Question from Subd modeler (Modo)

I think about buying Rhino license (I`m after trial). I have many subd meshes designed in Modo and Zbrush (mainly for 3d printing). I would like to mix them with nurbs and do some cad operations.

Please tell me (or better show me) how looks Subd conversion to nurbs in Rhino 7. Is it dense?
I would like to import many subd meshes and do booleans operations on it in Rhino 7, next maybe fillets after that and thickening (for 3d print). Is it an easy process in Rhino 7? Or rather problematic with full of errors?

How Rhino 7 handle Booleans -> Fillets -> Thickening on Subd meshes with edge loops (almost hard edges)

I’ve attached my sample mesh only to show how it’s complicated. There is a lot of edge loops (subd creases) for almost hard edges.

Modo is IMO best Subd modeler with workplanes, falloffs and procedural meshes.
I think it would be great to model those things in Modo and then import it to Rhino to do booleans, fillets and thickening on it. With current subd tools even mesh edition would be possible.

I hope that soon in Rhino 7 those both worlds will mix together seamlessly.
Make CNC routing on meshes is hard but making iterations and fast prototypes are very fast in subd.
I hope that I will take Zbrush+Modo+Rhino and mix them together.

Thanks for any help.

Maybe I will be more specific.

I`ve uploaded two files with subd meshes. Like I showed below:

Is it easy in Rhino 7 to make booleans addition on those two meshes and then do some fillets like I`ve shown below:

After that, I would like to thicken that mesh to 3mm and do some 3mm hole in the bottom.

I would like how easy that process is in Rhino 7. Is it easy or there is a mass of errors which have to be manually corrected?
That example will help me to understand it. Is it ready for mixing those both worlds or not yet :wink: (5.9 KB)

There are a few ways to solve this. While I haven’t downloaded your files, I tried myself with similar geometry.

First approach was with a sphere and three boxes. I split the surfaces a few times to make Quad Remeshing easier and then booled all the split surfaces. Quad Remeshing takes some trial and error but the SubD mesh on the left is created that way. It’s fairly easy to create a SubD that way.

  1. If you want a SubD with the least number of faces, starting with a SubD Sphere would be a quicker solution. You can split some of the faces and extrude them to create your shape. Thickening is easy. A hole could be create by deleting some faces and bridging the edges. Or you type ToNURBS and you can use the Solid tools to create a hole. Filleting hole edges can result in problems depending on radius and proximity to other edges.

If you use Quad Remesh and create a SubD with a lot of faces, you will run into issues with self intersections, should your offset / thickening be too much.

20_03_06_mrtn_subd.3dm (1.3 MB)

Thanks for reply.

First of all sorry for error inside cross mesh (I`ve uploaded it again).

Maybe that example wasn’t good (it wasn’t complicated enough) because Ive done it in MoI3d v4 (import those both OBJs as subd to nurbs-> booleans -> fillet -> thickening -> carve the hole) without bigger problems (it's not a solid - only one problem but its my fault).

I want to import to Rhino 7 many complex subd meshes with edge loops and creases. Next I would like to convert them to nurbs. If I will have nurbs then I would like ONLY to boolean it, next do some fillet on edges and make thickening in the end (or carve a hole in it but not as subd). Meshes are complex as in my first post.

If I would do quad remesh on my grid from my first post then I would loose all details which I’ve created in subd. I know quad remesher from Zbrush and it’s mostly good on triangulated meshes (f.e. 3d scans).

example.3dm (3.2 MB)


example.3dm (2.0 MB)

@Inju - Thanks.
What type of item is the cross. It doesn`t look like subd? I can’t see thickening in the hole also.

I’m after Rhino trial and I can’t open it. MoI3d won’t open Rhino 3dm also (I`m MoI3d user also).

See the example.
I can do the thickening, it’s not a problem for Rhino 7.



Thanks again

Can Modo or Zbrush export a facetted view of a subD object as a mesh?

Importing that to Rhino and running _toSubD should work pretty well. I’ve done it with Clayoo objects with pretty good results. Not perfect, but easy enough to repair the few errors in the object after import.

OBJ always is exported as facetted mesh (not smoothed with subdivision surfaces). Subd is software feature, not a file feature. So yes. Export from Modo and Zbrush is always in that way. Please look on my both OBJ above. They should look facetted. I exported those both from Modo.

Below you can see how this subd mesh is exported (it`s not smoothed during export):

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Take a look at the Rhino plugin
There is also a stand alone product that does not need Rhino.

Thanks. It looks similar to Topology Pen in Modo:

I know that this has more features than pure manual retopology. Automatic reshape is avaible in Zbrush (named Zremesher). There are also free remeshers in Blender and standalone Instant Meshes (

I like those features of Mesh2Surface which helps draw circles and flat planes.

I`ve thought that I will be able to do retopo in Modo (like I showed on youtube above) and after that import those subd (facetted version - unsmoothed) meshes into Rhino 7 to do some operations on it.

What kind of object Mesh2Surface produce Subd or NUBRS (or both)?

It makes a nurbs surface.

This is a reverse engineering job, your mesh model is essentially scan data (although you built it manually).

What if I will import similar retopo (reverse engineering) made in Modo polygonally as subd mesh to Rhino 7 and convert it to NURBS. Will it be same functional as those meshes created by Mesh2Surface plugin?

I’ve made many polygonal retopo of 3d scans so I think it`s similar. Mostly to fit new designed parts to other design.

Below you can see my hobby (free time scan and subd retopo - unfinished):

Will I be able to convert it to fully functional NURBS in Rhino 7 (without heavy work)?

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I don’t know if Mesh2Surface is using subd for its automated patch construction.

You would probably want to define the conversion manually and then use trimming and fillets to provide the best quality CAD surface.

Since the rounded edges are already baked into your mesh, you will have fewer options I think.

I don’t fully understand but I can see it’s not a straightforward process. I’ve thought that if Rhino 7 has so many subd features than that coversion is almost seamless.

So I`ve thought that if I will import final complex subd model to Rhino 7(facetted but with additional edge loops on creases - ready to subd smooth) then it will be very easy to boolean it (same as native NURBS), fillet it (same as native NURBS) and thicken it (same as native NURBS).

I would like to know it before I will buy license :slight_smile: that’s why I`m asking

I like to build my subd meshes in Modo. I would like to have easy and EXACT conversion from subd polygonal meshes to NURBS which will have same functionality as native one (booleans, fillets, thickening). I don`t want to fully rebuild my designs. I would like to import it and use it in Rhino.

I understand that maybe I`m a dreamer :wink:

Rhino has a Clayoo plug-in (works in 7 WIP), can convert mesh, nurbs and subD, as well as supports manual retopology.
This organic model was made at Clayoo’s Rhino.

Thanks for that link. Your work is amazing also. Have you done it as subd?

That’s all nice but I have all that tools present (subd) in Modo and few others in Zbrush. That plugin cost is almost same as Rhino. I don’t need 90% of those tools because my subd are ready during import. I need only make boolean on it, fillets and thicken it. Is there any way to do this without this plugin or it’s a must to do what I`m asking about.

Maybe in other way, below you can see my coat of arms in subd.

Every feather is a separate mesh item. I would like to import it to Rhino 7 and change it to NURBS (do booleans, maybe do some fillets also and make proper thickening). I would like to do this to give that file to CNC milling (they need NURBS file to make a mold). Is it possible without Clayoo?

I have 4hrs ban (too many posts for fresh user :slight_smile: )
Below I uploaded feathers in OBJ and 3DM from Modo :
Eagle (123.3 KB)