Hi Andrei,

> Because there is Surface Modeling and it is also Nurbs and allow to create
> very complex organic shapes.

Although this is sort of technically true, in actual practical use trying to do organic shapes with NURBS surfacing is a very advanced and finicky type of workflow. In the far past NURBS used to be used for organic characters too in things like Alias PowerAnimator, before sub-d modeling became generally available. But during the past 10-15 years or so sub-d modeling has really totally replaced this type of NURBS use (for organic characters), because the way sub-d modeling works is just inherently easier for organic shapes.

Continuity tools do not just automatically make complex organic NURBS surfacing very easy - even in the most full featured and super expensive NURBS tools like Alias it is still a very finicky process, it gets particularly difficult to deal with surfacing irregular boundaries and when there is pressure being put on a patch trying to make it smooth from multiple sides.

Over the many years I have been involved with NURBS modeling I have seen many many many people try to do patch-by-patch organic skins with them and only the very most experienced users tend to have much luck with it.


> Here we say that there is Nurbs for hard surface and SubD for Organic. I think
> it is right only in context of MoI

No, not at all - it's a very difficult and advanced style of modeling for NURBS, in any NURBS based program. It may be especially difficult in MoI because I have not really focused much effort on trying to support that workflow because I know through experience that it is a difficult and finicky type of workflow and so I don't really want to waste my limited development type working on something that is not a good fit for the technology. Instead MoI is focused on the areas where NURBS modeling is a natural and easy fit which is for mechanical models formed mostly through use of 2D curves. That's the area where NURBS modeling provides the most natural fit and shows its most power and modeling speed.

Different toolsets tend to be better at certain kinds of modeling - NURBS toolsets tend to handle mechanical shapes very well, while the sub-d modeling approach becomes extremely unwieldy and difficult when you want to cut a hole in something. For many organic shapes the reverse is true - NURBS modeling (in any package including the most expensive and fancy ones) struggles with organic shaping while sub-d modeling handles it very well since you can connect polygons in any kind of topology you want and have them automatically smoothed down. This is just the nature of the 2 toolsets, they have different approaches and you will have greater success and less frustration if you use these toolsets on cases where they are strong in. You will run into frustration if you try to use a toolset in an area where it is weaker. This is important advice for someone just learning these toolsets to understand so that they can use the right tool for the particular job at hand.

At some point in the future I would like to add in poly modeling tools in MoI too so that people can also do organic shapes better with MoI. But the initial (and still current) main focus of MoI is trying to make the best parts of NURBS modeling (mechanical shapes from 2D profile curves) available to people other than just mechanical engineers, because for the right type of model you can gain a huge amount of speed using NURBS and it is also a lot more accurate for making things like precise circles and stuff like that.

Back a while ago many people in the entertainment industry were saying "NURBS are dead", because they were awkward to use in 3D animation programs like Maya and Max and users struggled trying to use them for organic character shapes but were much more successful using sub-d modeling. But these tools did not focus very much on the particular areas where NURBS is actually very strong in, so many of these people just didn't know that they were not really using the right tool for the job. MoI was created in order to show how NURBS modeling can be useful and quick for many types of models, other than organic shapes.

- Michael