Help with FilletEdge Error

Help with Fillet Issue in Rhino

Hi everyone!

I was trying to do a fillet to round up the inside of an object, but it makes this weird error…

On the opposite side, it looks fine, and I was able to do a NetworkSrf to give it a polished edge look. (If anyone also has tips on how to make it more organic, I’ll also take them!)

However, on this side, it creates this weird triangle error off the surface…

I tried:

  • Checking the original extrusion curves
  • Substituting the fillet for a sweep

Nothing seems to work. Any advice or help?

Here goes the file as well:
troublemaker.3dm (5.0 MB)

Hi @mara_1
The reason that the fillet is failing is because of the underlying geometry being rather messy. If the curves included are your construction lines, I’d advise to go back and clean them up by rebuilding/refitting them to tolerance, making sure that they are symmetrical (if that’s the intention) and tangent - and then try to build the whole thing with as few (and clean, in terms of structure) surfaces as possible. I’m attaching a VERY quick version, just to show you how I would approach this - I’ve jumped the fence by just rebuilding your curves, instead of re-constructing them from scratch, but notice how the sides are a single surface, instead of being made up from numerous surfaces There’s both a filleted and un-filleted version in the file.
troublemaker_JN.3dm (629.1 KB)

HTH, Jakob

2 Likes

Oh, I forgot to attach this earlier…
If you need the whole thing to be more organic, I’d go with Sub-D instead of NURBS


-Jakob

3 Likes

Why is your geometry so bad? No wonder it won’t fillet.

Thank you so much for all the help! The front part of the filleted version looks wonderful, can I ask what command you used?
I’m a relatively intermediate user of Rhino, and I haven’t tried SubD like you mentioned in a previous comment… Do you have any recommendation on videos/tips on how to start?
Again, thank you so much for all the wonderful help :slight_smile:

Hi @mara_1
It’s mostly lofts and sweeps, I think. The trick with the front part was to create a new arc for the lower “lip” of the “roof”, so that it hits the corners of the sloping sides precisely. I’m not at my computer now, but I’ll make you a short video tomorrow, showing you how I approached it - as always in Rhino, there’s at least 10 different ways to go about it :slight_smile:
-Jakob

Oh thank you so much!

Hi @mara_1
Here’s a quick video of my approach. I create a new arc on the offset version of the top surface by:
a) Placing the midpoint using the one-shot Osnap OnSrf and snapping to the midpoint of the overlying arc.
b) Creating an intersection curve between the inner wall and the underside of the top to get the end points.
c) Using Arc’s Startpoint/Endpoint/Point on to create the arc that is almost identical to the upper arc, but meets up with inner wall and front faces.
I hope it makes sense :slight_smile:

-Jakob

PS So it’s actually just Loft and PlanarSrf (and a lot of trim/split)

PPS Looks as if video isn’t working - here’s a link to the video in a zipped file:

Wow! Thank you for taking the time! I’ll watch it a few times to understand!