Fillet edging of surfaces with different angles

Hi!

It’s my first project in Rhino and I’m quite happy with the first results. But what I’ve been struggling with and got stuck with is fillet edging of the sides of the guitar body and spherical belly cut.


body+heelpocket+armrest+top_edge+belly_std.3dm (616.7 KB)

I’ve tried probably everything in a filleting tool, tried to make corners of the cut smoother, even tried to trim surfaces pipe, and add surface, but no luck at all.

Could you please help me, what I’ve missed or did wrong? Or probably there is some technique that suits my needs?

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Hi Eugene - is the attached something like what you want? I replaced the cut surface, which looks a little messy - I don’t say it is quite right but maybe close enough. For a contant radius fillet, it should be less than R=1 as you have an existing vertical fillet that is R=1. There are ways around that but for now this is .75 or so all around - are we on the right track?

body+heelpocket+armrest+top_edge+belly_std_Maybe.3dm (1.3 MB)

If you start without the vertical fillets:
image

You can do them all at once at 1.

@Eugene_K - if that ‘spherical cut’ is really meant to be spherical, you can trim out a piece of a sphere -

image

-Pascal

2 Likes

@pascal, Wow, after 4 days of struggling with the issue, I can’t believe it’s even possible!

In fact, the fillet around the neck heel should be like you did, around 0.75, and where the horns begin, it should gradually increase up to 3.175 as on the top edge. It’s not a big deal to add new handles in the places I want.

That’s how I built the belly cut following a video tutorial:

  1. Created a curve of the needed shape that is projected to the side.
  2. Split the 90-degree edge by those curves on the side and on the back.
  3. Removed the split part and created a surface by lofting with default settings.

Could you please explain what my problem was that caused the impossibility to fillet those edges? And how did you create a smooth surface for the cut?

P.S. It’s not necessarily needed to cut it by a sphere. It’s just how I wanted to explain the problem area.

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Hi Eugene - your fillet was not working because it is a bit messy right here

As for cleanliness of the cut surface itself, it looks like maybe you trimmed back the side and bottom surfaces and then lofted between them? The density and un-even isocurve distribution suggests that is likely - in general I would avoid making surfaces directly from trimmed edges. Trimmed edges are complex, and are almosat certainly not compatible, structually, with any other curve or edge, so Rhino is forced to make a dense and messy surface.

A better strategy is usually to make a surface you like from clean curves and then trim the existing surfaces with the surface. In my quick and dirty example I made a clean new curve at the base plane and extruded it (ExtrudeCrvAlongCrv)
image

-Pascal

3 Likes

Hi Pascal

Thank you for highlighting my mistakes and clear explanation of the best practices :+1:t2:

And you are right, I did built loft surface directly by the edges of cut surfaces

Kind regards!

You need to get guides (after cutting the surfaces) from the edges of the surfaces (DupEdge). Create a curve profile (possible with a radius of 2.25 (as you used)) and use Sweep2 (Sweep 2 Rails) in one direction, then in the other direction.
1 body+heelpocket+armrest+top_edge+belly_std

2 body+heelpocket+armrest+top_edge+belly_std

3 body+heelpocket+armrest+top_edge+belly_std

4 body+heelpocket+armrest+top_edge+belly_std

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Pipe trim is going to be your friend

See video-

2 Likes

:slight_smile: Just right for a beginner.