src/BulletCollision/NarrowPhaseCollision/btRaycastCallback.cpp

   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
  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
  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
 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
 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 }