8 replies to this topic

[bongo]

This might be kind of a broad topic here but I'm sure it will help alot of new people to 3d too.

So What's the difference between Poly modeling and Nurbs modeling?

how are they used in the industry??

Are certain objects more easily modeled with Nurbs and other objects with poly modeling? does it work like that or do all objects work with either way and it's just a matter of preference?

I heard nurbs is good for smooth objects and polygon modeling with everything else. Is this true??

[stevehewitt1950]

It's quite a lengthy answer. Which industry are you talking about here?

[spedler]

In a NURBS modeller the model essentially consists of curves/lines which are described mathematically rather than point-by-point as in a poly modeller. This makes it much easier to implement things like booleans (a staple of NURBS modelling) and filleting, things which don't work quite so well in a poly modeller.

Because of this, a NURBS modeller is much better used for hard-surface modelling, such as mechanical or man-made objects. It would be very difficult to model a human head in a NURBS modeller, although people have done it. A poly modeller is much better suited to organic models. To use a NURBS model in a poly modeller, you first have to convert it into a polygon mesh, and the quality of the mesher is critical to how well this works; you don't want to have to spend a lot of time cleaning up imported meshes.

A NURBS modeller makes an excellent partner for a poly modeller like C4D. The quintessential NURBS modeller is probably Rhino, but that's overkill in some ways for C4D users, and a better (and much cheaper) choice is MoI. Once you've used MoI to model a mechanical object you won't want to go back to a poly modeller for that. Its mesher is superb (better than Rhino's) and it makes a great adjunct to C4D.

[tarc]

Hi,

Steve has described it quite well, some things are way faster to implement in Nurbs, but it may lack flexibility if you want to do organic stuff or a subd oriented model.

I second Moi3d, a fantastic modeler with an awesome mesher.

To know each protocol's strength is another feather in your modeling hat and will get things done faster.

Tarc

[hulaboy]

As far as 'industry' goes, it might be reasonable to say that things which are to be manufactured are almost always designed using NURBS-based software, which is inherently more mathematically precise when describing complex geometry. Poly/SDS modelling is much more widely used in the sphere of CGI for entertainment and illustration, simply because it generates much 'lighter' and more flexible geometry.

One thing you should not do is to mistake Cinema4D's 'Hypernurbs' modelling procedures for true NURBS modelling. In general, 'Hypernurbs' is simply MAXON's marketing term for Subdivision Surfaces, although the parametric nature of the combination of Hypernurbs objects with splines does mimic basic NURBS functionality to some (limited) degree.

Mark

[bongo]

Thanks guys, you gave me alot of advice. By the way, is there any plugin to cinema 4d that gives access to nurbs modeling? If there is, i won't have to buy, install, and learn the interface of an entire new program like Mol or rhino

[spedler]

No such plugin AFAIK. MoI's interface was deliberately designed to be easy to use for 3D artists rather than CAD users. It was written by the same programmer who did a lot of the work on Rhino, so he really knows what he's doing. Writing such a thing is very complex and if there was a plugin, it would be almost like a new program anyway.

Why not download the MoI demo and give it a try?

[bongo]

ok thanks for all your help

[3DKiwi]

We even have a couple of MoI tutorials here by me.

3DKiwi