Fillet fail example - V5SR10

I found a bug in Fillet.
Maybe it’s already known, but you can add this on the examples.

bug.3dm (286.1 KB)

Rhino V5 SR10 and previous

You have some narrow surfaces that mess things up:

fillet-fix.3dm (557.9 KB)

(I had to retrim the bottom, as the edges were not coplanar. Check the dimensions, and scale 1D.)

I see. Thanks.
That srf was made by the chamfer tools, so I have to rename the post :wink:

This time I checked everything and the Fillet still fail.

I’m expecting a conic srf in the angled part, but not.

bug_2.3dm (374.4 KB)


Hi Riccardo - one of the things that simply does not work in FilletEdge is when a fillet is required to jump across to a surface which is not part of the original edge selection. This is what happens in this case where the chamfer surface tapers away to a point - for the fillet to work, it would need to jump across to consider the vertical surface as it approaches the point. So yes it is a bug/limitation and it is known and on the pile for the developer.

Edit: I am not even sure what the right answer is at that location - maybe this?



Thanks Pascal,
But my problem it’s on the vertical edge not this one.
Probably I was not clear enough, sorry.

The real problem look like the chamfer.
When you made the chamfer you can’t be able to fillet the corner anymore.

Yes … I think Rhino is not (yet) able to extend a fillet onto a couple of surfaces (joined by an edge obviously).
Just for testing, I looked for a way and that’s what I found:

bug_3.3dm (466.6 KB)

  1. Explode the solid
  2. Rebuild the two planar chamfer surfaces as untrimmed surfs (using Loft)
  3. Merge these two surfaces into a single surf
  4. Re Join
  5. Now Rhino is able to fillet the lower (vertical) edge
  6. Explode again
  7. Split back the previously merged surface into two surfaces (I also shrank them, maybe unneeded)
  8. Re Join
  9. Now Rhino can also fillet the upper edge

Yeah, OK … not the quickest work in the world :wink:

BTW, does a tool to turn four-sided (or three-sided) planar trimmed surfaces into untrimmed ones exist ?
I need it sometimes … just like here
(EDIT: the surface needs not be planar, two opposite linear sides are enough to turn it into a ruled surf)
Also …should this hypothetical command and the other regular commands (e.g. MergeSrf, Split etc) be able to directly work on polysurfaces, that would be really really fine :smiley:


The next step might be a command that, picking an edge, would turn (when possible and needed) the two surfaces joined by the edge into untrimmed surfaces and then merge them into a single surface.
Plus obviously the command to pick the isocurve (the edge turned into an isocurve) and split the surface back recreating the old edge.
This would turn the above command sequence into 4 commands only

Why conic ?
Without giving the command the different radius values ?