Defining Physical Surfaces after Boolean operations
Hello.
I am trying to define physical groups for models that have been created in gmsh(+opencascade) using Boolean operations.
I am familiar with defining physical groups when the models are made out of elementary entities. However, when I use boolean operations on volumes, I do not have any elementary surfaces to access. I was wondering if I could assign physical surfaces to the new surfaces created via Boolean operations on volumes.
For example, the following script creates a cube with a spherical hole inside.
SetFactory("OpenCASCADE");
Box(1) = {-1,-1,-1, 2, 2, 2};
Sphere(2) = {0,0,0, 0.5};
BooleanDifference (3) = { Volume {1}; Delete; }{ Volume {2}; Delete; };
Physical Volume(4) = {3};
I wish to define a separate physical surface for the outer surface of the cube and a second physical surface for the inner spherical hole. Is this possible without elementary entities?
Thank you for your attention.