Bullet Collision Detection & Physics Library
btSubSimplexConvexCast.cpp
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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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
16
19
22#include "btPointCollector.h"
24
26:m_simplexSolver(simplexSolver),
27m_convexA(convexA),m_convexB(convexB)
28{
29}
30
33#ifdef BT_USE_DOUBLE_PRECISION
34#define MAX_ITERATIONS 64
35#else
36#define MAX_ITERATIONS 32
37#endif
39 const btTransform& fromA,
40 const btTransform& toA,
41 const btTransform& fromB,
42 const btTransform& toB,
43 CastResult& result)
44{
45
46 m_simplexSolver->reset();
47
48 btVector3 linVelA,linVelB;
49 linVelA = toA.getOrigin()-fromA.getOrigin();
50 linVelB = toB.getOrigin()-fromB.getOrigin();
51
52 btScalar lambda = btScalar(0.);
53
54 btTransform interpolatedTransA = fromA;
55 btTransform interpolatedTransB = fromB;
56
58 btVector3 r = (linVelA-linVelB);
59 btVector3 v;
60
61 btVector3 supVertexA = fromA(m_convexA->localGetSupportingVertex(-r*fromA.getBasis()));
62 btVector3 supVertexB = fromB(m_convexB->localGetSupportingVertex(r*fromB.getBasis()));
63 v = supVertexA-supVertexB;
64 int maxIter = MAX_ITERATIONS;
65
66 btVector3 n;
67 n.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
68
69 btVector3 c;
70
71
72
73
74 btScalar dist2 = v.length2();
75#ifdef BT_USE_DOUBLE_PRECISION
76 btScalar epsilon = btScalar(0.0001);
77#else
78 btScalar epsilon = btScalar(0.0001);
79#endif //BT_USE_DOUBLE_PRECISION
80 btVector3 w,p;
81 btScalar VdotR;
82
83 while ( (dist2 > epsilon) && maxIter--)
84 {
85 supVertexA = interpolatedTransA(m_convexA->localGetSupportingVertex(-v*interpolatedTransA.getBasis()));
86 supVertexB = interpolatedTransB(m_convexB->localGetSupportingVertex(v*interpolatedTransB.getBasis()));
87 w = supVertexA-supVertexB;
88
89 btScalar VdotW = v.dot(w);
90
91 if (lambda > btScalar(1.0))
92 {
93 return false;
94 }
95
96 if ( VdotW > btScalar(0.))
97 {
98 VdotR = v.dot(r);
99
100 if (VdotR >= -(SIMD_EPSILON*SIMD_EPSILON))
101 return false;
102 else
103 {
104 lambda = lambda - VdotW / VdotR;
105 //interpolate to next lambda
106 // x = s + lambda * r;
107 interpolatedTransA.getOrigin().setInterpolate3(fromA.getOrigin(),toA.getOrigin(),lambda);
108 interpolatedTransB.getOrigin().setInterpolate3(fromB.getOrigin(),toB.getOrigin(),lambda);
109 //m_simplexSolver->reset();
110 //check next line
111 w = supVertexA-supVertexB;
112
113 n = v;
114
115 }
116 }
118 if (!m_simplexSolver->inSimplex(w))
119 m_simplexSolver->addVertex( w, supVertexA , supVertexB);
120
121 if (m_simplexSolver->closest(v))
122 {
123 dist2 = v.length2();
124
125 //todo: check this normal for validity
126 //n=v;
127 //printf("V=%f , %f, %f\n",v[0],v[1],v[2]);
128 //printf("DIST2=%f\n",dist2);
129 //printf("numverts = %i\n",m_simplexSolver->numVertices());
130 } else
131 {
132 dist2 = btScalar(0.);
133 }
134 }
135
136 //int numiter = MAX_ITERATIONS - maxIter;
137// printf("number of iterations: %d", numiter);
138
139 //don't report a time of impact when moving 'away' from the hitnormal
140
141
142 result.m_fraction = lambda;
143 if (n.length2() >= (SIMD_EPSILON*SIMD_EPSILON))
144 result.m_normal = n.normalized();
145 else
146 result.m_normal = btVector3(btScalar(0.0), btScalar(0.0), btScalar(0.0));
147
148 //don't report time of impact for motion away from the contact normal (or causes minor penetration)
149 if (result.m_normal.dot(r)>=-result.m_allowedPenetration)
150 return false;
151
152 btVector3 hitA,hitB;
153 m_simplexSolver->compute_points(hitA,hitB);
154 result.m_hitPoint=hitB;
155 return true;
156}
157
158
159
160
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292
#define SIMD_EPSILON
Definition: btScalar.h:521
#define btSimplexSolverInterface
#define MAX_ITERATIONS
Typically the conservative advancement reaches solution in a few iterations, clip it to 32 for degene...
The btConvexShape is an abstract shape interface, implemented by all convex shapes such as btBoxShape...
Definition: btConvexShape.h:32
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const =0
btSubsimplexConvexCast(const btConvexShape *shapeA, const btConvexShape *shapeB, btSimplexSolverInterface *simplexSolver)
const btConvexShape * m_convexA
btSimplexSolverInterface * m_simplexSolver
virtual bool calcTimeOfImpact(const btTransform &fromA, const btTransform &toA, const btTransform &fromB, const btTransform &toB, CastResult &result)
SimsimplexConvexCast calculateTimeOfImpact calculates the time of impact+normal for the linear cast (...
const btConvexShape * m_convexB
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:112
btVector3 & getOrigin()
Return the origin vector translation.
Definition: btTransform.h:117
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:84
void setInterpolate3(const btVector3 &v0, const btVector3 &v1, btScalar rt)
Definition: btVector3.h:503
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition: btVector3.h:235
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition: btVector3.h:652
btVector3 normalized() const
Return a normalized version of this vector.
Definition: btVector3.h:964
btScalar length2() const
Return the length of the vector squared.
Definition: btVector3.h:257
RayResult stores the closest result alternatively, add a callback method to decide about closest/all ...
Definition: btConvexCast.h:37