113 lines
4.9 KiB
C++
113 lines
4.9 KiB
C++
/****************************************************************************
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* VCGLib o o *
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* Visual and Computer Graphics Library o o *
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* _ O _ *
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* Copyright(C) 2004-2012 \/)\/ *
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* Visual Computing Lab /\/| *
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* ISTI - Italian National Research Council | *
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* \ *
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* All rights reserved. *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License (http://www.gnu.org/licenses/gpl.txt) *
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* for more details. *
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* *
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****************************************************************************/
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/*! \file trimesh_fitting.cpp
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\ingroup code_sample
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\brief A small example about sampling and fitting
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Given a mesh (an icosahedron) for each face we get a few random samples over it, and then we recover:
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- the plane fitting them (that coincide with the face plane and exactly approximate all the sample points)
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- the plane fitting the perturbed version of this set
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- the plane fitting the perturbed version of the set but using a weighted fitting scheme.
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*/
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#include<vcg/complex/complex.h>
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#include<vcg/complex/algorithms/update/topology.h>
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#include<vcg/complex/algorithms/update/normal.h>
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#include<vcg/complex/algorithms/create/platonic.h>
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#include<vcg/complex/algorithms/point_sampling.h>
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#include<wrap/io_trimesh/import_off.h>
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#include<vcg/space/fitting3.h>
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class MyEdge;
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class MyFace;
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class MyVertex;
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struct MyUsedTypes : public vcg::UsedTypes< vcg::Use<MyVertex> ::AsVertexType,
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vcg::Use<MyEdge> ::AsEdgeType,
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vcg::Use<MyFace> ::AsFaceType>{};
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class MyVertex : public vcg::Vertex<MyUsedTypes, vcg::vertex::Coord3f, vcg::vertex::Normal3f, vcg::vertex::BitFlags >{};
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class MyFace : public vcg::Face< MyUsedTypes, vcg::face::FFAdj, vcg::face::VertexRef, vcg::face::Normal3f, vcg::face::BitFlags > {};
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class MyEdge : public vcg::Edge<MyUsedTypes>{};
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class MyMesh : public vcg::tri::TriMesh< std::vector<MyVertex>, std::vector<MyFace> , std::vector<MyEdge> > {};
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float EvalPlane(vcg::Plane3f &pl, std::vector<vcg::Point3f> posVec)
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{
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float off=0;
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for(size_t i=0;i<posVec.size();++i)
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off += fabs(vcg::SignedDistancePlanePoint(pl,posVec[i]));
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off/=float(posVec.size());
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return off;
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}
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int main( )
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{
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MyMesh m;
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vcg::tri::Icosahedron(m);
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vcg::tri::UpdateNormal<MyMesh>::PerVertexNormalizedPerFaceNormalized(m);
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vcg::tri::UpdateBounding<MyMesh>::Box(m);
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// As a simple test just run over all the faces of a mesh
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// get a few random points over it, perturb them and fit a plane on them.
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vcg::Plane3f ple,plf,plw;
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int cnt=0;
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float scaleFac = m.bbox.Diag()/10.0f;
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printf("ScaleFac %f\n\n",scaleFac);
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vcg::math::MarsenneTwisterRNG rnd;
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for(int i=0;i<m.FN();++i)
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{
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std::vector<vcg::Point3f> ExactVec;
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std::vector<vcg::Point3f> PerturbVec;
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std::vector<float> WeightVec;
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vcg::Plane3f pl;
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pl.Init(vcg::Barycenter(m.face[i]),m.face[i].N());
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for(int j=0;j<200;++j)
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{
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vcg::Point3f p = vcg::tri::SurfaceSampling<MyMesh>::RandomPointInTriangle(m.face[i]);
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ExactVec.push_back(p);
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vcg::Point3f off = vcg::math::GeneratePointInUnitBallUniform<float>(rnd);
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p+=off*scaleFac;
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float w = std::max(0.0, 1.0f-fabs(vcg::SignedDistancePlanePoint(pl,p))/scaleFac);
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PerturbVec.push_back(p);
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WeightVec.push_back(w*w); // as weight we use the square of (1-distance)
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}
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vcg::FitPlaneToPointSet(ExactVec,ple);
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float err=EvalPlane(ple,ExactVec);
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vcg::FitPlaneToPointSet(PerturbVec,plf);
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float err0=EvalPlane(plf,ExactVec);
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vcg::WeightedFitPlaneToPointSet(PerturbVec,WeightVec,plw);
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float err1=EvalPlane(plw,ExactVec);
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printf("Exact %5.3f Fit to Perturbed %5.3f Weighted fit to perturbed %5.3f\n",err,err0,err1);
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if(err0>err1) cnt++;
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}
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printf("\nWeighted Fitting was better %i on %i\n",cnt,m.FN());
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return 0;
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}
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