Blender  V3.3
btGeometryUtil.cpp
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1 /*
2 Copyright (c) 2003-2006 Gino van den Bergen / Erwin Coumans http://continuousphysics.com/Bullet/
3 
4 This software is provided 'as-is', without any express or implied warranty.
5 In no event will the authors be held liable for any damages arising from the use of this software.
6 Permission is granted to anyone to use this software for any purpose,
7 including commercial applications, and to alter it and redistribute it freely,
8 subject to the following restrictions:
9 
10 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.
11 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
12 3. This notice may not be removed or altered from any source distribution.
13 */
14 
15 #include "btGeometryUtil.h"
16 
17 /*
18  Make sure this dummy function never changes so that it
19  can be used by probes that are checking whether the
20  library is actually installed.
21 */
22 extern "C"
23 {
24  void btBulletMathProbe();
25 
27 }
28 
30 {
31  int numbrushes = planeEquations.size();
32  for (int i = 0; i < numbrushes; i++)
33  {
34  const btVector3& N1 = planeEquations[i];
35  btScalar dist = btScalar(N1.dot(point)) + btScalar(N1[3]) - margin;
36  if (dist > btScalar(0.))
37  {
38  return false;
39  }
40  }
41  return true;
42 }
43 
45 {
46  int numvertices = vertices.size();
47  for (int i = 0; i < numvertices; i++)
48  {
49  const btVector3& N1 = vertices[i];
50  btScalar dist = btScalar(planeNormal.dot(N1)) + btScalar(planeNormal[3]) - margin;
51  if (dist > btScalar(0.))
52  {
53  return false;
54  }
55  }
56  return true;
57 }
58 
59 bool notExist(const btVector3& planeEquation, const btAlignedObjectArray<btVector3>& planeEquations);
60 
61 bool notExist(const btVector3& planeEquation, const btAlignedObjectArray<btVector3>& planeEquations)
62 {
63  int numbrushes = planeEquations.size();
64  for (int i = 0; i < numbrushes; i++)
65  {
66  const btVector3& N1 = planeEquations[i];
67  if (planeEquation.dot(N1) > btScalar(0.999))
68  {
69  return false;
70  }
71  }
72  return true;
73 }
74 
76 {
77  const int numvertices = vertices.size();
78  // brute force:
79  for (int i = 0; i < numvertices; i++)
80  {
81  const btVector3& N1 = vertices[i];
82 
83  for (int j = i + 1; j < numvertices; j++)
84  {
85  const btVector3& N2 = vertices[j];
86 
87  for (int k = j + 1; k < numvertices; k++)
88  {
89  const btVector3& N3 = vertices[k];
90 
91  btVector3 planeEquation, edge0, edge1;
92  edge0 = N2 - N1;
93  edge1 = N3 - N1;
94  btScalar normalSign = btScalar(1.);
95  for (int ww = 0; ww < 2; ww++)
96  {
97  planeEquation = normalSign * edge0.cross(edge1);
98  if (planeEquation.length2() > btScalar(0.0001))
99  {
100  planeEquation.normalize();
101  if (notExist(planeEquation, planeEquationsOut))
102  {
103  planeEquation[3] = -planeEquation.dot(N1);
104 
105  //check if inside, and replace supportingVertexOut if needed
106  if (areVerticesBehindPlane(planeEquation, vertices, btScalar(0.01)))
107  {
108  planeEquationsOut.push_back(planeEquation);
109  }
110  }
111  }
112  normalSign = btScalar(-1.);
113  }
114  }
115  }
116  }
117 }
118 
120 {
121  const int numbrushes = planeEquations.size();
122  // brute force:
123  for (int i = 0; i < numbrushes; i++)
124  {
125  const btVector3& N1 = planeEquations[i];
126 
127  for (int j = i + 1; j < numbrushes; j++)
128  {
129  const btVector3& N2 = planeEquations[j];
130 
131  for (int k = j + 1; k < numbrushes; k++)
132  {
133  const btVector3& N3 = planeEquations[k];
134 
135  btVector3 n2n3;
136  n2n3 = N2.cross(N3);
137  btVector3 n3n1;
138  n3n1 = N3.cross(N1);
139  btVector3 n1n2;
140  n1n2 = N1.cross(N2);
141 
142  if ((n2n3.length2() > btScalar(0.0001)) &&
143  (n3n1.length2() > btScalar(0.0001)) &&
144  (n1n2.length2() > btScalar(0.0001)))
145  {
146  //point P out of 3 plane equations:
147 
148  // d1 ( N2 * N3 ) + d2 ( N3 * N1 ) + d3 ( N1 * N2 )
149  //P = -------------------------------------------------------------------------
150  // N1 . ( N2 * N3 )
151 
152  btScalar quotient = (N1.dot(n2n3));
153  if (btFabs(quotient) > btScalar(0.000001))
154  {
155  quotient = btScalar(-1.) / quotient;
156  n2n3 *= N1[3];
157  n3n1 *= N2[3];
158  n1n2 *= N3[3];
159  btVector3 potentialVertex = n2n3;
160  potentialVertex += n3n1;
161  potentialVertex += n1n2;
162  potentialVertex *= quotient;
163 
164  //check if inside, and replace supportingVertexOut if needed
165  if (isPointInsidePlanes(planeEquations, potentialVertex, btScalar(0.01)))
166  {
167  verticesOut.push_back(potentialVertex);
168  }
169  }
170  }
171  }
172  }
173  }
174 }
in reality light always falls off quadratically Particle Retrieve the data of the particle that spawned the object for example to give variation to multiple instances of an object Point Retrieve information about points in a point cloud Retrieve the edges of an object as it appears to Cycles topology will always appear triangulated Convert a blackbody temperature to an RGB value Normal Generate a perturbed normal from an RGB normal map image Typically used for faking highly detailed surfaces Generate an OSL shader from a file or text data block Image Sample an image file as a texture Sky Generate a procedural sky texture Noise Generate fractal Perlin noise Wave Generate procedural bands or rings with noise Voronoi Generate Worley noise based on the distance to random points Typically used to generate textures such as or biological cells Brick Generate a procedural texture producing bricks Texture Retrieve multiple types of texture coordinates nTypically used as inputs for texture nodes Vector Convert a point
bool notExist(const btVector3 &planeEquation, const btAlignedObjectArray< btVector3 > &planeEquations)
void btBulletMathProbe()
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:314
SIMD_FORCE_INLINE btScalar btFabs(btScalar x)
Definition: btScalar.h:497
btVector3
btVector3 can be used to represent 3D points and vectors. It has an un-used w component to suit 16-by...
Definition: btVector3.h:82
SIMD_FORCE_INLINE int size() const
return the number of elements in the array
SIMD_FORCE_INLINE void push_back(const T &_Val)
static void getVerticesFromPlaneEquations(const btAlignedObjectArray< btVector3 > &planeEquations, btAlignedObjectArray< btVector3 > &verticesOut)
static bool areVerticesBehindPlane(const btVector3 &planeNormal, const btAlignedObjectArray< btVector3 > &vertices, btScalar margin)
static void getPlaneEquationsFromVertices(btAlignedObjectArray< btVector3 > &vertices, btAlignedObjectArray< btVector3 > &planeEquationsOut)
static bool isPointInsidePlanes(const btAlignedObjectArray< btVector3 > &planeEquations, const btVector3 &point, btScalar margin)