Real-Time Physics Simulation Forum

Code: Select all

void WorldSetup::stepSimulation(float deltaTime) {
		btTransform local_position;
		local_position.setIdentity();
		m_dynamicsWorld->getNonStaticRigidBodies().at(0)->setWorldTransform(local_position);
		m_dynamicsWorld->getNonStaticRigidBodies().at(1)->setWorldTransform(local_position);
	
		auto obj1_transform = m_dynamicsWorld->getNonStaticRigidBodies().at(0)->getCenterOfMassTransform().inverse();
		auto obj2_transform = m_dynamicsWorld->getNonStaticRigidBodies().at(1)->getCenterOfMassTransform().inverse();
		translation_data.push_back(obj1_transform);
		translation_data.push_back(obj2_transform);
		//Now the translation_data vecotr is sent to my main code where I apply the translation and rotation to their old position.
}

Code: Select all

void WorldSetup::initPhysics()
{
	//code initializing the ground, solver, and more in the code above that I did not mention...
	
	//creating a static object
	btCollisionShape* shape;
	btDefaultMotionState* motionState;
	btTransform bodyTransform;
	btScalar mass;
	
	mass = 0.0;
	shape = new btBoxShape(btVector3(0.5, 0.5, 0.5));
	btVector3 localInertia = btVector3(0, 0, 0);
	bodyTransform.setIdentity();
	motionState = new btDefaultMotionState(bodyTransform);
	btRigidBody* staticBody = new btRigidBody(mass, motionState, shape, localInertia);


	float pos1[4]{ 100,100, 100, 0 };
	float color1[4]{ 0.2666, 0.2745, 0.29019, 1 };

	float pos2[4]{ 100, 100, 100, 0 };
	float color2[4]{ 0.2, 0.141, 0.078, 1 };
	
	//loading the mesh objects
	m_data->m_TranslateSpringBodies.push_back(loadMyMesh(m_vertices_list[0], m_faces_list[0], pos1, color1, 50.0f));
	m_dynamicsWorld->addRigidBody(m_data->m_TranslateSpringBodies.at(0));

	m_data->m_TranslateSpringBodies.push_back(loadMyMesh(m_vertices_list[1], m_faces_list[1], pos2, color2, 50.0f));
	m_dynamicsWorld->addRigidBody(m_data->m_TranslateSpringBodies.at(1));
	
	//adding a single constraint to force object 0 to stay in a single spot (with the static object)
	btTransform localA;
	btTransform localB;
	localA.setIdentity();
	localB.setIdentity();
	btGeneric6DofSpring2Constraint* constraint = new btGeneric6DofSpring2Constraint(*staticBody, *m_data->m_TranslateSpringBodies.at(0), localA, localB EXTRAPARAMS);

	constraint->setLimit(3, 0, 0);
	constraint->setLimit(4, 0, 0);
	constraint->setLimit(5, 0, 0);

	constraint->enableSpring(0, true);
	constraint->enableSpring(1, true);
	constraint->enableSpring(2, true);


	constraint->setStiffness(0, 50);
	constraint->setStiffness(1, 50);
	constraint->setStiffness(2, 50);

	constraint->setDamping(0, 0.5);
	constraint->setDamping(1, 0.5);
	constraint->setDamping(2, 0.5);

	constraint->setDbgDrawSize(btScalar(5.f));
	m_dynamicsWorld->addConstraint(constraint, true);
	
	//adding a spring constraint between object 0 and object 1
	localA.setIdentity();
	localA.setOrigin(btVector3(-0.2, 5, 8));
	localB.setIdentity();
	localB.setOrigin(btVector3(-3, 3, 14));
	btGeneric6DofSpring2Constraint* constraint2 = new btGeneric6DofSpring2Constraint(*m_data->m_TranslateSpringBodies.at(index_a), *m_data->m_TranslateSpringBodies.at(index_b), localA, localB EXTRAPARAMS);

	constraint2 ->enableSpring(0, true);
	constraint2 ->enableSpring(1, true);
	constraint2 ->enableSpring(2, true);
	constraint2 ->enableSpring(3, true);
	constraint2 ->enableSpring(4, true);
	constraint2 ->enableSpring(5, true);

	constraint2 ->setStiffness(0, 50);
	constraint2 ->setStiffness(1, 50);
	constraint2 ->setStiffness(2, 50);
	constraint2 ->setStiffness(3, 50);
	constraint2 ->setStiffness(4, 50);
	constraint2 ->setStiffness(5, 50);

	constraint2 ->setDamping(0, 0.5);
	constraint2 ->setDamping(1, 0.5);
	constraint2 ->setDamping(2, 0.5);
	constraint2 ->setDamping(3, 0.5);
	constraint2 ->setDamping(4, 0.5);
	constraint2 ->setDamping(5, 0.5);

	m_dynamicsWorld->addConstraint(constraint2 , true);
	constraint2 ->setDbgDrawSize(btScalar(5.f));
}

Code: Select all

void WorldSetup::stepSimulation(float deltaTime) {
		auto obj1_transform = m_dynamicsWorld->getNonStaticRigidBodies().at(0)->getCenterOfMassTransform().inverse();
		auto obj2_transform = m_dynamicsWorld->getNonStaticRigidBodies().at(1)->getCenterOfMassTransform().inverse();
		translation_data.push_back(obj1_transform);
		translation_data.push_back(obj2_transform);
		//Now, the translation_data vector is sent to my main code, where I apply the translation and rotation to their old position.
}