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#1105 Workaround for CGAL problem: Don't trust normal vectors from Nef polyhedrons, normalize calculated normal vectors

master
Marius Kintel 2015-01-06 22:51:44 -05:00
parent 5537e82274
commit 1941a7fc0d
2 changed files with 8 additions and 3 deletions
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2
src/cgalutils-tess.cc
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@ -107,6 +107,8 @@ namespace CGALUtils {
else {
// Calculate best guess at face normal using Newell's method
CGAL::normal_vector_newell_3(polygons.front().begin(), polygons.front().end(), normalvec);
double sqrl = normalvec.squared_length();
if (sqrl > 0.0) normalvec = normalvec / sqrt(sqrl);
}
// Pass the normal vector to the (undocumented)

9
src/cgalutils.cc
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@ -917,10 +917,13 @@ namespace CGALUtils {
and let the tessellater deal with the holes, and then
just output the resulting 3d triangles*/
CGAL::Vector_3<CGAL_Kernel3> nvec = plane.orthogonal_vector();
K::Vector_3 normal(CGAL::to_double(nvec.x()), CGAL::to_double(nvec.y()), CGAL::to_double(nvec.z()));
// We cannot trust the plane from Nef polyhedron to be correct.
// Passing an incorrect normal vector can cause a crash in the constrained delaunay triangulator
// See http://cgal-discuss.949826.n4.nabble.com/Nef3-Wrong-normal-vector-reported-causes-triangulator-crash-tt4660282.html
// CGAL::Vector_3<CGAL_Kernel3> nvec = plane.orthogonal_vector();
// K::Vector_3 normal(CGAL::to_double(nvec.x()), CGAL::to_double(nvec.y()), CGAL::to_double(nvec.z()));
std::vector<Polygon> triangles;
bool err = CGALUtils::tessellatePolygonWithHoles(polyholes, triangles, &normal);
bool err = CGALUtils::tessellatePolygonWithHoles(polyholes, triangles, NULL);
if (!err) {
BOOST_FOREACH(const Polygon &p, triangles) {
if (p.size() != 3) {