Indeed I'm not a tspline expert & I totally agree on that rhino is very slow compared to silo/modo etc. BUT there plenty of benefits for designer, perhaps not so many for Viz artists. ( I hope the new pixar engine for Modo will make things easier).

So yes SubDNURBS import for MoI would be great. The fact that the library comes from the same Co. as the engine MoI is using is a big Plus. (So lets hope we get it before Autodesk buys them :)

LOL that's true like what happened with Unity's Beast lighting system...

Autodesk loves grabbing up tech to store in their coffers or to squash any perceived competition!

-Will

Hi olio,

> i don't really see a difference between Moi and Rhino
> workflow, its very similar...

Well, since I designed both of them there are certainly several similarities, but also there are many differences in MoI that solve particular problems in Rhino's workflow.

One of the big ones is that in MoI you can easily pre-select sub objects like edges or faces, before running a command. That allows a command to become more context aware and work on the selection, enabling a reduction in the number of commands.

For example MoI's one Fillet command does the equivalent of 4 Rhino commands (FilletEdge, FilletSrf, Fillet, FilletCorners), depending on what you selected. That kind of concentration of functionality into a smaller number of commands has a major impact on making MoI's UI much, much less overwhelming than Rhino's.

There are a lot of other differences than that too, like the 2D edit frame in MoI that lets you quickly rotate or scale 2D objects similar to if you were in a 2D illustration program, Scene Browser that lets you have quick access to named objects and allows for actions like "hide all solids" with 1 click, a center object snap that doesn't get confused with "near" object snap, a mini dialog UI for command options with things like checkboxes and sliders rather than Rhino's text-based command-line UI, construction lines in MoI enable various kinds of snaps that require extra steps in Rhino, etc...

That's quite a lot of differences, I'm surprised you haven't noticed them. Have you not spent much time drawing things in MoI instead of Rhino?

- Michael

Hi PaQ,

> So a simple import option would be just fine in MoI I guess,

So unfortunately if the library costs a significant amount of money, it is just not economically feasible for me to license it just for a single isolated feature like importing.

I think it would make sense for these companies to make their own simplified stand-alone Sub-d to NURBS converter apps. I've suggested that to the T-splines guys several times before.


> and if edges creasing is supported it would be even better.
> (there are many way to define crease in sub-d poly modeling,
> 3dsmax can use smoothing group, modo and maya handle
> weightmap).

It can be a problem to transfer the creasing information through some kinds of export formats, like OBJ format for instance totally predates sub-d modeling and doesn't have any channel in it for defining weightmaps.

- Michael

Hi Michael,

I can understand about the price problem.
As for the format, .fbx seems fine for this kind of transfer, seems to work pretty well to export modo sub-d weight to maya.

++

OT BUT I think that is very interesting for Modo & MoI... users. Son Kim posted this @ the Modo Forum http://forums.luxology.com/discussion/topic.aspx?id=51113

[I got a email reply from the CTO Gary Crocker, it seems positive:

"Thanks for the forum post. We are in contact with the modo team about our technology. One option we will consider is a plug-in. Modo is probably the premiere sub-d platform. We are excited about the possibility of working with them.

Gary Crocker"

In another reply he writes:

"Tell me more about what you would like to see in a NURBS to Sub-D converter?

Gary"

This was a reply about my question of plugin for MOI to Modo.]

I don't really have a whole lot of confidence that the reverse direction of starting with NURBS and going to Sub-d is very feasible in a robust dependable way.

It could be possible for some special cases like when you have untrimmed surfaces. But once you have done any trimming or boolean operations, that will put trim curves on the surfaces, which means that the control point structure of the underlying surface can no longer just be used directly to convert over to a sub-d mesh, instead a completely new set of quads have to be created that attempt to follow the trim curves of the NURBS surface.

Then even after that, Sub-d surfaces are quite sensitive to the topology of the control mesh - if there is any irregularity to the topology it will result in things like ripples and bumps in the sub-d surface.

There is a good overview here on the different kinds of artifacts that are caused by poor sub-d topology:
http://guerrillacg.org/home/3d-polygon-modeling/subdivision-topology-artifacts

It's very difficult to make a clean topology with a totally automatic method, particularly with CAD models that may have a mix of sharp edges and smooth pieces as well as a mixture of small and larger features within the same model.

Here's a simple example - here I have created an extruded NURBS surface and then trimmed some areas of it away.



How would you then expect for that surface with the holes in it to be converted into a sub-d mesh?

It's going to be very difficult for an automated tiling mechanism to produce a very nice topology on that, especially in areas where 2 trim curves come close to each other.

And as you can see in the video linked to above, defects in sub-d topology result in things like ripples and bumps in the sub-d surface itself, so a conversion that generates poor topology will tend to mutate the shape and potentially introduce defects in what was previously a totally smooth extruded NURBS surface.

If that kind of shape mutation doesn't bother you, then your project probably fits more naturally just being done with sub-d from the beginning rather than in NURBS.

- Michael

And beyond just getting ripples and bumps, applying sub-d smoothing just generally produces a sort of melting effect, which means that various aspects of your model's shape will be altered in a NURBS to Sub-d conversion attempt.

So that whole process of a NURBS to Sub-d conversion would be pretty weird - things like crisp accurate mechanical shapes (which is normally what you want to be using a NURBS modeler to produce) will become kind of melted saggy things potentially with ripples and bumps in areas that used to be perfectly smooth in the original NURBS model.

Certainly there could be uses for that kind of melting mutation, but it's kind of a weird and poorly fitting workflow since the advantages of NURBS modeling are that you can produce crisp and accurate stuff with it.

If you want melted non-mechanical stuff, you should most likely be creating that as a sub-d model from the start rather than trying to use a tool like NURBS modeling that has a completely different focus.

- Michael

But the other direction, Sub-d to NURBS, as mentioned originally in this thread is much more workable because it doesn't require a completely new topology to be magically created as is needed with trimmed NURBS to Sub-d.

- Michael

Thats a really good point Michael.

It's funny how many people don't understand the fundamental differences between nurbs and poly modeling.

For sculptural work with high detail, you are going to use polys if you want to be efficient and produce the best detail. And you can program a toolpath for a CNC machine from a polygonal model. Thats the advantage of SubDs ... you can make the polys small enough so that you will never see them in the machined piece.

I suppose you could model anything with nurbs, if you made the patches small enough, and you didn't care about the time.

Chris

Hi Michael,

Yes, you are right, there are a lot of big improvements in Moi over Rhino and ofcourse a lot of things that Rhino can do that Moi can't.

But in general workflow and 'feel' than I see a lot of similarities, and that could be down to the fact it is designed by the same person:), I know I would like my products to reflect the 'feel' I am about, although with improvements:))

I love Moi & Rhino so I must really appreciate your work ;)

Thanks Olio, I'm glad that you like Rhino too! :)

Rhino and MoI actually have fairly different focus areas - Rhino was fairly focused on making things comfortable to someone who had experience using AutoCAD, while MoI tries to be more friendly to people who may not have any prior CAD experience at all.

These different focus areas have a pretty broad effect on things, like since Rhino is focused on a more technical user it is more of a pattern in Rhino to have some thousands of commands for doing a ton of different things. But MoI with much more of a focus on ease of use tries not to have that kind of complexity in it and the UI design for MoI goes much more slowly and carefully than just adding in tons of stuff rapidly... Anyway, these different focuses do lead to differences in workflow as well.

- Michael

Yes, I personally find MoI much easier to work with than other programs. I have been doing fairly simple (though some have been complex) architectural modeling for about 25 years and MoI definitely speeds up my work flow. I rarely have to revert to other tools throughout the model building process. Love MoI and it gets better and better.
eric

Just my thoughts on the Rhino vs Moi thing.

I bought Rhino while I was a student for a very good price (they let you use it commercially too which is very nice of them). I tried to learn it however and always ended up feeling frustrated, it was just too different from everything I learned up to that point.

Fast forward about 3 years and I start to realize most of my personal work (mechanical modeling, ships, cars, bikes, planes) is much better suited to nurbs than SubD modeling (I can make SubD's do what I want and need, but it is painful sometimes) so I dig out my copy of Rhino and give it a whirl. Same old frustrations. Fast forward another 6 months and I discover Moi and for the first time nurbs just kind of click. I'm totally hooked now. :)

It's also funny how learning MoI kindof opens up "RHINO"!! Although, rhino needs time put in to figure out the plethora..

True, I opened up Rhino yesterday just to see how my MOI model looked in Rhino. It definately clicked a bit more then it used to, but it's still just a massive program. I am sure if my needs ever outgrow MOI, I would be able to jump into Rhino relatively easily. I don't see that happening though as I'm not a car designer or industrial designer, or engineer, I'm an artist and I just want to get out the ideas that I have swimming in my head.

Andy

Hi Andy,

Btw, in case you didnt know, you can just clipboard copy your models/curves (ctrl-C / ctrl-V ) between MoI and Rhino ;)