Break line (Feature line) and sharp edge reconstruction
The software provides tools to compute polylines following sharp edges, fillets or small radii on a mesh.
It is good to know that the curvature of a mesh can be negative or positive:
A negative curvature has its center inside the mesh; the shape is convex.
A positive curvature has its center outside the mesh; the shape is concave.
Two types of lines can be extracted from a mesh:
The single Break line is the line on the sharp edge.
The fictive line is the line which can be used to recreate the sharp edge (i.e. planar intersection line).
The extracted lines could also be useful for constraint meshing. See chapter Meshing and mesh improvement.