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 //#include <stdio.h>
17
18 #include "BulletCollision/CollisionShapes/btConvexShape.h"
19 #include "BulletCollision/CollisionShapes/btTriangleShape.h"
20 #include "BulletCollision/NarrowPhaseCollision/btSubSimplexConvexCast.h"
21 #include "BulletCollision/NarrowPhaseCollision/btGjkConvexCast.h"
22 #include "BulletCollision/NarrowPhaseCollision/btContinuousConvexCollision.h"
23 #include "BulletCollision/NarrowPhaseCollision/btGjkEpaPenetrationDepthSolver.h"
24 #include "btRaycastCallback.h"
25
btTriangleRaycastCallback(const btVector3 & from,const btVector3 & to,unsigned int flags)26 btTriangleRaycastCallback::btTriangleRaycastCallback(const btVector3& from,const btVector3& to, unsigned int flags)
27 :
28 m_from(from),
29 m_to(to),
30 //@BP Mod
31 m_flags(flags),
32 m_hitFraction(btScalar(1.))
33 {
34
35 }
36
37
38
processTriangle(btVector3 * triangle,int partId,int triangleIndex)39 void btTriangleRaycastCallback::processTriangle(btVector3* triangle,int partId, int triangleIndex)
40 {
41 const btVector3 &vert0=triangle[0];
42 const btVector3 &vert1=triangle[1];
43 const btVector3 &vert2=triangle[2];
44
45 btVector3 v10; v10 = vert1 - vert0 ;
46 btVector3 v20; v20 = vert2 - vert0 ;
47
48 btVector3 triangleNormal; triangleNormal = v10.cross( v20 );
49
50 const btScalar dist = vert0.dot(triangleNormal);
51 btScalar dist_a = triangleNormal.dot(m_from) ;
52 dist_a-= dist;
53 btScalar dist_b = triangleNormal.dot(m_to);
54 dist_b -= dist;
55
56 if ( dist_a * dist_b >= btScalar(0.0) )
57 {
58 return ; // same sign
59 }
60
61 if (((m_flags & kF_FilterBackfaces) != 0) && (dist_a <= btScalar(0.0)))
62 {
63 // Backface, skip check
64 return;
65 }
66
67
68 const btScalar proj_length=dist_a-dist_b;
69 const btScalar distance = (dist_a)/(proj_length);
70 // Now we have the intersection point on the plane, we'll see if it's inside the triangle
71 // Add an epsilon as a tolerance for the raycast,
72 // in case the ray hits exacly on the edge of the triangle.
73 // It must be scaled for the triangle size.
74
75 if(distance < m_hitFraction)
76 {
77
78
79 btScalar edge_tolerance =triangleNormal.length2();
80 edge_tolerance *= btScalar(-0.0001);
81 btVector3 point; point.setInterpolate3( m_from, m_to, distance);
82 {
83 btVector3 v0p; v0p = vert0 - point;
84 btVector3 v1p; v1p = vert1 - point;
85 btVector3 cp0; cp0 = v0p.cross( v1p );
86
87 if ( (btScalar)(cp0.dot(triangleNormal)) >=edge_tolerance)
88 {
89
90
91 btVector3 v2p; v2p = vert2 - point;
92 btVector3 cp1;
93 cp1 = v1p.cross( v2p);
94 if ( (btScalar)(cp1.dot(triangleNormal)) >=edge_tolerance)
95 {
96 btVector3 cp2;
97 cp2 = v2p.cross(v0p);
98
99 if ( (btScalar)(cp2.dot(triangleNormal)) >=edge_tolerance)
100 {
101 //@BP Mod
102 // Triangle normal isn't normalized
103 triangleNormal.normalize();
104
105 //@BP Mod - Allow for unflipped normal when raycasting against backfaces
106 if (((m_flags & kF_KeepUnflippedNormal) == 0) && (dist_a <= btScalar(0.0)))
107 {
108 m_hitFraction = reportHit(-triangleNormal,distance,partId,triangleIndex);
109 }
110 else
111 {
112 m_hitFraction = reportHit(triangleNormal,distance,partId,triangleIndex);
113 }
114 }
115 }
116 }
117 }
118 }
119 }
120
121
btTriangleConvexcastCallback(const btConvexShape * convexShape,const btTransform & convexShapeFrom,const btTransform & convexShapeTo,const btTransform & triangleToWorld,const btScalar triangleCollisionMargin)122 btTriangleConvexcastCallback::btTriangleConvexcastCallback (const btConvexShape* convexShape, const btTransform& convexShapeFrom, const btTransform& convexShapeTo, const btTransform& triangleToWorld, const btScalar triangleCollisionMargin)
123 {
124 m_convexShape = convexShape;
125 m_convexShapeFrom = convexShapeFrom;
126 m_convexShapeTo = convexShapeTo;
127 m_triangleToWorld = triangleToWorld;
128 m_hitFraction = 1.0f;
129 m_triangleCollisionMargin = triangleCollisionMargin;
130 m_allowedPenetration = 0.f;
131 }
132
133 void
processTriangle(btVector3 * triangle,int partId,int triangleIndex)134 btTriangleConvexcastCallback::processTriangle (btVector3* triangle, int partId, int triangleIndex)
135 {
136 btTriangleShape triangleShape (triangle[0], triangle[1], triangle[2]);
137 triangleShape.setMargin(m_triangleCollisionMargin);
138
139 btVoronoiSimplexSolver simplexSolver;
140 btGjkEpaPenetrationDepthSolver gjkEpaPenetrationSolver;
141
142 //#define USE_SUBSIMPLEX_CONVEX_CAST 1
143 //if you reenable USE_SUBSIMPLEX_CONVEX_CAST see commented out code below
144 #ifdef USE_SUBSIMPLEX_CONVEX_CAST
145 btSubsimplexConvexCast convexCaster(m_convexShape, &triangleShape, &simplexSolver);
146 #else
147 //btGjkConvexCast convexCaster(m_convexShape,&triangleShape,&simplexSolver);
148 btContinuousConvexCollision convexCaster(m_convexShape,&triangleShape,&simplexSolver,&gjkEpaPenetrationSolver);
149 #endif //#USE_SUBSIMPLEX_CONVEX_CAST
150
151 btConvexCast::CastResult castResult;
152 castResult.m_fraction = btScalar(1.);
153 castResult.m_allowedPenetration = m_allowedPenetration;
154 if (convexCaster.calcTimeOfImpact(m_convexShapeFrom,m_convexShapeTo,m_triangleToWorld, m_triangleToWorld, castResult))
155 {
156 //add hit
157 if (castResult.m_normal.length2() > btScalar(0.0001))
158 {
159 if (castResult.m_fraction < m_hitFraction)
160 {
161 /* btContinuousConvexCast's normal is already in world space */
162 /*
163 #ifdef USE_SUBSIMPLEX_CONVEX_CAST
164 //rotate normal into worldspace
165 castResult.m_normal = m_convexShapeFrom.getBasis() * castResult.m_normal;
166 #endif //USE_SUBSIMPLEX_CONVEX_CAST
167 */
168 castResult.m_normal.normalize();
169
170 reportHit (castResult.m_normal,
171 castResult.m_hitPoint,
172 castResult.m_fraction,
173 partId,
174 triangleIndex);
175 }
176 }
177 }
178 }
179