Facediscretizer and visualization problems...

Hello,

I read an IGES file and I want to discretize the face's, for that is use BRepMesh_FastDiscret(...) and I want to visualize the whole body with the discretized geometry.
For that, I get the BRepMesh_FastDiscret(...) triangulation and create the faces from the triangles.
1. the first problem is that the BRepMesh_FastDiscret(...) wrongly discretizes a concav face. Because faceting like a convex face and create "dangling" area.
2. the second problem is in visualization: the OCC hilight the whole body with the triangulated surface. But I only want to hilight the border edges of the body. I have an idea, create two layer, first with the border edges, second with inner edges, but I don't know how to change between? It can give some type for visualization to resolve this situation?

I thank you forward for any idea, or solution.

Sandor.