DGtal  1.5.beta
exampleRationalBallDelaunay3D.cpp
1
52 #include "DGtal/base/Common.h"
53 #include "DGtal/kernel/PointVector.h"
54 #include "DGtal/shapes/SurfaceMesh.h"
55 #include "DGtal/io/writers/SurfaceMeshWriter.h"
56 #include "DGtal/geometry/volumes/ConvexityHelper.h"
57
58 using namespace DGtal;
59 using namespace DGtal::Z3i;
60 int main( int argc, char* argv[] )
61 {
62  int nb = argc > 1 ? atoi( argv[ 1 ] ) : 100; // nb points
63  double dR = argc > 2 ? atof( argv[ 2 ] ) : 10.; // radius of balla
64  double eps = argc > 3 ? atof( argv[ 3 ] ) : 0.1; // retraction
65  double precision = argc > 4 ? atof( argv[ 4 ] ) : 100.0; // precision
68  // (1) create range of random points in ball
69  std::vector< RealPoint > V;
70  const auto R2 = dR * dR;
71  for ( int i = 0; i < nb; ) {
72  RealPoint p( ( rand() / (double) RAND_MAX * 2.0 - 1.0 ) * dR,
73  ( rand() / (double) RAND_MAX * 2.0 - 1.0 ) * dR,
74  ( rand() / (double) RAND_MAX * 2.0 - 1.0 ) * dR );
75  if ( p.squaredNorm() <= R2 ) { V.push_back( p ); i++; }
76  }
77  // (2) compute convex hull
78  bool ok =
80  precision, true );
81  if ( ! ok )
82  {
83  trace.error() << "Input set of points is not full dimensional." << std::endl;
84  return 1;
85  }
86  dcomplex.requireFaceGeometry();
87  std::cout << dcomplex << std::endl;
88  // (3) build the mesh that is made of the exploded 3d cells
89  std::vector< RealPoint > positions;
90  std::vector< std::vector< Index > > facets;
91  Index idxv = 0;
92  for ( auto c = 0; c < dcomplex.nbCells(); ++c )
93  {
94  RealPoint b = dcomplex.cellBarycenter( c );
95  auto c_vtcs = dcomplex.cellVertices( c );
96  std::map< Index, Index > v2v;
97  for ( auto v : c_vtcs ) {
98  RealPoint x = dcomplex.position( v );
99  v2v[ v ] = idxv++;
100  positions.push_back( b + ( x - b ) * ( 1.0 - eps ) );
101  }
102  for ( const auto& f : dcomplex.cellFaces( c ) ) {
103  auto f_vtcs = dcomplex.faceVertices( f );
104  for ( auto& vertex : f_vtcs )
105  vertex = v2v[ vertex ];
106  facets.push_back( f_vtcs );
107  }
108  }
110  SMesh mesh( positions.cbegin(), positions.cend(),
111  facets.cbegin(), facets.cend() );
112  // (4) output result as OBJ file
113  std::ofstream out( "delaunay3d.obj" );
115  ::writeOBJ( out, mesh );
116  out.close();
117  return 0;
118 }
119
Aim: Implements basic operations that will be used in Point and Vector classes.
Definition: PointVector.h:593
std::ostream & error()
SurfaceMesh< RealPoint, RealVector > SMesh
SMesh::Index Index
Z3i this namespace gathers the standard of types for 3D imagery.
DGtal is the top-level namespace which contains all DGtal functions and types.
Trace trace
Definition: Common.h:153
Aim: represents a d-dimensional complex in a d-dimensional space with the following properties and re...
const VertexRange & cellVertices(const Cell c) const
Point position(const Vertex v) const
VertexRange faceVertices(const Face f) const
RealPoint cellBarycenter(const Cell c) const
void requireFaceGeometry()
Forces the computation of face geometry.
const FaceRange & cellFaces(const Cell c) const
static bool computeDelaunayCellComplex(ConvexCellComplex< Point > &cell_complex, const PointRange &input_points, bool remove_duplicates=true)
static bool writeOBJ(std::ostream &output, const SurfaceMesh &smesh)
Aim: Represents an embedded mesh as faces and a list of vertices. Vertices may be shared among faces ...
Definition: SurfaceMesh.h:92
int main(int argc, char **argv)