numLinks, baseMass, baseInertiaDiag, !floating, canSleep, isMultiDof); m_multiBody = pMultiBody; btQuaternion baseOriQuat(0.f, 0.f, 0.f, 1.f); pMultiBody->setBasePos(basePosition); pMultiBody->setWorldToBaseRot(baseOriQuat); btVector3 vel(0, 0, 0); // pMultiBody->setBaseVel(vel); //init the links btVector3 hingeJointAxis(1, 0, 0); float linkMass = 1.f; btVector3 linkInertiaDiag(0.f, 0.f, 0.f); btCollisionShape *pTempBox = new btBoxShape(btVector3(linkHalfExtents[0], linkHalfExtents[1], linkHalfExtents[2])); pTempBox->calculateLocalInertia(linkMass, linkInertiaDiag); delete pTempBox; //y-axis assumed up btVector3 parentComToCurrentCom(0, -linkHalfExtents[1] * 2.f, 0); //par body's COM to cur body's COM offset btVector3 currentPivotToCurrentCom(0, -linkHalfExtents[1], 0); //cur body's COM to cur body's PIV offset btVector3 parentComToCurrentPivot = parentComToCurrentCom - currentPivotToCurrentCom; //par body's COM to cur body's PIV offset ////// btScalar q0 = 0.f * SIMD_PI/ 180.f; btQuaternion quat0(btVector3(0, 1, 0).normalized(), q0); quat0.normalize(); ///// for(int i = 0; i < numLinks; ++i) { if(!spherical) pMultiBody->setupRevolute(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), hingeJointAxis, parentComToCurrentPivot, currentPivotToCurrentCom, false); else //pMultiBody->setupPlanar(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f)/*quat0*/, btVector3(1, 0, 0), parentComToCurrentPivot*2, false); pMultiBody->setupSpherical(i, linkMass, linkInertiaDiag, i - 1, btQuaternion(0.f, 0.f, 0.f, 1.f), parentComToCurrentPivot, currentPivotToCurrentCom, false); } //pMultiBody->finalizeMultiDof(); btMultiBodyDynamicsWorld* world = m_dynamicsWorld; /// world->addMultiBody(pMultiBody); btMultiBody* mbC = pMultiBody; mbC->setCanSleep(canSleep); mbC->setHasSelfCollision(selfCollide); mbC->setUseGyroTerm(gyro); // if(!damping) { mbC->setLinearDamping(0.f); mbC->setAngularDamping(0.f); }else { mbC->setLinearDamping(0.1f); mbC->setAngularDamping(0.9f); } // btVector3 gravity(0,0,0); //gravity[upAxis] = -9.81; m_dynamicsWorld->setGravity(gravity); ////////////////////////////////////////////// if(numLinks > 0) { btScalar q0 = 45.f * SIMD_PI/ 180.f; if(!spherical) if(mbC->isMultiDof()) mbC->setJointPosMultiDof(0, &q0); else mbC->setJointPos(0, q0); else { btQuaternion quat0(btVector3(1, 1, 0).normalized(), q0); quat0.normalize(); mbC->setJointPosMultiDof(0, quat0); } } /// btAlignedObjectArray<btQuaternion> world_to_local; world_to_local.resize(pMultiBody->getNumLinks() + 1); btAlignedObjectArray<btVector3> local_origin; local_origin.resize(pMultiBody->getNumLinks() + 1); world_to_local[0] = pMultiBody->getWorldToBaseRot(); local_origin[0] = pMultiBody->getBasePos(); double friction = 1; { // float pos[4]={local_origin[0].x(),local_origin[0].y(),local_origin[0].z(),1}; float quat[4]={-world_to_local[0].x(),-world_to_local[0].y(),-world_to_local[0].z(),world_to_local[0].w()}; if (1) { btCollisionShape* box = new btBoxShape(baseHalfExtents); m_guiHelper->createCollisionShapeGraphicsObject(box); btMultiBodyLinkCollider* col= new btMultiBodyLinkCollider(pMultiBody, -1); col->setCollisionShape(box); btTransform tr; tr.setIdentity(); //if we don't set the initial pose of the btCollisionObject, the simulator will do this //when syncing the btMultiBody link transforms to the btMultiBodyLinkCollider tr.setOrigin(local_origin[0]); tr.setRotation(btQuaternion(quat[0],quat[1],quat[2],quat[3])); col->setWorldTransform(tr); world->addCollisionObject(col, 2,1+2); btVector3 color(0.0,0.0,0.5); m_guiHelper->createCollisionObjectGraphicsObject(col,color); col->setFriction(friction); pMultiBody->setBaseCollider(col); } } for (int i=0; i < pMultiBody->getNumLinks(); ++i) { const int parent = pMultiBody->getParent(i); world_to_local[i+1] = pMultiBody->getParentToLocalRot(i) * world_to_local[parent+1]; local_origin[i+1] = local_origin[parent+1] + (quatRotate(world_to_local[i+1].inverse() , pMultiBody->getRVector(i))); } for (int i=0; i < pMultiBody->getNumLinks(); ++i) { btVector3 posr = local_origin[i+1]; // float pos[4]={posr.x(),posr.y(),posr.z(),1}; float quat[4]={-world_to_local[i+1].x(),-world_to_local[i+1].y(),-world_to_local[i+1].z(),world_to_local[i+1].w()}; btCollisionShape* box = new btBoxShape(linkHalfExtents); m_guiHelper->createCollisionShapeGraphicsObject(box); btMultiBodyLinkCollider* col = new btMultiBodyLinkCollider(pMultiBody, i); col->setCollisionShape(box); btTransform tr; tr.setIdentity(); tr.setOrigin(posr); tr.setRotation(btQuaternion(quat[0],quat[1],quat[2],quat[3])); col->setWorldTransform(tr); col->setFriction(friction); world->addCollisionObject(col,2,1+2); btVector4 color = colors[curColor]; curColor++; curColor&=3; m_guiHelper->createCollisionObjectGraphicsObject(col,color); pMultiBody->getLink(i).m_collider=col; } } }