STEP geometry: Boundaries

Hello all,

I have a STEP geometry, a box. I can build a mesh from this geometry (with nglib) and I can explore the topology hierarchy, but i want to get and identify some boundaries (faces and edges) in order to create face groups.

At this point I wonder if it is possible to extract a submesh that corresponds to a topology, or in another way, if it is possible to identify each element (triangle or tetra), from the mesh, with any topology.

Are there any function/method for this?

I accept any suggest. Thanks! :D

Roman Lygin's picture

Hi Victor,
I bet the answer is no. Native Netgen-OCC binding does not support a notion of submesh and face-to-{set_of_elements} mapping. At least in 4.9.x.
You might want to consider Salome's SMESH which does this or make your own implementation of that.
Hope this helps.
P.S. The question is probably more relevant to Netgen than to OCC forum though.

victorsv's picture

wow! what a quick response! Thanks :D

Ok, I will post the same message in the Netgen forum.

Anyway, i was reading some of the "Modeling Data User's Guide" and i find the "Extrema" in the geometry utilities. I think that knowing the distance of a point to an edge or a surface will be enought to know if this point belongs to the edge or the surface.

What do you know?