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Diffstat (limited to 'thirdparty/bullet/BulletSoftBody/btDeformableBackwardEulerObjective.h')
| -rw-r--r-- | thirdparty/bullet/BulletSoftBody/btDeformableBackwardEulerObjective.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/thirdparty/bullet/BulletSoftBody/btDeformableBackwardEulerObjective.h b/thirdparty/bullet/BulletSoftBody/btDeformableBackwardEulerObjective.h new file mode 100644 index 0000000000..86579e71ac --- /dev/null +++ b/thirdparty/bullet/BulletSoftBody/btDeformableBackwardEulerObjective.h @@ -0,0 +1,173 @@ +/* + Written by Xuchen Han <xuchenhan2015@u.northwestern.edu> + + 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. + */ + +#ifndef BT_BACKWARD_EULER_OBJECTIVE_H +#define BT_BACKWARD_EULER_OBJECTIVE_H +//#include "btConjugateGradient.h" +#include "btDeformableLagrangianForce.h" +#include "btDeformableMassSpringForce.h" +#include "btDeformableGravityForce.h" +#include "btDeformableCorotatedForce.h" +#include "btDeformableMousePickingForce.h" +#include "btDeformableLinearElasticityForce.h" +#include "btDeformableNeoHookeanForce.h" +#include "btDeformableContactProjection.h" +#include "btPreconditioner.h" +#include "btDeformableMultiBodyDynamicsWorld.h" +#include "LinearMath/btQuickprof.h" + +class btDeformableBackwardEulerObjective +{ +public: + typedef btAlignedObjectArray<btVector3> TVStack; + btScalar m_dt; + btAlignedObjectArray<btDeformableLagrangianForce*> m_lf; + btAlignedObjectArray<btSoftBody *>& m_softBodies; + Preconditioner* m_preconditioner; + btDeformableContactProjection m_projection; + const TVStack& m_backupVelocity; + btAlignedObjectArray<btSoftBody::Node* > m_nodes; + bool m_implicit; + MassPreconditioner* m_massPreconditioner; + KKTPreconditioner* m_KKTPreconditioner; + + btDeformableBackwardEulerObjective(btAlignedObjectArray<btSoftBody *>& softBodies, const TVStack& backup_v); + + virtual ~btDeformableBackwardEulerObjective(); + + void initialize(){} + + // compute the rhs for CG solve, i.e, add the dt scaled implicit force to residual + void computeResidual(btScalar dt, TVStack& residual); + + // add explicit force to the velocity + void applyExplicitForce(TVStack& force); + + // apply force to velocity and optionally reset the force to zero + void applyForce(TVStack& force, bool setZero); + + // compute the norm of the residual + btScalar computeNorm(const TVStack& residual) const; + + // compute one step of the solve (there is only one solve if the system is linear) + void computeStep(TVStack& dv, const TVStack& residual, const btScalar& dt); + + // perform A*x = b + void multiply(const TVStack& x, TVStack& b) const; + + // set initial guess for CG solve + void initialGuess(TVStack& dv, const TVStack& residual); + + // reset data structure and reset dt + void reinitialize(bool nodeUpdated, btScalar dt); + + void setDt(btScalar dt); + + // add friction force to residual + void applyDynamicFriction(TVStack& r); + + // add dv to velocity + void updateVelocity(const TVStack& dv); + + //set constraints as projections + void setConstraints(const btContactSolverInfo& infoGlobal); + + // update the projections and project the residual + void project(TVStack& r) + { + BT_PROFILE("project"); + m_projection.project(r); + } + + // perform precondition M^(-1) x = b + void precondition(const TVStack& x, TVStack& b) + { + m_preconditioner->operator()(x,b); + } + + // reindex all the vertices + virtual void updateId() + { + size_t node_id = 0; + size_t face_id = 0; + m_nodes.clear(); + for (int i = 0; i < m_softBodies.size(); ++i) + { + btSoftBody* psb = m_softBodies[i]; + for (int j = 0; j < psb->m_nodes.size(); ++j) + { + psb->m_nodes[j].index = node_id; + m_nodes.push_back(&psb->m_nodes[j]); + ++node_id; + } + for (int j = 0; j < psb->m_faces.size(); ++j) + { + psb->m_faces[j].m_index = face_id; + ++face_id; + } + } + } + + const btAlignedObjectArray<btSoftBody::Node*>* getIndices() const + { + return &m_nodes; + } + + void setImplicit(bool implicit) + { + m_implicit = implicit; + } + + // Calculate the total potential energy in the system + btScalar totalEnergy(btScalar dt); + + void addLagrangeMultiplier(const TVStack& vec, TVStack& extended_vec) + { + extended_vec.resize(vec.size() + m_projection.m_lagrangeMultipliers.size()); + for (int i = 0; i < vec.size(); ++i) + { + extended_vec[i] = vec[i]; + } + int offset = vec.size(); + for (int i = 0; i < m_projection.m_lagrangeMultipliers.size(); ++i) + { + extended_vec[offset + i].setZero(); + } + } + + void addLagrangeMultiplierRHS(const TVStack& residual, const TVStack& m_dv, TVStack& extended_residual) + { + extended_residual.resize(residual.size() + m_projection.m_lagrangeMultipliers.size()); + for (int i = 0; i < residual.size(); ++i) + { + extended_residual[i] = residual[i]; + } + int offset = residual.size(); + for (int i = 0; i < m_projection.m_lagrangeMultipliers.size(); ++i) + { + const LagrangeMultiplier& lm = m_projection.m_lagrangeMultipliers[i]; + extended_residual[offset + i].setZero(); + for (int d = 0; d < lm.m_num_constraints; ++d) + { + for (int n = 0; n < lm.m_num_nodes; ++n) + { + extended_residual[offset + i][d] += lm.m_weights[n] * m_dv[lm.m_indices[n]].dot(lm.m_dirs[d]); + } + } + } + } +}; + +#endif /* btBackwardEulerObjective_h */ |