2011 m. spalio 27 d., ketvirtadienis

Coffee Break Tutorial: NURBS in Maya Part 1

Hey there,

       I am Dmitrij,i am a 3D designer,animator,coffee maniac and i got four dicks. And this is a tutorial about the difficult world of NURBS in Maya.

      I decided to make tutorials every now and then just to keep my filthy hands busy and help anyone who's havin' trouble with Maya's constant bitchin',though in return people will have to read through my philosophical bullsh*t about 3D,since i'm just that passionate.

     First thoughts. (this can be skipped)
     Often CG and 3D animators and designers usually think that our job is to make something using the tools at hand,to make models out of virtual mesh and then add motion to that mesh in order to create animation. But THAT is NOT our job. Our job is creating and solving problems. In simple terms here's a fictional example: A director approaches to me with an idea for the film "Exploding Vaginas from Space". Here's how the workflow will go. There are two groups of artists: Those who think everything in advance to avoid problems in the work flow and make stuff just to make production easier,these people usually stay in production houses at the lowest chain making leaves or just flowers for the scenes or bringin' coffee to their co-workers. And the other group are those who create everything properly and even more by solving problems given,working hard and drinking more coffee than seeing actual real people,these people show amazing results and get to higher places to poop on people like pigeons. So just keep that in mind.

     Thoughts about NURBS.
     Nurbs are a b*tch to handle. But they do make amazing results. The simple thing about NURBS that should be understood is that it's different from Poly modeling. Imagine a big blob of mesh or a clay ball made by whipping clay at a ball made out of metal wires. The ball form is created out of clay thanks to the inner metal wires. So to change the form would changing the the path and position of the wires,not the clay. In real life that would be impossible. But in the virtual world of 3D, these wires are the splines. And splines are controlled by the vertices or vector anchor tanget points if we're talking about Bezier splines or 3 point splines. So what you need to concentrate on working with isn't the polies or the mesh,it's the splines that create the form.

     Main aim.
     "Make a 3D Model using NURBS" is a funny project cause what people tend to do at first is open menus from Polygon tab and make a sphere from the Create NURBS menu.

That is the usual mistake. When the right option would be turning on the Surfaces menu tabs. And concentrating on the Curves and Surface tabs on the lower menu.

And don't f*ckin' judge my blue highlighting,this is my tutorial,i'll do whatever the f*ck i want.

Anywhore,let us get on to the actual practical tutorialism. Though do keep in mind,the amount of information of working with Nurbs here will be limited to allow you to work your big fat hands to a simple project. I won't get in to super extreme details of working Nurbs out in to one of your new virtual girlfriends.

Part 1. 
You can simply make a model with polies and then convert them to NURBS

It should be easier to do that,but you it won't be. Simply enough the developers didn't plan on making a function on coverting polygon models in to NURBS cause there's no real reason for that,cause if you made a model out of polies,why would you want it to be a NURB. I don't actually mean you can't do that. You can. But it'll just make problems for you and all of that sh*t i wrote and you had to read till now became a waste of your life. Huzzah!

REAL Part 1.
This is real but useless.

Make a NURB primitive and try editing its' control vertices or isoparm. Also,a bonus to this method is that you will burn in hell.

Part 2.
Make your own NURB object with the following functions:
1. Revolve
2. Extrude along a spline
3. Create geometry between curves by lofting

Part 2.1 - Revolve

Thing about Revolve is that it uses a shape of a spline and revolves it around a particular axis to create a shape. It's useful if you want to make a lamp,vase or a dildo. Simple enough.

First thing needed for this is a spline. In the example i made a bezier spline in a shape of a.....sock.

I know,my art is beautiful. Next thing to is to select the Revolve function in the Surface Tab in the upper menu.

Sexier than life itself. I know. So as you can see i made this mushroom like object with my spline revolving around the Y axis. But i want to make a lamp out of this instead. Right Click on Object > Control Vertex.
As you can see,i am now in control of the vertecies of my spline and i can move them about. And since the spline created an object by revolving,the changes will occure around the model,just like global warming.

Move some there and move some here. And as you can see,by editing the spline i edited my object and i have something similar to a lamp.

Part 2.2 - Extruding along a spline

There are two ways you work by extruding along the spline. First one is similar to Revolve.

Firstly i'll make a spline.

Pssssst! I wanted to make an elephant,but it didn't work,so don't tell anyone! Anyway,i made this open spline,again,with bezier spline creation tool. After that i would make a circle spline.

Back to the Surface menu>Extrude.

Sexy buttons of Maya! Ah yeeeeah!

As depressed as Maya can seem right now,this is what you might get. I actually don't advise using this method cause it can often screw up on you and you can get a better result in Loft,but heck.

The useful part about this technique is that you make a linear change to the model by editing the control vertecies on the circle spline.

That was one way to use extrude. Which you should burn out of your brains and never remember again until it's time to bury your own family. Now let us move on to the proper way of using Extrude. I made a spline. Again.

Made a circle at the beginning of that spline. And then adjusted the vertecies on that circle to a custom form cause i'm too lazy to make my own shape.

Now extruuuuuuuuuuuuuuuuuuuuuuuuude~

I did that randomly to be honest,but heck,that looks like a children's slide,so might as well do it properly now. Make more splines,says i,and extrude them the same way!

Now here's a little problem for the extruded object. When you extrude something,the pivot is always in the center of the world axis. Press Insert and you'll be in Pivot orientation mode. Move the pivot closer to your extruded object. It's always usefull to do this cause,y'know,we're supposed to be proffesional and organised.

Press Insert again to get out of the Pivot orientation mode. Now select the extruded object,together with the circle spline and the bezier spline, and duplicate them all together with CTRL + D and move them to a proper position for our slide. Continue the spline explotation.

Huzzah! We finally got this lovely slide! It is monstrous and horribly lookin',but the f*ck do i care! I'll love the way it is!

Part 3 - Creating geometry between curves by using Loft

Observe as i create this wiggly spline and duplicate it!

Now by selecting the Loft option i can create geometry between these splines.

Now the funky part about this is that you don't need to really touch that extruded object,it can be deformed just by customizing the splines. Now loft is the most popular function for Nurbs simply enough that it can already do what other functions can do. Also,you can shoot the loft through several splines to get  ahold of more control over the generated mesh.

It looks like a curtain.
Simple tools and useful in a lot of ways.

Now this is as simple as drinking cyanide. But how do we edit these created meshes in to something sexy like a virtual girlfriend,which,i shall add,you will NOT do,for if i find out that you use 3D for being a pervert,i will go to jail for murder. Enough talk about weather and politics,let's move on!

Part 3

Now editing your Nurb mesh will excite you till you throw up dead babies. Fun!

But let's take a quick coffee break here!

How have you guys been? How's the course? Fun?

Hey,i got a 3D joke for you! Ask me what i did last night?


I boned some models! Zing! It's funny cause perverts bone prostitutes by having sex with them and in 3D that's what they call putting bones in to a 3D model! Funny,eh?

Here's another one!

If you're not in to the whole "boning model" thing,you get to skin them! Zing! Get it? Perverts skin prostitutes by tearing off their skin while in 3D that's what the call putting weight connection between bones and the mesh!

People find that weird when i tell those jokes to 3D buddies in a cafe,i might get arrested for that some day hahaha!

Alright,that's enough of that! Let's continue the mental NURBS rape.

For all the examples i will use just a NURB primitive cylinder cause i'm just gonna show you how you can edit the NURB objects.

Here's my sexy cylinder.

I made him myself! Be proud,mom and dad! Let us go through basic "rape" techniques you can use to defoul this little weak creature of 3D.

Make a circle spline and shape it in to a heart.

Why a heart you might ask? Cause that is what keeps our girlfriends in the kitchen,boys! Zing! Now select both the heart and the cylinder and in the upper menu in the Edit Nurbs menu find Project Curve on Surface.

You should get something like this.

This function generated some new geometry on the surface of our cylinder. BUT do keep in my that sometimes you might want to change the viewport in the way you want it to be projected,for example here i went to FRONT view. Do keep in mind it goes through the whole model. Otherwise the shape can just be projected on the side of your model in weird shapes. Now select the Cylinder and open Edit Nurbs menu and select the trim tool.

You should see something like this.

Press once on the cylinder,BUT any place EXCEPT the heart ones. That way you selected the mesh that belongs to the cylinder. The heart shapes are separate NURBS geometry. Though the trim tool can work by just selecting the heart shapes only,instead of the cylinder,just so that you would know. Now press Enter,you should get something like this.

Just so that you would know,you can always undo that trim with the Untrim Surfaces in the same Edit Nurbs menu.

Sweet! You can also move around the basic heart shape and the projection will move around the model the same way. Now let us continue experimentation. Right click on the model > Trim Edges. Select the hearts counter.

Now go the Edit Curves menu and select Duplicate Surface Curves.

Now you've created a Spline on top of that curve,move it a bit to the front.

Now select this Trim Edge on the Cylinder and then also select the new spline with jest made. After that Loft them. and you get some new geometry now.

That is the magic of how useful can the trim tool can be useful.

That is all for today,i will finish the rast of the editing options for the NURBS tommorow and do a demo video of me modeling in NURBS.

"Think you got what it takes to be "creative"? Then welcome to the other side of sanity."

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