[Gmsh] Physical names and step files

[Wayne Christopher]

Dear Gmsh Users,

I would like to write a Step file (from my app which uses OpenCascade), 
read it into gmsh and create a mesh in batch mode, and read the msh file 
back into my app, associating the triangles and tetras with the original 
shapes.

What I am seeing is that there is no PhysicalNames section in the output 
msh file, and the values of the physical names tag seems arbitrary.  
(Also the numbers used for triangle regions and tetra regions overlap).

I'm assuming that the right way to handle this requires me to attach 
labels to the volume, surface, curve entities in the step file and 
somehow tell gmsh to use these labels as the PhysicalNames in the output 
file.  Is this correct and if so how would I specify this?

The other fly in the ointment here is that OpenCascade seems to ignore 
the labels I attach to sub-shapes and this seems to be a long-standing 
problem - see http://www.opencascade.org/org/forum/thread_14829 ..  Has 
anybody dealt with this issue?

Thanks for the help!

     Wayne