Purpose of NURBS
 

I hope this is the right forum.

What exactly are NURBS used for? I mean, I know you can make cool pictures and animations, but if you took out the poly part of Maya then you would be paying upwards of $2,000 for a NURBS modelling program. Now, are these things good for anything but having fun with, and perhaps product renderings?

What are poly's for? ;)

I say this because I generally use Nurbs 99 out of 100 times for anything I do.

As far as Maya being a Nurb's only program without Poly's, perhaps you hadn't noticed the Dynamics, Animation, Paint Effects, Cloth, Live, Particles, Character Rigging, etc. tools? ;)

Darkon

NonUniformRationalBasisSplines is a basic modelling format that is nearly perfect for organic modelling. (However, I have just begun working with Maya's sub-D modelling option. It seems to blend polygonal and NURBS modelling technique.) NURBS allows one to model complex characters and the renderer only converts the model to polys once. I have found NURBS to be a very powerful technique for modelling virtually everything that I have needed.

Nurbs vs. Poly
 

Poly's are easier to handle...while working with nurbs is more like "chewing-gum" ;O)

For Nurbs-Surfaces you need less Isoparms and CV's to get a round look whereas polys are only direct connections between the vertices. SubdivisionSurfaces have both...the advantages of poly-modelling (with extruding aso) and the perfect roundness of Nurbs-Surfaces.

Nurbs Surfaces are usually faster to render than poly one's....When rendering with Renderman, Nubs are always the better choice, because renderman doesn't need to tesselate the nurbs surface. It can handle them as they are (that's one reason why they use nurbs-patches for production). I've heard that SubD's are even faster to render than Nurbs-Surfaces....that's why they have changed the models from final fantasy later on from Nurbs to Subd's.

Nurbs are not more expensive than Polys..you can't say that.,...remember Animation master ?? A complete Spline-Patch Program as i know.

Hope this helps

b u l l e t

Wait, hold on a sec. You can render NURBS as polygons once? Does it turn it into an ultra-high poly thing?

Tesselation
 

Nurbs surfaces need to be tesselated before rendering (just take a look at the tesselation settings of your objects, turn on hardware tesselation, and you can see, what the renderer does with the surface, when it comes to rendering). An Exception is Renderman, who treats curves as curves

i dont like nurbs cos well, its like chewing gum :)

Bazooka Joe
 

Even chewing gum has it's advantages....in most cases i'm working with nurbs....prefer the floating lines, and the modelling possibilities....keeps the mesh light

b u l l e t

yeah, thats one thing i love about nurbs, denseness isnt an issue :D but it doesnt give you very sharp corners which i dnt like

It's not very often you try modeling sharp corners with Nurbs, yet people go out of there way to use Polys to make smoth surfaces, who'd a thought? ;)

Darkon

usually theres an ounce of truth in that :)

well NURBS are a pain in the arse, mainly cos you can't add detail locally, and then trying to work with patches to keep the detail local, then having to make sure they're all tangent is a nightmare.

As someone said, they render a whole lot faster in PRMan, which I guess is the reason they use them most in production, but of course now SubD's are taking over: Monsters Inc was done with SubD's too. Also Maya works a lot faster with NURBS in the viewport: Maya is designed to be NURBS software, after all you can't use paint effects on polys and fur on polys is a nightmare.

For me the best workflow is model and animate in Polys then convert to SubD's for rendering. The only place where this falls down is that polys are a nightmare to texture but in Maya 4.5 that's going to be fixed: You can convert your SubD surfaces to NURBS, which essentially means you can convert polys to NURBS! joy and rapture!

SubD's to Nurbs
 

Ever tried this convertion ? I did, and i've never seen so many patches before, after converting a subdivision head into nurbs...had even more patches than Alex Alvarez in Nurbs-Modelling 2 from Gnomon *gg*...something like 200 Nurbs-Patches...therefore: think twice before you do such a convertion, because afterwards don't even think about adding details ;O))

b u l l e t

Jeezus, knew there had to be a catch. Would it be possible to stitch some of these together? Mind you with 200, that would take ages!

Stitch
 

To Stitch them together right, you have to reparametrize the whole mesh. Afterwards the Nurbs-Object would be as heavy as if you were working with a hi-res poly object....only good for the beginning.