Commit a7450f15 authored by Jan Möbius's avatar Jan Möbius

Fixed wrong normal calculation in calc_face_normal for Poly Meshes.

closes #2427


git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@1247 fdac6126-5c0c-442c-9429-916003d36597
parent 07ab9c4b
......@@ -97,33 +97,38 @@ calc_face_normal(FaceHandle _fh) const
ConstFaceVertexIter fv_it(this->cfv_iter(_fh));
Point p0 = this->point(*fv_it);
Point p0i = p0; //save point of vertex 0
++fv_it;
const Point p0i = p0; //save point of vertex 0
// Safeguard for 1-gons
if (!(++fv_it).is_valid()) return Normal(0, 0, 0);
Point p1 = this->point(*fv_it);
Point p1i = p1; //save point of vertex 1
const Point p1i = p1; //save point of vertex 1
++fv_it;
Point p2;
// Safeguard for 2-gons
if (!(++fv_it).is_valid()) return Normal(0, 0, 0);
//calculate area-weighted average normal of polygon's ears
Normal n(0,0,0);
for(; fv_it.is_valid(); ++fv_it)
{
p2 = this->point(*fv_it);
n += vector_cast<Normal>(calc_face_normal(p0, p1, p2));
const Point p2 = this->point(*fv_it);
n += vector_cast<Normal>(calc_face_normal(p0, p1, p2));
p0 = p1;
p1 = p2;
}
//two additional steps since we started at vertex 2, not 0
n += vector_cast<Normal>(calc_face_normal(p0i, p0, p1));
n += vector_cast<Normal>(calc_face_normal(p1i, p0i, p1));
n += vector_cast<Normal>(calc_face_normal(p0, p1, p0i));
n += vector_cast<Normal>(calc_face_normal(p1, p0i, p1i));
typename vector_traits<Normal>::value_type norm = n.length();
const typename vector_traits<Normal>::value_type norm = n.length();
// The expression ((n *= (1.0/norm)),n) is used because the OpenSG
// vector class does not return self after component-wise
// self-multiplication with a scalar!!!
return (norm != typename vector_traits<Normal>::value_type(0)) ? ((n *= (typename vector_traits<Normal>::value_type(1)/norm)),n) : Normal(0,0,0);
return (norm != typename vector_traits<Normal>::value_type(0))
? ((n *= (typename vector_traits<Normal>::value_type(1)/norm)), n)
: Normal(0, 0, 0);
}
//-----------------------------------------------------------------------------
......
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