02b97a714a
The new algorithm provides robust quality triangulations of non-convex polygons. It also produces a best attempt for polygons that are badly warped or self intersecting by minimising the area in which the local normal is in the opposite direction to the overal polygon normal. It is memory efficient when applied to multiple polygons as it maintains and reuses its workspace. This algorithm replaces implementations in the face and faceTriangulation classes, which have been removed. Faces can no longer be decomposed into mixtures of tris and quadrilaterals. Polygonal faces with more than 4 sides are now decomposed into triangles in foamToVTK and in paraFoam.
122 lines
3.4 KiB
C++
122 lines
3.4 KiB
C++
/*---------------------------------------------------------------------------*\
|
|
========= |
|
|
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
|
|
\\ / O peration | Website: https://openfoam.org
|
|
\\ / A nd | Copyright (C) 2021 OpenFOAM Foundation
|
|
\\/ M anipulation |
|
|
-------------------------------------------------------------------------------
|
|
License
|
|
This file is part of OpenFOAM.
|
|
|
|
OpenFOAM 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 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
OpenFOAM 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
|
|
for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
\*---------------------------------------------------------------------------*/
|
|
|
|
#include "argList.H"
|
|
#include "clock.H"
|
|
#include "OBJstream.H"
|
|
#include "polygonTriangulate.H"
|
|
|
|
using namespace Foam;
|
|
|
|
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
argList::validArgs.append("number of edges");
|
|
argList::addOption
|
|
(
|
|
"error",
|
|
"value",
|
|
"polygon error - default is 0"
|
|
);
|
|
argList::addOption
|
|
(
|
|
"seed",
|
|
"value",
|
|
"random number generator seed - default is clock time"
|
|
);
|
|
argList::addBoolOption
|
|
(
|
|
"simple",
|
|
"assume polygon as no self intersections"
|
|
);
|
|
argList::addBoolOption
|
|
(
|
|
"nonOptimal",
|
|
"do not optimise the triangulation quality"
|
|
);
|
|
|
|
Foam::argList args(argc, argv);
|
|
Info<< nl;
|
|
|
|
// Get the size of the polygon
|
|
const label n = args.argRead<label>(1);
|
|
|
|
// Initialise the random number generator
|
|
label seed;
|
|
if (args.optionFound("seed"))
|
|
{
|
|
seed = args.optionRead<label>("seed");
|
|
}
|
|
else
|
|
{
|
|
seed = clock::getTime();
|
|
Info<< "Seeding random number generator with value " << seed
|
|
<< nl << endl;
|
|
}
|
|
Random rndGen(seed);
|
|
|
|
// Get controls
|
|
const bool simple = args.optionFound("simple");
|
|
const bool nonOptimal = args.optionFound("nonOptimal");
|
|
|
|
// Generate a random polygon
|
|
const List<point> polygon =
|
|
polygonTriangulate::randomPolygon
|
|
(
|
|
rndGen,
|
|
n,
|
|
args.optionLookupOrDefault<scalar>("error", 0)
|
|
);
|
|
|
|
// Write the polygon
|
|
{
|
|
OBJstream os(args[0] + "_polygon.obj");
|
|
os.write(face(identity(polygon.size())), polygon, false);
|
|
}
|
|
|
|
// Triangulate the polygon
|
|
const List<triFace> triPoints =
|
|
polygonTriangulate().triangulate(polygon, simple, !nonOptimal);
|
|
|
|
// Write the triangulation
|
|
faceList triFacePoints(triPoints.size());
|
|
forAll(triPoints, trii)
|
|
{
|
|
triFacePoints[trii] = triPoints[trii];
|
|
}
|
|
{
|
|
OBJstream os(args[0] + "_triangulation.obj");
|
|
os.write(triFacePoints, pointField(polygon), false);
|
|
}
|
|
|
|
Info<< "End" << nl << endl;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
// ************************************************************************* //
|