Bullet Collision Detection & Physics Library: btSubSimplexConvexCast.cpp Source File

Bullet Collision Detection & Physics Library

btSubSimplexConvexCast.cpp
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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
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
17 #include "btSubSimplexConvexCast.h"
18 #include "BulletCollision/CollisionShapes/btConvexShape.h"
19
20 #include "BulletCollision/CollisionShapes/btMinkowskiSumShape.h"
21 #include "BulletCollision/NarrowPhaseCollision/btSimplexSolverInterface.h"
22 #include "btPointCollector.h"
23 #include "LinearMath/btTransformUtil.h"
24
25 btSubsimplexConvexCast::btSubsimplexConvexCast (const btConvexShape* convexA,const btConvexShape* convexB,btSimplexSolverInterface* simplexSolver)
26 :m_simplexSolver(simplexSolver),
27 m_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
38 bool btSubsimplexConvexCast::calcTimeOfImpact(
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
SIMD_EPSILON
#define SIMD_EPSILON
Definition: btScalar.h:521
btTransformUtil.h
btConvexShape::localGetSupportingVertex
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const =0
btConvexCast::CastResult::m_fraction
btScalar m_fraction
Definition: btConvexCast.h:57
btPointCollector.h
btVector3::setValue
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition: btVector3.h:652
MAX_ITERATIONS
#define MAX_ITERATIONS
Typically the conservative advancement reaches solution in a few iterations, clip it to 32 for degene...
Definition: btSubSimplexConvexCast.cpp:36
btSubsimplexConvexCast::m_convexA
const btConvexShape * m_convexA
Definition: btSubSimplexConvexCast.h:31
btVector3::length2
btScalar length2() const
Return the length of the vector squared.
Definition: btVector3.h:257
btSubsimplexConvexCast::m_simplexSolver
btSimplexSolverInterface * m_simplexSolver
Definition: btSubSimplexConvexCast.h:30
btConvexShape.h
btVector3::normalized
btVector3 normalized() const
Return a normalized version of this vector.
Definition: btVector3.h:964
btConvexCast::CastResult::m_normal
btVector3 m_normal
Definition: btConvexCast.h:55
btConvexShape
The btConvexShape is an abstract shape interface, implemented by all convex shapes such as btBoxShape...
Definition: btConvexShape.h:31
btConvexCast::CastResult::m_allowedPenetration
btScalar m_allowedPenetration
Definition: btConvexCast.h:59
btConvexCast::CastResult
RayResult stores the closest result alternatively, add a callback method to decide about closest/all ...
Definition: btConvexCast.h:36
btTransform::getOrigin
btVector3 & getOrigin()
Return the origin vector translation.
Definition: btTransform.h:117
btSimplexSolverInterface
#define btSimplexSolverInterface
Definition: btSimplexSolverInterface.h:26
btVector3::dot
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition: btVector3.h:235
btSubsimplexConvexCast::calcTimeOfImpact
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 (...
Definition: btSubSimplexConvexCast.cpp:38
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:112
btSubsimplexConvexCast::btSubsimplexConvexCast
btSubsimplexConvexCast(const btConvexShape *shapeA, const btConvexShape *shapeB, btSimplexSolverInterface *simplexSolver)
Definition: btSubSimplexConvexCast.cpp:25
btSubsimplexConvexCast::m_convexB
const btConvexShape * m_convexB
Definition: btSubSimplexConvexCast.h:32
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
btSubSimplexConvexCast.h
btConvexCast::CastResult::m_hitPoint
btVector3 m_hitPoint
Definition: btConvexCast.h:56
btSimplexSolverInterface.h
btVector3::setInterpolate3
void setInterpolate3(const btVector3 &v0, const btVector3 &v1, btScalar rt)
Definition: btVector3.h:503
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292
btMinkowskiSumShape.h