Comparison between Rhino and Blender SubD

Hi,

Quick test of SubDFromMesh, using good ol’ Suzanne as the guinea pig.

I’ve attached a Rhino file with some layers:

  • Cage - Mesh cage for the monkey
  • Level 1 - Blender subdivision modifier with 1 iteration
  • Level 2 - Same, with 2 iterations
  • Level 3 - Same, with 3 iterations
  • SubD - SubD object created from the mesh cage using SubDFromMesh

Some obvious areas where they don’t quite match up, so I assume the sub-d algorithms are different. FWIW, Blender uses a Catmull-Clark method. Parity between Blender models and SubD models in Rhino would be awesome!

Tom

Blender_Rhino_Subd_01.3dm (1.7 MB)

we do not have LOD’s for our subd- Only box and smooth.

Does it exist on the roadmap? Only asking because running What on a SubD returns :

Geometry:
SubD[2]: texture domain type = Unset.
Levels:
SubD level 0 topology: 382 vertices, 760 edges, 380 quads

Hi Jonathan -

Hi - we have an internal document (RH-51208) to be able to track requests for subdivision levels.
Can you provide further information on how you would use such feature and why that would be important to you?
-wim

I’m still getting to grips with SubD stuff really. At the moment I’ve been keeping the minimum amount of geometry needed for detail which has given the desired result. So I think any subdividing up to a higher poly count would only be as a means to getting the count back down again ( or subdividing locally, then drawing faces back in to amend the layout ). Can’t say its’s something that’s personally high on my list, was more out of curiosity.

without brush based tools like zbrush or 3d coat , LOD in this type of subd typically causes more harm than help…

making an massively complex subd with high LOD makes it really tough to mod with a mouse and gumball. If we had a full suite of procedural modifiers this gets more useful but that is not where we are today. We have fairly blunt tools ATM which is the bad news…the good news is sund is a 1st class citizen in rhino now and development will continue from her onto the foreseeable horizon. Will we get to brush based sculpting? No idea, but the foundation we are building here opens the possibility. It’s likely our 3rd party plug in developers will take that challenge and run with it but that is speculation at best.

However, tell me what I’m missing here in the short term … we are very interested to know where LOD higher than 1 would be useful now.

Yeah I would basically agree - craft something more cleanly with the blunt tools, which I must add are enjoyable to use, rather than just having dense geometry for the sake of it.

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Hi
So I looked up LOD and now I know what it means…
The way forward with SubD, in my view does not need to go in the direction of smaller details. but rather developing a better way to interact with these softwares the excels in those fields.
For example developing a rhino GoZ. Now with the very good quad mesh output of SubD , it can be used directly in Zbrush without modification, only divided a few times. with the lower division maintained on a live link with rhino…
so you create the part in Rhino. send in one click to Zbrush to add some small details, and back again to rhino to continue with precision modelling.

thanks a lot
akash

I would’ve said semi-sharp creases is of far greater use/importance to Rhino users, for what I’m sure are obvious reasons, to dial in and control edges in a somewhat measured manner (to remove the need for adding lots of bevels and introducing more geometry).

I’m sure somewhere I read that this is not scheduled or perhaps not even possible though? And stuff about it not travelling well into other software.

creases are a subject of much internal debate. The design folks here say we need a way to fade a crease way better than we do now (cuz the current method sucks) , the math guys say that is a big task and won’t happen for release of v7, but could happen as subd develops over service releases in the future. The more users ask for it the higher it goes on the list. I am but one (not so) humble designer…whereas you are many. Let your voices be heard-

Big task is better than impossible :slight_smile:

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Hello @tom_svilans sir,
I checked your rhino file where you have 2 models of suzzane as a mesh and as a subD model from Rhino and few layers of cage level1, level2 & level3. My question is how did you import suzzane from blender into rhino and have it as a subD model. I usually export from blender as .obj (wavefront file) and in Rhino it is imported as a mesh. I tried SubDFromMesh command on a mesh in rhino6 but it gives me a message “Use the SubD command to create a SubD from a Mesh or Surface” and doesn’t work. If you could help me on this, I would appreciate it Thank you in advance.
Regards,
Naitik

toSubD command.