Just like everyone else, I’m having trouble with fillets on extruded edges in Grasshopper. I have a delauney mesh that is producing a bunch of triangles. The goal is to be able to fabricate the mesh with 3/4" plywood. So each of these triangles is extruded 3/4". I then want to fillet the edges of one face of the extruded object to simulate running a roundover bit around the perimeter of the piece of plywood. I think I have actually managed to get all the indices of the edges I want to fillet, but it’s still giving me an error. Any help would be greatly appreciated.

I’m deconstructing the brep produced by the extrude, then culling the index of the faces list to remove 0, 1, 2, and 3. This leaves the ‘front’ face (the one that is the same shape as the initial curve, but is the result of the extrude). I then find the center of that face and feed that point into and “edges from faces” component. Based on the previews I see in Rhino, it seems like I’ve selected the correct edges, but the fillet component is giving me an error: “You may not specify more radii than edge indices”

This is what I see with the “edges from faces” component is selected:

You need to generate a list of edge indices, not the edges themselves. Be careful to not exceed the limits of filleting by passing a large number to radii.

Thank you both so much! @martinsiegrist I will definitely need to learn more about data trees, thank you for the link.

The edges that need to be filleted are the ones that are not touching the original control points. The ones that are highlighted in green in my third screenshot.

Thank you! This solves my original question, but I’m still trying to understand two things about your file (if you have time).

I see that you took the full set of edges from the breps created by the extrude, and did a set difference with the original set of edges. For some reason, this works and results in only the edges I wanted, but I don’t understand why the results don’t also include the edges along the extrude path? Those edges are definitely not in the original surface (since it’s only 2D).

Immediately before the set difference component, why do you have to feed those sets through a text component first? It looks like the exact same data in a panel.

The extruded polysurfaces have nine edges. Their indices are 0 - 8. Using list length, the series count would adapt, should one of your initial surfaces all of a sudden have four corners or more.

The Cull Duplicates component takes all points and eliminates the duplicates. The P output is a list of the points without duplicates.

Edges from Points with the valence input set to ‘1’ extracts all edges which touch at least one of these ten points.

The Set Difference component works with text and not integers, hence the integers need to be converted to text.