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/****************************************************************************
* 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: gen_normal.h,v $
****************************************************************************/
#ifndef __VCG_GEN_NORMAL
#define __VCG_GEN_NORMAL
#include <algorithm>
namespace vcg {
template <class ScalarType>
class GenNormal
{
public:
typedef Point3<ScalarType> Point3x;
static void Random(int vn, std::vector<Point3<ScalarType > > &NN)
{
NN.clear();
while(NN.size()<vn)
{
Point3x pp(((float)rand())/RAND_MAX,
((float)rand())/RAND_MAX,
((float)rand())/RAND_MAX);
pp=pp*2.0-Point3x(1,1,1);
if(pp.SquaredNorm()<1)
{
Normalize(pp);
NN.push_back(pp);
}
}
}
static void UniformCone(int vn, std::vector<Point3<ScalarType > > &NN, ScalarType AngleRad, Point3x dir=Point3x(0,1,0))
{
std::vector<Point3<ScalarType > > NNT;
NN.clear();
// per prima cosa si calcola il volume della spherical cap di angolo AngleRad
ScalarType Height= 1.0 - cos(AngleRad); // height is measured from top...
// Surface is the one of the tangent cylinder
ScalarType CapArea = 2.0*M_PI*Height;
ScalarType Ratio = CapArea / (4.0*M_PI );
printf("----------AngleRad %f Angledeg %f ratio %f vn %i vn2 %i \n",AngleRad,math::ToDeg(AngleRad),Ratio,vn,int(vn/Ratio));
Uniform(vn/Ratio,NNT);
printf("asked %i got %i (expecting %i instead of %i)\n", int(vn/Ratio), NNT.size(), int(NNT.size()*Ratio), vn);
typename std::vector<Point3<ScalarType> >::iterator vi;
ScalarType DotProd = cos(AngleRad);
for(vi=NNT.begin();vi!=NNT.end();++vi)
{
if(dir.dot(*vi) >= DotProd) NN.push_back(*vi);
}
}
static void Uniform(int vn, std::vector<Point3<ScalarType > > &NN)
{
OctaLevel pp;
int ll=10;
while(pow(4.0f,ll)+2>vn) ll--;
pp.Init(ll);
sort(pp.v.begin(),pp.v.end());
int newsize = unique(pp.v.begin(),pp.v.end())-pp.v.begin();
pp.v.resize(newsize);
NN=pp.v;
Perturb(NN);
}
static void Perturb(std::vector<Point3<ScalarType > > &NN)
{
float width=0.2f/sqrt(float(NN.size()));
typename std::vector<Point3<ScalarType> >::iterator vi;
for(vi=NN.begin(); vi!=NN.end();++vi)
{
Point3x pp(((float)rand())/RAND_MAX,
((float)rand())/RAND_MAX,
((float)rand())/RAND_MAX);
pp=pp*2.0-Point3x(1,1,1);
pp*=width;
(*vi)+=pp;
(*vi).Normalize();
}
}
/*
Trova la normale piu vicina a quella data.
Assume che tutte normale in ingresso sia normalizzata;
*/
static int BestMatchingNormal(const Point3x &n, std::vector<Point3x> &nv)
{
int ret=-1;
ScalarType bestang=-1;
ScalarType cosang;
typename std::vector<Point3x>::iterator ni;
for(ni=nv.begin();ni!=nv.end();++ni)
{
cosang=(*ni).dot(n);
if(cosang>bestang) {
bestang=cosang;
ret=ni-nv.begin();
}
}
assert(ret>=0 && ret <int(nv.size()));
return ret;
}
private :
class OctaLevel
{
public:
std::vector<Point3x> v;
int level;
int sz;
Point3x &Val(int i, int j) {
assert(i>=0 && i<sz);
assert(j>=0 && j<sz);
return v[i+j*sz];
}
void Init(int lev)
{
sz=pow(2.0f,lev+1)+1;
v.resize(sz*sz);
if(lev==0)
{
Val(0,0)=Point3x( 0, 0,-1); Val(0,1)=Point3x( 0, 1, 0); Val(0,2)=Point3x( 0, 0,-1);
Val(1,0)=Point3x(-1, 0, 0); Val(1,1)=Point3x( 0, 0, 1); Val(1,2)=Point3x( 1, 0, 0);
Val(2,0)=Point3x( 0, 0,-1); Val(2,1)=Point3x( 0,-1, 0); Val(2,2)=Point3x( 0, 0,-1);
}
else
{
OctaLevel tmp;
tmp.Init(lev-1);
int i,j;
for(i=0;i<sz;++i)
for(j=0;j<sz;++j)
{
if((i%2)==0 && (j%2)==0)
Val(i,j)=tmp.Val(i/2,j/2);
if((i%2)!=0 && (j%2)==0)
Val(i,j)=(tmp.Val(i/2+0,j/2)+tmp.Val(i/2+1,j/2))/2.0;
if((i%2)==0 && (j%2)!=0)
Val(i,j)=(tmp.Val(i/2,j/2+0)+tmp.Val(i/2,j/2+1))/2.0;
if((i%2)!=0 && (j%2)!=0)
Val(i,j)=(tmp.Val(i/2+0,j/2+0)+tmp.Val(i/2+0,j/2+1)+tmp.Val(i/2+1,j/2+0)+tmp.Val(i/2+1,j/2+1))/4.0;
}
typename std::vector<Point3<ScalarType> >::iterator vi;
for(vi=v.begin(); vi!=v.end();++vi)
(*vi).Normalize();
}
}
};
};
}
#endif
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