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