Best way to hollow out a building

I’m doing exterior renderings for a high-rise and need some advice to make my life easier. The architect gives me a DWG file to import into Rhino. Inside the model of the building, there’s a bunch of structural stuff that I don’t need (because I’m just rendering the exterior) and it really slows down my computer.

I’m trying to figure out the easiest way to just delete all the stuff inside. I can do it manually but that’s really time-consuming. I’m trying to figure out a way to draw a box inside the building and delete everything in it. The entire model is mesh. I was hoping MeshBooleanDifference would do it but that’s not turning out like I expected.

Hello - are the inner bits separate objects? Is the outer shell a closed polysurface ? If so SelVolumeObject might help.
Are any of the bits on separate layers?


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Hard to say without seeing a model. Is it a single mesh? Is it a single mesh that consists of multiple disjoint meshes? SelSmall could help in that case after using _SplitDisjointMesh

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They are separate objects. Many little single meshes. There are several different layers.

If you don’t bother the meshes to stay in your model and they can have the same material, but it slows down your system, another thing you can do is Join the meshes into a single Disjoint mesh.

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Hi @parchitects
Another trick is using SelVisible to get the exterior surfaces and then hide those to access the inner objects.
HTH, Jakob


use drape and trim a little bit from the bottom, voila all buildings as a single volume. it might lose a little detail though :smiley:

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I use a combination of selcolor, selmaterialname to try and select any qualities that make them unique to the shell. You can also consider using lasso tool in a plan view (try using the different variations i.e. crossing). It often requires a lot of whittling down! You can also look at blockmanager depending how the model is.

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