DGtal  1.2.0
exampleLatticeBallDelaunay3D.cpp
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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
67  // (1) create range of random points in ball
68  std::vector< Point > V;
69  const auto R2 = dR * dR;
70  const int R = ceil( dR );
71  for ( int i = 0; i < nb; ) {
72  Point p( rand() % (2*R+1) - R, rand() % (2*R+1) - R, rand() % (2*R+1) - R );
73  if ( p.squaredNorm() <= R2 ) { V.push_back( p ); i++; }
74  }
75  // (2) compute convex hull
76  bool ok =
78  if ( ! ok )
79  {
80  trace.error() << "Input set of points is not full dimensional." << std::endl;
81  return 1;
82  }
83  dcomplex.requireFaceGeometry();
84  std::cout << dcomplex << std::endl;
85  // (3) build the mesh that is made of the exploded 3d cells
86  std::vector< RealPoint > positions;
87  std::vector< std::vector< Index > > facets;
88  Index idxv = 0;
89  for ( auto c = 0; c < dcomplex.nbCells(); ++c )
90  {
91  RealPoint b = dcomplex.cellBarycenter( c );
92  auto c_vtcs = dcomplex.cellVertices( c );
93  std::map< Index, Index > v2v;
94  for ( auto v : c_vtcs ) {
95  RealPoint x = dcomplex.toReal( dcomplex.position( v ) );
96  v2v[ v ] = idxv++;
97  positions.push_back( b + ( x - b ) * ( 1.0 - eps ) );
98  }
99  for ( const auto& f : dcomplex.cellFaces( c ) ) {
100  auto f_vtcs = dcomplex.faceVertices( f );
101  for ( auto& vertex : f_vtcs )
102  vertex = v2v[ vertex ];
103  facets.push_back( f_vtcs );
104  }
105  }
107  SMesh mesh( positions.cbegin(), positions.cend(),
108  facets.cbegin(), facets.cend() );
109  // (4) output result as OBJ file
110  std::ofstream out( "delaunay3d.obj" );
112  ::writeOBJ( out, mesh );
113  out.close();
114  return 0;
115 }
116
std::ostream & error()
int main(int argc, char *argv[])
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:154
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 toReal(const Point p) 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 std::vector< Point > &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