Contrib snapEdgeDescription
From OpenFOAMWiki
The idea behind snapEdge is pretty straightforward and I will try to describe it below.
The first step is to extract the features from the STL. An STL is just a collection of triangles and every edge thus has 2 triangles associated to it. If it doesnt, it is a an edge and will be added to the feature lines. Otherwise the dot product of the face normals is calculated (and normalized) If it is equal to 1 it means that the two planes are parallel and if it is equal to 0 the planes are perpendicular. The feaureAngle decides which features should be included in the snapping.
