Bullet Collision Detection & Physics Library
btMultiBodyConstraint.h
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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2013 Erwin Coumans http://bulletphysics.org
4 
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10 
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_MULTIBODY_CONSTRAINT_H
17 #define BT_MULTIBODY_CONSTRAINT_H
18 
19 #include "LinearMath/btScalar.h"
21 #include "btMultiBody.h"
22 
23 class btMultiBody;
24 struct btSolverInfo;
25 
27 
29 {
31  btAlignedObjectArray<btScalar> m_deltaVelocitiesUnitImpulse; //holds the joint-space response of the corresp. tree to the test impulse in each constraint space dimension
32  btAlignedObjectArray<btScalar> m_deltaVelocities; //holds joint-space vectors of all the constrained trees accumulating the effect of corrective impulses applied in SI
38 
39 };
40 
41 
43 {
44 protected:
45 
48  int m_linkA;
49  int m_linkB;
50 
51  int m_numRows;
55 
59 
60 
61  // warning: the data block lay out is not consistent for all constraints
62  // data block laid out as follows:
63  // cached impulses. (one per row.)
64  // jacobians. (interleaved, row1 body1 then row1 body2 then row2 body 1 etc)
65  // positions. (one per row.)
67 
68  void applyDeltaVee(btMultiBodyJacobianData& data, btScalar* delta_vee, btScalar impulse, int velocityIndex, int ndof);
69 
72  btScalar* jacOrgA, btScalar* jacOrgB,
73  const btVector3& contactNormalOnB,
74  const btVector3& posAworld, const btVector3& posBworld,
75  btScalar posError,
76  const btContactSolverInfo& infoGlobal,
77  btScalar lowerLimit, btScalar upperLimit,
78  btScalar relaxation = 1.f,
79  bool isFriction = false, btScalar desiredVelocity=0, btScalar cfmSlip=0);
80 
81 public:
82 
83  btMultiBodyConstraint(btMultiBody* bodyA,btMultiBody* bodyB,int linkA, int linkB, int numRows, bool isUnilateral);
84  virtual ~btMultiBodyConstraint();
85 
86  void updateJacobianSizes();
88 
89  virtual void finalizeMultiDof()=0;
90 
91  virtual int getIslandIdA() const =0;
92  virtual int getIslandIdB() const =0;
93 
94  virtual void createConstraintRows(btMultiBodyConstraintArray& constraintRows,
96  const btContactSolverInfo& infoGlobal)=0;
97 
98  int getNumRows() const
99  {
100  return m_numRows;
101  }
102 
104  {
105  return m_bodyA;
106  }
108  {
109  return m_bodyB;
110  }
111 
112  void internalSetAppliedImpulse(int dof, btScalar appliedImpulse)
113  {
114  btAssert(dof>=0);
115  btAssert(dof < getNumRows());
116  m_data[dof] = appliedImpulse;
117  }
118 
120  {
121  btAssert(dof>=0);
122  btAssert(dof < getNumRows());
123  return m_data[dof];
124  }
125  // current constraint position
126  // constraint is pos >= 0 for unilateral, or pos = 0 for bilateral
127  // NOTE: ignored position for friction rows.
128  btScalar getPosition(int row) const
129  {
130  return m_data[m_posOffset + row];
131  }
132 
133  void setPosition(int row, btScalar pos)
134  {
135  m_data[m_posOffset + row] = pos;
136  }
137 
138 
139  bool isUnilateral() const
140  {
141  return m_isUnilateral;
142  }
143 
144  // jacobian blocks.
145  // each of size 6 + num_links. (jacobian2 is null if no body2.)
146  // format: 3 'omega' coefficients, 3 'v' coefficients, then the 'qdot' coefficients.
147  btScalar* jacobianA(int row)
148  {
149  return &m_data[m_numRows + row * m_jacSizeBoth];
150  }
151  const btScalar* jacobianA(int row) const
152  {
153  return &m_data[m_numRows + (row * m_jacSizeBoth)];
154  }
155  btScalar* jacobianB(int row)
156  {
157  return &m_data[m_numRows + (row * m_jacSizeBoth) + m_jacSizeA];
158  }
159  const btScalar* jacobianB(int row) const
160  {
161  return &m_data[m_numRows + (row * m_jacSizeBoth) + m_jacSizeA];
162  }
163 
165  {
166  return m_maxAppliedImpulse;
167  }
169  {
170  m_maxAppliedImpulse = maxImp;
171  }
172 
173  virtual void debugDraw(class btIDebugDraw* drawer)=0;
174 
175 };
176 
177 #endif //BT_MULTIBODY_CONSTRAINT_H
178 
btScalar fillMultiBodyConstraint(btMultiBodySolverConstraint &solverConstraint, btMultiBodyJacobianData &data, btScalar *jacOrgA, btScalar *jacOrgB, const btVector3 &contactNormalOnB, const btVector3 &posAworld, const btVector3 &posBworld, btScalar posError, const btContactSolverInfo &infoGlobal, btScalar lowerLimit, btScalar upperLimit, btScalar relaxation=1.f, bool isFriction=false, btScalar desiredVelocity=0, btScalar cfmSlip=0)
btScalar getMaxAppliedImpulse() const
btScalar * jacobianB(int row)
1D constraint along a normal axis between bodyA and bodyB. It can be combined to solve contact and fr...
btAlignedObjectArray< btScalar > scratch_r
btAlignedObjectArray< btScalar > m_deltaVelocities
virtual void createConstraintRows(btMultiBodyConstraintArray &constraintRows, btMultiBodyJacobianData &data, const btContactSolverInfo &infoGlobal)=0
btAlignedObjectArray< btSolverBody > * m_solverBodyPool
btScalar getAppliedImpulse(int dof)
void internalSetAppliedImpulse(int dof, btScalar appliedImpulse)
#define btAssert(x)
Definition: btScalar.h:113
btScalar * jacobianA(int row)
virtual void debugDraw(class btIDebugDraw *drawer)=0
btAlignedObjectArray< btMatrix3x3 > scratch_m
virtual int getIslandIdB() const =0
btAlignedObjectArray< btScalar > m_deltaVelocitiesUnitImpulse
virtual void finalizeMultiDof()=0
btScalar getPosition(int row) const
The btIDebugDraw interface class allows hooking up a debug renderer to visually debug simulations...
Definition: btIDebugDraw.h:29
btAlignedObjectArray< btScalar > m_data
btAlignedObjectArray< btScalar > m_jacobians
virtual int getIslandIdA() const =0
const btScalar * jacobianA(int row) const
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btAlignedObjectArray< btVector3 > scratch_v
void setPosition(int row, btScalar pos)
void setMaxAppliedImpulse(btScalar maxImp)
btMultiBodyConstraint(btMultiBody *bodyA, btMultiBody *bodyB, int linkA, int linkB, int numRows, bool isUnilateral)
const btScalar * jacobianB(int row) const
void applyDeltaVee(btMultiBodyJacobianData &data, btScalar *delta_vee, btScalar impulse, int velocityIndex, int ndof)
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:278