Bullet Collision Detection & Physics Library: btDeformableContactProjection.h Source File

Bullet Collision Detection & Physics Library

btDeformableContactProjection.h
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1/*
2 Written by Xuchen Han <xuchenhan2015@u.northwestern.edu>
3
4 Bullet Continuous Collision Detection and Physics Library
5 Copyright (c) 2019 Google Inc. http://bulletphysics.org
6 This software is provided 'as-is', without any express or implied warranty.
7 In no event will the authors be held liable for any damages arising from the use of this software.
8 Permission is granted to anyone to use this software for any purpose,
9 including commercial applications, and to alter it and redistribute it freely,
10 subject to the following restrictions:
11 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.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15
16#ifndef BT_CONTACT_PROJECTION_H
17#define BT_CONTACT_PROJECTION_H
18#include "btCGProjection.h"
19#include "btSoftBody.h"
20#include "BulletDynamics/Featherstone/btMultiBodyLinkCollider.h"
21#include "BulletDynamics/Featherstone/btMultiBodyConstraint.h"
22#include "btDeformableContactConstraint.h"
23#include "LinearMath/btHashMap.h"
24#include "LinearMath/btReducedVector.h"
25#include "LinearMath/btModifiedGramSchmidt.h"
26#include <vector>
27
28 struct LagrangeMultiplier
29{
30 int m_num_constraints; // Number of constraints
31 int m_num_nodes; // Number of nodes in these constraints
32 btScalar m_weights[3]; // weights of the nodes involved, same size as m_num_nodes
33 btVector3 m_dirs[3]; // Constraint directions, same size of m_num_constraints;
34 int m_indices[3]; // indices of the nodes involved, same size as m_num_nodes;
35};
36
37 class btDeformableContactProjection
38{
39public:
40 typedef btAlignedObjectArray<btVector3> TVStack;
41 btAlignedObjectArray<btSoftBody*>& m_softBodies;
42
43 // all constraints involving face
44 btAlignedObjectArray<btDeformableContactConstraint*> m_allFaceConstraints;
45#ifndef USE_MGS
46 // map from node index to projection directions
47 btHashMap<btHashInt, btAlignedObjectArray<btVector3> > m_projectionsDict;
48#else
49 btAlignedObjectArray<btReducedVector> m_projections;
50#endif
51
52 btAlignedObjectArray<LagrangeMultiplier> m_lagrangeMultipliers;
53
54 // map from node index to static constraint
55 btAlignedObjectArray<btAlignedObjectArray<btDeformableStaticConstraint> > m_staticConstraints;
56 // map from node index to node rigid constraint
57 btAlignedObjectArray<btAlignedObjectArray<btDeformableNodeRigidContactConstraint> > m_nodeRigidConstraints;
58 // map from node index to face rigid constraint
59 btAlignedObjectArray<btAlignedObjectArray<btDeformableFaceRigidContactConstraint> > m_faceRigidConstraints;
60 // map from node index to deformable constraint
61 btAlignedObjectArray<btAlignedObjectArray<btDeformableFaceNodeContactConstraint> > m_deformableConstraints;
62 // map from node index to node anchor constraint
63 btAlignedObjectArray<btAlignedObjectArray<btDeformableNodeAnchorConstraint> > m_nodeAnchorConstraints;
64
65 bool m_useStrainLimiting;
66
67 btDeformableContactProjection(btAlignedObjectArray<btSoftBody*>& softBodies)
68 : m_softBodies(softBodies)
69 {
70 }
71
72 virtual ~btDeformableContactProjection()
73 {
74 }
75
76 // apply the constraints to the rhs of the linear solve
77 virtual void project(TVStack& x);
78
79 // add friction force to the rhs of the linear solve
80 virtual void applyDynamicFriction(TVStack& f);
81
82 // update and solve the constraints
83 virtual btScalar update(btCollisionObject** deformableBodies, int numDeformableBodies, const btContactSolverInfo& infoGlobal);
84
85 // Add constraints to m_constraints. In addition, the constraints that each vertex own are recorded in m_constraintsDict.
86 virtual void setConstraints(const btContactSolverInfo& infoGlobal);
87
88 // Set up projections for each vertex by adding the projection direction to
89 virtual void setProjection();
90
91 virtual void reinitialize(bool nodeUpdated);
92
93 btScalar solveSplitImpulse(btCollisionObject** deformableBodies, int numDeformableBodies, const btContactSolverInfo& infoGlobal);
94
95 virtual void setLagrangeMultiplier();
96
97 void checkConstraints(const TVStack& x);
98};
99#endif /* btDeformableContactProjection_h */
btCGProjection.h
btDeformableContactConstraint.h
btHashMap.h
btModifiedGramSchmidt.h
btMultiBodyConstraint.h
btMultiBodyLinkCollider.h
btReducedVector.h
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition btScalar.h:314
btSoftBody.h
btAlignedObjectArray
The btAlignedObjectArray template class uses a subset of the stl::vector interface for its methods It...
Definition btAlignedObjectArray.h:46
btCollisionObject
btCollisionObject can be used to manage collision detection objects.
Definition btCollisionObject.h:51
btDeformableContactProjection::update
virtual btScalar update(btCollisionObject **deformableBodies, int numDeformableBodies, const btContactSolverInfo &infoGlobal)
Definition btDeformableContactProjection.cpp:20
btDeformableContactProjection::setLagrangeMultiplier
virtual void setLagrangeMultiplier()
Definition btDeformableContactProjection.cpp:460
btDeformableContactProjection::m_lagrangeMultipliers
btAlignedObjectArray< LagrangeMultiplier > m_lagrangeMultipliers
Definition btDeformableContactProjection.h:52
btDeformableContactProjection::setConstraints
virtual void setConstraints(const btContactSolverInfo &infoGlobal)
Definition btDeformableContactProjection.cpp:90
btDeformableContactProjection::project
virtual void project(TVStack &x)
Definition btDeformableContactProjection.cpp:153
btDeformableContactProjection::reinitialize
virtual void reinitialize(bool nodeUpdated)
Definition btDeformableContactProjection.cpp:614
btDeformableContactProjection::m_useStrainLimiting
bool m_useStrainLimiting
Definition btDeformableContactProjection.h:65
btDeformableContactProjection::m_softBodies
btAlignedObjectArray< btSoftBody * > & m_softBodies
Definition btDeformableContactProjection.h:41
btDeformableContactProjection::m_deformableConstraints
btAlignedObjectArray< btAlignedObjectArray< btDeformableFaceNodeContactConstraint > > m_deformableConstraints
Definition btDeformableContactProjection.h:61
btDeformableContactProjection::btDeformableContactProjection
btDeformableContactProjection(btAlignedObjectArray< btSoftBody * > &softBodies)
Definition btDeformableContactProjection.h:67
btDeformableContactProjection::checkConstraints
void checkConstraints(const TVStack &x)
Definition btDeformableContactProjection.cpp:442
btDeformableContactProjection::solveSplitImpulse
btScalar solveSplitImpulse(btCollisionObject **deformableBodies, int numDeformableBodies, const btContactSolverInfo &infoGlobal)
Definition btDeformableContactProjection.cpp:61
btDeformableContactProjection::~btDeformableContactProjection
virtual ~btDeformableContactProjection()
Definition btDeformableContactProjection.h:72
btDeformableContactProjection::setProjection
virtual void setProjection()
Definition btDeformableContactProjection.cpp:202
btDeformableContactProjection::m_nodeRigidConstraints
btAlignedObjectArray< btAlignedObjectArray< btDeformableNodeRigidContactConstraint > > m_nodeRigidConstraints
Definition btDeformableContactProjection.h:57
btDeformableContactProjection::TVStack
btAlignedObjectArray< btVector3 > TVStack
Definition btDeformableContactProjection.h:40
btDeformableContactProjection::m_projectionsDict
btHashMap< btHashInt, btAlignedObjectArray< btVector3 > > m_projectionsDict
Definition btDeformableContactProjection.h:47
btDeformableContactProjection::m_staticConstraints
btAlignedObjectArray< btAlignedObjectArray< btDeformableStaticConstraint > > m_staticConstraints
Definition btDeformableContactProjection.h:55
btDeformableContactProjection::m_faceRigidConstraints
btAlignedObjectArray< btAlignedObjectArray< btDeformableFaceRigidContactConstraint > > m_faceRigidConstraints
Definition btDeformableContactProjection.h:59
btDeformableContactProjection::m_nodeAnchorConstraints
btAlignedObjectArray< btAlignedObjectArray< btDeformableNodeAnchorConstraint > > m_nodeAnchorConstraints
Definition btDeformableContactProjection.h:63
btDeformableContactProjection::applyDynamicFriction
virtual void applyDynamicFriction(TVStack &f)
Definition btDeformableContactProjection.cpp:563
btDeformableContactProjection::m_allFaceConstraints
btAlignedObjectArray< btDeformableContactConstraint * > m_allFaceConstraints
Definition btDeformableContactProjection.h:44
btHashMap
The btHashMap template class implements a generic and lightweight hashmap.
Definition btHashMap.h:220
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition btVector3.h:82
LagrangeMultiplier
Definition btDeformableContactProjection.h:29
LagrangeMultiplier::m_num_nodes
int m_num_nodes
Definition btDeformableContactProjection.h:31
LagrangeMultiplier::m_indices
int m_indices[3]
Definition btDeformableContactProjection.h:34
LagrangeMultiplier::m_num_constraints
int m_num_constraints
Definition btDeformableContactProjection.h:30
LagrangeMultiplier::m_dirs
btVector3 m_dirs[3]
Definition btDeformableContactProjection.h:33
LagrangeMultiplier::m_weights
btScalar m_weights[3]
Definition btDeformableContactProjection.h:32
btContactSolverInfo
Definition btContactSolverInfo.h:76