manolas
/
vcglib
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
vcglib/vcg/complex/trimesh/point_sampling.h

705 lines
22 KiB
C++
Raw Blame History

/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt) *
* for more details. *
* *
****************************************************************************/
/****************************************************************************
History
$Log: sampling.h,v $
The sampling Class has a set of static functions, that you can call to sample the surface of a mesh.
Each function is templated on the mesh and on a Sampler object s.
Each function calls many time the sample object with the sampling point as parameter.
****************************************************************************/
#ifndef __VCGLIB_POINT_SAMPLING
#define __VCGLIB_POINT_SAMPLING
#include <vcg/complex/trimesh/stat.h>
namespace vcg
{
namespace tri
{
template <class MetroMesh, class VertexSampler>
class SurfaceSampling
{
typedef typename MetroMesh::CoordType CoordType;
typedef typename MetroMesh::ScalarType ScalarType;
typedef typename MetroMesh::VertexType VertexType;
typedef typename MetroMesh::VertexPointer VertexPointer;
typedef typename MetroMesh::VertexIterator VertexIterator;
typedef typename MetroMesh::FaceIterator FaceIterator;
typedef typename MetroMesh::FaceType FaceType;
typedef typename MetroMesh::FaceContainer FaceContainer;
public:
static
void AllVertex(MetroMesh & m, VertexSampler &ps)
{
VertexIterator vi;
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD())
{
ps.AddVert(*vi);
}
}
/// Sample the vertices in a weighted way. Each vertex has a probabiltiy of being chosen
/// that is proportional to its quality.
/// It assumes that you are asking a number of vertices smaller than nv;
/// Algorithm:
/// 1) normalize quality so that sum q == 1;
/// 2) shuffle vertices.
/// 3) for each vertices choose it if rand > thr;
static void VertexWeighted(MetroMesh & m, VertexSampler &ps, int sampleNum)
{
ScalarType qSum = 0;
VertexIterator vi;
for(vi = m.vert.begin(); vi != m.vert.end(); ++vi)
if(!(*vi).IsD())
qSum += (*vi).Q();
ScalarType samplePerUnit = sampleNum/qSum;
ScalarType floatSampleNum =0;
std::vector<VertexPointer> vertVec;
FillAndShuffleVertexPointVector(m,vertVec);
std::vector<bool> vertUsed(m.vn,false);
int i=0; int cnt=0;
while(cnt < sampleNum)
{
if(vertUsed[i])
{
floatSampleNum += vertVec[i]->Q() * samplePerUnit;
int vertSampleNum = (int) floatSampleNum;
floatSampleNum -= (float) vertSampleNum;
// for every sample p_i in T...
if(vertSampleNum > 1)
{
ps.AddVert(*vertVec[i]);
cnt++;
vertUsed[i]=true;
}
}
i = (i+1)%m.vn;
}
}
/// Sample the vertices in a uniform way. Each vertex has a probabiltiy of being chosen
/// that is proportional to the area it represent.
static void VertexAreaUniform(MetroMesh & m, VertexSampler &ps, int sampleNum)
{
VertexIterator vi;
for(vi = m.vert.begin(); vi != m.vert.end(); ++vi)
if(!(*vi).IsD())
(*vi).Q() = 0;
FaceIterator fi;
for(fi = m.face.begin(); fi != m.face.end(); ++fi)
if(!(*fi).IsD())
{
ScalarType areaThird = DoubleArea(*fi)/6.0;
(*fi).V(0).Q()+=areaThird;
(*fi).V(1).Q()+=areaThird;
(*fi).V(2).Q()+=areaThird;
}
VertexWeighted(m,ps,sampleNum);
}
static void FillAndShuffleVertexPointVector(MetroMesh & m, std::vector<VertexPointer> vertVec)
{
VertexIterator vi;
for(vi=m.vert.begin();vi!=m.vert.end();++vi)
if(!(*vi).IsD()) vertVec.push_back(&*vi);
assert(vertVec.size()=m.vn);
std::random_shuffle(vertVec.begin(),vertVec.end());
}
/// Sample the vertices in a uniform way. Each vertex has the same probabiltiy of being chosen.
static void VertexUniform(MetroMesh & m, VertexSampler &ps, int sampleNum)
{
if(sampleNum>=m.vn)
{
AllVertex(m,ps);
return;
}
std::vector<VertexPointer> vertVec;
FillAndShuffleVertexPointVector(m,vertVec);
for(int i =0; i< sampleNum; ++i)
ps.AddVert(*vertVec[i]);
}
static void AllFace(MetroMesh & m, VertexSampler &ps)
{
FaceIterator fi;
for(fi=m.face.begin();fi!=m.face.end();++fi)
if(!(*fi).IsD())
{
ps.AddFace(*fi,Barycenter(*fi));
}
}
static void AllEdge(MetroMesh & m, VertexSampler &ps)
{
// Edge sampling.
typedef typename UpdateTopology<MetroMesh>::PEdge SimpleEdge;
std::vector< SimpleEdge > Edges;
UpdateTopology<MetroMesh>::FillEdgeVector(m,Edges);
sort(Edges.begin(), Edges.end()); // Lo ordino per vertici
typename std::vector< SimpleEdge>::iterator newEnd = unique(Edges.begin(), Edges.end());
typename std::vector<SimpleEdge>::iterator ei;
qDebug("Edges %i (unique %i) ",Edges.size(),newEnd-Edges.begin());
Edges.resize(newEnd-Edges.begin());
for(ei=Edges.begin(); ei!=Edges.end(); ++ei)
{
Point3f interp(0,0,0);
interp[ (*ei).z ]=.5;
interp[((*ei).z+1)%3]=.5;
ps.AddFace(*(*ei).f,interp);
}
}
/*
// sample edges.
typename std::vector<pvv>::iterator ei;
double n_samples_per_length_unit;
double n_samples_decimal = 0.0;
int cnt=0;
if(Flags & SamplingFlags::FACE_SAMPLING) n_samples_per_length_unit = sqrt((double)n_samples_per_area_unit);
else n_samples_per_length_unit = n_samples_per_area_unit;
for(ei=Edges.begin(); ei!=Edges.end(); ++ei)
{
n_samples_decimal += Distance((*ei).first->cP(),(*ei).second->cP()) * n_samples_per_length_unit;
n_samples = (int) n_samples_decimal;
SampleEdge((*ei).first->cP(), (*ei).second->cP(), (int) n_samples);
n_samples_decimal -= (double) n_samples;
}
*/
// Get the baricentric coords of a random point over a single face.
static CoordType RandomBaricentric()
{
CoordType interp;
interp[1] = (double)rand() / (double)RAND_MAX;
interp[2] = (double)rand() / (double)RAND_MAX;
if(interp[1] + interp[2] > 1.0)
{
interp[1] = 1.0 - interp[1];
interp[2] = 1.0 - interp[2];
}
assert(interp[1] + interp[2] <= 1.0);
interp[0]=1.0-(interp[1] + interp[2]);
return interp;
}
static void Montecarlo(MetroMesh & m, VertexSampler &ps,int sampleNum)
{
ScalarType area = Stat<MetroMesh>::ComputeMeshArea(m);
ScalarType samplePerAreaUnit = sampleNum/area;
qDebug("samplePerAreaUnit %f",samplePerAreaUnit);
// Montecarlo sampling.
double floatSampleNum = 0.0;
FaceIterator fi;
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 += 0.5*DoubleArea(*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;
}
}
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 vcg
#endif
#if 0
struct SamplingFlags{
enum{
VERTEX_SAMPLING = 0x0002,
EDGE_SAMPLING = 0x0004,
FACE_SAMPLING = 0x0008,
MONTECARLO_SAMPLING = 0x0010,
SUBDIVISION_SAMPLING = 0x0020,
SIMILAR_SAMPLING = 0x0040,
INCLUDE_UNREFERENCED_VERTICES = 0x0200,
};
};
// -----------------------------------------------------------------------------------------------
template <class MetroMesh>
class Sampling
{
public:
unsigned int n_samples_per_face ;
float n_samples_edge_to_face_ratio ;
float bbox_factor ;
float inflate_percentage ;
unsigned int min_size ;
int n_hist_bins ;
int print_every_n_elements ;
int referredBit ;
// parameters
double dist_upper_bound;
double n_samples_per_area_unit;
unsigned long n_samples_target;
int Flags;
// results
unsigned long n_total_samples;
unsigned long n_total_area_samples;
unsigned long n_total_edge_samples;
unsigned long n_total_vertex_samples;
double max_dist;
double mean_dist;
double RMS_dist;
double volume;
double area_S1;
// globals
int n_samples;
// private methods
inline double ComputeMeshArea(MetroMesh & mesh);
float AddSample(const Point3x &p);
inline void AddRandomSample(FaceIterator &T);
inline void SampleEdge(const Point3x & v0, const Point3x & v1, int n_samples_per_edge);
void VertexSampling();
void EdgeSampling();
void FaceSubdiv(const Point3x & v0, const Point3x &v1, const Point3x & v2, int maxdepth);
void SimilarTriangles(const Point3x &v0, const Point3x &v1, const Point3x &v2, int n_samples_per_edge);
void MontecarloFaceSampling();
void SubdivFaceSampling();
void SimilarFaceSampling();
public :
// public methods
Sampling(MetroMesh &_s1, MetroMesh &_s2);
~Sampling();
double GetDistVolume() {return volume;}
unsigned long GetNSamples() {return n_total_samples;}
unsigned long GetNAreaSamples() {return n_total_area_samples;}
unsigned long GetNEdgeSamples() {return n_total_edge_samples;}
unsigned long GetNVertexSamples() {return n_total_vertex_samples;}
double GetNSamplesPerAreaUnit() {return n_samples_per_area_unit;}
unsigned long GetNSamplesTarget() {return n_samples_target;}
void SetFlags(int flags) {Flags = flags;}
void ClearFlag(int flag) {Flags &= (flag ^ -1);}
void SetParam(double _n_samp) {n_samples_target = _n_samp;}
void SetSamplesTarget(unsigned long _n_samp);
void SetSamplesPerAreaUnit(double _n_samp);
};
// -----------------------------------------------------------------------------------------------
// constructor
template <class MetroMesh>
Sampling<MetroMesh>::Sampling(MetroMesh &_s1, MetroMesh &_s2):S1(_s1),S2(_s2)
{
Flags = 0;
area_S1 = ComputeMeshArea(_s1);
// set default numbers
n_samples_per_face = 10;
n_samples_edge_to_face_ratio = 0.1f;
bbox_factor = 0.1f;
inflate_percentage = 0.02f;
min_size = 125; /* 125 = 5^3 */
n_hist_bins = 256;
print_every_n_elements = S1.fn/100;
if(print_every_n_elements <= 1)
print_every_n_elements = 2;
referredBit = VertexType::NewBitFlag();
// store the unreferred vertices
FaceIterator fi; VertexIterator vi; int i;
for(fi = _s1.face.begin(); fi!= _s1.face.end(); ++fi)
for(i=0;i<3;++i) (*fi).V(i)->SetUserBit(referredBit);
}
template <class MetroMesh>
Sampling<MetroMesh>::~Sampling()
{
VertexType::DeleteBitFlag(referredBit);
}
// set sampling parameters
template <class MetroMesh>
void Sampling<MetroMesh>::SetSamplesTarget(unsigned long _n_samp)
{
n_samples_target = _n_samp;
n_samples_per_area_unit = n_samples_target / (double)area_S1;
}
template <class MetroMesh>
void Sampling<MetroMesh>::SetSamplesPerAreaUnit(double _n_samp)
{
n_samples_per_area_unit = _n_samp;
n_samples_target = (unsigned long)((double) n_samples_per_area_unit * area_S1);
}
// auxiliary functions
template <class MetroMesh>
inline double Sampling<MetroMesh>::ComputeMeshArea(MetroMesh & mesh)
{
FaceIterator face;
double area = 0.0;
for(face=mesh.face.begin(); face != mesh.face.end(); face++)
if(!(*face).IsD())
area += DoubleArea(*face);
return area/2.0;
}
template <class MetroMesh>
float Sampling<MetroMesh>::AddSample(const Point3x &p )
{
SampleVec.push_back(p);
}
// -----------------------------------------------------------------------------------------------
// --- Vertex Sampling ---------------------------------------------------------------------------
template <class MetroMesh>
void Sampling<MetroMesh>::VertexSampling()
{
VertexIterator vi;
for(vi=S1.vert.begin();vi!=S1.vert.end();++vi)
if( (*vi).IsUserBit(referredBit) || // it is referred
((Flags&SamplingFlags::INCLUDE_UNREFERENCED_VERTICES) != 0) ) //include also unreferred
{
AddSample((*vi).cP());
}
}
// -----------------------------------------------------------------------------------------------
// --- Edge Sampling -----------------------------------------------------------------------------
template <class MetroMesh>
inline void Sampling<MetroMesh>::SampleEdge(const Point3x & v0, const Point3x & v1, int n_samples_per_edge)
{
// uniform sampling of the segment v0v1.
Point3x e((v1-v0)/(double)(n_samples_per_edge+1));
for(int i=1; i <= n_samples_per_edge; i++)
{
AddSample(v0 + e*i);
n_total_edge_samples++;
}
}
template <class MetroMesh>
void Sampling<MetroMesh>::EdgeSampling()
{
// Edge sampling.
typedef std::pair<VertexPointer, VertexPointer> pvv;
std::vector< pvv > Edges;
printf("Edge sampling\n");
// compute edge list.
FaceIterator fi;
for(fi=S1.face.begin(); fi != S1.face.end(); fi++)
for(int i=0; i<3; ++i)
{
Edges.push_back(make_pair((*fi).V0(i),(*fi).V1(i)));
if(Edges.back().first > Edges.back().second)
swap(Edges.back().first, Edges.back().second);
}
sort(Edges.begin(), Edges.end());
typename std::vector< pvv>::iterator edgeend = unique(Edges.begin(), Edges.end());
Edges.resize(edgeend-Edges.begin());
// sample edges.
typename std::vector<pvv>::iterator ei;
double n_samples_per_length_unit;
double n_samples_decimal = 0.0;
int cnt=0;
if(Flags & SamplingFlags::FACE_SAMPLING) n_samples_per_length_unit = sqrt((double)n_samples_per_area_unit);
else n_samples_per_length_unit = n_samples_per_area_unit;
for(ei=Edges.begin(); ei!=Edges.end(); ++ei)
{
n_samples_decimal += Distance((*ei).first->cP(),(*ei).second->cP()) * n_samples_per_length_unit;
n_samples = (int) n_samples_decimal;
SampleEdge((*ei).first->cP(), (*ei).second->cP(), (int) n_samples);
n_samples_decimal -= (double) n_samples;
}
}
// -----------------------------------------------------------------------------------------------
// --- Face Sampling -----------------------------------------------------------------------------
// Montecarlo sampling.
template <class MetroMesh>
inline void Sampling<MetroMesh>::AddRandomSample(FaceIterator &T)
{
// random sampling over the input face.
double rnd_1, rnd_2;
// vertices of the face T.
Point3x p0(T->V(0)->cP());
Point3x p1(T->V(1)->cP());
Point3x p2(T->V(2)->cP());
// calculate two edges of T.
Point3x v1(p1 - p0);
Point3x v2(p2 - p0);
// choose two random numbers.
rnd_1 = (double)rand() / (double)RAND_MAX;
rnd_2 = (double)rand() / (double)RAND_MAX;
if(rnd_1 + rnd_2 > 1.0)
{
rnd_1 = 1.0 - rnd_1;
rnd_2 = 1.0 - rnd_2;
}
// add a random point on the face T.
AddSample (p0 + (v1 * rnd_1 + v2 * rnd_2));
n_total_area_samples++;
}
template <class MetroMesh>
void Sampling<MetroMesh>::MontecarloFaceSampling()
{
// Montecarlo sampling.
int cnt = 0;
double n_samples_decimal = 0.0;
FaceIterator fi;
for(fi=S1.face.begin(); fi != S1.face.end(); fi++)
if(!(*fi).IsD())
{
// compute # samples in the current face.
n_samples_decimal += 0.5*DoubleArea(*fi) * n_samples_per_area_unit;
n_samples = (int) n_samples_decimal;
// for every sample p_i in T...
for(int i=0; i < n_samples; i++)
AddRandomSample(fi);
n_samples_decimal -= (double) n_samples;
}
}
// Subdivision sampling.
template <class MetroMesh>
void Sampling<MetroMesh>::FaceSubdiv(const Point3x & v0, const Point3x & v1, const Point3x & v2, int maxdepth)
{
// recursive face subdivision.
if(maxdepth == 0)
{
// ground case.
AddSample((v0+v1+v2)/3.0f);
n_total_area_samples++;
return;
}
// compute the longest edge.
double maxd01 = SquaredDistance(v0,v1);
double maxd12 = SquaredDistance(v1,v2);
double 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;
// break the input triangle along the median to the the longest edge.
Point3x pp;
switch(res)
{
case 0 : pp = (v0+v1)/2;
FaceSubdiv(v0,pp,v2,maxdepth-1);
FaceSubdiv(pp,v1,v2,maxdepth-1);
break;
case 1 : pp = (v1+v2)/2;
FaceSubdiv(v0,v1,pp,maxdepth-1);
FaceSubdiv(v0,pp,v2,maxdepth-1);
break;
case 2 : pp = (v2+v0)/2;
FaceSubdiv(v0,v1,pp,maxdepth-1);
FaceSubdiv(pp,v1,v2,maxdepth-1);
break;
}
}
template <class MetroMesh>
void Sampling<MetroMesh>::SubdivFaceSampling()
{
// Subdivision sampling.
int cnt = 0, maxdepth;
double n_samples_decimal = 0.0;
typename MetroMesh::FaceIterator fi;
printf("Subdivision face sampling\n");
for(fi=S1.face.begin(); fi != S1.face.end(); fi++)
{
// compute # samples in the current face.
n_samples_decimal += 0.5*DoubleArea(*fi) * n_samples_per_area_unit;
n_samples = (int) n_samples_decimal;
if(n_samples)
{
// face sampling.
maxdepth = ((int)(log((double)n_samples)/log(2.0)));
n_samples = 0;
FaceSubdiv((*fi).V(0)->cP(), (*fi).V(1)->cP(), (*fi).V(2)->cP(), maxdepth);
}
n_samples_decimal -= (double) n_samples;
// print progress information
if(!(++cnt % print_every_n_elements))
printf("Sampling face %d%%\r", (100 * cnt/S1.fn));
}
printf(" \r");
}
// Similar Triangles sampling.
template <class MetroMesh>
void Sampling<MetroMesh>::SimilarTriangles(const Point3x & v0, const Point3x & v1, const Point3x & v2, int n_samples_per_edge)
{
Point3x V1((v1-v0)/(double)(n_samples_per_edge-1));
Point3x V2((v2-v0)/(double)(n_samples_per_edge-1));
int i, j;
// face sampling.
for(i=1; i < n_samples_per_edge-1; i++)
for(j=1; j < n_samples_per_edge-1-i; j++)
{
AddSample( v0 + (V1*(double)i + V2*(double)j) );
n_total_area_samples++;
n_samples++;
}
}
template <class MetroMesh>
void Sampling<MetroMesh>::SimilarFaceSampling()
{
// Similar Triangles sampling.
int cnt = 0, n_samples_per_edge;
double n_samples_decimal = 0.0;
FaceIterator fi;
printf("Similar Triangles face sampling\n");
for(fi=S1.face.begin(); fi != S1.face.end(); fi++)
{
// compute # samples in the current face.
n_samples_decimal += 0.5*DoubleArea(*fi) * n_samples_per_area_unit;
n_samples = (int) n_samples_decimal;
if(n_samples)
{
// face sampling.
n_samples_per_edge = (int)((sqrt(1.0+8.0*(double)n_samples) +5.0)/2.0);
n_samples = 0;
SimilarTriangles((*fi).V(0)->cP(), (*fi).V(1)->cP(), (*fi).V(2)->cP(), n_samples_per_edge);
}
n_samples_decimal -= (double) n_samples;
// print progress information
if(!(++cnt % print_every_n_elements))
printf("Sampling face %d%%\r", (100 * cnt/S1.fn));
}
printf(" \r");
}
}
#endif
Reference in New Issue View Git Blame Copy Permalink