Nurbs Patch Modelling, Your comments

# 1 30-12-2004 , 03:03 PM

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Hi there guys... Mike, Kurt.. Danny,, JSprog, others..,

Ok i know,,, been missing or MIA for some months now,,, hehe ok here is a question i am wanting answered or at least commented on.

I have read explored a bit, nurbs modelling seems to be a staple if you want to get into the industry, it helps to know how to handle nurbs. People still stand by it.... Hmm???

Why is that so? Is it because of the easy adjusting you can do in terms of subdivisions... detail in where you want it. Or is it a fact that renderman can render out quads as apposed to tris... like most renderers...

How easy is texturing with nurbs? Overall why studios choose nurbs modelling? Any input or ideas thrown around is welcomed.

Oh ya, when you create a full character,, in patches,,, use global stitch and so on.. the character is in different patches or surfaces. Does that mean the vertex,, are still seperate, just in the same location or ??? Seems a little confusing on the whole idea. And i want to get into nurbs modelling so that in a few years,,, if i am lucky... can get in some studio... althought poly modelling and so on i am not too worried... have so many tutorials to choose from here.

Cheers to one and all,
Merry Christmas and a happy new year... in advanced.
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Kumar

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# 2 02-01-2005 , 08:06 PM

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Well for maya Nurbs is the way to go, as nurbs is the main thing for maya.

Polys were added later for maya so polys won't be up to the same standard as nurbs in maya, not sure about sub-divs.

I've came from 3D studio max and maya doesn't seem to have any patch modeling in it well compared to 3D studio 2 different programs, that work in different ways.

Nurbs in maya is way way better than 3D studio max it seems to be much more flexiable in maya than 3D studio max, so in maya at least you'd be best to use nurbs to get your object sorted then use polys or sub-div to sort out any detail problems you might have then output the object how ever you want or need to after that.

Nurbs don't have vertex that's a part of poly modeling nurbs is based purely upon comlex maths, and that's why you'll get prefect cruves and smoother surfaces for a object where as in polys you are dealing with each and every face as a seprate item.

When you render out a nurbs object the render turns it into a poly then renders out the poly, the differeance is that the mesh will have much smaller faces thus you get a smoother looking object in the render.

The nurbs objects will be a 1 piece item not in parts so the different parts are welded together rather than left apart, this will be done so that the animators can move the objects without them falling apart all the time.

Nurbs will take longer to manage on a slower computer and render slower but it depends on what your doing, movie studios shell out heaps of cash to buy render farms and to get the right programs so they can do what they need.

Processing power isn't an issuse for them because they can simply go and buy more if they really need it, also movies need really detailed objects so they look right in the movie looking at toy story 1 and you will see textures are streached here and there.

If you look at yoda from esp 2 in star wars you won't see textures streaching and he looks real instead of plastic looking.

Shrek 1 and 2 have kept the plastic type look but you don't get any textures streaching.

In final fantasy the movie the girl was rendered in 2 parts the girls face and body was 1 part and the hair all 10,000 trands of it was rendered seprately and then added in later.

The final fantasy movie is what setup maya as a movie object/render program, as maya was made specially for this movie versions 1 and 2 weren't sold to the public as it was an in-house render for the movie and they used version 3 for the rendering of the movie and after the movie was released then then released maya version 3 to the public to use.

So if you remember final fantasy the movie it was all done by maya, and the movie paid for it's development, so it's probably had the hardest alpha and beta testing of any program.

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# 3 03-01-2005 , 04:05 AM

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The nurbs objects will be a 1 piece item not in parts so the different parts are welded together rather than left apart, this will be done so that the animators can move the objects without them falling apart all the time.

If you look at yoda from esp 2 in star wars you won't see textures streaching and he looks real instead of plastic looking.

Shrek 1 and 2 have kept the plastic type look but you don't get any textures streaching.

Originally Posted by

Thanks for the comments.. i was starting to feel i should have posted this somewhere else.

Ok, nurbs objects will be a 1 piece item,,, i have heard this on dvds and so on, then the surfaces are seperate right, because i can see them selecting it. They use the global sitch and other tools to bring their nurbs surfaces together, if they are not using a vertex,, then are the surfaces really welded together or just the handles that control the spline..

Hmm,, the yoda is a nurbs character or sub-d. All i can remember is the golum character from LOTR is a sub-d. I remember them talking about nurbs and sub-d.

So which one is the one with texture stretching, the polys or nurbs. How easy is a nurbs model to texture. i have often heard ppl saying its more difficult to texture a nurbs model.

Last edited by Kumar; 03-01-2005 at 04:18 AM.

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# 4 03-01-2005 , 04:51 AM

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Nurbs have seprate parts, the same as polys.

In polys you have 3 different parts.

Vertex (Dots)
Edges (Lines)
Faces (flat)

In nurbs you have the same thing but they are different names and work differently.

There's 2 parts to control nurbs objects.

You have nurbs curves and nurbs surfaces.

These belong to a nurbs curve.

Edit points (Dots/Vertex)

they are an X along a line and they join spans the line together you can move these edit points to change the curve, you can insert more Edit points by using the insert knot tool.

Control Vertices [CVs]

These control the weight of the curve, they control how much of a curve you can have, say if you wanted a sweeping curve you can use the CVs to change the degree of the curve. this will also change the other side of the curve as well, so it flows correctly along the whole curve.

Curve Points

These allow you to select a point along the curve you want to either snip a curve in half or to insert an edit point.

Hulls

Hulls are the straight lines that connect the CVs together.

Nurbs surfaces

Have some things the same as Nurbs curves

They have 3 extra things in them.

Isoparms (Edges)

These are the same as a nurbs curve but you can't dircetly control them, they show you the size of a nurbs patch.

Surface Points

Same as a Cruve Point

Surface Patch.

The square inside isoparms.

You'll probably find that Stiching and welding are the exact same thing, You select CVs or Isoparms and then weld those together.

You have to be careful though as you can have problems with Nurbs when you start branching things off like arms from a body.

If you watch the tute videos here you find they start off in nurbs to quickly get to the rough shape then they might swap to the sub-divs to better define the shape then swap to polys to fix up any slight detail problems or to fix up polys that arn't right, so you end up using a little bit of everything.

take a good look at the cartoon dog tute videos as they will show you how to use nurbs to make a poly dog model.

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# 5 03-01-2005 , 05:02 AM

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Originally posted by Kumar
So which one is the one with texture stretching, the polys or nurbs. How easy is a nurbs model to texture. i have often heard ppl saying its more difficult to texture a nurbs model.

Originally Posted by

The toy story movies have texture stretching in them, the texture looks blurly and stuff.

Texturing will come down to how you want to do it, UV mapping is one way there's are other ways some are good some are bad, as in they will take longer to render etc.

UV mapping is good if you want to use a single texture map for your model, that's how the game engines like to do it, you can also use single maps for an object.

Maya has a few tools to help with UV mapping as has an auto UVmap lay out thing, where it chops up all the faces and lays them out flat onto an image for you.

Or

You can use the 3D paint tools and you can paint a layout onto a texture so you know whats what, and it will lay out the seprate bits.

I can't really help you heaps as I'm only learning maya myself but I got a book to help me out with knowing how to use the tools better.

There's some really interneting things you can do with the 3D paint tool from what I've read as you can use it to see if a texture will be ok or not, and other things.

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