Issues modeling engagement ring


I have only recently started getting onto the realm of rhino and am attempting to model an engagement ring for my partner. I have created the overall body I am looking for and just need to finalize the surfaces and add fillets etc. But I have been having a wide range of issues.

Overlapping surfaces
Cannot create fillets from geometry.
Surfaces are made up of small short curves and not sure how to create large edges from them.

Would anyone be able to give me some tips on how I can finish this off and get it ready to 3d print?
Engagement ring.rar (10.2 MB)

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@Roman2 even if the model did not have issues your design does have IMO. My tip would be to show your file to the jeweller you are intending to get to finish this ring and set the gems into it before doing any more work on this in Rhino.

He/she will give you advice on issues with it, which there are quite a few, especially considering you intend to set an Opal into it. You need to make sure that setting area is spot on for the Opal.

They will more than likely want to address the diamonds as you have them laid out as well especially the areas that border the Opal.

BTW modelling a design like this is much easier in SubD IMO…in particular when it comes to modifying it as the design evolves. Good luck.


The ring has a lot of errors in modeling from start to finish, it’s easier to make a new one than to correct this file. The thickness of the ring is too large, the stone is not even, small stones have different seats and there is no way to fix the central stone…

What are the parameters? Dimensions? etc…

So far, I believe I’ve found a few anomalies:

Next, I will check tolerances n’ such. And I’m not sure how to approach those interesting faucet srf’s, but I’ll see what happens…

Next things I’m seeing are some naked edges. These can definitely lead to some trouble:

I’m seeing a lack of symmetry in one particular spot where the gem cuts through the body edge, which may lead to some possible trouble idk:

depends on fillet locations and dimensions.

It could take an hour to several hrs or more, depending on design intent and extent required to clean up the edges, densities, etc, and make it water tight for down the line processes.

I’d recommend attempting to use symmetry as an advantage. An object like this might have a potential of two axes of symmetry – depending on intent. Theoretically you might be able to focus on 1/4 of the total geometry and symmetrize it later.

Another method I use is where I explode everything, and ‘rebuildedges’ then re ‘join’ everything to find out how tight or loose it all is. Then I see the true naked edges:

so, these would be the areas that could be leading to problematic issues down the road.

Guess I’m curious where this piece of opal came from. Not very symmetrical…

I’d probably still try making the ring and seat symmetrical. And pay attention to where the edgelines coincide:

This is what I’d focus on during a cleanup revision process, then add symmetry later to close it all up. Fillets should be more successful at that point – depending on intent.

Engagement (12.9 MB)

Hi Sochin,

Thank you for your advice I may just model it in fusion as it is what I usually use. As I think this model is too complicated for my skill level in rhino.



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Hi Cad Cam CNC,

Thank you for your help.

The stone is not symmetrical to start with meaning that the seat will have to be non-symmetrical.

The overall design intent was pretty much done just needed to add a small filet to everything to create the more rounded intended final design. Is there an easy way to fill in the sections cut out for the diamonds? So that I can fix that up? Yeah, modeling the ring in 1/4 sections is a good idea. I may give that a go.

Thankyou for your help on this.


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I’m not familiar with why that would mean the ring couldn’t be symmetrical. If you fit a ring too closely to one particular stone, it might be an issue later if the stone has to be replaced by another one with a different shape.

The seat size, imo, seems that there can be some tolerance that would allow for the ring to be more mathematically symmetrical but still work with stones that are not.

But I’m not experienced with seating stones. I’m mostly relating it to a machinist background that deals with tolerances of +/-0.0001".

I guess it depends how the stones are seated, and what the buffer might be if there is any buffer.

I’m not sure what you mean by ‘fill in the sections’? What’s wrong that needs to be fixed?

Fusion is a really gimmicky and hype-y style program. Yes it has alot of potential, and yes Autodesk is doing a tremendous job developing it. But the whole ‘cloud’ thing is a breach of security, fundamentally, and they charge an arm and a leg for a temporary license.

Rhino is perfectly suited for creating any geometry anyone will ever need for anything – unless you need high detailed meshes like those crazy voxel programs are suited for. :sweat_smile:

@Roman2 I’ve been doing some srf revisions on your part, and noticed your ‘isocurve densities’ are greater than a factor of 1. I normally don’t think it’s a good idea to have it higher than 1. What’s interesting though is it possibly helped me extract more accurate wireframes, with the workflow I was using…

I’ll probably put this to a factor of 1 while I mess around with it some more though.

I prefer seeing the true-densities while I work.

sry if I’m being too critical but , I’m willing to bet some of these bumps aren’t intentional:

also seeing some edge deviations:

just pointing out some things I might modify…

It’s interesting how the geometry on the right has a nice 0.1mm radius fillet, but the geometry on the left is merged into a single surface, but has some deviations. The design intent here may have been intended to be more consistent, idk:

I’m not sure what the intent is, but might be best to make the left side more like the right side…

The tricks I use to find details like this are:

1.) select all
2.) explode
3.) rebuild edges


although I normally work with (inch) units

I do see some other geometries that appear to be from previous state scenarios, so I’m not sure what developed over time upto recent states.

I could keep messing with your geometry, but I’ll just be guessing too much on the intents. :beers:

There’s just a few more naked edges that’d have to be addressed before filleting should be attempted:

And the big question is, what size fillets and where?