# Fillet Edge of Surface Problem

I want to fillet the sharp edges of the following open brep, but nothing seems to work:

I manually identified the edges that I want to fillet, but I get an error in the filletEdge grasshopper function called “Edge index exceeds edge count of Brep”. This makes no sense because I get the edge index directly from the Brep Edges function in grasshopper. Anyway, if anyone has an idea on how to fillet this 2D surface, that would be helpful.FilletProblem.3dm (4.4 MB) FilletProblem.gh (7.7 KB)

FilletProblem_2020Feb22a.gh (19.6 KB)

You can select specific “corners” (Disc, Discontinuities) with the yellow text panel or just do them all, as shown.

Internalized brep (below):
FilletProblem_2020Feb22aa.gh (414.2 KB)

P.S. The radius of the Pipe can be reduced considerably but its effectiveness as a “cutter” for the brep depends on the radius of the fillet. This wouldn’t be necessary if the brep was a single surface as the white curve could then be pulled to it…

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Ok this is a very smart way at solving the problem. For future reference, what is the relationship with the radius of the pipe and its effectiveness as a cutter? And how does that relationship change if the sphere becomes smaller/larger? I notice that when the sphere size is 6mm, everything fails. Would a considerably pipe radius fix that?

Forget about the Pipe, this version creates a better “cutter” (Loft in purple group):

FilletProblem_2020Feb22b.gh (423.8 KB)

It was failing for large radii due to the method I used for culling pieces of the curve cut by BCX, the sphere intersections. This version uses a different method but will still fail if the spheres overlap, so I made them visible. Good up to radius = 13 for this shape.

FilletProblem_2020Feb22c.gh (424.4 KB)

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but I get an error in the filletEdge grasshopper function called “Edge index exceeds edge count of Brep”

Just for clarity so you understand why that didn’t work. That component is for filleting faces at an edge shared by two faces of a polysurface brep, not for filleting the trim curve edge of a face.

Like seen in this image.

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