How do I get the top surface of the elements and the outline of the Difference?

[Dornan_Luke]

I selected the slab and beam and converted the surface.
But I don’t know how to handle the top surface and the difference.

Any advise is greatly appreciated.

TSF-0357-Q1.dyn (6.9 KB)

[lucamanzoni]

Something like this should work:

Basically I filtered the surfaces according to the Z elevation of their middle point and took only the upper one.

[Dornan_Luke]

Thank @lucamanzoni
However, what should I do if I ask the slab to do a multi-object difference?
Thank you!

[lucamanzoni]

You are welcome. In that case you have to use Solid.DifferenceAll

http://dictionary.dynamobim.com/#/Geometry/Solid/Action/DifferenceAll

[lucamanzoni]

This way should work better:

you need to merge the solids to subtract with Solid.ByUnion

[Dornan_Luke]

Thank @lucamanzoni