Bullet Collision Detection & Physics Library
btMultiBodyFixedConstraint.cpp
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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2013 Erwin Coumans http://bulletphysics.org
4
5This software is provided 'as-is', without any express or implied warranty.
6In no event will the authors be held liable for any damages arising from the use of this software.
7Permission is granted to anyone to use this software for any purpose,
8including commercial applications, and to alter it and redistribute it freely,
9subject to the following restrictions:
10
111. 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.
122. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
133. This notice may not be removed or altered from any source distribution.
14*/
15
17
23
24#define BTMBFIXEDCONSTRAINT_DIM 6
25
26btMultiBodyFixedConstraint::btMultiBodyFixedConstraint(btMultiBody* body, int link, btRigidBody* bodyB, const btVector3& pivotInA, const btVector3& pivotInB, const btMatrix3x3& frameInA, const btMatrix3x3& frameInB)
28 m_rigidBodyA(0),
29 m_rigidBodyB(bodyB),
30 m_pivotInA(pivotInA),
31 m_pivotInB(pivotInB),
32 m_frameInA(frameInA),
33 m_frameInB(frameInB)
34{
35 m_data.resize(BTMBFIXEDCONSTRAINT_DIM);//at least store the applied impulses
36}
37
38btMultiBodyFixedConstraint::btMultiBodyFixedConstraint(btMultiBody* bodyA, int linkA, btMultiBody* bodyB, int linkB, const btVector3& pivotInA, const btVector3& pivotInB, const btMatrix3x3& frameInA, const btMatrix3x3& frameInB)
39 :btMultiBodyConstraint(bodyA,bodyB,linkA,linkB,BTMBFIXEDCONSTRAINT_DIM,false),
40 m_rigidBodyA(0),
41 m_rigidBodyB(0),
42 m_pivotInA(pivotInA),
43 m_pivotInB(pivotInB),
44 m_frameInA(frameInA),
45 m_frameInB(frameInB)
46{
47 m_data.resize(BTMBFIXEDCONSTRAINT_DIM);//at least store the applied impulses
48}
49
51{
52 //not implemented yet
53 btAssert(0);
54}
55
57{
58}
59
60
62{
63 if (m_rigidBodyA)
64 return m_rigidBodyA->getIslandTag();
65
66 if (m_bodyA)
67 {
69 if (col)
70 return col->getIslandTag();
71 for (int i=0;i<m_bodyA->getNumLinks();i++)
72 {
75 }
76 }
77 return -1;
78}
79
81{
82 if (m_rigidBodyB)
83 return m_rigidBodyB->getIslandTag();
84 if (m_bodyB)
85 {
87 if (col)
88 return col->getIslandTag();
89
90 for (int i=0;i<m_bodyB->getNumLinks();i++)
91 {
92 col = m_bodyB->getLink(i).m_collider;
93 if (col)
94 return col->getIslandTag();
95 }
96 }
97 return -1;
98}
99
101{
102 int numDim = BTMBFIXEDCONSTRAINT_DIM;
103 for (int i=0;i<numDim;i++)
104 {
105 btMultiBodySolverConstraint& constraintRow = constraintRows.expandNonInitializing();
106 constraintRow.m_orgConstraint = this;
107 constraintRow.m_orgDofIndex = i;
108 constraintRow.m_relpos1CrossNormal.setValue(0,0,0);
109 constraintRow.m_contactNormal1.setValue(0,0,0);
110 constraintRow.m_relpos2CrossNormal.setValue(0,0,0);
111 constraintRow.m_contactNormal2.setValue(0,0,0);
112 constraintRow.m_angularComponentA.setValue(0,0,0);
113 constraintRow.m_angularComponentB.setValue(0,0,0);
114
115 constraintRow.m_solverBodyIdA = data.m_fixedBodyId;
116 constraintRow.m_solverBodyIdB = data.m_fixedBodyId;
117
118 // Convert local points back to world
119 btVector3 pivotAworld = m_pivotInA;
120 btMatrix3x3 frameAworld = m_frameInA;
121 if (m_rigidBodyA)
122 {
123
126 frameAworld = frameAworld.transpose()*btMatrix3x3(m_rigidBodyA->getOrientation());
127
128 } else
129 {
130 if (m_bodyA) {
131 pivotAworld = m_bodyA->localPosToWorld(m_linkA, m_pivotInA);
132 frameAworld = m_bodyA->localFrameToWorld(m_linkA, frameAworld);
133 }
134 }
135 btVector3 pivotBworld = m_pivotInB;
136 btMatrix3x3 frameBworld = m_frameInB;
137 if (m_rigidBodyB)
138 {
141 frameBworld = frameBworld.transpose()*btMatrix3x3(m_rigidBodyB->getOrientation());
142
143 } else
144 {
145 if (m_bodyB) {
146 pivotBworld = m_bodyB->localPosToWorld(m_linkB, m_pivotInB);
147 frameBworld = m_bodyB->localFrameToWorld(m_linkB, frameBworld);
148 }
149 }
150
151 btMatrix3x3 relRot = frameAworld.inverse()*frameBworld;
152 btVector3 angleDiff;
154
155 btVector3 constraintNormalLin(0,0,0);
156 btVector3 constraintNormalAng(0,0,0);
157 btScalar posError = 0.0;
158 if (i < 3) {
159 constraintNormalLin[i] = -1;
160 posError = (pivotAworld-pivotBworld).dot(constraintNormalLin);
161 fillMultiBodyConstraint(constraintRow, data, 0, 0, constraintNormalAng,
162 constraintNormalLin, pivotAworld, pivotBworld,
163 posError,
164 infoGlobal,
166 );
167 }
168 else { //i>=3
169 constraintNormalAng = frameAworld.getColumn(i%3);
170 posError = angleDiff[i%3];
171 fillMultiBodyConstraint(constraintRow, data, 0, 0, constraintNormalAng,
172 constraintNormalLin, pivotAworld, pivotBworld,
173 posError,
174 infoGlobal,
176 );
177 }
178 }
179}
180
182{
183 btTransform tr;
184 tr.setIdentity();
185
186 if (m_rigidBodyA)
187 {
189 tr.setOrigin(pivot);
190 drawer->drawTransform(tr, 0.1);
191 }
192 if (m_bodyA)
193 {
195 tr.setOrigin(pivotAworld);
196 drawer->drawTransform(tr, 0.1);
197 }
198 if (m_rigidBodyB)
199 {
200 // that ideally should draw the same frame
202 tr.setOrigin(pivot);
203 drawer->drawTransform(tr, 0.1);
204 }
205 if (m_bodyB)
206 {
208 tr.setOrigin(pivotBworld);
209 drawer->drawTransform(tr, 0.1);
210 }
211}
#define BTMBFIXEDCONSTRAINT_DIM
This file was written by Erwin Coumans.
btScalar dot(const btQuaternion &q1, const btQuaternion &q2)
Calculate the dot product between two quaternions.
Definition: btQuaternion.h:878
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292
#define btAssert(x)
Definition: btScalar.h:131
void resize(int newsize, const T &fillData=T())
int getIslandTag() const
int getCompanionId() const
static bool matrixToEulerXYZ(const btMatrix3x3 &mat, btVector3 &xyz)
The btIDebugDraw interface class allows hooking up a debug renderer to visually debug simulations.
Definition: btIDebugDraw.h:30
virtual void drawTransform(const btTransform &transform, btScalar orthoLen)
Definition: btIDebugDraw.h:166
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition: btMatrix3x3.h:48
btMatrix3x3 inverse() const
Return the inverse of the matrix.
Definition: btMatrix3x3.h:1003
btMatrix3x3 transpose() const
Return the transpose of the matrix.
Definition: btMatrix3x3.h:958
btVector3 getColumn(int i) const
Get a column of the matrix as a vector.
Definition: btMatrix3x3.h:134
btAlignedObjectArray< btScalar > m_data
btScalar fillMultiBodyConstraint(btMultiBodySolverConstraint &solverConstraint, btMultiBodyJacobianData &data, btScalar *jacOrgA, btScalar *jacOrgB, const btVector3 &constraintNormalAng, const btVector3 &constraintNormalLin, const btVector3 &posAworld, const btVector3 &posBworld, btScalar posError, const btContactSolverInfo &infoGlobal, btScalar lowerLimit, btScalar upperLimit, bool angConstraint=false, btScalar relaxation=1.f, bool isFriction=false, btScalar desiredVelocity=0, btScalar cfmSlip=0)
virtual void debugDraw(class btIDebugDraw *drawer)
btMultiBodyFixedConstraint(btMultiBody *body, int link, btRigidBody *bodyB, const btVector3 &pivotInA, const btVector3 &pivotInB, const btMatrix3x3 &frameInA, const btMatrix3x3 &frameInB)
virtual void createConstraintRows(btMultiBodyConstraintArray &constraintRows, btMultiBodyJacobianData &data, const btContactSolverInfo &infoGlobal)
btVector3 localPosToWorld(int i, const btVector3 &vec) const
int getNumLinks() const
Definition: btMultiBody.h:164
const btMultibodyLink & getLink(int index) const
Definition: btMultiBody.h:119
const btMultiBodyLinkCollider * getBaseCollider() const
Definition: btMultiBody.h:134
btMatrix3x3 localFrameToWorld(int i, const btMatrix3x3 &mat) const
The btRigidBody is the main class for rigid body objects.
Definition: btRigidBody.h:63
btQuaternion getOrientation() const
const btTransform & getCenterOfMassTransform() const
Definition: btRigidBody.h:359
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
void setIdentity()
Set this transformation to the identity.
Definition: btTransform.h:172
void setOrigin(const btVector3 &origin)
Set the translational element.
Definition: btTransform.h:150
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:84
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition: btVector3.h:652
1D constraint along a normal axis between bodyA and bodyB. It can be combined to solve contact and fr...
btMultiBodyConstraint * m_orgConstraint