add vcglib

vcglib/apps/sample/trimesh_fitting/trimesh_fitting.cpp

@@ -0,0 +1,110 @@
+/****************************************************************************
+* VCGLib                                                            o o     *
+* Visual and Computer Graphics Library                            o     o   *
+*                                                                _   O  _   *
+* Copyright(C) 2004-2016                                           \/)\/    *
+* 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.                                                         *
+*                                                                           *
+****************************************************************************/
+/*! \file trimesh_fitting.cpp
+\ingroup code_sample
+
+\brief A small example about sampling and fitting
+
+Given a mesh (an icosahedron) for each face we get a few random samples over it, and then we recover:
+- the plane fitting them (that coincide with the face plane and exactly approximate all the sample points)
+- the plane fitting the perturbed version of this set
+- the plane fitting the perturbed version of the set but using a weighted fitting scheme.
+*/
+
+#include<vcg/complex/complex.h>
+#include<vcg/complex/algorithms/create/platonic.h>
+#include<vcg/complex/algorithms/point_sampling.h>
+#include<wrap/io_trimesh/import_off.h>
+#include<vcg/space/fitting3.h>
+
+
+class MyEdge;
+class MyFace;
+class MyVertex;
+struct MyUsedTypes : public vcg::UsedTypes<	vcg::Use<MyVertex>   ::AsVertexType,
+                                        vcg::Use<MyEdge>     ::AsEdgeType,
+                                        vcg::Use<MyFace>     ::AsFaceType>{};
+
+class MyVertex  : public vcg::Vertex<MyUsedTypes, vcg::vertex::Coord3f, vcg::vertex::Normal3f, vcg::vertex::BitFlags  >{};
+class MyFace    : public vcg::Face< MyUsedTypes, vcg::face::FFAdj,  vcg::face::VertexRef, vcg::face::Normal3f, vcg::face::BitFlags > {};
+class MyEdge    : public vcg::Edge<MyUsedTypes>{};
+class MyMesh    : public vcg::tri::TriMesh< std::vector<MyVertex>, std::vector<MyFace> , std::vector<MyEdge>  > {};
+
+float EvalPlane(vcg::Plane3f &pl, std::vector<vcg::Point3f> posVec)
+{
+  float off=0;
+  for(size_t i=0;i<posVec.size();++i)
+    off += fabs(vcg::SignedDistancePlanePoint(pl,posVec[i]));
+
+  off/=float(posVec.size());
+  return off;
+}
+
+
+int main( )
+{
+  MyMesh m;
+  vcg::tri::Icosahedron(m);
+  vcg::tri::UpdateNormal<MyMesh>::PerVertexNormalizedPerFaceNormalized(m);
+  vcg::tri::UpdateBounding<MyMesh>::Box(m);
+
+  // As a simple test just run over all the faces of a mesh
+  // get a few random points over it, perturb them and fit a plane on them.
+  vcg::Plane3f ple,plf,plw;
+  int cnt=0;
+  float scaleFac = m.bbox.Diag()/10.0f;
+  printf("ScaleFac %f\n\n",scaleFac);
+  vcg::math::MarsenneTwisterRNG rnd;
+  for(int i=0;i<m.FN();++i)
+  {
+    std::vector<vcg::Point3f> ExactVec;
+    std::vector<vcg::Point3f> PerturbVec;
+    std::vector<float> WeightVec;
+    vcg::Plane3f pl;
+    pl.Init(vcg::Barycenter(m.face[i]),m.face[i].N());
+    for(int j=0;j<200;++j)
+    {
+      vcg::Point3f p = vcg::tri::SurfaceSampling<MyMesh>::RandomPointInTriangle(m.face[i]);
+      ExactVec.push_back(p);
+      vcg::Point3f off = vcg::math::GeneratePointInUnitBallUniform<float>(rnd);
+      p+=off*scaleFac;
+      float w =  std::max(0.0f, 1.0f-fabs(vcg::SignedDistancePlanePoint(pl,p))/scaleFac);
+      PerturbVec.push_back(p);
+      WeightVec.push_back(w*w); // as weight we use the square of  (1-distance)
+    }
+
+    vcg::FitPlaneToPointSet(ExactVec,ple);
+    float err=EvalPlane(ple,ExactVec);
+
+    vcg::FitPlaneToPointSet(PerturbVec,plf);
+    float err0=EvalPlane(plf,ExactVec);
+
+    vcg::WeightedFitPlaneToPointSet(PerturbVec,WeightVec,plw);
+    float err1=EvalPlane(plw,ExactVec);
+    printf("Exact %5.3f Fit to Perturbed %5.3f Weighted fit to perturbed %5.3f\n",err,err0,err1);
+    if(err0>err1) cnt++;
+  }
+
+  printf("\nWeighted Fitting was better %i on %i\n",cnt,m.FN());
+  return 0;
+}