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Added weighted area sampling

This commit is contained in:
Paolo Cignoni 2008-05-29 06:17:09 +00:00
parent 8a6dbded39
commit ca47599bd5
1 changed files with 38 additions and 0 deletions
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38
vcg/complex/trimesh/point_sampling.h
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@ -180,6 +180,44 @@ static void Montecarlo(MetroMesh & m, VertexSampler &ps,int sampleNum)
} }
} }
static ScalarType WeightedArea(FaceType f)
{
ScalarType averageQ = ( f.V(0)->Q() + f.V(1)->Q() + f.V(2)->Q() ) /3.0;
return DoubleArea(f)*averageQ/2.0;
}
/// Compute a sampling of the surface that is weighted by the quality
/// the area of each face is multiplied by the average of the quality of the vertices.
/// So the a face with a zero quality on all its vertices is never sampled and a face with average quality 2 get twice the samples of a face with the same area but with an average quality of 1;
static void WeightedMontecarlo(MetroMesh & m, VertexSampler &ps, int sampleNum)
{
assert(tri::HasPerVertexQuality(m));
ScalarType weightedArea = 0;
FaceIterator fi;
for(fi = m.face.begin(); fi != m.face.end(); ++fi)
if(!(*fi).IsD())
weightedArea += WeightedArea(*fi);
ScalarType samplePerAreaUnit = sampleNum/weightedArea;
qDebug("samplePerAreaUnit %f",samplePerAreaUnit);
// Montecarlo sampling.
double floatSampleNum = 0.0;
for(fi=m.face.begin(); fi != m.face.end(); fi++)
if(!(*fi).IsD())
{
// compute # samples in the current face (taking into account of the remainders)
floatSampleNum += WeightedArea(*fi) * samplePerAreaUnit;
int faceSampleNum = (int) floatSampleNum;
// for every sample p_i in T...
for(int i=0; i < faceSampleNum; i++)
ps.AddFace(*fi,RandomBaricentric());
floatSampleNum -= (double) faceSampleNum;
}
}
}; };
} // end namespace tri } // end namespace tri