How to offset curves on a mesh?

What is the easiest way to offset the naked edges of a mesh on top of the surface of the mesh? (Meaning on its inside)

Offset Lines on a Mesh.gh (13.4 KB)

This uses a Project to Mesh component I got from somewhere and Clipper. It “looks” alright in this case because your mesh is relatively flat along the edges. It’s not really doing what I believe the Offset Curve on Surface does, if that’s what you’re looking for.

Offset Lines on a Mesh-b.gh (19.4 KB)

Yes, but the distance is not uniform. I want to control the distance from the edge to the offseted curve preciselly. There are number of ways to project a curve on a mesh.

One way can be to pipe the curve you want to offset, then take the intersection of that pipe with the mesh

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Doesn’t this suffer from the same problem as my suggestion? It looks OK here because the mesh is pretty flat, but if you tried it on the same mesh, but scaled in the z direction four or five times, you’d see the offset is not uniform. Or, maybe I’m misinterpreting the idea of offset on a mesh or surface?

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This is simple and clever and will do great job for this particular task. As Ethan has said, not so sure for more complex cases. Thank you both!

It depends what metric you want uniform distances in.
The cylinder intersection will give you a curve at uniform distance in 3D space from your original.
I agree that this will be different from an offset at uniform geodesic distance measured along the mesh.
For small offset distances/smooth meshes they will be similar though.

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Maybe like this

Offset Lines on a Mesh__.gh (24.9 KB)

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Yes, this is the first way I’ve tried to skin that cat :slight_smile: