I would be interested to know if there is any way tags attached to triangles (and/or points) could be passed to the STL surface mesher and retrieved from the output in terms of the new triangles/points?
I would mark the boundary conditions in the geometry (STL mesh) and then would like to create a new surface with better quality, but still have boundary conditions information on the new surface mesh.
Is this possible using the nglib API or any lower level netgen code?
See this thread "On which STL triangle a mesh node lies?". Not exactly what you're asking but it should achieve the same goal.