Maya for 3D Printing - Rapid Prototyping
In this course we're going to look at something a little different, creating technically accurate 3D printed parts.
# 1 03-09-2004 , 06:34 PM
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nurbs/polys...

hey, could anyone tell me what is better to create models of characters with? nurbs or polygons? im not so sure what the difference is betewwn tehm both.
thank you

# 2 03-09-2004 , 07:04 PM
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it's good to know both. Having said that, I prefer polygons and recomend you use them first as they are easier to work with in my opinion.

# 3 04-09-2004 , 06:02 PM
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I find NURBS are the best way for me to quickly prototype shapes that have a lot of curves, such as organic character bodys, the outlines of vehicles or landscapes. You can draw the curves freehand, duplicate, adjust, and then loft the shapes you want. You can easily modify the resulting shapes by tweaking the curves.


Scratching out a head with NURBS though is a bit odd and counter intuitive. You can build a face very quickly by manipulating a NURBS sphere, but as you add other NURBS shapes for eyelids and ears you will probably wish you started patch modelling from the get go. I find Polys (starting from a primitive) better for character faces and much better for hands and such. In fact, I wouldn't advise trying to build hands from NURBS at all. A NURB is basically a rectangle at the end of the day with a single pole you can shape round (spherically or cylindrically), they're great and simple, but not so if you want multiple appendages from the same surface (you only have one 'hole' on a pole, whereas polys can grow from any face or edge). POLYs are excellant for heads, hands and feet though. For example to create a character I rough out the torso, legs and arms with NURBS. Then I convert it to a Poly object keeping all details and standard fit. Then I use the poly shape to 'grow' the hands and wrists from, then the head. Then I convert to SUBD, to smooth it on the cheap processor and performance wise, and add details.

Furniture, interiors, buildings, polygons rule, no question, they are very quick to use. I'd also say you do need both. As Polys have been around a lot longer the tools to manipulate them are very many. On the whole I find I start with NURBS as outlines and then go to polys as I said above. Also, animating and rigging a poly object is a helluva lot easier than NURBS I've found.

This is just my opinion though, the only way is to get a grip with all 3 approaches Nurbs, Polys and Subds and develop your own workflow for each 'type' of model you create,


Last edited by geezbtw; 04-09-2004 at 06:12 PM.
# 4 04-09-2004 , 06:52 PM
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I myself haven't really explored sub-d's yet, but I must say I totally agree to mike here that polygons are the easiest to work with for most projects.

# 5 05-09-2004 , 08:15 PM
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NURBS THINK RUBBERY (organic) . . . . POLYS THINK SOLID (non-organic)

When animating WITHOUT painting weights you can vividly see the difference. A poly will crease at it's edges where a nurb "does not crease at its isoparms"

TO SEE IT: Create a nurbs cylinder scale up in "Y" to about 6.
In inputs: set sections & spans to 8 & 8. In skeleton > joint tool Place about 6 clicks top to bottom in your SIDE view, > enter, have skeleton selected, shift select cylinder. Go to skin > bind skin & ridged bind. Select some middle bones & pull.
Move it out of the way in all views & do the same for a poly cylinder, in inputs you change subdaxis & subdheight to 8 & 8. You will see the creasing.

Smooth bind would give better results for a poly. Try it. But when you give extream bends with edges in the way you will still notice a slight kink. Painting weights will help here.

# 6 05-09-2004 , 08:37 PM
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Originally posted by DrMayanstein
NURBS THINK RUBBERY (organic) . . . . POLYS THINK SOLID (non-organic)

here.

i disagree..
look at studio tools or rhino or other CAD softwares,
that are primarily design tools for hrad surface and general products, and use NURBS. not becasue NURBS are "rubbery" but they allow the flexibility and control for different surface types. a poly or subD model can look just as good as a nurbs patch model. it's really up to the modelor and what he/she feels more confortable with.


Last edited by vladimirjp; 05-09-2004 at 09:36 PM.
# 7 05-09-2004 , 11:01 PM
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I agree with Vlad. I do all my characters and stuff with polys. user added image

# 8 06-09-2004 , 12:32 AM
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Hi guys, Was just trying to give a generalized meaning. Not have a debate. There's enough of that going around. I agree on the modeling issue. It's the animation afterwards I was refering to & not all animation but as Iv'e said before, there are many ways in Maya to create the same thing.

How would you create a pyramid. 3 sides & a bottom. Take it another step & make it equalateral.

By the way I respect both of your guys imput on the site.

# 9 06-09-2004 , 04:59 AM
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thansk!

hey guys, you have all been so much help to me,
im trying to leanr it all too fast i guess...BABY STEPS!!
thanks for all the input i think so far the po,lys pretty easy to me so ill go for that first then move on up!

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