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#ifndef COMPUTE_NORMALS_H
#define COMPUTE_NORMALS_H
#include <CGAL/boost/graph/helpers.h>
#include <boost/foreach.hpp>
template <typename TriangleMesh, typename FaceVectorMap, typename Kernel>
const typename Kernel::Vector_3
computeFacetsAverageUnitNormal(const TriangleMesh& tm,
typename boost::graph_traits<TriangleMesh>::vertex_descriptor v,
FaceVectorMap fvm,
const Kernel& )
{
typename boost::graph_traits<TriangleMesh>::halfedge_descriptor h;
typename boost::graph_traits<TriangleMesh>::face_descriptor f;
typename Kernel::Vector_3 sum(0., 0., 0.), n;
CGAL::Halfedge_around_target_circulator<TriangleMesh> hedgeb(halfedge(v,tm),tm), hedgee = hedgeb;
do
{
h = *hedgeb;
if (is_border_edge(h,tm))
{
hedgeb++;
continue;
}
f = face(h,tm);
n = get(fvm,f);
sum = (sum + n);
hedgeb++;
}
while (hedgeb != hedgee);
sum = sum / std::sqrt(sum * sum);
return sum;
}
template <typename TriangleMesh, typename FaceVectorMap,typename Kernel>
void compute_facets_normals(const TriangleMesh& tm,
FaceVectorMap fvm,
const Kernel& )
{
typedef typename boost::property_traits<FaceVectorMap>::value_type Vector_3;
typedef typename boost::property_map<TriangleMesh,CGAL::vertex_point_t>::const_type VPM;
VPM vpm = get(CGAL::vertex_point,tm);
BOOST_FOREACH(typename boost::graph_traits<TriangleMesh>::face_descriptor f, faces(tm)){
typename boost::graph_traits<TriangleMesh>::halfedge_descriptor h = halfedge(f,tm);
Vector_3 normal =
CGAL::cross_product(get(vpm, target(h,tm)) -
get(vpm, target(opposite(h,tm),tm)),
get(vpm, target(next(h,tm),tm)) -
get(vpm, target(opposite(h,tm),tm)));
put(fvm, f, normal / CGAL::sqrt(normal * normal));
}
}
#endif
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