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added a slightly faster version of the longest edge stratified subdivision sampling

This commit is contained in:
Paolo Cignoni 2009-12-04 08:36:49 +00:00
parent 6e3f10928e
commit 1c0ae1268c
1 changed files with 141 additions and 39 deletions
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180
vcg/complex/trimesh/point_sampling.h
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@ -463,58 +463,56 @@ static int SingleFaceSubdivision(int sampleNum, const CoordType & v0, const Coor
if(sampleNum == 1)
{
// ground case.
CoordType SamplePoint;
if(randSample)
{
CoordType rb=RandomBaricentric();
SamplePoint=v0*rb[0]+v1*rb[1]+v2*rb[2];
}
else SamplePoint=((v0+v1+v2)/3.0f);
CoordType SampleBary;
InterpolationParameters(*fp,SamplePoint,SampleBary[0],SampleBary[1],SampleBary[2]);
ps.AddFace(*fp,SampleBary);
return 1;
}
CoordType SamplePoint;
if(randSample)
{
CoordType rb=RandomBaricentric();
SamplePoint=v0*rb[0]+v1*rb[1]+v2*rb[2];
}
else SamplePoint=((v0+v1+v2)*(1.0f/3.0f));
int s0 = sampleNum /2;
int s1 = sampleNum-s0;
assert(s0>0);
assert(s1>0);
ps.AddFace(*fp,SamplePoint);
return 1;
}
int s0 = sampleNum /2;
int s1 = sampleNum-s0;
assert(s0>0);
assert(s1>0);
ScalarType w0 = ScalarType(s1)/ScalarType(sampleNum);
ScalarType w1 = 1.0-w0;
ScalarType w0 = ScalarType(s1)/ScalarType(sampleNum);
ScalarType w1 = 1.0-w0;
// compute the longest edge.
double maxd01 = SquaredDistance(v0,v1);
double maxd12 = SquaredDistance(v1,v2);
double maxd20 = SquaredDistance(v2,v0);
ScalarType maxd01 = SquaredDistance(v0,v1);
ScalarType maxd12 = SquaredDistance(v1,v2);
ScalarType maxd20 = SquaredDistance(v2,v0);
int res;
if(maxd01 > maxd12)
if(maxd01 > maxd20) res = 0;
else res = 2;
else res = 2;
else
if(maxd12 > maxd20) res = 1;
else res = 2;
else res = 2;
int faceSampleNum=0;
// break the input triangle along the midpoint of the longest edge.
CoordType pp;
switch(res)
{
case 0 : pp = v0*w0 + v1*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,pp,v2,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,pp,v1,v2,ps,fp,randSample);
break;
case 1 : pp = v1*w0 + v2*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,v1,pp,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,v0,pp,v2,ps,fp,randSample);
break;
case 2 : pp = v0*w0 + v2*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,v1,pp,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,pp,v1,v2,ps,fp,randSample);
break;
case 0 : pp = v0*w0 + v1*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,pp,v2,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,pp,v1,v2,ps,fp,randSample);
break;
case 1 : pp = v1*w0 + v2*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,v1,pp,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,v0,pp,v2,ps,fp,randSample);
break;
case 2 : pp = v0*w0 + v2*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,v1,pp,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,pp,v1,v2,ps,fp,randSample);
break;
}
return faceSampleNum;
return faceSampleNum;
}
@ -527,12 +525,114 @@ static void FaceSubdivision(MetroMesh & m, VertexSampler &ps,int sampleNum, bool
//qDebug("samplePerAreaUnit %f",samplePerAreaUnit);
std::vector<FacePointer> faceVec;
FillAndShuffleFacePointerVector(m,faceVec);
tri::UpdateNormals<MetroMesh>::PerFaceNormalized(m);
tri::UpdateFlags<MetroMesh>::FaceProjection(m);
double floatSampleNum = 0.0;
int faceSampleNum;
// Subdivision sampling.
typename std::vector<FacePointer>::iterator fi;
for(fi=faceVec.begin(); fi!=faceVec.end(); fi++)
{
const CoordType b0(1.0, 0.0, 0.0);
const CoordType b1(0.0, 1.0, 0.0);
const CoordType b2(0.0, 0.0, 1.0);
// compute # samples in the current face.
floatSampleNum += 0.5*DoubleArea(**fi) * samplePerAreaUnit;
faceSampleNum = (int) floatSampleNum;
if(faceSampleNum>0)
faceSampleNum = SingleFaceSubdivision(faceSampleNum,b0,b1,b2,ps,*fi,randSample);
floatSampleNum -= (double) faceSampleNum;
}
}
//---------
// Subdivision sampling of a single face.
// return number of added samples
static int SingleFaceSubdivisionOld(int sampleNum, const CoordType & v0, const CoordType & v1, const CoordType & v2, VertexSampler &ps, FacePointer fp, bool randSample)
{
// recursive face subdivision.
if(sampleNum == 1)
{
// ground case.
CoordType SamplePoint;
if(randSample)
{
CoordType rb=RandomBaricentric();
SamplePoint=v0*rb[0]+v1*rb[1]+v2*rb[2];
}
else SamplePoint=((v0+v1+v2)*(1.0f/3.0f));
CoordType SampleBary;
// int axis;
// if(fp->Flags() & FaceType::NORMX ) axis = 0;
// else if(fp->Flags() & FaceType::NORMY ) axis = 1;
// else {
// assert(fp->Flags() & FaceType::NORMZ) ;
// axis =2;
// }
// InterpolationParameters(*fp,axis,SamplePoint,SampleBary);
InterpolationParameters(*fp,SamplePoint,SampleBary[0],SampleBary[1],SampleBary[2]);
ps.AddFace(*fp,SampleBary);
return 1;
}
int s0 = sampleNum /2;
int s1 = sampleNum-s0;
assert(s0>0);
assert(s1>0);
ScalarType w0 = ScalarType(s1)/ScalarType(sampleNum);
ScalarType w1 = 1.0-w0;
// compute the longest edge.
ScalarType maxd01 = SquaredDistance(v0,v1);
ScalarType maxd12 = SquaredDistance(v1,v2);
ScalarType maxd20 = SquaredDistance(v2,v0);
int res;
if(maxd01 > maxd12)
if(maxd01 > maxd20) res = 0;
else res = 2;
else
if(maxd12 > maxd20) res = 1;
else res = 2;
int faceSampleNum=0;
// break the input triangle along the midpoint of the longest edge.
CoordType pp;
switch(res)
{
case 0 : pp = v0*w0 + v1*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,pp,v2,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,pp,v1,v2,ps,fp,randSample);
break;
case 1 : pp = v1*w0 + v2*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,v1,pp,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,v0,pp,v2,ps,fp,randSample);
break;
case 2 : pp = v0*w0 + v2*w1;
faceSampleNum+=SingleFaceSubdivision(s0,v0,v1,pp,ps,fp,randSample);
faceSampleNum+=SingleFaceSubdivision(s1,pp,v1,v2,ps,fp,randSample);
break;
}
return faceSampleNum;
}
/// Compute a sampling of the surface where the points are regularly scattered over the face surface using a recursive longest-edge subdivision rule.
static void FaceSubdivisionOld(MetroMesh & m, VertexSampler &ps,int sampleNum, bool randSample)
{
ScalarType area = Stat<MetroMesh>::ComputeMeshArea(m);
ScalarType samplePerAreaUnit = sampleNum/area;
//qDebug("samplePerAreaUnit %f",samplePerAreaUnit);
std::vector<FacePointer> faceVec;
FillAndShuffleFacePointerVector(m,faceVec);
tri::UpdateNormals<MetroMesh>::PerFaceNormalized(m);
tri::UpdateFlags<MetroMesh>::FaceProjection(m);
double floatSampleNum = 0.0;
int faceSampleNum;
// Subdivision sampling.
typename std::vector<FacePointer>::iterator fi;
for(fi=faceVec.begin(); fi!=faceVec.end(); fi++)
{
// compute # samples in the current face.
floatSampleNum += 0.5*DoubleArea(**fi) * samplePerAreaUnit;
@ -544,6 +644,8 @@ static void FaceSubdivision(MetroMesh & m, VertexSampler &ps,int sampleNum, bool
}
//---------
// Similar Triangles sampling.
// Skip vertex and edges
// Sample per edges includes vertexes, so here we should expect n_samples_per_edge >=4