Offsetting surface parallelly

Hello everyone, hope you all are doing well. I have a bunch of planar surfaces which I want to offset parallelly. I tried offsetting them with the center but the edge surfaces are too bent and i wont be able to fabricate it.

I also tried to offset them in a set of 5 but that is also not working as they are criss crossing after a certain distance. It will be really helpful if you can guide me in how to offset then parallelly so, I get planar faces for fabrication.

Thank you in advance.

offsetSurfaceParalle.gh (46.1 KB)

Offset Brep from Parakeet might help…


offsetSurfaceParalle_2020Nov22a.gh (57.0 KB)

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Thank you Jakinta, I have not used Parakeet yet but will download and try this method.

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Wow, this is great. Thank you so much Joseph, now I feel stupid for not exploring more hahaha.

Here’s another way, similar but using the whole polysurface instead of separate squares.


offsetSurfaceParalle_2020Nov22b.gh (50.3 KB)

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Thanks a ton, Joseph. I am actually planning to unroll those breps, laser cut them and assemble like boxes. Then put them on top of each other.

Thank you once again for all your help :slight_smile:

In that case, you’ll want the first solution which builds an enclosed box for each square. 50 boxes is a lot of work! How long is it?

For quad meshes, even when the faces are parallel, it is usually not possible to make a parallel offset of the faces and have the nodes of the faces of the offset mesh still meet.
The offset planes of 3 faces always intersect in a point, but typically when you have 4 faces around a vertex, these points for each combination of 3 of the faces will not coincide. So you end up with non planar faces and twisting beams or extra little corners on the faces.
You can optimize a mesh so that it can be offset like this though- it needs to be a conical mesh (see the links in this thread for more info).

Here’s an example showing how this can be done for your shape.
It turns out what you have is actually already very close to conical, so the vertices only need to move a tiny amount - you can even get away with skipping this optimisation step here, but perhaps it is interesting for others to see an approach which can also work for more general shapes which don’t already have this property.
Then it uses Kangaroo’s FaceFace offset component to create the parallel offset with all faces at the same distance apart and torsion free beams, and makes boxes out of them
offsetSurfaceParall_conical.gh (50.9 KB)

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Hi Joseph,

Yeah the first solution works well for me. The model is 64cm x 32cm x 16cm, it is not 1:1 scale but by making it bigger it will be easy to fold and assemble the model.

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