1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
#include "b3FixedConstraint.h"
#include "Bullet3Collision/NarrowPhaseCollision/shared/b3RigidBodyData.h"
#include "Bullet3Common/b3TransformUtil.h"
#include <new>
b3FixedConstraint::b3FixedConstraint(int rbA,int rbB, const b3Transform& frameInA,const b3Transform& frameInB)
:b3TypedConstraint(B3_FIXED_CONSTRAINT_TYPE,rbA,rbB)
{
m_pivotInA = frameInA.getOrigin();
m_pivotInB = frameInB.getOrigin();
m_relTargetAB = frameInA.getRotation()*frameInB.getRotation().inverse();
}
b3FixedConstraint::~b3FixedConstraint ()
{
}
void b3FixedConstraint::getInfo1 (b3ConstraintInfo1* info,const b3RigidBodyData* bodies)
{
info->m_numConstraintRows = 6;
info->nub = 6;
}
void b3FixedConstraint::getInfo2 (b3ConstraintInfo2* info, const b3RigidBodyData* bodies)
{
//fix the 3 linear degrees of freedom
const b3Vector3& worldPosA = bodies[m_rbA].m_pos;
const b3Quaternion& worldOrnA = bodies[m_rbA].m_quat;
const b3Vector3& worldPosB= bodies[m_rbB].m_pos;
const b3Quaternion& worldOrnB = bodies[m_rbB].m_quat;
info->m_J1linearAxis[0] = 1;
info->m_J1linearAxis[info->rowskip+1] = 1;
info->m_J1linearAxis[2*info->rowskip+2] = 1;
b3Vector3 a1 = b3QuatRotate(worldOrnA,m_pivotInA);
{
b3Vector3* angular0 = (b3Vector3*)(info->m_J1angularAxis);
b3Vector3* angular1 = (b3Vector3*)(info->m_J1angularAxis+info->rowskip);
b3Vector3* angular2 = (b3Vector3*)(info->m_J1angularAxis+2*info->rowskip);
b3Vector3 a1neg = -a1;
a1neg.getSkewSymmetricMatrix(angular0,angular1,angular2);
}
if (info->m_J2linearAxis)
{
info->m_J2linearAxis[0] = -1;
info->m_J2linearAxis[info->rowskip+1] = -1;
info->m_J2linearAxis[2*info->rowskip+2] = -1;
}
b3Vector3 a2 = b3QuatRotate(worldOrnB,m_pivotInB);
{
// b3Vector3 a2n = -a2;
b3Vector3* angular0 = (b3Vector3*)(info->m_J2angularAxis);
b3Vector3* angular1 = (b3Vector3*)(info->m_J2angularAxis+info->rowskip);
b3Vector3* angular2 = (b3Vector3*)(info->m_J2angularAxis+2*info->rowskip);
a2.getSkewSymmetricMatrix(angular0,angular1,angular2);
}
// set right hand side for the linear dofs
b3Scalar k = info->fps * info->erp;
b3Vector3 linearError = k*(a2+worldPosB-a1-worldPosA);
int j;
for (j=0; j<3; j++)
{
info->m_constraintError[j*info->rowskip] = linearError[j];
//printf("info->m_constraintError[%d]=%f\n",j,info->m_constraintError[j]);
}
//fix the 3 angular degrees of freedom
int start_row = 3;
int s = info->rowskip;
int start_index = start_row * s;
// 3 rows to make body rotations equal
info->m_J1angularAxis[start_index] = 1;
info->m_J1angularAxis[start_index + s + 1] = 1;
info->m_J1angularAxis[start_index + s*2+2] = 1;
if ( info->m_J2angularAxis)
{
info->m_J2angularAxis[start_index] = -1;
info->m_J2angularAxis[start_index + s+1] = -1;
info->m_J2angularAxis[start_index + s*2+2] = -1;
}
// set right hand side for the angular dofs
b3Vector3 diff;
b3Scalar angle;
b3Quaternion qrelCur = worldOrnA *worldOrnB.inverse();
b3TransformUtil::calculateDiffAxisAngleQuaternion(m_relTargetAB,qrelCur,diff,angle);
diff*=-angle;
for (j=0; j<3; j++)
{
info->m_constraintError[(3+j)*info->rowskip] = k * diff[j];
}
}
|