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Diffstat (limited to 'examples/ReducedDeformableDemo/ConservationTest.cpp')
| -rw-r--r-- | examples/ReducedDeformableDemo/ConservationTest.cpp | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/examples/ReducedDeformableDemo/ConservationTest.cpp b/examples/ReducedDeformableDemo/ConservationTest.cpp new file mode 100644 index 000000000..05b7394da --- /dev/null +++ b/examples/ReducedDeformableDemo/ConservationTest.cpp @@ -0,0 +1,316 @@ +/* + Bullet Continuous Collision Detection and Physics Library + Copyright (c) 2019 Google Inc. http://bulletphysics.org + This software is provided 'as-is', without any express or implied warranty. + In no event will the authors be held liable for any damages arising from the use of this software. + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it freely, + subject to the following restrictions: + 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. + 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. + */ + +#include "ConservationTest.h" +///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files. +#include "btBulletDynamicsCommon.h" +#include "BulletSoftBody/btDeformableMultiBodyDynamicsWorld.h" +#include "BulletSoftBody/BulletReducedDeformableBody/btReducedDeformableBody.h" +#include "BulletSoftBody/BulletReducedDeformableBody/btReducedDeformableBodyHelpers.h" +#include "BulletSoftBody/BulletReducedDeformableBody/btReducedDeformableBodySolver.h" +#include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h" +#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h" +#include "../CommonInterfaces/CommonParameterInterface.h" +#include <stdio.h> //printf debugging +#include <random> + +#include "../CommonInterfaces/CommonDeformableBodyBase.h" +#include "../Utils/b3ResourcePath.h" + +static btScalar damping_alpha = 0.0; +static btScalar damping_beta = 0.0; +static int start_mode = 6; +static int num_modes = 20; + +class ConservationTest : public CommonDeformableBodyBase +{ + btScalar sim_time; + bool first_step; + + // get deformed shape + void getDeformedShape(btReducedDeformableBody* rsb, const int mode_n, const btScalar scale = 1) + { + // for (int i = 0; i < rsb->m_nodes.size(); ++i) + // for (int k = 0; k < 3; ++k) + // rsb->m_nodes[i].m_x[k] += rsb->m_modes[mode_n][3 * i + k] * scale; + + // rsb->m_reducedDofs[mode_n] = scale; + // rsb->m_reducedDofsBuffer[mode_n] = scale; + + srand(1); + for (int r = 0; r < rsb->m_nReduced; r++) + { + rsb->m_reducedDofs[r] = (btScalar(rand()) / btScalar(RAND_MAX) - 0.5); + rsb->m_reducedDofsBuffer[r] = rsb->m_reducedDofs[r]; + } + + rsb->mapToFullPosition(rsb->getRigidTransform()); + // std::cout << "-----------\n"; + // 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'; + // std::cout << "-----------\n"; + } + +public: + ConservationTest(struct GUIHelperInterface* helper) + : CommonDeformableBodyBase(helper) + { + sim_time = 0; + first_step = true; + } + virtual ~ConservationTest() + { + } + void initPhysics(); + + void exitPhysics(); + + // TODO: disable pick force, non-interactive for now. + bool pickBody(const btVector3& rayFromWorld, const btVector3& rayToWorld) { + return false; + } + + void resetCamera() + { + float dist = 10; + float pitch = 0; + float yaw = 90; + float targetPos[3] = {0, 3, 0}; + m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]); + } + + void checkMomentum(btReducedDeformableBody* rsb) + { + btVector3 x_com(0, 0, 0); + btVector3 total_linear(0, 0, 0); + btVector3 total_angular(0, 0, 0); + { + std::ofstream myfile("center_of_mass.txt", std::ios_base::app); + for (int i = 0; i < rsb->m_nFull; ++i) + { + x_com += rsb->m_nodalMass[i] * rsb->m_nodes[i].m_x; + } + x_com /= rsb->getTotalMass(); + myfile << sim_time << "\t" << x_com[0] << "\t" << x_com[1] << "\t" << x_com[2] << "\n"; + myfile.close(); + } + { + std::ofstream myfile("linear_momentum.txt", std::ios_base::app); + for (int i = 0; i < rsb->m_nFull; ++i) + { + total_linear += rsb->m_nodalMass[i] * rsb->m_nodes[i].m_v; + } + myfile << sim_time << "\t" << total_linear[0] << "\t" << total_linear[1] << "\t" << total_linear[2] << "\n"; + myfile.close(); + } + { + std::ofstream myfile("angular_momentum.txt", std::ios_base::app); + // btVector3 ri(0, 0, 0); + // for (int i = 0; i < rsb->m_nFull; ++i) + // { + // ri = rsb->m_nodes[i].m_x - x_com; + // total_angular += rsb->m_nodalMass[i] * ri.cross(rsb->m_nodes[i].m_v); + // } + total_angular = rsb->computeTotalAngularMomentum(); + myfile << sim_time << "\t" << total_angular[0] << "\t" << total_angular[1] << "\t" << total_angular[2] << "\n"; + myfile.close(); + } + { + btVector3 angular_rigid(0, 0, 0); + std::ofstream myfile("angular_momentum_rigid.txt", std::ios_base::app); + btVector3 ri(0, 0, 0); + for (int i = 0; i < rsb->m_nFull; ++i) + { + ri = rsb->m_nodes[i].m_x - x_com; + btMatrix3x3 ri_star = Cross(ri); + angular_rigid += rsb->m_nodalMass[i] * (ri_star.transpose() * ri_star * rsb->getAngularVelocity()); + } + myfile << sim_time << "\t" << angular_rigid[0] << "\t" << angular_rigid[1] << "\t" << angular_rigid[2] << "\n"; + myfile.close(); + } + + { + std::ofstream myfile("reduced_velocity.txt", std::ios_base::app); + myfile << sim_time << "\t" << rsb->m_reducedVelocity[0] << "\t" << rsb->m_reducedDofs[0] << "\n"; + myfile.close(); + } + } + + void stepSimulation(float deltaTime) + { + // add initial deformation + btReducedDeformableBody* rsb = static_cast<btReducedDeformableBody*>(static_cast<btDeformableMultiBodyDynamicsWorld*>(m_dynamicsWorld)->getSoftBodyArray()[0]); + if (first_step /* && !rsb->m_bUpdateRtCst*/) + { + getDeformedShape(rsb, 0, 1); + first_step = false; + } + + float internalTimeStep = 1. / 240.f; + m_dynamicsWorld->stepSimulation(deltaTime, 4, internalTimeStep); + + sim_time += internalTimeStep; + checkMomentum(rsb); + } + + virtual void renderScene() + { + CommonDeformableBodyBase::renderScene(); + btDeformableMultiBodyDynamicsWorld* deformableWorld = getDeformableDynamicsWorld(); + + for (int i = 0; i < deformableWorld->getSoftBodyArray().size(); i++) + { + btReducedDeformableBody* rsb = static_cast<btReducedDeformableBody*>(deformableWorld->getSoftBodyArray()[i]); + { + btSoftBodyHelpers::DrawFrame(rsb, deformableWorld->getDebugDrawer()); + btSoftBodyHelpers::Draw(rsb, deformableWorld->getDebugDrawer(), deformableWorld->getDrawFlags()); + + btVector3 origin = rsb->getRigidTransform().getOrigin(); + btVector3 line_x = rsb->getRigidTransform().getBasis() * 2 * btVector3(1, 0, 0) + origin; + btVector3 line_y = rsb->getRigidTransform().getBasis() * 2 * btVector3(0, 1, 0) + origin; + btVector3 line_z = rsb->getRigidTransform().getBasis() * 2 * btVector3(0, 0, 1) + origin; + + deformableWorld->getDebugDrawer()->drawLine(origin, line_x, btVector3(1, 0, 0)); + deformableWorld->getDebugDrawer()->drawLine(origin, line_y, btVector3(0, 1, 0)); + deformableWorld->getDebugDrawer()->drawLine(origin, line_z, btVector3(0, 0, 1)); + + deformableWorld->getDebugDrawer()->drawSphere(btVector3(0, 0, 0), 0.1, btVector3(1, 1, 1)); + deformableWorld->getDebugDrawer()->drawSphere(btVector3(0, 2, 0), 0.1, btVector3(1, 1, 1)); + deformableWorld->getDebugDrawer()->drawSphere(btVector3(0, 4, 0), 0.1, btVector3(1, 1, 1)); + } + } + } +}; + +void ConservationTest::initPhysics() +{ + m_guiHelper->setUpAxis(1); + + ///collision configuration contains default setup for memory, collision setup + m_collisionConfiguration = new btSoftBodyRigidBodyCollisionConfiguration(); + + ///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(); + btReducedDeformableBodySolver* reducedSoftBodySolver = new btReducedDeformableBodySolver(); + btVector3 gravity = btVector3(0, 0, 0); + reducedSoftBodySolver->setGravity(gravity); + + btDeformableMultiBodyConstraintSolver* sol = new btDeformableMultiBodyConstraintSolver(); + sol->setDeformableSolver(reducedSoftBodySolver); + m_solver = sol; + + m_dynamicsWorld = new btDeformableMultiBodyDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, reducedSoftBodySolver); + m_dynamicsWorld->setGravity(gravity); + m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld); + + // create volumetric reduced deformable body + { + std::string file_path("../../../data/reduced_beam/"); + std::string vtk_file("beam_mesh_origin.vtk"); + btReducedDeformableBody* rsb = btReducedDeformableBodyHelpers::createReducedDeformableObject( + getDeformableDynamicsWorld()->getWorldInfo(), + file_path, + vtk_file, + num_modes, + false); + + getDeformableDynamicsWorld()->addSoftBody(rsb); + rsb->getCollisionShape()->setMargin(0.1); + + btTransform init_transform; + init_transform.setIdentity(); + init_transform.setOrigin(btVector3(0, 4, 0)); + // init_transform.setRotation(btQuaternion(btVector3(0, 1, 0), SIMD_PI / 2.0)); + rsb->transformTo(init_transform); + + rsb->setStiffnessScale(100); + rsb->setDamping(damping_alpha, damping_beta); + + rsb->m_cfg.kKHR = 1; // collision hardness with kinematic objects + rsb->m_cfg.kCHR = 1; // collision hardness with rigid body + rsb->m_cfg.kDF = 0; + rsb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD; + rsb->m_cfg.collisions |= btSoftBody::fCollision::SDF_RDN; + rsb->m_sleepingThreshold = 0; + btSoftBodyHelpers::generateBoundaryFaces(rsb); + + // rsb->setVelocity(btVector3(0, -COLLIDING_VELOCITY, 0)); + // rsb->setRigidVelocity(btVector3(0, 1, 0)); + // rsb->setRigidAngularVelocity(btVector3(1, 0, 0)); + } + getDeformableDynamicsWorld()->setImplicit(false); + getDeformableDynamicsWorld()->setLineSearch(false); + getDeformableDynamicsWorld()->setUseProjection(false); + getDeformableDynamicsWorld()->getSolverInfo().m_deformable_erp = 0.3; + getDeformableDynamicsWorld()->getSolverInfo().m_deformable_cfm = 0.2; + getDeformableDynamicsWorld()->getSolverInfo().m_deformable_maxErrorReduction = btScalar(200); + getDeformableDynamicsWorld()->getSolverInfo().m_leastSquaresResidualThreshold = 1e-3; + getDeformableDynamicsWorld()->getSolverInfo().m_splitImpulse = false; + getDeformableDynamicsWorld()->getSolverInfo().m_numIterations = 100; + + m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld); +} + +void ConservationTest::exitPhysics() +{ + //cleanup in the reverse order of creation/initialization + removePickingConstraint(); + //remove the rigidbodies from the dynamics world and delete them + int i; + for (i = m_dynamicsWorld->getNumCollisionObjects() - 1; i >= 0; i--) + { + btCollisionObject* obj = m_dynamicsWorld->getCollisionObjectArray()[i]; + btRigidBody* body = btRigidBody::upcast(obj); + if (body && body->getMotionState()) + { + delete body->getMotionState(); + } + m_dynamicsWorld->removeCollisionObject(obj); + delete obj; + } + // delete forces + for (int j = 0; j < m_forces.size(); j++) + { + btDeformableLagrangianForce* force = m_forces[j]; + delete force; + } + m_forces.clear(); + + //delete collision shapes + for (int j = 0; j < m_collisionShapes.size(); j++) + { + btCollisionShape* shape = m_collisionShapes[j]; + delete shape; + } + m_collisionShapes.clear(); + + delete m_dynamicsWorld; + + delete m_solver; + + delete m_broadphase; + + delete m_dispatcher; + + delete m_collisionConfiguration; +} + + + +class CommonExampleInterface* ReducedConservationTestCreateFunc(struct CommonExampleOptions& options) +{ + return new ConservationTest(options.m_guiHelper); +} + + |