crown-engine/third/bullet3/examples/MultiBody/MultiDofDemo.cpp

#include "MultiDofDemo.h"
#include "../OpenGLWindow/SimpleOpenGL3App.h"
#include "btBulletDynamicsCommon.h"

#include "BulletDynamics/Featherstone/btMultiBody.h"
#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
#include "BulletDynamics/Featherstone/btMultiBodyDynamicsWorld.h"
#include "BulletDynamics/Featherstone/btMultiBodyLinkCollider.h"
#include "BulletDynamics/Featherstone/btMultiBodyLink.h"
#include "BulletDynamics/Featherstone/btMultiBodyJointLimitConstraint.h"
#include "BulletDynamics/Featherstone/btMultiBodyJointMotor.h"
#include "BulletDynamics/Featherstone/btMultiBodyPoint2Point.h"

#include "../OpenGLWindow/GLInstancingRenderer.h"
#include "BulletCollision/CollisionShapes/btShapeHull.h"

#include "../CommonInterfaces/CommonMultiBodyBase.h"


class MultiDofDemo : public CommonMultiBodyBase
{
	
public:

	MultiDofDemo(GUIHelperInterface* helper);
	virtual ~MultiDofDemo();

	virtual void	initPhysics();

	virtual void	stepSimulation(float deltaTime);

	virtual void resetCamera()
	{
		float dist = 1;
		float pitch = 50;
		float yaw = 35;
		float targetPos[3]={-3,2.8,-2.5};
		m_guiHelper->resetCamera(dist,pitch,yaw,targetPos[0],targetPos[1],targetPos[2]);
	}


	btMultiBody* createFeatherstoneMultiBody_testMultiDof(class btMultiBodyDynamicsWorld* world, int numLinks, const btVector3& basePosition, const btVector3 &baseHalfExtents, const btVector3 &linkHalfExtents, bool spherical = false, bool floating = false);
	void addColliders_testMultiDof(btMultiBody *pMultiBody, btMultiBodyDynamicsWorld *pWorld, const btVector3 &baseHalfExtents, const btVector3 &linkHalfExtents);
	void addBoxes_testMultiDof();


};

static bool g_floatingBase = false;
static bool g_firstInit = true;
static float scaling = 0.4f;
static float friction = 1.;
#define ARRAY_SIZE_X 5
#define ARRAY_SIZE_Y 5
#define ARRAY_SIZE_Z 5

//maximum number of objects (and allow user to shoot additional boxes)
#define MAX_PROXIES (ARRAY_SIZE_X*ARRAY_SIZE_Y*ARRAY_SIZE_Z + 1024)


#define START_POS_X -5
//#define START_POS_Y 12
#define START_POS_Y 2
#define START_POS_Z -3



MultiDofDemo::MultiDofDemo(GUIHelperInterface* helper)
:CommonMultiBodyBase(helper)
{
	m_guiHelper->setUpAxis(1);
}
MultiDofDemo::~MultiDofDemo()
{
}

void	MultiDofDemo::stepSimulation(float deltaTime)
{
	//use a smaller internal timestep, there are stability issues
	float internalTimeStep = 1./240.f;
	m_dynamicsWorld->stepSimulation(deltaTime,10,internalTimeStep);
}


void	MultiDofDemo::initPhysics()
{	


	m_guiHelper->setUpAxis(1);

	if(g_firstInit)
	{
		m_guiHelper->getRenderInterface()->getActiveCamera()->setCameraDistance(btScalar(10.*scaling));
		m_guiHelper->getRenderInterface()->getActiveCamera()->setCameraPitch(50);
		g_firstInit = false;
	}	
	///collision configuration contains default setup for memory, collision setup
	m_collisionConfiguration = new btDefaultCollisionConfiguration();

	///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
	m_dispatcher = new	btCollisionDispatcher(m_collisionConfiguration);

	m_broadphase = new btDbvtBroadphase();

	//Use the btMultiBodyConstraintSolver for Featherstone btMultiBody support
	btMultiBodyConstraintSolver* sol = new btMultiBodyConstraintSolver;
	m_solver = sol;

	//use btMultiBodyDynamicsWorld for Featherstone btMultiBody support
	btMultiBodyDynamicsWorld* world = new btMultiBodyDynamicsWorld(m_dispatcher,m_broadphase,sol,m_collisionConfiguration);
	m_dynamicsWorld = world;
//	m_dynamicsWorld->setDebugDrawer(&gDebugDraw);
	m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
	m_dynamicsWorld->setGravity(btVector3(0,-10,0));

	///create a few basic rigid bodies
	btVector3 groundHalfExtents(50,50,50);
	btCollisionShape* groundShape = new btBoxShape(groundHalfExtents);
	//groundShape->initializePolyhedralFeatures();
//	btCollisionShape* groundShape = new btStaticPlaneShape(btVector3(0,1,0),50);
	
	m_collisionShapes.push_back(groundShape);

	btTransform groundTransform;
	groundTransform.setIdentity();
	groundTransform.setOrigin(btVector3(0,-50,00));

	/////////////////////////////////////////////////////////////////	
	/////////////////////////////////////////////////////////////////
	
	bool damping = true;
	bool gyro = true;
	int numLinks = 5;
	bool spherical = true;					//set it ot false -to use 1DoF hinges instead of 3DoF sphericals		
	bool multibodyOnly = false;
	bool canSleep = true;
	bool selfCollide = false;	
	btVector3 linkHalfExtents(0.05, 0.37, 0.1);
	btVector3 baseHalfExtents(0.05, 0.37, 0.1);

	btMultiBody* mbC = createFeatherstoneMultiBody_testMultiDof(world, numLinks, btVector3(-0.4f, 3.f, 0.f), linkHalfExtents, baseHalfExtents, spherical, g_floatingBase);	
	//mbC->forceMultiDof();							//if !spherical, you can comment this line to check the 1DoF algorithm		

	g_floatingBase = ! g_floatingBase;
	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, -9.81 ,0));	
	//////////////////////////////////////////////
	if(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);				
		}			
	}		
	///
	addColliders_testMultiDof(mbC, world, baseHalfExtents, linkHalfExtents);	

	
	/////////////////////////////////////////////////////////////////	
	btScalar groundHeight = -51.55;
	if (!multibodyOnly)
	{
		btScalar mass(0.);

		//rigidbody is dynamic if and only if mass is non zero, otherwise static
		bool isDynamic = (mass != 0.f);

		btVector3 localInertia(0,0,0);
		if (isDynamic)
			groundShape->calculateLocalInertia(mass,localInertia);

		//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
		groundTransform.setIdentity();
		groundTransform.setOrigin(btVector3(0,groundHeight,0));
		btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
		btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,groundShape,localInertia);
		btRigidBody* body = new btRigidBody(rbInfo);

		//add the body to the dynamics world
		m_dynamicsWorld->addRigidBody(body,1,1+2);//,1,1+2);

		


	}
	/////////////////////////////////////////////////////////////////
	if(!multibodyOnly)
	{
		btVector3 halfExtents(.5,.5,.5);
		btBoxShape* colShape = new btBoxShape(halfExtents);
		//btCollisionShape* colShape = new btSphereShape(btScalar(1.));
		m_collisionShapes.push_back(colShape);

		/// Create Dynamic Objects
		btTransform startTransform;
		startTransform.setIdentity();

		btScalar	mass(1.f);

		//rigidbody is dynamic if and only if mass is non zero, otherwise static
		bool isDynamic = (mass != 0.f);

		btVector3 localInertia(0,0,0);
		if (isDynamic)
			colShape->calculateLocalInertia(mass,localInertia);

		startTransform.setOrigin(btVector3(
							btScalar(0.0),
							-0.95,
							btScalar(0.0)));

			
		//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
		btDefaultMotionState* myMotionState = new btDefaultMotionState(startTransform);
		btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,colShape,localInertia);
		btRigidBody* body = new btRigidBody(rbInfo);
					
		m_dynamicsWorld->addRigidBody(body);//,1,1+2);	


	}

	m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);

	/////////////////////////////////////////////////////////////////
}


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, 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();

	///
	pWorld->addMultiBody(pMultiBody);
	///
	return pMultiBody;
}

void MultiDofDemo::addColliders_testMultiDof(btMultiBody *pMultiBody, btMultiBodyDynamicsWorld *pWorld, const btVector3 &baseHalfExtents, const btVector3 &linkHalfExtents)
{			
	
	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();
	
	{
			
	//	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* box = new btBoxShape(baseHalfExtents);			
			btMultiBodyLinkCollider* col= new btMultiBodyLinkCollider(pMultiBody, -1);			
			col->setCollisionShape(box);
								
			btTransform tr;
			tr.setIdentity();
			tr.setOrigin(local_origin[0]);
			tr.setRotation(btQuaternion(quat[0],quat[1],quat[2],quat[3]));			
			col->setWorldTransform(tr);
				
			pWorld->addCollisionObject(col, 2,1+2);

	

			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* box = new btBoxShape(linkHalfExtents);
		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);
		pWorld->addCollisionObject(col,2,1+2);
	
			
		pMultiBody->getLink(i).m_collider=col;		
	}
}

void MultiDofDemo::addBoxes_testMultiDof()
{
	//create a few dynamic rigidbodies
	// Re-using the same collision is better for memory usage and performance

	btBoxShape* colShape = new btBoxShape(btVector3(1,1,1));
	//btCollisionShape* colShape = new btSphereShape(btScalar(1.));
	m_collisionShapes.push_back(colShape);

	/// Create Dynamic Objects
	btTransform startTransform;
	startTransform.setIdentity();

	btScalar	mass(1.f);

	//rigidbody is dynamic if and only if mass is non zero, otherwise static
	bool isDynamic = (mass != 0.f);

	btVector3 localInertia(0,0,0);
	if (isDynamic)
		colShape->calculateLocalInertia(mass,localInertia);

	float start_x = START_POS_X - ARRAY_SIZE_X/2;
	float start_y = START_POS_Y;
	float start_z = START_POS_Z - ARRAY_SIZE_Z/2;

	for (int k=0;k<ARRAY_SIZE_Y;k++)
	{
		for (int i=0;i<ARRAY_SIZE_X;i++)
		{
			for(int j = 0;j<ARRAY_SIZE_Z;j++)
			{
				startTransform.setOrigin(btVector3(
									btScalar(3.0*i + start_x),
									btScalar(3.0*k + start_y),
									btScalar(3.0*j + start_z)));

			
				//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
				btDefaultMotionState* myMotionState = new btDefaultMotionState(startTransform);
				btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,colShape,localInertia);
				btRigidBody* body = new btRigidBody(rbInfo);
					
				m_dynamicsWorld->addRigidBody(body);//,1,1+2);
			}
		}
	}
}

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