the intention of this topic is to collect examples, where fillets fails. Please post screenshots and .3dm files or links to other topics.
the idea of this topic is NOT to discuss single cases - but provide a nice overview / COLLECTION of the fails…
Yep… Many, if not most of the fillet edge failures are due to the fillet needing to end past the far edge of the face attached to the selected edge… I would say this likely falls into that category even though it is not strictly past
I tried this model when you first posted it and FilletSrf in the WIP seemed to work more elegantly albeit maxing out around a fillet radius of 10 instead of the 15 you want. Now I’m getting strange results. I opened this issue for you.
I do not get a nice result in Rhino-mac, V7 (see edit)
I think it would be nice, or might avoid some errors, if filletEdge would look at a version of the brep, where the coplanarfaces are merged. - without changing the typology / facedesign of the original brep - just to get the fillets rails / trims / …
Hidden in the abstract art is the correct answer, which isn’t quite as nice as the revolved surface. The other stuff is an added bonus. I guess you’d rather not have it there, and I’ll figure out what’s going wrong. If you just delete it, you’ll be left with this.
… but the algorithm somehow generates points far beyond anything that makes sense, no change to have some kind of test to stop it doing this ?
some kind of simple boundingbox - check at the end of the algorithm… ?
follow by some conditional clean up ?
or some user interaction … (which part do you want to keep ?)
if i would have studied geometry / mathematic instead of design i would head for a paper:
“traces of spheres in foggy circumstances”. (but maybe this is more a novel…)
for fillets i always imagine a path of a sphere movement…
and as soon as the radius / curvature of the target surface is (nearly) the same (“foggy”) the trajectory should be more careful, more stable, have more inertia…
same for “pointy” fillets - that should and in one point.
sometimes i think, rhinos problematic fillets are also linked to problems of intersect, offset-Surface and Pull…
this is a nice unsolved issue:
there was another crazy example.
(Edit - i found it:)
The problem with Rhino’s pointy fillets and pull and intersect commands is that when there is a plethora of possible solutions Rhino picks the worst one instead of the best.
The best solution of course is not the solution best for Rhino developers but the one is best for the user. In other words, its not the solution that the developer can claim is correct (in this case all the possible solutions are correct), it is the solution that doesn’t sabotage the users efforts to create a sound 3d model.
So when Rhino’s Intersect command is generating a set of points that will be used to create an output curve and the algorithm arrives at an area where both surfaces are tangent (i.e. have the same surface normal direction) it should not dive for the nearest boundary. That strategy may be the easy way out for the developer, but is disastrous for the user. What the algorithm should do is pick that next point that is closest to being in a straight line with the last 2 points the algorithm generated.
The same thing applies for the pointy fillets. The problem with pointy fillets just like the intersect command is that when it gets close enough to an edge it gets sucked to that edge instead of proceeding in the direction closest to which it is currently going. If any edge is going to be involved in the algorithm then it should only be at the point where the edge of both surfaces are closest.