Maya Curves - How to define faces?

Below was my initial question, I think there's a lot more inormation in here from Chosen Few that other's could use on various aspects of Maya... I hope my questions and her answers help everyone!

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Hey all. I've been watching a number of tutorials for NURBs in Maya. Particularly the Curves feature.
I found this tutorial while searching for some help:
http://webpages.charter.net/talilal/Balloon%20Tutorial
so I know somehow it's possible, I would just like to know... how. So. I know the rule of 32, 16x16 spans & sections when it comes to the sphere... ala courtesy:
http://www.landgasthof-waldschaenke.de/sculptytutorial/quick_maya_sculpty_tutorial_v1.1.pdf
How do I define the faces regarding curves? They're much easier to work with and shape as opposed to wasting so much time pinching and pulling basic shapes.

Anyone care to help? I would be most appreciative (pleasepleaseplease<3)

It looks like you've actually got more questions than I think you realize. Allow me to chop up your post a bit, to try to isolate each one. I'll start with the one in the title of the thread, and go from there.



I'm not sure what you mean by "define the faces". Can you explain?

For now, let me point out that NURBS surfaces do not have "faces", per se. They have sections and spans. The entire surface is considered one face. The isoparms that appear divvy up the surface into sections and spans are not the same thing as the edges that divide the faces of polygonal surfaces. They're just there to provide a basic control framework, from which the actual surface is interpolated. They're factors in an equation, really, nothing more.




Lofted surfaces can be a little tricky for sculpties. It can be done, but you have to be really careful in your order of operations, and you have to keep it relatively simplistic. You're far better off starting with a primitive that you already know works (sphere, cylinder, torus, or plane), and then deforming it to make the shape you want.

If what attracted you to lofts was the ease of use in editing control curves, you can get the same type of functionality from hulls. Simply go into component mode, and turn on hulls in the selection mask at the top of the screen. You'll now see lines connecting the rows and columns of control vertices. Click on a line to grab an entire row or column (hull), and then scale it, rotate it, move it, etc., just like you would with a control curve.

And if you take the extra step of learning to use deformers, it gets even quicker and easier. You'll find deformers in the Animation section of Maya, which may seem a little strange, since you'll be using them as modeling tools. They fit both categories, really. They're very powerful animation aids, but they're also fantastic for modeling, especially for NURBS modeling.




I'm not sure to what "rule" you're referring. If you're thinking in terms of polygons, then yes, a source model for a sculpty should have 32x32 quadrangular faces, and in the exporters for programs like Wings, those faces are pre-defined. But that doesn't really have anything to do with the way the Maya sculpty exporter works. Since it's optimized for NURBS, it samples the shape of the surface. It doesn't really care exactly where the vertices are. What it cares about is the surface shape that happened to result from wherever you happened to place the vertices before it got involved.

That said, it's generally not a good idea to use more than 16x16 sections & spans. In actual practice, you can use as many or as few as you want, and it will still work. It's just that the sculpty exporter won't be able to preserve all the detail if you use too many. Remember, it's translating a NURBS surface with infinite resolution to a polygonal surface with a (very low) fixed resolution. Some restraint must be practiced if you want the translation to be accurate. 16x16 sections & spans works flawlessly. Any more, and you're taking a risk.



From Wings, you probably have a pretty good understanding of polygonal modeling practices. That's a bit of a different animal from NURBS modeling. Many of the principles are similar, of course, but be prepared for the fact that you've got a lot of new rules and new techniques yet to learn.



Again, I'm not sure what you mean by "define the faces".



Again, explore the use of deformers. Once you get used to them, you'll find them to be significantly faster and easier than lofts for this kind of work. And for bulk editing of rows or columns of vertices, again, use hulls. That's what they're for.

For what it's worth, you seem to be discovering NURBS modeling the same way I did in the beginning. My background was as a 2D artist, and to me, using lofts felt a lot like drawing. The curves were the "lines", and the lofted surface would be the "coloring it in". I used to loft everything.

Then one day a friend turned me on to deformers, and I've never looked back. Getting used to them requires a little bit of reversing of your thought process, but once you make that transition, I'm sure you'll agree that it's a better way to work.



The most common cause of distorted sculpties from Maya is simple user error. You must remove all history and transformation data from your objects prior to export, or the sculpties will most likely come out wavy or lumpy. Here's what to do:

1. Highlight the object(s) you want to export.

2. Click Edit -> Delete by type -> History

3. Click Modify -> Freeze Transforations

4. Click Modify -> Reset Transformations

5. Click Edit -> Delete by type -> History (again)

Removing history tells Maya that the state the object is in now is the state it's always been in. You're effectively erasing Maya's memory of the steps that were involved in creating the shape. As far as it knows, the surface was just born that way.

Freezing and resetting transformations tells Maya that the object is default size, default location, and default rotation. Basically, Maya now believes the object's size is 1x1x1, and that it's location and rotation are 0,0,0.

Forget to do any of those steps, and your sculpties will more often than not come out messed up. Remember to do them every time, and you shouldn't have any problems.

If you're already doing all that, and your sculpties are still coming out messed up, then my next guess is it's got something to do with your lofting technique. Try importing something not lofted, like a simple elongated sphere or something, just to verify that it works at all. If it does, then you know the lofting is the problem.

I'm afraid I don't have much specific advice on how to avoid common pitfalls with lofted sculpts. I don't use lofts for sculpties myself. If you describe your technique in detail, though, I could maybe pinpoint the trouble spot.




Good strategy. I only wish more people were willing to go one step at a time.

Whoo! You rock Chosen :3 thank you so much. I edited my post as you were replying, sorry about that XD; I thought it sounded too mixed up rather then the simple create/export technique I was looking for. You've helped a lot though! I did try to just illongate a sphere and used the advanced export tool, like so:
http://img.photobucket.com/albums/v38/neko-vamp/SculptProcess.gif

unfortunately, it came out with a weird taper:
http://smg.photobucket.com/albums/v38/neko-vamp/?action=view&current=Sculpt.gif
(primscripts only used for baking, right?)

that sculpt behind it was a random object I made after noticing there was a spans definitive during lofting.. and I restrained the EP Curve I was creating to 16... so I made all lofting and curves 16. I used the Bend Fillet tool as well, to get a smoothe connection, but unfortunately there was no controlling the spans in that. It seemed to preset itself to 2 and 40... hmm. You're absolutely right, trying to do this with a 2D mindset can be rather complicated.




No explanation needed, really XD; I'm no friend to 3D terminology just yet, but you targeted the definitions precisely. I downloaded the 2009 Maya .mov tutorials to help learn to deform objects, which I've been referring back to a lot, the Fillet and Loft seemed the quickest way to making what I needed... that is, a bow. Just the swoop part, like this:
http://img.photobucket.com/albums/v38/neko-vamp/loftybow.gif

I didn't bother paying attention to any of SL-Maya requirements when I made it, being that I didn't know much of it (<3 thanks for helping me with this)


Actually, I did throw my hands up at one point before work today to play with a torus, but it seemed to work similar to a curve, the span/sections weren't properly able to be defined, only visible once you've placed it. I'll experiment more with this though.



Thanks! The videos I have didn't go into too much explanation of what Hulls could do :3 I'll play with them as well.


hmm, I skipped over the Animation tutorial vids thinking I couldn't use any of them, I'll go back and check them out. The guy made a couple references to some tools in NURBs that were readily used for animation :3



Exactly. I've been on so many different How-To/HelpMe! sites, I couldn't tell you how many times 32 and 16 came up. I stopped using Wings3D early on to switch to Blender(which was a nightmare just staring at the interface), to Lightwave. Ggood program, but I heard Maya is optimal for sculpties... so I figure starting with a not-so scary looking Maya would be best. I'm surprised there aren't too many SL tutorials regarding the program :x I'll have the terms down to a fine art before the month is out!



I know, the introduction to NURBs was very interesting, unfortunately it's gotten to be a greater feat then I'd anticipated XD; I will learn!



I'll definitely have to try this out too! (/is so going to veg here for a week with this)

To fix the rift in the sculpty shape, rotate the map 90 degrees in any image editing program. In the future, make sure to check the Correct Orientation checkbox in the exporter. That's what it's for.


Primscript is for automated assembly of multi-sculpty objects. Basically it records the relative positions of all selected sculpties in the scene, so that an assembler app like importprimscript or Qlab can place the sculpties in the same relative locations in-world. For more info on that, read the article where you got the advanced exporter script. It includes instructions to auto-assemble the ant example. (Note, Qlab may or may not be working at this point. Working versions of importprimscript are on the wiki.)




Two words: Options Box. Just about every tool in Maya has one. To the right of most menu commands, you'll see a little box icon. Click on that to bring up the options for each command.

For example, if you click Create -> NURBS Primitives -> Torus Options Box, a dialog will appear with all the variables involved in constructing a NURBS torus. If you don't know what anything is, just click Help at the top of the dialog, for complete explanations. Maya's help is fantastic.

Don't fret if you create something with the wrong options. Until and unless you delete history on an object, all of its creation inputs are changeable, even though it's already been created. Simply grab the object, and then open up the Channel Box. If you inadvertently created that torus with 116 spans instead of 16, just go to the makeNurbTorus node in the Channel Box, and make the appropriate change there. Since you're editing the input, Maya will believe the new value is the one that has always been there. Half of the genius and true power of Maya is the way construction history works.




Don't skip anything. It's all relevant.





What's "optimal" depends on the user's preference. I use Maya for sculpties because it's what I know and like best. It also happens to be what sculpties were first developed with. But if you happen to like Lightwave or anything else, you'll do just fine with that. They all work.

In some ways, the sculpty scripts that have been developed for programs like Blender and Max are actually far more sophisticated than the one for Maya. In other ways, the Maya ones are better. It really boils down to how you prefer to work, and what kinds of things you want to make.





Again, great attitude! It sounds like you're having a lot of fun with each new discovery. Like I said, I really wish everyone would look at it that way.

So everything's looking good so far! I made a broom stick the other night out of a cylinder. Due to the two ends being flat surfaces, it wouldn't let me export it as one object, error reading: "Object list must contain a surface and a texture".
When I deleted the two capped ends, it exported fine, I just pinched the sides to close it up :3

I would like to know though the nature of that error and why it reads surface/texture over the two end caps and not the rounded shape itself? or maybe it's because it's all "unlinked"? Is there a way to mold together the surfaces, like I was trying with that bow, or will it distort the vertex parameters?

Another question I had, when I uploaded the stick sculpt into SL, it was.. rather tiny... I tried making the actual sculpt in Maya much larger to see if that would work (I know it was a little common-sense that just rescaling it in the same program wouldn't do anything XD; but it couldn't hurt to try.) My concern about getting it bigger is this:

http://img.photobucket.com/albums/v38/neko-vamp/Sculptyloadref.gif

The left one is the one I made and the right one is one I bought. As you can see, scaling it to a proportional avatar size (the stick figure) makes it load as one massive bubble. For faster connections/gfx cards that shouldn't be a problem for more then a couple seconds, but having experience with a slower computer... I don't want to start making things on a selling-level and have them load so... gauntly, slower connections having to walk around with a tumor on their hand :\
The right broomstick is an observational know-how that it is possible to have smaller load bubbles, or bubbles proportionate to the sculpt-size, but how? @_@

That's how to do it. Don't use end caps. They're not readily sculpty-compatible. If you really, really want to, you could make it work, but it would be a waste of time and resources.



The specific reason for the error will depend on how you created the end caps.

If you gave the caps separate transforms, take a look at your hypergraph. You'll see that the caps are children of the cylinder. The error is telling you you've got something other than a surface selected, because it doesn't know how to recognize children. It doesn't understand hierarchy at all. It just knows is you've got something selected that it doesn't understand. The wording of the error message doesn't make that entirely clear, but that's what's going on.

In order for it to work, all objects to be exported must be ungrouped and unparented. Middle-drag the caps out from underneath the cylinder in the hypergraph to unparent them, and they'll export just fine. I still wouldn't recommend using them, though, because as I said, they're a waste of resources. Each cap adds one more sculpt prim, and 2048 more polygons to your model, whereas pinching an edge to form a pole adds nothing at all.

If you didn't give the caps separate transforms, then they're sharing transforms with the cylinder. In that case, the exporter has no prayer of understanding them at all. It's got no way of knowing what they are if they don't have their own inputs and outputs.

The same error would trigger, by the way, if you'd selected a light or a projector or anything else that is not a surface. The wording of the message would make more obvious sense in a case like that, of course. But either way, the point is you've got something selected that the exporter doesn't know how to export.



You could attach the surfaces, but it would be far more trouble than it would be worth. It's much easier just to start with an uncapped cylinder, and then snap the top and bottom vertices to form poles. Depending on the project, even easier than that can be to start with a sphere in the first place, so you've already got your poles.




Two things. First, don't forget to freeze and reset transformations after you do your scaling in Maya. If Maya believes the object is 1x1x1 in size, then that's the size the base sphere will be in SL (unless you rescale it in-world after the fact, of course). Second, if you want the base sphere to be more proportional to the visual shape of the sculpty, instead of perfectly round, check Maximize Scale in the exporter dialog. That's what it's for.

Whoo! So I was about to ask how to do that before I realized you mentioned it in your first reply:
1. Highlight the object(s) you want to export.

2. Click Edit -> Delete by type -> History

3. Click Modify -> Freeze Transforations

4. Click Modify -> Reset Transformations

5. Click Edit -> Delete by type -> History (again)

I did that and it's working perfectly! It rezzes in-world all scrunched up, I don't know if it's meant to be like that or not, but stretching it out it appears to be just fine. Is the scrunch normal or should I be reseting/freezing in a different order?

and does Maximizing scale to get the shape better upon loading do anything at all to the actual sculpt?

Hey~ another question for you all (hope you're still here Chosen XD )

I decided to try and make a belt, I've been catching up on texturing videos lately and I noted Lightwave wasn't able to get rounded edged curves, so I tried a relatively same shape in Maya. It came out perfect in terms of shape, except for one minor detail....

there's an unidentified surface on it:
http://smg.photobucket.com/albums/v38/neko-vamp/?action=view&current=bed.gif

kinda looks like a kitty bed or something... the sculpt in Maya looks like this:
http://smg.photobucket.com/albums/v38/neko-vamp/?action=view&current=BeltWIP.gif


any ideas?

Change the stitching type in-world for the sculpty from sphere to torus. The extra surface you're seeing is the result of SL trying to close the poles, since the default sculpty shape is a sphere. If you want the topology to be toroidal, you have to tell it that.

The same goes for a plane or a cylinder. You have to set the stitching type appropriately for your desired topology.

Thanks Chosen XD I didn't know there was a feature like that, makes sense.

Can you help me with this next one? I made a pipe out of a torus, reduced he sweep to get either end open... but it imported weird:
http://img.photobucket.com/albums/v38/neko-vamp/pipe.gif
I set it to Planar and that's the closest to the sculpty shape I could get, but it's still rather off :\
http://img.photobucket.com/albums/v38/neko-vamp/pipemaya.gif

Try this:

1. After you change the sweep, delete history.

2. Reverse the surface direction on both axes, and then delete history again.

3. Export your sculpt map. If you compare it with your old one, you should see that it's been rotated 90 degrees.

4. Upload and apply the new map, and set the stitching type to Cylinder.

It should work now.


So you know, the reason you want a cylinder instead of a plane is because you do want the surface to be stitched along the sides. If it's a plane, it won't be stitched at all, and you'll have an open seam running along the length. The only openings you want are at the top and bottom.

The reason for reversing the surface direction (rotating the sculpt map) is to get it properly oriented with the cylindrical stitching. It will only stitch the "sides", not the "top & bottom", so you need to be sure your "sides" in Maya are the same edges as the "sides" in SL. If you built your torus around the up axis in Maya, it will be oriented 90 degrees from how SL does it, until you reverse the surface direction.

With that in mind, there's another obvious alternative. Build your torus around a different axis right from the start. That will save you the step of having to reverse the surface direction.

And of course, another option is just to use a cylinder in the first place, instead of using a torus at all.

Thankyou again Chosen~! I haven't got it to work just yet, but I think I'ma scrap it and start all over with a cylinder. I began with a torus, forgetting about the planar options in SL thinking it'd help to already have something curved... which makes little sense considering it'snot wholly curved anyway, eh @_@

Ok! So my next question is one that I've been dying over for months. I originally started playing with Maya so I could have a better UVMapper-type program to see the skins and clothes I was making in a better light/UI setting from Photoshop. I would really -really- like to be able to play with the specularity with the clothes and skins I've made in Maya so I can give more realism to them. My only problem is, how do I resave the jpg/bmp/psd file once I've tweaked them in Maya? All the exports I see in the Hypershade and Multilister windows show only .ma/.mb/.mov options. Do I need a plug-in for this?

If I'm reading your question right, the answer is you'll want to render a baked texture. The best renderer for that is Turtle. But if you don't feel like spending $1400 on a renderer, Maya comes with a couple of renderers you can use: the Maya Software renderer, and Mental Ray.

Between the two, I recommend Mental Ray. Maya Software is good for things that are unique to Maya, such as 3D paint effects, hair, fur, etc., but it's not all that great for more everyday things. Mental Ray is far superior for what you're looking to do.

Here's a pretty decent overview of how to output a baked texture from both renderers: http://fromthehill.nl/tutorials/bake/index.html

Awsoooommme, but another question XD

http://img.photobucket.com/albums/v38/neko-vamp/ffffffffff.gif
I tried getting the convert to work from the tutorial you gave me (using a top I pulled outta zerospace for practice) and it either gives me that all-black shading result..

orr, if I don't select the assigned portion of the object/avi where the texture is, I get all the UV maps together in the baking process, like so:
http://img.photobucket.com/albums/v38/neko-vamp/Material_Upperbody-polySurface11.jpg

T-T what to do?

If a texture come put all black, it usually means one of three things. Either you don't have any lights in the scene, or the normals are inside out on the selected surface, or you've got an empty node somewhere in your shader network.

As for why all three textures are baking to the same canvas, that will happen if you combine the mesh. It doesn't look like you did that, though, so I'm not sure what's going on. I'm sorry, but I don't have much expertise with Mental Ray. I've been using Turtle for years.

Also, in your picture of the mesh, the upper body area looks really strange. I've never seen that kind of flat dithering pattern masking a surface before. What did you do to get Maya to display it that way?


On a side note, you really need to clean up your mesh. It looks like you've got duplicate vertices all along where various parts meet. For example, you've got a hard edge where the legs meet the pelvis. I'm guessing you simply combined the pieces, but then you didn't merge the overlapping vertices. Select the whole model, and hit Merge -> Options Box. Set the Threshold very, very low, like 0.0001, and then hit Apply. Then soften your normals (Normals -> Soften Edge). That hard edge should now be gone.

Afterwards, you might want to go back and selectively harden a few normals, for better detailing. A little hardening around the mouth, eyes, and nose, for example, can go a long way. Notice, RL humans have somewhat of a hard edge where the lips meet the skin of the face. Put the same kind of detail in your model, and you'll get a more realistic lighting effect when you render the face.

Ack, it was black because of the lack of lights. /dunce XD; So I've been playing around with it a little more, think I'm getting the hang of it.
Also, as for it baking all the meshes together, I always get this message when I drag the Av.obj into Maya,
"Your OBJ file contains faces shared by multiple groups. Maya cannot create multiple objects for this file. A single mesh object will be created instead. The OBJ group information wlll be captured in Maya sets."
So that might be the reason... I figured it was fine since in Hypershade, I see three different sections for the textures @_@


I thought I could bypass the baking of the head and lower half by selecting only the portion with which I had a texture on... so I clicked the torso texture in Hypershade -> Edit -> Select Objects with Materials. Then I converted to texture just below it. It comes out selected like that @_@

I was able to get a copy of Turtle this weekend, but I haven't touched it much other then exploring the options. I can't seem to find a way to output an image like the Maya baking @_@;;


thankyouthankyouthankyou. The person who was origianlly showing me how to use Maya for applying skins/ textures told me to unlock normals and click smoothe and that was it XD; since it's all new, I wasn't sure if there was more I could do to even it out more, thankyouthankyouthankyou~~!