| 1 | /* | 
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| 2 | Bullet Continuous Collision Detection and Physics Library | 
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| 3 | Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org | 
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| 4 |  | 
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| 5 | This software is provided 'as-is', without any express or implied warranty. | 
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| 6 | In no event will the authors be held liable for any damages arising from the use of this software. | 
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| 7 | Permission is granted to anyone to use this software for any purpose,  | 
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| 8 | including commercial applications, and to alter it and redistribute it freely,  | 
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| 9 | subject to the following restrictions: | 
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| 10 |  | 
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| 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. | 
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| 12 | 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. | 
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| 13 | 3. This notice may not be removed or altered from any source distribution. | 
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| 14 | */ | 
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| 15 |  | 
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| 16 | //btShapeHull was implemented by John McCutchan. | 
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| 17 |  | 
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| 18 |  | 
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| 19 | #include "btShapeHull.h" | 
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| 20 | #include "LinearMath/btConvexHull.h" | 
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| 21 |  | 
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| 22 | #define NUM_UNITSPHERE_POINTS 42 | 
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| 23 |  | 
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| 24 | btShapeHull::btShapeHull (const btConvexShape* shape) | 
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| 25 | { | 
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| 26 |         m_shape = shape; | 
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| 27 |         m_vertices.clear (); | 
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| 28 |         m_indices.clear(); | 
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| 29 |         m_numIndices = 0; | 
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| 30 | } | 
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| 31 |  | 
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| 32 | btShapeHull::~btShapeHull () | 
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| 33 | { | 
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| 34 |         m_indices.clear();       | 
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| 35 |         m_vertices.clear (); | 
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| 36 | } | 
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| 37 |  | 
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| 38 | bool | 
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| 39 | btShapeHull::buildHull (btScalar /*margin*/) | 
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| 40 | { | 
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| 41 |         int numSampleDirections = NUM_UNITSPHERE_POINTS; | 
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| 42 |         { | 
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| 43 |                 int numPDA = m_shape->getNumPreferredPenetrationDirections(); | 
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| 44 |                 if (numPDA) | 
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| 45 |                 { | 
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| 46 |                         for (int i=0;i<numPDA;i++) | 
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| 47 |                         { | 
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| 48 |                                 btVector3 norm; | 
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| 49 |                                 m_shape->getPreferredPenetrationDirection(i,norm); | 
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| 50 |                                 getUnitSpherePoints()[numSampleDirections] = norm; | 
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| 51 |                                 numSampleDirections++; | 
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| 52 |                         } | 
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| 53 |                 } | 
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| 54 |         } | 
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| 55 |  | 
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| 56 |         btVector3 supportPoints[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2]; | 
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| 57 |         int i; | 
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| 58 |         for (i = 0; i < numSampleDirections; i++) | 
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| 59 |         { | 
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| 60 |                 supportPoints[i] = m_shape->localGetSupportingVertex(getUnitSpherePoints()[i]); | 
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| 61 |         } | 
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| 62 |  | 
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| 63 |         HullDesc hd; | 
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| 64 |         hd.mFlags = QF_TRIANGLES; | 
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| 65 |         hd.mVcount = static_cast<unsigned int>(numSampleDirections); | 
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| 66 |  | 
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| 67 | #ifdef BT_USE_DOUBLE_PRECISION | 
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| 68 |         hd.mVertices = &supportPoints[0]; | 
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| 69 |         hd.mVertexStride = sizeof(btVector3); | 
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| 70 | #else | 
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| 71 |         hd.mVertices = &supportPoints[0]; | 
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| 72 |         hd.mVertexStride = sizeof (btVector3); | 
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| 73 | #endif | 
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| 74 |  | 
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| 75 |         HullLibrary hl; | 
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| 76 |         HullResult hr; | 
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| 77 |         if (hl.CreateConvexHull (hd, hr) == QE_FAIL) | 
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| 78 |         { | 
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| 79 |                 return false; | 
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| 80 |         } | 
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| 81 |  | 
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| 82 |         m_vertices.resize (static_cast<int>(hr.mNumOutputVertices)); | 
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| 83 |  | 
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| 84 |  | 
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| 85 |         for (i = 0; i < static_cast<int>(hr.mNumOutputVertices); i++) | 
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| 86 |         { | 
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| 87 |                 m_vertices[i] = hr.m_OutputVertices[i]; | 
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| 88 |         } | 
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| 89 |         m_numIndices = hr.mNumIndices; | 
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| 90 |         m_indices.resize(static_cast<int>(m_numIndices)); | 
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| 91 |         for (i = 0; i < static_cast<int>(m_numIndices); i++) | 
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| 92 |         { | 
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| 93 |                 m_indices[i] = hr.m_Indices[i]; | 
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| 94 |         } | 
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| 95 |  | 
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| 96 |         // free temporary hull result that we just copied | 
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| 97 |         hl.ReleaseResult (hr); | 
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| 98 |  | 
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| 99 |         return true; | 
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| 100 | } | 
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| 101 |  | 
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| 102 | int | 
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| 103 | btShapeHull::numTriangles () const | 
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| 104 | { | 
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| 105 |         return static_cast<int>(m_numIndices / 3); | 
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| 106 | } | 
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| 107 |  | 
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| 108 | int | 
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| 109 | btShapeHull::numVertices () const | 
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| 110 | { | 
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| 111 |         return m_vertices.size (); | 
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| 112 | } | 
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| 113 |  | 
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| 114 | int | 
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| 115 | btShapeHull::numIndices () const | 
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| 116 | { | 
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| 117 |         return static_cast<int>(m_numIndices); | 
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| 118 | } | 
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| 119 |  | 
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| 120 |  | 
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| 121 | btVector3* btShapeHull::getUnitSpherePoints() | 
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| 122 | { | 
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| 123 |         static btVector3 sUnitSpherePoints[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2] =  | 
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| 124 |         { | 
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| 125 |                 btVector3(btScalar(0.000000) , btScalar(-0.000000),btScalar(-1.000000)), | 
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| 126 |                 btVector3(btScalar(0.723608) , btScalar(-0.525725),btScalar(-0.447219)), | 
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| 127 |                 btVector3(btScalar(-0.276388) , btScalar(-0.850649),btScalar(-0.447219)), | 
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| 128 |                 btVector3(btScalar(-0.894426) , btScalar(-0.000000),btScalar(-0.447216)), | 
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| 129 |                 btVector3(btScalar(-0.276388) , btScalar(0.850649),btScalar(-0.447220)), | 
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| 130 |                 btVector3(btScalar(0.723608) , btScalar(0.525725),btScalar(-0.447219)), | 
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| 131 |                 btVector3(btScalar(0.276388) , btScalar(-0.850649),btScalar(0.447220)), | 
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| 132 |                 btVector3(btScalar(-0.723608) , btScalar(-0.525725),btScalar(0.447219)), | 
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| 133 |                 btVector3(btScalar(-0.723608) , btScalar(0.525725),btScalar(0.447219)), | 
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| 134 |                 btVector3(btScalar(0.276388) , btScalar(0.850649),btScalar(0.447219)), | 
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| 135 |                 btVector3(btScalar(0.894426) , btScalar(0.000000),btScalar(0.447216)), | 
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| 136 |                 btVector3(btScalar(-0.000000) , btScalar(0.000000),btScalar(1.000000)), | 
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| 137 |                 btVector3(btScalar(0.425323) , btScalar(-0.309011),btScalar(-0.850654)), | 
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| 138 |                 btVector3(btScalar(-0.162456) , btScalar(-0.499995),btScalar(-0.850654)), | 
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| 139 |                 btVector3(btScalar(0.262869) , btScalar(-0.809012),btScalar(-0.525738)), | 
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| 140 |                 btVector3(btScalar(0.425323) , btScalar(0.309011),btScalar(-0.850654)), | 
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| 141 |                 btVector3(btScalar(0.850648) , btScalar(-0.000000),btScalar(-0.525736)), | 
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| 142 |                 btVector3(btScalar(-0.525730) , btScalar(-0.000000),btScalar(-0.850652)), | 
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| 143 |                 btVector3(btScalar(-0.688190) , btScalar(-0.499997),btScalar(-0.525736)), | 
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| 144 |                 btVector3(btScalar(-0.162456) , btScalar(0.499995),btScalar(-0.850654)), | 
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| 145 |                 btVector3(btScalar(-0.688190) , btScalar(0.499997),btScalar(-0.525736)), | 
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| 146 |                 btVector3(btScalar(0.262869) , btScalar(0.809012),btScalar(-0.525738)), | 
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| 147 |                 btVector3(btScalar(0.951058) , btScalar(0.309013),btScalar(0.000000)), | 
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| 148 |                 btVector3(btScalar(0.951058) , btScalar(-0.309013),btScalar(0.000000)), | 
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| 149 |                 btVector3(btScalar(0.587786) , btScalar(-0.809017),btScalar(0.000000)), | 
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| 150 |                 btVector3(btScalar(0.000000) , btScalar(-1.000000),btScalar(0.000000)), | 
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| 151 |                 btVector3(btScalar(-0.587786) , btScalar(-0.809017),btScalar(0.000000)), | 
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| 152 |                 btVector3(btScalar(-0.951058) , btScalar(-0.309013),btScalar(-0.000000)), | 
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| 153 |                 btVector3(btScalar(-0.951058) , btScalar(0.309013),btScalar(-0.000000)), | 
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| 154 |                 btVector3(btScalar(-0.587786) , btScalar(0.809017),btScalar(-0.000000)), | 
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| 155 |                 btVector3(btScalar(-0.000000) , btScalar(1.000000),btScalar(-0.000000)), | 
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| 156 |                 btVector3(btScalar(0.587786) , btScalar(0.809017),btScalar(-0.000000)), | 
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| 157 |                 btVector3(btScalar(0.688190) , btScalar(-0.499997),btScalar(0.525736)), | 
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| 158 |                 btVector3(btScalar(-0.262869) , btScalar(-0.809012),btScalar(0.525738)), | 
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| 159 |                 btVector3(btScalar(-0.850648) , btScalar(0.000000),btScalar(0.525736)), | 
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| 160 |                 btVector3(btScalar(-0.262869) , btScalar(0.809012),btScalar(0.525738)), | 
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| 161 |                 btVector3(btScalar(0.688190) , btScalar(0.499997),btScalar(0.525736)), | 
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| 162 |                 btVector3(btScalar(0.525730) , btScalar(0.000000),btScalar(0.850652)), | 
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| 163 |                 btVector3(btScalar(0.162456) , btScalar(-0.499995),btScalar(0.850654)), | 
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| 164 |                 btVector3(btScalar(-0.425323) , btScalar(-0.309011),btScalar(0.850654)), | 
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| 165 |                 btVector3(btScalar(-0.425323) , btScalar(0.309011),btScalar(0.850654)), | 
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| 166 |                 btVector3(btScalar(0.162456) , btScalar(0.499995),btScalar(0.850654)) | 
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| 167 |         }; | 
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| 168 |         return sUnitSpherePoints; | 
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| 169 | } | 
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| 170 |  | 
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