redgpu/bullet: Bullet Physics SDK: real-time collision detection and multi-physics simulation for VR, games, visual effects, robotics, machine learning etc.

examples/MultiBody/MultiBodyConstraintFeedback.cpp
431 строка14 KB
yunfeibai
Swap yaw and pitch in camera computation. Add functions to convert view matrix to camera position, and camera position to camera yaw pitch roll.
02 июн 2017, 01:30
02 июн 2017, 01:30e6d1a8c
#include "MultiBodyConstraintFeedback.h"

#include "BulletDynamics/Featherstone/btMultiBodyLinkCollider.h"
#include "BulletDynamics/Featherstone/btMultiBodyJointFeedback.h"
#include "BulletDynamics/Featherstone/btMultiBodyJointMotor.h"
							
#include "../CommonInterfaces/CommonMultiBodyBase.h"

static btScalar radius(0.2);

struct MultiBodyConstraintFeedbackSetup : public CommonMultiBodyBase
{
    btMultiBody* m_multiBody;
	btAlignedObjectArray<btMultiBodyJointFeedback*> m_jointFeedbacks;
	btMultiBodyJointMotor* m_motor;
    bool m_once;
public:

    MultiBodyConstraintFeedbackSetup(struct GUIHelperInterface* helper);
    virtual ~MultiBodyConstraintFeedbackSetup();

    virtual void initPhysics();

    virtual void stepSimulation(float deltaTime);

	virtual void resetCamera()
	{
		float dist = 5;
		float pitch = -21;
		float yaw = 270;
		float targetPos[3]={-1.34,3.4,-0.44};
		m_guiHelper->resetCamera(dist,yaw,pitch,targetPos[0],targetPos[1],targetPos[2]);
	}


};

MultiBodyConstraintFeedbackSetup::MultiBodyConstraintFeedbackSetup(struct GUIHelperInterface* helper)
:CommonMultiBodyBase(helper),
m_motor(0),
m_once(true)
{
}

MultiBodyConstraintFeedbackSetup::~MultiBodyConstraintFeedbackSetup()
{

}

///this is a temporary global, until we determine if we need the option or not
extern  bool gJointFeedbackInWorldSpace;
extern bool gJointFeedbackInJointFrame;
void MultiBodyConstraintFeedbackSetup::initPhysics()
{
    int upAxis = 2;
	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(10,10,0.2);
            btBoxShape* box = new btBoxShape(groundHalfExtents);
            box->initializePolyhedralFeatures();

            m_guiHelper->createCollisionShapeGraphicsObject(box);
            btTransform start; start.setIdentity();
            btVector3 groundOrigin(-0.4f, 3.f, 0.f);
			//btVector3 basePosition = btVector3(-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, 0.5, 0.1);
        btVector3 baseHalfExtents(0.05, 0.5, 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 = 0.01f;

        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;
        }

        
        btMultiBody *pMultiBody = new btMultiBody(numLinks, baseMass, baseInertiaDiag, !floating, canSleep);
		
        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 = i==0? 0.0001 : 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, -linkHalfExtents[1], 0);						//par body's COM to cur body's COM offset
					btVector3 currentPivotToCurrentCom(0, 0, 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);
				}
					
				//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)
			{
                   mbC->setJointPosMultiDof(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* 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);
				int collisionFilterGroup = isDynamic? int(btBroadphaseProxy::DefaultFilter) : int(btBroadphaseProxy::StaticFilter);
				int collisionFilterMask = isDynamic? 	int(btBroadphaseProxy::AllFilter) : 	int(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};

            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* 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);
			int collisionFilterGroup = isDynamic? int(btBroadphaseProxy::DefaultFilter) : int(btBroadphaseProxy::StaticFilter);
			int collisionFilterMask = isDynamic? 	int(btBroadphaseProxy::AllFilter) : 	int(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;
			}
         
        }
	int link=0;
	int targetVelocity=0.f;
	btScalar maxForce = 100000;
	 m_motor = new btMultiBodyJointMotor(pMultiBody,link,targetVelocity,maxForce);
	m_dynamicsWorld->addMultiBodyConstraint(m_motor);
    }
}

void MultiBodyConstraintFeedbackSetup::stepSimulation(float deltaTime)
{
	//m_multiBody->addLinkForce(0,btVector3(100,100,100));
    if (0)//m_once)
    {
       m_once=false;
        m_multiBody->addJointTorque(0, 10.0);
    
        btScalar torque = m_multiBody->getJointTorque(0);
        b3Printf("t = %f,%f,%f\n",torque,torque,torque);//[0],torque[1],torque[2]);
    }
   btScalar timeStep = 1./240.f;
 
    m_dynamicsWorld->stepSimulation(timeStep,0);

	static int count = 0;
	if ((count& 0x0f)==0)
	{
	if (m_motor)
	{
	float force = m_motor->getAppliedImpulse(0)/timeStep;
	b3Printf("motor applied force = %f\n", force);
	}	

	for (int i=0;i<m_jointFeedbacks.size();i++)
	{
			b3Printf("F_reaction[%i] linear:%f,%f,%f, angular:%f,%f,%f",
			i,
			m_jointFeedbacks[i]->m_reactionForces.m_topVec[0],
			m_jointFeedbacks[i]->m_reactionForces.m_topVec[1],
			m_jointFeedbacks[i]->m_reactionForces.m_topVec[2],

		m_jointFeedbacks[i]->m_reactionForces.m_bottomVec[0],
			m_jointFeedbacks[i]->m_reactionForces.m_bottomVec[1],
			m_jointFeedbacks[i]->m_reactionForces.m_bottomVec[2]

		);

	}
	}
	count++;


	/*
    b3Printf("base angvel = %f,%f,%f",m_multiBody->getBaseOmega()[0],
             m_multiBody->getBaseOmega()[1],
             m_multiBody->getBaseOmega()[2]
             );
    */
   // btScalar jointVel =m_multiBody->getJointVel(0);
    
//    b3Printf("child angvel = %f",jointVel);
    
    
    
}


class CommonExampleInterface*    MultiBodyConstraintFeedbackCreateFunc(struct CommonExampleOptions& options)
{
	return new MultiBodyConstraintFeedbackSetup(options.m_guiHelper);
}