meshvolume.cpp
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00001 #include "meshvolume.h"
00002 
00058 namespace ConvexDecomposition
00059 {
00060 
00061 
00062 inline double det(const double *p1,const double *p2,const double *p3)
00063 {
00064   return  p1[0]*p2[1]*p3[2] + p2[0]*p3[1]*p1[2] + p3[0]*p1[1]*p2[2] -p1[0]*p3[1]*p2[2] - p2[0]*p1[1]*p3[2] - p3[0]*p2[1]*p1[2];
00065 }
00066 
00067 double computeMeshVolume(const double *vertices,unsigned int tcount,const unsigned int *indices)
00068 {
00069         double volume = 0;
00070 
00071         const double *p0 = vertices;
00072         for (unsigned int i=0; i<tcount; i++,indices+=3)
00073         {
00074 
00075                 const double *p1 = &vertices[ indices[0]*3 ];
00076                 const double *p2 = &vertices[ indices[1]*3 ];
00077                 const double *p3 = &vertices[ indices[2]*3 ];
00078 
00079                 volume+=det(p1,p2,p3); // compute the volume of the tetrahedran relative to the origin.
00080         }
00081 
00082         volume*=(1.0f/6.0f);
00083         if ( volume < 0 )
00084                 volume*=-1;
00085         return volume;
00086 }
00087 
00088 
00089 inline void CrossProduct(const double *a,const double *b,double *cross)
00090 {
00091         cross[0] = a[1]*b[2] - a[2]*b[1];
00092         cross[1] = a[2]*b[0] - a[0]*b[2];
00093         cross[2] = a[0]*b[1] - a[1]*b[0];
00094 }
00095 
00096 inline double DotProduct(const double *a,const double *b)
00097 {
00098         return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
00099 }
00100 
00101 inline double tetVolume(const double *p0,const double *p1,const double *p2,const double *p3)
00102 {
00103         double a[3];
00104         double b[3];
00105         double c[3];
00106 
00107   a[0] = p1[0] - p0[0];
00108   a[1] = p1[1] - p0[1];
00109   a[2] = p1[2] - p0[2];
00110 
00111         b[0] = p2[0] - p0[0];
00112         b[1] = p2[1] - p0[1];
00113         b[2] = p2[2] - p0[2];
00114 
00115   c[0] = p3[0] - p0[0];
00116   c[1] = p3[1] - p0[1];
00117   c[2] = p3[2] - p0[2];
00118 
00119   double cross[3];
00120 
00121   CrossProduct( b, c, cross );
00122 
00123         double volume = DotProduct( a, cross );
00124 
00125   if ( volume < 0 )
00126    return -volume;
00127 
00128   return volume;
00129 }
00130 
00131 inline double det(const double *p0,const double *p1,const double *p2,const double *p3)
00132 {
00133   return  p1[0]*p2[1]*p3[2] + p2[0]*p3[1]*p1[2] + p3[0]*p1[1]*p2[2] -p1[0]*p3[1]*p2[2] - p2[0]*p1[1]*p3[2] - p3[0]*p2[1]*p1[2];
00134 }
00135 
00136 double computeMeshVolume2(const double *vertices,unsigned int tcount,const unsigned int *indices)
00137 {
00138         double volume = 0;
00139 
00140         const double *p0 = vertices;
00141         for (unsigned int i=0; i<tcount; i++,indices+=3)
00142         {
00143 
00144                 const double *p1 = &vertices[ indices[0]*3 ];
00145                 const double *p2 = &vertices[ indices[1]*3 ];
00146                 const double *p3 = &vertices[ indices[2]*3 ];
00147 
00148                 volume+=tetVolume(p0,p1,p2,p3); // compute the volume of the tetrahdren relative to the root vertice
00149         }
00150 
00151   return volume * (1.0f / 6.0f );
00152 }
00153 
00154 
00155 //** Float versions
00156 
00157 inline float det(const float *p1,const float *p2,const float *p3)
00158 {
00159   return  p1[0]*p2[1]*p3[2] + p2[0]*p3[1]*p1[2] + p3[0]*p1[1]*p2[2] -p1[0]*p3[1]*p2[2] - p2[0]*p1[1]*p3[2] - p3[0]*p2[1]*p1[2];
00160 }
00161 
00162 float computeMeshVolume(const float *vertices,unsigned int tcount,const unsigned int *indices)
00163 {
00164         float volume = 0;
00165 
00166         const float *p0 = vertices;
00167         for (unsigned int i=0; i<tcount; i++,indices+=3)
00168         {
00169 
00170                 const float *p1 = &vertices[ indices[0]*3 ];
00171                 const float *p2 = &vertices[ indices[1]*3 ];
00172                 const float *p3 = &vertices[ indices[2]*3 ];
00173 
00174                 volume+=det(p1,p2,p3); // compute the volume of the tetrahedran relative to the origin.
00175         }
00176 
00177         volume*=(1.0f/6.0f);
00178         if ( volume < 0 )
00179                 volume*=-1;
00180         return volume;
00181 }
00182 
00183 
00184 inline void CrossProduct(const float *a,const float *b,float *cross)
00185 {
00186         cross[0] = a[1]*b[2] - a[2]*b[1];
00187         cross[1] = a[2]*b[0] - a[0]*b[2];
00188         cross[2] = a[0]*b[1] - a[1]*b[0];
00189 }
00190 
00191 inline float DotProduct(const float *a,const float *b)
00192 {
00193         return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
00194 }
00195 
00196 inline float tetVolume(const float *p0,const float *p1,const float *p2,const float *p3)
00197 {
00198         float a[3];
00199         float b[3];
00200         float c[3];
00201 
00202   a[0] = p1[0] - p0[0];
00203   a[1] = p1[1] - p0[1];
00204   a[2] = p1[2] - p0[2];
00205 
00206         b[0] = p2[0] - p0[0];
00207         b[1] = p2[1] - p0[1];
00208         b[2] = p2[2] - p0[2];
00209 
00210   c[0] = p3[0] - p0[0];
00211   c[1] = p3[1] - p0[1];
00212   c[2] = p3[2] - p0[2];
00213 
00214   float cross[3];
00215 
00216   CrossProduct( b, c, cross );
00217 
00218         float volume = DotProduct( a, cross );
00219 
00220   if ( volume < 0 )
00221    return -volume;
00222 
00223   return volume;
00224 }
00225 
00226 inline float det(const float *p0,const float *p1,const float *p2,const float *p3)
00227 {
00228   return  p1[0]*p2[1]*p3[2] + p2[0]*p3[1]*p1[2] + p3[0]*p1[1]*p2[2] -p1[0]*p3[1]*p2[2] - p2[0]*p1[1]*p3[2] - p3[0]*p2[1]*p1[2];
00229 }
00230 
00231 float computeMeshVolume2(const float *vertices,unsigned int tcount,const unsigned int *indices)
00232 {
00233         float volume = 0;
00234 
00235         const float *p0 = vertices;
00236         for (unsigned int i=0; i<tcount; i++,indices+=3)
00237         {
00238 
00239                 const float *p1 = &vertices[ indices[0]*3 ];
00240                 const float *p2 = &vertices[ indices[1]*3 ];
00241                 const float *p3 = &vertices[ indices[2]*3 ];
00242 
00243                 volume+=tetVolume(p0,p1,p2,p3); // compute the volume of the tetrahdren relative to the root vertice
00244         }
00245 
00246   return volume * (1.0f / 6.0f );
00247 }
00248 
00249 
00250 };
00251 


convex_decomposition
Author(s): John W. Ratcliff
autogenerated on Sat Jun 8 2019 20:01:17