mirror of
https://github.com/bulletphysics/bullet3
synced 2024-12-14 05:40:05 +00:00
317 lines
12 KiB
C++
317 lines
12 KiB
C++
/*
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2019 Google Inc. http://bulletphysics.org
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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 "ConservationTest.h"
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///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
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#include "btBulletDynamicsCommon.h"
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#include "BulletSoftBody/btDeformableMultiBodyDynamicsWorld.h"
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#include "BulletSoftBody/BulletReducedDeformableBody/btReducedDeformableBody.h"
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#include "BulletSoftBody/BulletReducedDeformableBody/btReducedDeformableBodyHelpers.h"
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#include "BulletSoftBody/BulletReducedDeformableBody/btReducedDeformableBodySolver.h"
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#include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h"
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#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
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#include "../CommonInterfaces/CommonParameterInterface.h"
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#include <stdio.h> //printf debugging
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#include <random>
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#include "../CommonInterfaces/CommonDeformableBodyBase.h"
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#include "../Utils/b3ResourcePath.h"
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static btScalar damping_alpha = 0.0;
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static btScalar damping_beta = 0.0;
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static int start_mode = 6;
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static int num_modes = 20;
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class ConservationTest : public CommonDeformableBodyBase
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{
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btScalar sim_time;
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bool first_step;
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// get deformed shape
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void getDeformedShape(btReducedDeformableBody* rsb, const int mode_n, const btScalar scale = 1)
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{
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// for (int i = 0; i < rsb->m_nodes.size(); ++i)
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// for (int k = 0; k < 3; ++k)
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// rsb->m_nodes[i].m_x[k] += rsb->m_modes[mode_n][3 * i + k] * scale;
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// rsb->m_reducedDofs[mode_n] = scale;
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// rsb->m_reducedDofsBuffer[mode_n] = scale;
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srand(1);
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for (int r = 0; r < rsb->m_nReduced; r++)
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{
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rsb->m_reducedDofs[r] = (btScalar(rand()) / btScalar(RAND_MAX) - 0.5);
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rsb->m_reducedDofsBuffer[r] = rsb->m_reducedDofs[r];
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}
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rsb->mapToFullPosition(rsb->getRigidTransform());
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// std::cout << "-----------\n";
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// std::cout << rsb->m_nodes[0].m_x[0] << '\t' << rsb->m_nodes[0].m_x[1] << '\t' << rsb->m_nodes[0].m_x[2] << '\n';
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// std::cout << "-----------\n";
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}
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public:
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ConservationTest(struct GUIHelperInterface* helper)
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: CommonDeformableBodyBase(helper)
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{
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sim_time = 0;
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first_step = true;
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}
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virtual ~ConservationTest()
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{
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}
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void initPhysics();
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void exitPhysics();
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// TODO: disable pick force, non-interactive for now.
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bool pickBody(const btVector3& rayFromWorld, const btVector3& rayToWorld) {
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return false;
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}
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void resetCamera()
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{
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float dist = 10;
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float pitch = 0;
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float yaw = 90;
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float targetPos[3] = {0, 3, 0};
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m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
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}
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void checkMomentum(btReducedDeformableBody* rsb)
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{
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btVector3 x_com(0, 0, 0);
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btVector3 total_linear(0, 0, 0);
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btVector3 total_angular(0, 0, 0);
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{
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std::ofstream myfile("center_of_mass.txt", std::ios_base::app);
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for (int i = 0; i < rsb->m_nFull; ++i)
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{
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x_com += rsb->m_nodalMass[i] * rsb->m_nodes[i].m_x;
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}
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x_com /= rsb->getTotalMass();
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myfile << sim_time << "\t" << x_com[0] << "\t" << x_com[1] << "\t" << x_com[2] << "\n";
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myfile.close();
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}
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{
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std::ofstream myfile("linear_momentum.txt", std::ios_base::app);
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for (int i = 0; i < rsb->m_nFull; ++i)
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{
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total_linear += rsb->m_nodalMass[i] * rsb->m_nodes[i].m_v;
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}
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myfile << sim_time << "\t" << total_linear[0] << "\t" << total_linear[1] << "\t" << total_linear[2] << "\n";
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myfile.close();
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}
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{
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std::ofstream myfile("angular_momentum.txt", std::ios_base::app);
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// btVector3 ri(0, 0, 0);
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// for (int i = 0; i < rsb->m_nFull; ++i)
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// {
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// ri = rsb->m_nodes[i].m_x - x_com;
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// total_angular += rsb->m_nodalMass[i] * ri.cross(rsb->m_nodes[i].m_v);
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// }
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total_angular = rsb->computeTotalAngularMomentum();
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myfile << sim_time << "\t" << total_angular[0] << "\t" << total_angular[1] << "\t" << total_angular[2] << "\n";
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myfile.close();
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}
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{
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btVector3 angular_rigid(0, 0, 0);
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std::ofstream myfile("angular_momentum_rigid.txt", std::ios_base::app);
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btVector3 ri(0, 0, 0);
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for (int i = 0; i < rsb->m_nFull; ++i)
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{
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ri = rsb->m_nodes[i].m_x - x_com;
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btMatrix3x3 ri_star = Cross(ri);
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angular_rigid += rsb->m_nodalMass[i] * (ri_star.transpose() * ri_star * rsb->getAngularVelocity());
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}
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myfile << sim_time << "\t" << angular_rigid[0] << "\t" << angular_rigid[1] << "\t" << angular_rigid[2] << "\n";
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myfile.close();
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}
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{
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std::ofstream myfile("reduced_velocity.txt", std::ios_base::app);
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myfile << sim_time << "\t" << rsb->m_reducedVelocity[0] << "\t" << rsb->m_reducedDofs[0] << "\n";
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myfile.close();
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}
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}
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void stepSimulation(float deltaTime)
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{
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// add initial deformation
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btReducedDeformableBody* rsb = static_cast<btReducedDeformableBody*>(static_cast<btDeformableMultiBodyDynamicsWorld*>(m_dynamicsWorld)->getSoftBodyArray()[0]);
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if (first_step /* && !rsb->m_bUpdateRtCst*/)
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{
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getDeformedShape(rsb, 0, 1);
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first_step = false;
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}
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float internalTimeStep = 1. / 240.f;
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m_dynamicsWorld->stepSimulation(deltaTime, 4, internalTimeStep);
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sim_time += internalTimeStep;
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checkMomentum(rsb);
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}
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virtual void renderScene()
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{
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CommonDeformableBodyBase::renderScene();
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btDeformableMultiBodyDynamicsWorld* deformableWorld = getDeformableDynamicsWorld();
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for (int i = 0; i < deformableWorld->getSoftBodyArray().size(); i++)
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{
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btReducedDeformableBody* rsb = static_cast<btReducedDeformableBody*>(deformableWorld->getSoftBodyArray()[i]);
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{
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btSoftBodyHelpers::DrawFrame(rsb, deformableWorld->getDebugDrawer());
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btSoftBodyHelpers::Draw(rsb, deformableWorld->getDebugDrawer(), deformableWorld->getDrawFlags());
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btVector3 origin = rsb->getRigidTransform().getOrigin();
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btVector3 line_x = rsb->getRigidTransform().getBasis() * 2 * btVector3(1, 0, 0) + origin;
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btVector3 line_y = rsb->getRigidTransform().getBasis() * 2 * btVector3(0, 1, 0) + origin;
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btVector3 line_z = rsb->getRigidTransform().getBasis() * 2 * btVector3(0, 0, 1) + origin;
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deformableWorld->getDebugDrawer()->drawLine(origin, line_x, btVector3(1, 0, 0));
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deformableWorld->getDebugDrawer()->drawLine(origin, line_y, btVector3(0, 1, 0));
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deformableWorld->getDebugDrawer()->drawLine(origin, line_z, btVector3(0, 0, 1));
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deformableWorld->getDebugDrawer()->drawSphere(btVector3(0, 0, 0), 0.1, btVector3(1, 1, 1));
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deformableWorld->getDebugDrawer()->drawSphere(btVector3(0, 2, 0), 0.1, btVector3(1, 1, 1));
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deformableWorld->getDebugDrawer()->drawSphere(btVector3(0, 4, 0), 0.1, btVector3(1, 1, 1));
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}
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}
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}
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};
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void ConservationTest::initPhysics()
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{
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m_guiHelper->setUpAxis(1);
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///collision configuration contains default setup for memory, collision setup
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m_collisionConfiguration = new btSoftBodyRigidBodyCollisionConfiguration();
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///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
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m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);
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m_broadphase = new btDbvtBroadphase();
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btReducedDeformableBodySolver* reducedSoftBodySolver = new btReducedDeformableBodySolver();
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btVector3 gravity = btVector3(0, 0, 0);
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reducedSoftBodySolver->setGravity(gravity);
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btDeformableMultiBodyConstraintSolver* sol = new btDeformableMultiBodyConstraintSolver();
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sol->setDeformableSolver(reducedSoftBodySolver);
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m_solver = sol;
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m_dynamicsWorld = new btDeformableMultiBodyDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, reducedSoftBodySolver);
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m_dynamicsWorld->setGravity(gravity);
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m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
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// create volumetric reduced deformable body
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{
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std::string file_path("../../../data/reduced_beam/");
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std::string vtk_file("beam_mesh_origin.vtk");
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btReducedDeformableBody* rsb = btReducedDeformableBodyHelpers::createReducedDeformableObject(
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getDeformableDynamicsWorld()->getWorldInfo(),
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file_path,
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vtk_file,
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num_modes,
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false);
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getDeformableDynamicsWorld()->addSoftBody(rsb);
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rsb->getCollisionShape()->setMargin(0.1);
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btTransform init_transform;
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init_transform.setIdentity();
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init_transform.setOrigin(btVector3(0, 4, 0));
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// init_transform.setRotation(btQuaternion(btVector3(0, 1, 0), SIMD_PI / 2.0));
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rsb->transformTo(init_transform);
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rsb->setStiffnessScale(100);
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rsb->setDamping(damping_alpha, damping_beta);
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rsb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
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rsb->m_cfg.kCHR = 1; // collision hardness with rigid body
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rsb->m_cfg.kDF = 0;
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rsb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
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rsb->m_cfg.collisions |= btSoftBody::fCollision::SDF_RDN;
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rsb->m_sleepingThreshold = 0;
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btSoftBodyHelpers::generateBoundaryFaces(rsb);
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// rsb->setVelocity(btVector3(0, -COLLIDING_VELOCITY, 0));
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// rsb->setRigidVelocity(btVector3(0, 1, 0));
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// rsb->setRigidAngularVelocity(btVector3(1, 0, 0));
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}
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getDeformableDynamicsWorld()->setImplicit(false);
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getDeformableDynamicsWorld()->setLineSearch(false);
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getDeformableDynamicsWorld()->setUseProjection(false);
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getDeformableDynamicsWorld()->getSolverInfo().m_deformable_erp = 0.3;
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getDeformableDynamicsWorld()->getSolverInfo().m_deformable_cfm = 0.2;
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getDeformableDynamicsWorld()->getSolverInfo().m_deformable_maxErrorReduction = btScalar(200);
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getDeformableDynamicsWorld()->getSolverInfo().m_leastSquaresResidualThreshold = 1e-3;
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getDeformableDynamicsWorld()->getSolverInfo().m_splitImpulse = false;
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getDeformableDynamicsWorld()->getSolverInfo().m_numIterations = 100;
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m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
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}
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void ConservationTest::exitPhysics()
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{
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//cleanup in the reverse order of creation/initialization
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removePickingConstraint();
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//remove the rigidbodies from the dynamics world and delete them
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int i;
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for (i = m_dynamicsWorld->getNumCollisionObjects() - 1; i >= 0; i--)
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{
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btCollisionObject* obj = m_dynamicsWorld->getCollisionObjectArray()[i];
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btRigidBody* body = btRigidBody::upcast(obj);
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if (body && body->getMotionState())
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{
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delete body->getMotionState();
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}
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m_dynamicsWorld->removeCollisionObject(obj);
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delete obj;
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}
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// delete forces
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for (int j = 0; j < m_forces.size(); j++)
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{
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btDeformableLagrangianForce* force = m_forces[j];
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delete force;
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}
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m_forces.clear();
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//delete collision shapes
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for (int j = 0; j < m_collisionShapes.size(); j++)
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{
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btCollisionShape* shape = m_collisionShapes[j];
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delete shape;
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}
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m_collisionShapes.clear();
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delete m_dynamicsWorld;
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delete m_solver;
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delete m_broadphase;
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delete m_dispatcher;
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delete m_collisionConfiguration;
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}
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class CommonExampleInterface* ReducedConservationTestCreateFunc(struct CommonExampleOptions& options)
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{
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return new ConservationTest(options.m_guiHelper);
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}
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