vcglib/apps/metro/sampling.h

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2004-05-05 13:30:37 +02:00
/*****************************************************************************
* VCGLib *
* *
* Visual Computing Group o> *
* IEI Institute, CNUCE Institute, CNR Pisa <| *
* / \ *
* Copyright(C) 1999 by Paolo Cignoni, Claudio Rocchini *
* All rights reserved. *
* *
* Permission to use, copy, modify, distribute and sell this software and *
* its documentation for any purpose is hereby granted without fee, provided *
* that the above copyright notice appear in all copies and that both that *
* copyright notice and this permission notice appear in supporting *
* documentation. the author makes no representations about the suitability *
* of this software for any purpose. It is provided "as is" without express *
* or implied warranty. *
* *
*****************************************************************************/
/****************************************************************************
History
2003 Dic 17 modifiche per conversione alla versione template (gano)
2004 Jan 19 qualche ->P() in ->cP() (Snarf)
****************************************************************************/
// -----------------------------------------------------------------------------------------------
#ifndef _SAMPLING_H
#define _SAMPLING_H
// -----------------------------------------------------------------------------------------------
// standard libraries.
#include <time.h>
// VCG library.
//#include <vcg/tools/xml/xml.h>
#include "min_dist_point.h"
//#include <vcg/tools/Align/Hist.h>
#include <vcg/space/box3.h>
#include <vcg/space/color4.h>
#include <vcg/space/index/grid_static_obj.h>
using namespace vcg;
// -----------------------------------------------------------------------------------------------
// flags.
#define FLAG_HIST 0x0001
#define FLAG_VERTEX_SAMPLING 0x0002
#define FLAG_EDGE_SAMPLING 0x0004
#define FLAG_FACE_SAMPLING 0x0008
#define FLAG_MONTECARLO_SAMPLING 0x0010
#define FLAG_SUBDIVISION_SAMPLING 0x0020
#define FLAG_SIMILAR_TRIANGLES_SAMPLING 0x0040
#define FLAG_SAVE_ERROR_DISPLACEMENT 0x0080
#define FLAG_SAVE_ERROR_AS_COLOUR 0x0100
// global constants
#define NO_SAMPLES_PER_FACE 10
#define N_SAMPLES_EDGE_TO_FACE_RATIO 0.1
#define BBOX_FACTOR 0.1
#define INFLATE_PERCENTAGE 0.02
#define MIN_SIZE 125 /* 125 = 5^3 */
#define N_HIST_BINS 256
#define PRINT_EVERY_N_ELEMENTS 1000
#define FILE_EXT_SMF "smf"
#define FILE_EXT_PLY "ply"
// -----------------------------------------------------------------------------------------------
template <class MetroMesh>
class Sampling
{
private:
typedef GridStaticObj< typename MetroMesh::FaceContainer > MetroMeshGrid;
typedef Point3<typename MetroMesh::ScalarType> Point3x;
// data structures
MetroMesh &S1;
MetroMesh &S2;
MetroMeshGrid gS2;
// parameters
double dist_upper_bound;
double n_samples_per_area_unit;
double n_samples_target;
int Flags;
// results
// Hist hist;
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(typename MetroMesh::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);
void Hausdorff();
double GetArea() {return area_S1;}
double GetDistMax() {return max_dist;}
double GetDistMean() {return mean_dist;}
double GetDistRMS() {return RMS_dist;}
double GetDistVolume() {return volume;}
double GetNSamples() {return n_total_samples;}
double GetNAreaSamples() {return n_total_area_samples;}
double GetNEdgeSamples() {return n_total_edge_samples;}
double GetNVertexSamples() {return n_total_vertex_samples;}
double GetNSamplesPerAreaUnit() {return n_samples_per_area_unit;}
double GetNSamplesTarget() {return n_samples_target;}
// Hist &GetHist() {return hist;}
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(int _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 sampling parameters
template <class MetroMesh>
void Sampling<MetroMesh>::SetSamplesTarget(int _n_samp)
{
n_samples_target = _n_samp;
n_samples_per_area_unit = (double) n_samples_target / area_S1;
}
template <class MetroMesh>
void Sampling<MetroMesh>::SetSamplesPerAreaUnit(double _n_samp)
{
n_samples_per_area_unit = _n_samp;
n_samples_target = (int)((double) n_samples_per_area_unit * area_S1);
}
// auxiliary functions
template <class MetroMesh>
inline double Sampling<MetroMesh>::ComputeMeshArea(MetroMesh & mesh)
{
MetroMesh::FaceIterator face;
double area = 0.0;
for(face=mesh.face.begin(); face != mesh.face.end(); face++)
if(!(*face).IsD())
area += face->Area();
return area;
}
template <class MetroMesh>
float Sampling<MetroMesh>::AddSample(const Point3x &p)
{
MetroMesh::FaceType *f=0;
Point3x normf, bestq, ip;
MetroMesh::ScalarType dist;
dist = dist_upper_bound;
// compute distance between p_i and the mesh S2
MinDistPoint(S2, p, gS2, dist, normf, bestq, f, ip);
// update distance measures
if(dist == dist_upper_bound)
return -1.0;
if(dist > max_dist)
max_dist = dist; // L_inf
mean_dist += dist; // L_1
RMS_dist += dist*dist; // L_2
n_total_samples++;
//if(Flags & FLAG_HIST)
// hist.Add((float)fabs(dist));
return (float)dist;
}
// -----------------------------------------------------------------------------------------------
// --- Vertex Sampling ---------------------------------------------------------------------------
template <class MetroMesh>
void Sampling<MetroMesh>::VertexSampling()
{
// Vertex sampling.
int cnt = 0;
float error;
printf("Vertex sampling\n");
MetroMesh::VertexIterator vi;
for(vi=S1.vert.begin();vi!=S1.vert.end();++vi)
{
error = AddSample((*vi).cP());
n_total_vertex_samples++;
// save vertex quality
if(Flags & (FLAG_SAVE_ERROR_DISPLACEMENT | FLAG_SAVE_ERROR_AS_COLOUR))
(*vi).Q() = error;
/*
if(Flags & FLAG_SAVE_ERROR_AS_COLOUR)
{
ColorUB col = ColorUB(ColorUB::White);
if(error < dist_upper_bound)
// colour mapped distance
col.ColorRamp(0, dist_upper_bound, dist_upper_bound-error);
//else
// no matching mesh patches -> white
(*vi).C() = col;
}
*/
// print progress information
if(!(++cnt % PRINT_EVERY_N_ELEMENTS))
printf("Sampling vertices %d%%\r", (100 * cnt/S1.vn));
}
printf(" \r");
}
// -----------------------------------------------------------------------------------------------
// --- 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));
int i;
for(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 pair<typename MetroMesh::VertexPointer, typename MetroMesh::VertexPointer> pvv;
vector< pvv > Edges;
printf("Edge sampling\n");
// compute edge list.
MetroMesh::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());
vector<pvv>::iterator edgeend = unique(Edges.begin(), Edges.end());
Edges.resize(edgeend-Edges.begin());
// sample edges.
vector<pvv>::iterator ei;
double n_samples_per_length_unit;
double n_samples_decimal = 0.0;
int cnt=0;
if(Flags & FLAG_FACE_SAMPLING)
n_samples_per_length_unit = sqrt(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;
// print progress information
if(!(++cnt % PRINT_EVERY_N_ELEMENTS))
printf("Sampling edge %d%%\r", (100 * cnt/Edges.size()));
}
printf(" \r");
}
// -----------------------------------------------------------------------------------------------
// --- Face Sampling -----------------------------------------------------------------------------
// Montecarlo sampling.
template <class MetroMesh>
inline void Sampling<MetroMesh>::AddRandomSample(typename MetroMesh::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;
MetroMesh::FaceIterator fi;
srand(clock());
// printf("Montecarlo face sampling\n");
for(fi=S1.face.begin(); fi != S1.face.end(); fi++)
if(!(*fi).IsD())
{
// compute # samples in the current face.
n_samples_decimal += fi->Area() * 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;
// print progress information
// if(!(++cnt % PRINT_EVERY_N_ELEMENTS))
// printf("Sampling face %d%%\r", (100 * cnt/S1.fn));
}
// printf(" \r");
}
// 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++;
n_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;
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 += fi->Area() * 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;
MetroMesh::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 += fi->Area() * 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");
}
// -----------------------------------------------------------------------------------------------
// --- Distance ----------------------------------------------------------------------------------
template <class MetroMesh>
void Sampling<MetroMesh>::Hausdorff()
{
Box3< MetroMesh::ScalarType> bbox;
// set grid meshes.
gS2.SetBBox(S2.bbox);
if(S2.face.size() < MIN_SIZE)
gS2.Set(S2.face, MIN_SIZE);
else
gS2.Set(S2.face);
// set bounding box
bbox = S2.bbox;
dist_upper_bound = /*BBOX_FACTOR * */bbox.Diag();
//if(Flags & FLAG_HIST)
// hist.SetRange(0.0, dist_upper_bound, N_HIST_BINS);
// initialize sampling statistics.
n_total_area_samples = n_total_edge_samples = n_total_vertex_samples = n_total_samples = n_samples = 0;
max_dist = -HUGE_VAL;
mean_dist = RMS_dist = 0;
// Vertex sampling.
if(Flags & FLAG_VERTEX_SAMPLING)
VertexSampling();
// Edge sammpling.
n_samples_target -= (int) n_total_samples;
if(n_samples_target > 0)
{
n_samples_per_area_unit = n_samples_target / area_S1;
if(Flags & FLAG_EDGE_SAMPLING)
{
EdgeSampling();
n_samples_target -= (int) n_total_samples;
}
// Face sampling.
if((Flags & FLAG_FACE_SAMPLING) && (n_samples_target > 0))
{
n_samples_per_area_unit = n_samples_target / area_S1;
if(Flags & FLAG_MONTECARLO_SAMPLING) MontecarloFaceSampling();
if(Flags & FLAG_SUBDIVISION_SAMPLING) SubdivFaceSampling();
if(Flags & FLAG_SIMILAR_TRIANGLES_SAMPLING) SimilarFaceSampling();
}
}
// compute vertex colour
if(Flags & FLAG_SAVE_ERROR_AS_COLOUR)
{
MetroMesh::VertexIterator vi;
float error;
int cnt = 0;
for(vi=S1.vert.begin();vi!=S1.vert.end();++vi)
{
Color4b col = Color4b(Color4b::White);
error = (*vi).Q();
if(error < dist_upper_bound)
// colour mapped distance
col.ColorRamp(0, (float)max_dist, (float)max_dist-error);
//else
// no matching mesh patches -> white
(*vi).C() = col;
// print progress information
if(!(++cnt % PRINT_EVERY_N_ELEMENTS))
printf("Computing vertex colour %d%%\r", (100 * cnt/S1.vn));
}
printf(" \r");
}
// compute statistics
n_samples_per_area_unit = (double) n_total_samples / area_S1;
volume = mean_dist / n_samples_per_area_unit / 2.0;
mean_dist /= n_total_samples;
RMS_dist = sqrt(RMS_dist / n_total_samples);
}
// -----------------------------------------------------------------------------------------------
//#undef FLAG_HIST
//#undef FLAG_VERTEX_SAMPLING
//#undef FLAG_EDGE_SAMPLING
//#undef FLAG_FACE_SAMPLING
//#undef FLAG_MONTECARLO_SAMPLING
//#undef FLAG_SUBDIVISION_SAMPLING
//#undef FLAG_SIMILAR_TRIANGLES_SAMPLING
//#undef FLAG_SAVE_ERROR_DISPLACEMENT
//#undef FLAG_SAVE_ERROR_AS_COLOUR
//
//// global constants
//#undef NO_SAMPLES_PER_FACE
//#undef N_SAMPLES_EDGE_TO_FACE_RATIO
//#undef BBOX_FACTOR
//#undef INFLATE_PERCENTAGE
//#undef MIN_SIZE
//#undef N_HIST_BINS
//#undef PRINT_EVERY_N_ELEMENTS
//#undef FILE_EXT_SMF
//#undef FILE_EXT_PLY
//
#endif
// -----------------------------------------------------------------------------------------------