Welcome to the Second Life Forums Archive

These forums are CLOSED. Please visit the new forums HERE

Importing from Maya to SL. How?

Gabriel Reich
Registered User
Join date: 7 Apr 2008
Posts: 13
04-07-2008 14:35
I create my objects from NURBs in Maya. What is the correct way to export to sl?
I've been using qarl lindens sculpt.mel script to export my objects but when I do the top vertices cut through my object and attach to the bottom.

I'm also getting jaged edges on my sculpt map when I export.
What am I missing?
Chosen Few
Alpha Channel Slave
Join date: 16 Jan 2004
Posts: 7,496
04-07-2008 19:41
From: Gabriel Reich
What am I missing?

It sounds like you're not giving your objects the correct spherical topology. Not just any arbitrary model will work. If you want one to work as a sculpted prim, you need to build it in a very specific way.

The reason you're seeing the top connecting to the bottom is because all sculpties by default are spheres*. The best way to make then in Maya (or any other 3D modeling program) is to start with spheres there too. You can deform a sphere into any shape you want, but make sure its topology remains spherical. That means don't tear the surface, and make sure both poles remain intact.

Here's an example of how a sphere can be deformed into a cylinder and then into a cube:





*Note: There are three other sculpt types besides sphere. These are plane, cylinder, and torus. They are not yet officially supported, but they are accessible via script. See the sculpty wiki for examples of the right scripts to use.

Topologically, the different types work as follows. The plane is self explanatory. The cylinder stitches the two sides together, and leaves the top and bottom open. The torus stitches the two sides together, and the top and bottom together. The sphere (the default), as we discussed, stitches the two sides, and collapses the top and bottom to form poles.
_____________________
.

Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.
Constant Alter
Registered User
Join date: 21 Dec 2007
Posts: 5
04-07-2008 19:59
From: Gabriel Reich
I create my objects from NURBs in Maya. What is the correct way to export to sl?
I've been using qarl lindens sculpt.mel script to export my objects but when I do the top vertices cut through my object and attach to the bottom.

I'm also getting jaged edges on my sculpt map when I export.
What am I missing?


It's the problem of Surface Direction. So go to Edit Nurbs/Reverse Surface Direction; reverse one of the directions or swap, export again, go to SL upload image, preview as sulpted prim. If it shows up as how it should be, you're good; if not, go back to Maya and reverse direction again.

Before exporting your nurbs surface, always rebuild it with Uniform checked. your map should occupy the whole uv space.

Good Luck!
Gabriel Reich
Registered User
Join date: 7 Apr 2008
Posts: 13
04-07-2008 20:24
The problem is the top and bottom of the sculpt map is razored like a saw. So when I upload the top of the scultpy attaches to the bottom.

How many vertices/sections,spans can there be on a nurbs objects when you upload to SL?
Constant Alter
Registered User
Join date: 21 Dec 2007
Posts: 5
04-07-2008 20:36
Could you try exporting an unedited nurbs sphere and see what happens?

I believe you can have 16 isoparms in both u and v directions.
Gabriel Reich
Registered User
Join date: 7 Apr 2008
Posts: 13
04-07-2008 23:44
I'm not sure what the issue is but its solved. It was causing really bad jagged edges.

Thanks for the help mates!
Chosen Few
Alpha Channel Slave
Join date: 16 Jan 2004
Posts: 7,496
04-08-2008 01:28
From: Gabriel Reich
The problem is the top and bottom of the sculpt map is razored like a saw. So when I upload the top of the scultpy attaches to the bottom.

If you're seeing saw teeth on the top and bottom of the map, it means you're using polygonal spheres instead of NURBS spheres. By definition, NURBS surfaces will always have a perfect UV space. But the way Maya UV-maps poly spheres by default is to put saw-teeth at the top and bottom (which makes perfect sense if you think about it, since the most efficient way to build a sphere is for the top and bottom rows to be composed of tris instead of quads).

You can use polygons if you want, but it it's spheres, you'll need to remap them. If you're not good with UV mapping, I'd suggest starting with an open cylinder (uncapped) instead of a sphere, and then snapping the top and bottom vertices to the center to form poles. Don't merge the vertices or you'll end up with saw teeth again. Simply snap them into place, and make sure they stay together.

I don't really recommend using polygons though, since the surface won't be sampled all that accurately when the map is generated. The loosely accurate sampling works out just fine for NURBS surfaces, since they're just interpolations anyway. It matches just about exactly with what you see when you look at a NURBS model at display level 2. With polygons, you notice the inaccuracy a whole lot more.

If you want total accuracy, you might want to export your model from Wings instead of from Maya. The Wings exporter uses actual vertex position reporting instead of ray sampling. I really wish somebody good with MEL would come up with a secondary Maya exporter that can do that too, but at this time, that hasn't happened.

From: Gabriel Reich
How many vertices/sections,spans can there be on a nurbs objects when you upload to SL?

If it's polygons, you want 32x32 quads (32x33 vertices). If it's NURBS, I recommend 16 sections and 15 spans, detail level 2. Strictly speaking, you can use more sections and spans if you want, but the more you have, the less of your details will be preserved when you generate your sculpt map. 16x15 usually works out very well.

Inside SL, sculpties have 32x32 quads.
_____________________
.

Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.
Gabriel Reich
Registered User
Join date: 7 Apr 2008
Posts: 13
04-08-2008 02:33
Would using less sections and span lower the detail even more?

sorry myy english not good.
Pygora Acronym
User
Join date: 20 Feb 2007
Posts: 222
04-08-2008 19:54
Some quick notes on polys here, just so they are represented by a modeler who uses polygons both for SL sculpties, and in a day-to-day production job.

Even if you are skilled at doing your own UV layouts I would recommend sticking with the cylinder setup Chosen Few details. No amount of UV ninja mastery will get rid of the sawtooth. Well, I take that back, a ninja master could do it, but he wouldn't, as just starting with a cylinder would take much less time.

I usually block in my poly details at 16x16 then subdivide the mesh one level. You can flip through the base and sub-d level 1 in Maya with the top row numbers 1 and 2 as you wrangle verts to see what you are going to get.

With vertex based sculpty exporters lower mesh resolutions can be used to create effects like the disco ball facet sculptys. Also, you can have variable resolution on a poly mesh as long as you keep UV space normalized.

Don't get to bound up in the notion of which modeling scheme has a better surface representation. It's a mis-characterization of polys to say they are inherently inferior due to surface inaccuracy. In the SL engine all surfaces are products of vertex location. Same with sculpties. The map you create is read as vertex coordinates for a mesh, not a mathematical function for a NURBS surface, in the engine. You could say you are actually a step closer to the engine level of detail when using poly modeling. If you want a vert on top of a vert in SL, you just put a vert on top of a vert when you are modeling, It's a one to one representation (at 32x32 pedant reader).

If you want that Nth degree of down to the micropolygon level surface accuracy with a poly model anyway, just crank up the Sub-D. But once you get over 64x64 detail you are in serous overkill land as far as SL exporting.

Oops, so much for "some quick notes..." Er, make that just some longer notes about polys to consider.

Remember, go with whatever floats your boats, and have fun doing it.
Gabriel Reich
Registered User
Join date: 7 Apr 2008
Posts: 13
04-08-2008 20:43
Thanks guys! The information is trickling in for me when i get a new post here relevant to the problems I encounter in Maya.

Btw, is anyone proficient with rendering in Maya 8?
I know my way around modelling but rendering is a little confusing for me. I've just been applying a lambert material then adding a ambient light to render with. But I would like to add bump maps, textures (like metal, stone, and skin), and just add a bit more realism.

Thank you all so much!
Pygora Acronym
User
Join date: 20 Feb 2007
Posts: 222
04-08-2008 21:50
I gotta admit, Maya isn't my primary 3d app any more, but maybe I can help with some general stuff.

First up, drop the ambient light and get some Spots or omnis in there. Ambient lights are omni-directional (and omni's are not, they radiate from a point, /shrug/) and will not give you specular highlights and your bumps will look unbumpy without directional hints. Second, kill the default Lambert shader and try a Blinn, better highlight model by a factor of win.

Textures can be added to the shader in the Attribute Editor by clicking on the checker box next to the attribute and selecting a node. If you want to put a texture map on something add a "file" node. Or you can go right for the throat and link nodes directly in the Hypershade.

I would highly HIGHLY recommend using the Mental Ray renderer.

Remember: the help files are your friends and we won't think any less of you for using them.
Chosen Few
Alpha Channel Slave
Join date: 16 Jan 2004
Posts: 7,496
04-09-2008 08:35
From: Pygora Acronym
Don't get to bound up in the notion of which modeling scheme has a better surface representation. It's a mis-characterization of polys to say they are inherently inferior due to surface inaccuracy.

Pygora, you seem to be confusing the issue a little. Let me explain. I'll take it point by point.

From: Pygora Acronym
In the SL engine all surfaces are products of vertex location. Same with sculpties.

Yes, of course. But that doesn't mean the locations of the vertices in SL are the same as those in Maya. They're not.


From: Pygora Acronym
The map you create is read as vertex coordinates for a mesh, not a mathematical function for a NURBS surface, in the engine.

Actually, it's neither. When you export a sculpt map from Maya, the surface shape is sampled at intervals. Exact vertex positions are not recorded, unless they happen to coincide with the sample points. From the sampled areas, the sculpt map generator is able to estimate the shape of the surface. The results are not an exact copy of the actual shape, just a loose approximation.

When sculpties first came out, this concept of approximation was clearly explained. Some of the language from that initial explanation still exists on the front page of the sculpty wiki, where it mentions that sculpties are intended for organic shapes. It no longer says that precision inorganic shapes are not the intent, since enterprising residents have solved that problem in programs like Wings 3D. But the Maya exporter is still the original, which was not designed for precision.

You have only to observe the results to see that they're not precise. Here's an easy example. Start with the kind of cylinder I mentioned above, and turn into any simple shape you like that demonstrates some degree of easily discernible precision. Compare the Maya model with its sculpty equivalent in SL, and you'll see that it's not even close to an exact match.

Here's are two screenshots from an example I just put together. The model is 32x32 quad cylinder, with its top and bottom vertices snapped to poles, and a good portion of its mid side vertices snapped to form a cubical shape. Were vertex reporting to be in play, this shape should be very easy to duplicate exactly. But that's not what happens. Take a look.

(Apolpgies in advance that the image is a bit large. It would have been difficult to see the details of the wireframe lines if it were made smaller.)

(Note: In the lower panel (SL wireframe view), I've lowered the saturation of the background the lines, to make the subject easier to see. No other image adjustments were made.)

Notice how imprecise the SL version (lower panel is). I'll list the various issues that can be seen in the pictures (there are more that are not visible from this angle):

1. In the Maya model, the pole is centered. In the SL version, it's not.

2. The Maya model has just one division on the cylinder's top. The SL version has two.

3. The Maya model has 4 evenly spaced vertical divisions along the shaft, between the top of the cuboid part and the top of the cylinder. The SL version only has three divisions there, and they're not evenly spaced.

4. In the Maya model, there is just one division on the top of the cubical part. In the SL version, there are two.

5. In the Maya model, all vertical edges are perfectly straight. In the SL version, the edges are zig-zagged.

6. In the Maya model, the horizontal edges of he cuboid are perfectly straight, so the cube's 4 sides are each totally flat. In the SL version, the the sides basically stay straight for the first seven columns of quads,and then angle inward 10-20 degrees on the eighth.


Quite obviously, vertex position reporting is not the method by which the sculpt map was generated. As I said, the surface was ray sampled. It's just an approximation, not an exact match.


From: Pygora Acronym
You could say you are actually a step closer to the engine level of detail when using poly modeling.

You could, but only if you misinterpret what's actually happening. With the Wings exporter, you'd be right, but not with the Maya one.

From: Pygora Acronym
If you want a vert on top of a vert in SL, you just put a vert on top of a vert when you are modeling, It's a one to one representation (at 32x32 pedant reader).

It's not 1:1 at the vertex level. I don't know how else to say it.

From: Pygora Acronym
If you want that Nth degree of down to the micropolygon level surface accuracy with a poly model anyway, just crank up the Sub-D. But once you get over 64x64 detail you are in serous overkill land as far as SL exporting.

Now you've completely lost me. All (spherical) sculpties have 32x32 quads in them. Not 64, not 128, ALWAYS 32. So how is it that you believe increasing the subdivisions of the source model beyond 32x32 could in any way effect the precision of the sculpty recreation. None of those extra faces will be preserved.

From: Pygora Acronym
Remember, go with whatever floats your boats, and have fun doing it.

Absolutely. But let's be careful not to assign assumption-based properties to the substance floating the boat, just because we like the notion of how it SHOULD work better than that of how it actually DOES work.
_____________________
.

Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.
Johan Durant
Registered User
Join date: 7 Aug 2006
Posts: 1,657
04-09-2008 09:48
From: Chosen Few

When you export a sculpt map from Maya, the surface shape is sampled at intervals.

the surface was ray sampled. It's just an approximation, not an exact match.

Just an addition to clarify the term "ray sampled," since not everyone will understand that particular bit of jargon. What he means is that rather than report where vertices in the mesh are, the exporter shoots rays at the mesh and reports where the rays hit the surface. This means that subtle details can be lost if the details are between rays. For example, in that cube he shows, the reason the corners aren't perfect is because rays hit the surface on either side of the corner, but not at the corners themselves.

If I wasn't busy right now I'd draw a diagram to illustrate that point.
_____________________
(Aelin 184,194,22)

The Motion Merchant - an animation store specializing in two-person interactions
2k Suisei
Registered User
Join date: 9 Nov 2006
Posts: 2,150
04-09-2008 10:48
From: Johan Durant
Just an addition to clarify the term "ray sampled," since not everyone will understand that particular bit of jargon. What he means is that rather than report where vertices in the mesh are, the exporter shoots rays at the mesh and reports where the rays hit the surface. This means that subtle details can be lost if the details are between rays. For example, in that cube he shows, the reason the corners aren't perfect is because rays hit the surface on either side of the corner, but not at the corners themselves.

If I wasn't busy right now I'd draw a diagram to illustrate that point.


I don't think it uses ray sampling. If it did then it would miss far more details than it currently does, especially on more convoluted objects.

I suspect it simply takes an average of the points/vertices of any given area. Whereas the more simpler convertors that are floating about will insist on you feeding them a 32x32 object so then they can map each vertex directly.
Chosen Few
Alpha Channel Slave
Join date: 16 Jan 2004
Posts: 7,496
04-09-2008 10:51
From: Gabriel Reich
I would like to add bump maps, textures (like metal, stone, and skin), and just add a bit more realism.

The Hypershade is your friend. It allows you to create shader networks very quickly, using an intuitive, node-based, hypergraph format. For best results, the Hypershade should be used in conjunction with the Attribute Editor (found on the right hand side of the main Maya window).

Here's a quick tutorial to make a shader with a 3D bump map and a 2D color texture:

1. Project Directory

Set up a proper project directory if you haven't done so already. This should always be the very first thing you do whenever you begin a new project in Maya. Otherwise, you'll end up overwriting your previous renderings with your new ones each time (among other problems). Obviously, you don't want to do that.

In the main Maya window, click File -> Project -> New. In the dialog that pops up, give your project a name. Then click Use Defaults to set up the proper directory structure. When you're done, click OK.


2. Take a look at the Hypershade (Window -> Rendering Editors -> Hypershade)

Take a good look at it. The layout is pretty simple. In the left hand pane, make sure the Create tab is showing. Don't worry about the Bins tab right now; you won't be needing it for this. Under the Create tab, you'll find creation nodes for all your various surface materials, 2D & 3D textures, utilities, etc.

On the right hand side, you'll find two panes. The upper one is simply called the Top Tabs (notice it's got a whole bunch of tabs at its top), and the lower one is called the Work Area. Put simply, the Top Tabs are where all your materials (and other rendering items) are kept organized, and the Work Area is where you edit them.

In the Top Tabs, the only tab we're going to use in this tutorial is the Materials tab. Don't worry about any of the others right now.

Navigating the Work Area is just like navigating any of the main viewer panes. Alt-left-drag zooms in and out. Alt-middle-drag pans. Alt-left-drag does not apply, since you can't rotate a 2D window.

Note, you don't have unlimited alt-zoom in the Top Tabs (don't ask me why). You just have 4 levels of maginfication, and you can only scroll vertically. Inconsistent as that is with just about everything else in Maya, it isn't that big a deal. It's not often (at least for SL work) that you'll have so many materials in your scene that you'll need to to much, if any, zooming in the Top Tabs (assuming you have a good size monitor, that is). You'll zoom all over the Work Area constantly, though.


3. Create a new material in the Hypershade

In the Create tab, click one of the buttons under the Surfaces heading to create a new material. Let's do a Lambert, since that's the simplest to understand (fewest attributes). Lambert shaders reflect light similarly to how matte (non-shiny) materials do in RL. (The other commonly used materials, so you know are are Blinn, which has a metallic look, Phong, which is glossy, and Anisotropic, which diffuses its reflections similarly to how brushed metal does.)

When you click the button, you'll notice that a new Lambert node appears in both the Top Tabs and in the Work Area. They're both the same material; you didn't actually create two. Remember, the Top Tabs shows all the materials in the scene. The Work Area shows whatever materials you happen to be working on at the moment. You can drag a material from the Top Tabs to the Work Area (with the middle mouse button) at any time to work on it. Since the one we're working on now is brand new, it's already in the Work Area by default. Maya assumes when you create something new it's because you intend to work on it right away.


4. Assign your material to your object

In any Maya viewer pane, click to select your object. Then in the Hypershade, right click on your new Lambert node, drag the mouse to the Assign intialShadingGroup To Selection button, and release. You can do this from either the Top Tabs or the Work Area. Your object now has your new material on it instead of the default material.


In the next step, we're going to take a quick look at the Attribute Editor. Before we go any further, let's get something clear right away. You don't actually need to be using the Hypershade at all. You could do everything directly in the Attribute Editor. However, the Hypershade makes it easier to understand what's happening, since you can see it all visually. If you prefer to work only with menus, then the Attribute Editor is just fine. I think you'll find that being able to see the graphical representation of your shader network is very helpful, though. With that in mind, let's take a look at the Attribute Editor.


5. Examine the material's attributes in the Attribute Editor

In the Work Area, double click on your new Lambert node (or just click it once, and then press ctrl-A). Take a look at the right hand side of your main Maya window. You'll see that the Attribute Editor has opened. There you can see all the attributes of your selected material. The names are pretty self explanatory (color, transparency, incandescence, etc.).

As I said above, you could just use the sliders, fields, and the options buttons next to each attribute to finish creating your shader from here. If you want to do that, there's nothing wrong with it. But again, the Hypershade helps you understand better what's actually happening, and it's a lot faster. So we'll using both in this tutorial. We'll construct the framework of the shader in the Hypershade, and edit each component's properties in the Attribute Editor.

What we are going to do with the Attibute Editor at this time is rename the material, so it's easy to keep track of. Toward the top, you'll see the word "Lambert:" with a white field to its right. In that field is the material's name. Right now, it's probably called Lambert2 or something, since if you've done nothing else, this is the second Lambert in the scene (Lambert1 is the defualt material). You can rename your Lambert to whatever you want. For this tutorial, let's go with "gabrielsFirstShader". Type that in the white field, and press Enter. You'll see the name shown the Hypershade instantly updates to reflect the change.


6. Color

You said you wanted to use an existing 2D texture for the material's color. Before we do anything else, grab that file, and copy it to the sourceImages folder of your current Maya project. The reason to do this is so your project will be self-contained. This way, if you ever want to move it to another machine, or give it to someone, or work collaboratively with another artist, etc., everything will be in one place. Otherwise, you'd need to hunt down every last file every time, and you'd then have to redirect all your materials' file references to the new locations. That can be a real pain. Use the directory structure properly, and you'll never have those problems.

Also, before we go any further, I should mention that technically, anything you could paint by hand in Photoshop (or any other paint program), you could also create procedurally in Maya. But learning to make complex imagery procedurally is a big subject. We're going to touch on it briefly in a few minutes when we make your 3D bump map, so you will get a taste of it, but since using a 2D texture for color is what you were asking about, that's what we're going to do here.

In the Create tab in the Hypershade, in the 3D Textures section, click the button for File. You'll see a new file node appear the Work area, along with a placement node. Depending on where you were already zoomed, the new nodes may have appeared directly on top of the old one. That's OK. To move them around, just left-drag them anywhere you want. Their positions on screen don't affect how they work. What's important is just to keep things organized so you can keep track of them.

For now, the simplest thing to do is to move the three nodes so that they're in a neat row, with the placement node on the left, the file node in the middle, and the material node (garbielsFirstShader) on the right.

As their names would suggest, the file node is what you'll use to pick your 2D image file, and the placement node is what you'll use to position it on your object's surface. (If it helps, think of the file node kind of like the texture picker in SL, and the 2D placement node as the repeats & offsets settings.) To pick a file, we'll be editing the file node's attributes in the Attribute Editor. So double click on the file node in the Hypershade. This will open it in the Attribute Editor, just like how we opened the material node a minute ago.

See where it says Image Name? Click on the little folder button to the right of that, and then navigate to wherever you've got your image stored. Notice the first place it looks by default is in sourceImages. Hopefully you put the file there like I told you. Technically you don't have to, but things can get messy if you don't.

Now, the only thing remaining is to tell Maya you want the file to be the color for your material. In the Hypershade Work Area, middle-drag the file node onto the material node and let go. In the popup menu that appears, click on Color. The file node is now mapped to the material's color channel. You should see the texture on the model now.

Be aware that depending on the complexity of the model's shape, and of the texture itself, the Maya viewer may not show you the texture in detail. It might look blurry right now. That's OK. To see it clearly, just do a quick test render. Remember, the viewer is optimized for performance. It's not intended to be a fully accurate display of every last thing in your scene. That's why we render.

If you want to adjust the positioning of the texture on the model double click the placement node in the Hypershade to open it in the Attribute Editor. The attributes are pretty self explanatory. You can change the repeats, rotation, offsets, etc., just like in SL (plus a few other things).


7. Bump

If you want to, you can assign an existing image file to the material's bump channel, the same way we just did it for the color channel. You could create a grayscale bump map in Photoshop (or any other paint program), and then repeat the process we just did, except this time, choose Bump instead of Color when you middle-drag the file node onto the material node.

But since you already know how to do that, let's take this opportunity to advance your knowledge one step further. Let's use a 3D texture this time instead of a 2D one. The advantage of 3D textures is that they get placed evenly across the entire model. The shape of the model does not cause them to squish, stretch, shear, etc., in any way. The disadvantage is they can break if you move the model (so they're not well suited for animation, for example). But for something as simple sculpties, that shouldn't be an issue.

In the Hypershade, scroll down the Create tab to the 3D Textures section. You can use any kind of texture you want for this. Let's go with Volume Noise. If you're familiar with the noise filter in Photoshop, this is basically the same thing, but in 3D. It works very well for creating all kinds of uniformly bumpy textures, from granite to stucco to leather to skin.

Click on the Volume Noise button. You'll see two new nodes appear, the volume noise node itself, plus a 3D texture placement node. As before, feel free to move the nodes around the Work Area any way you want, so that you can easily keep track of everything. Middle drag the volume noise node onto the material node, and in the popup menu, choose Bump. The noise is now mapped to the material's bump channel.

By default, the Maya viewer will not show you bump mapping. To see it, you can either do a test render, or you can switch the viewer to high quality rendering instead of default. For the latter, you'll need a powerful video card, and lots of RAM. If you're lacking in either, I'd suggest you don't try it. But if you have sufficient hardware, then in the white menu bar at the top of the perspective pane, click Renderer -> High Quality Rendering. Just be sure to save your file first. If your hardware isn't up to snuff for this, Maya may well crash on you.

Anyway, to adjust the properties of the volume noise, take a look at it in the Attribute Editor (you should know how by now; double click it in the Hypershade). The attributes are fairly self explanatory. Feel free to experiment with them to see what they all do.

To adjust the placement of the noise pattern on the surface, you guessed it, edit the 3D placement node in the Attribute Editor. Notice, though, that 2D attributes, like UV repeats and such, are not present. That's because this is a 3D placement node, not a 2D placement node. This node has no idea what UV's even are. All it knows is that a 3-dimensional pattern exists in space, and where that pattern happens to occupy the same space as your material surface, the former affects the latter in some way (which in this case happens to be by acting as a bump map).

At this point, you're probably going to end up doing lots and lots of test renders to get the bumps exactly how you want them. That's OK. That's exactly what you're supposed to do. These things take time. Don't be afraid to spend a lot of extra hours tweaking the attributes, and rendering to see the results.


Lighting & Baking

I would not recommend using ambient lights as your main light source, if at all. They are completely unrealistic. I also wouldn't recommend just using spot lights, as Pygora had suggested. That's totally unrealistic too.

What I would suggest is that you learn about global illumination, final gather, and ambient occlusion. That's where the foundation of realism is going to come from 90% of the time, especially with baked textures. Use spotlights, pointlights, etc. for accent, not for primary lighting.

This is counter to what most tutorials on lighting will tell you. That's because most tutorials are not written with baking in mind. When you're rendering a flat image from just one point of view, your lighting setup is often similar to RL stage lighting, and the effects can be stunning. But when you're baking, that kind of thing just doesn't work. You want your model to be lit from all sides at once, since it's going to be seen from every angle. That's where global illumination comes in. Final gather and/or ambient occlusion are tools which help surfaces shade properly when globally illuminated.

Lighting is way too big a subject for a basic tutorial like this one. To learn about it, you're going to need to read, read, read, and practice, practice, practice.

As for baking out the texture, I take it you already know how to do that since you didn't ask how. The instructions will vary greatly, depending on what renderer you're using. If you're in the market for a good renderer, I suggest Turtle. It's the only renderer in the world specifically designed for baking. Other renderers can do it, but Turtle puts everything in one convenient place, it's fast, and it produces very high quality results with relative ease. It takes a lot of work to get something like Mental Ray to yield results that look even close to as good as Turtle's results look by default.

If all you've got is Maya Software and Mental Ray, don't be discouraged, though. You can still get good results. It just takes a lot longer, and it's more complicated to set up. You can find some basic instructions for both at http://fromthehill.nl/tutorials/bake/index.html . I don't like the lighting scheme the author uses, but all the steps to output a texture are present.




I hope this has been helpful.
_____________________
.

Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.
Jamay Greene
Registered User
Join date: 2 Jan 2007
Posts: 75
04-09-2008 10:52
From: 2k Suisei
I don't think it uses ray sampling. If it did then it would miss far more details than it currently does, especially on more convoluted objects.

I suspect it simply takes an average of the points/vertices of any given area. Whereas the more simpler convertors that are floating about will insist on you feeding them a 32x32 object so then they can map each vertex directly.


Not only that. If it is using ray sampling then the UV layout should not match up for any textures baked in Maya.
2k Suisei
Registered User
Join date: 9 Nov 2006
Posts: 2,150
04-09-2008 10:57
From: Chosen Few


<Billions and billions of words>

I hope this has been helpful.



You're gonna get arthritis!
Keira Wells
Blender Sculptor
Join date: 16 Mar 2008
Posts: 2,371
04-09-2008 11:02
From: 2k Suisei
You're gonna get arthritis!

2,785 words
12,734 Characters not including spaces
15,580 Characters including spaces

0 actual spelling and/or grammar errors found by Microsoft Word. (A total of 3 unique words underlined for spelling, just not words in Word's dictionary)

Chosen Few, you are a force to be reckoned with!
And I have to ask.. do you type it all up in some word processor for spelling and such, or use a browser with it built in? If not then...wow.
You rock, either way! (Still)
_____________________
Tutorials for Sculpties using Blender!
Http://www.youtube.com/user/BlenderSL
Chosen Few
Alpha Channel Slave
Join date: 16 Jan 2004
Posts: 7,496
04-09-2008 11:15
From: Keira Wells
2,785 words
12,734 Characters not including spaces
15,580 Characters including spaces

0 actual spelling and/or grammar errors found by Microsoft Word. (A total of 3 unique words underlined for spelling, just not words in Word's dictionary)

Chosen Few, you are a force to be reckoned with!
And I have to ask.. do you type it all up in some word processor for spelling and such, or use a browser with it built in? If not then...wow.
You rock, either way! (Still)

Heh, thanks for the compliments, Keira. I typed it in Firefox. That little red underline for misspellings is really helpful (not that a few don't slip through every so often). Grammar is just something that was grilled into me practically since birth by my parents (not that I don't sometimes make mistakes with that too). Growing up in my house, you could write "on a 12th grade level", whatever that means, by the time you finished grammar school, or you were disowned.

Sometimes that actually works to my detriment, since I'm not comfortable writing in the loose language of the Internet. The result is sometimes people think I sound angrier than I intend, since my writing style is more formal than that of others around me. This has lead to many an unintended argument. But I don't know how to do it any other way, and for tutorials, it works. :)
_____________________
.

Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.
Johan Durant
Registered User
Join date: 7 Aug 2006
Posts: 1,657
04-09-2008 11:29
From: 2k Suisei
I don't think it uses ray sampling. If it did then it would miss far more details than it currently does, especially on more convoluted objects.

I suspect it simply takes an average of the points/vertices of any given area. Whereas the more simpler convertors that are floating about will insist on you feeding them a 32x32 object so then they can map each vertex directly.

*shrug* Maybe, I haven't actually inspected Qarl's script directly to know for certain, I was just explaining what Chosen meant by the term "ray sampled."

Although Jamay, note that ray sampling wouldn't preclude the sculpty UVs from matching the UVs in Maya. The rays could be reporting both the UVW as well as XYZ coordinates for where they strike the surface (I've done that in other contexts, used ray-casting to determine UV coordinates on a surface.) Not to mention, there is a tight relationship between UVs and XYZ coordinates for sculpties, so this simplifies things for the exporter.
_____________________
(Aelin 184,194,22)

The Motion Merchant - an animation store specializing in two-person interactions
Gabriel Reich
Registered User
Join date: 7 Apr 2008
Posts: 13
04-09-2008 12:13
I'm getting some weird hair lipping on my scultpies. I use 16 sections and 15 spans then when I finish I
modify-freeze Transformations
Modify-reset transformations
Delete by Type-History

Then I export with Qarl Lindens exporter.

Chosen Few
Alpha Channel Slave
Join date: 16 Jan 2004
Posts: 7,496
04-09-2008 12:22
Do you have Correct Orientation turned on in the exporter?
_____________________
.

Land now available for rent in Indigo. Low rates. Quiet, low-lag mainland sim with good neighbors. IM me in-world if you're interested.
Gabriel Reich
Registered User
Join date: 7 Apr 2008
Posts: 13
04-09-2008 12:28
I'm not sure how to tell Chosen. I'm sorry, I'm very dumb when it comes to scripts. How can I tell?
Pygora Acronym
User
Join date: 20 Feb 2007
Posts: 222
04-09-2008 12:31
Woah, woah woah there Choosen. That's a wall of text you threw up there. Well, at least now I know someone reads this stuff.

To me, it looks like you are confusing specific issues with Maya's exporter with issues polygon modeling for sculpty authoring in general. You don't use a spoon to hammer a nail. Go re-run your tests with a vert based exporter then tell me how wrong I am about everything. All you have shown me is that you are using the wrong tool for the job. And you know in excruciating detail how wrong it is, but blame something else entirely.

Now I can sorta see how you might have mistakenly thought I was talking about Maya's specific implementation of the exporter rendering out polys, as the OP is using Maya, but I was just trying to help with some quick notes about polys, (as in general points, not a specific step by step tutorial on polymodeling in only in Maya for sculpty export) from the perspective of someone who uses them regularly. You appeared to be quite knowledgeable about the specifics of Maya's NURBS but I was not (and still am not) seeing the same level of knowledge regarding how polys can be used represented here.

So I did make some assumptions. One, I assumed that a vert based exporter would be employed, not a NURBS optimized one, right tool for the job and all that. Two, I thought my quick notes would lead to people posting questions if they wanted more info on what I was on about, not a pedantic dissection on how wrong and clueless I was and how obviously superior they were.

Look, I know I can use poly modeling to get as close to a 1 to 1 representation in SL as you are going to get with all the various translations between formats. I don't need to argue on the internets about it, or prove I am smarter or superior by representing someone else as stupid, or whatever is going on here with all the jargon and loads of text.

If you want to tell everyone that it's just not possible, so don't bother, that's fine and dandy with me. But you could try to be a little more classy than telling me that I have no idea what I'm talking about by mis-representing what I'm saying, representing your opinion as fact, and then saying I'm the one making untrue assumptions.

Sheesh, I thought these forums were about discussing stuff. I've got better things to do than be condescended to.
Johan Durant
Registered User
Join date: 7 Aug 2006
Posts: 1,657
04-09-2008 13:03
Py, you accuse Chosen of taking a high-and-mighty tone with you, and while that is true, you started it. I mean, you clearly framed your lengthy discussion of polygons in terms of lecturing others because you are the expert. Also, while your comments do make sense for using a vertex-accurate exporter, you never specified that. Considering not only the topic of this thread (ie. importing from MAYA to SL) but also the fact that Chosen had already addressed the fact that vertex-accurate exporters are available for other tools but not for Maya, it's hardly reasonable for you to expect others will intuitively realize you aren't talking about Maya specifically.

Note this part of Chosen's second post:
From: Chosen Few

If you want total accuracy, you might want to export your model from Wings instead of from Maya. The Wings exporter uses actual vertex position reporting instead of ray sampling. I really wish somebody good with MEL would come up with a secondary Maya exporter that can do that too, but at this time, that hasn't happened.

There he is stating that one can get perfect vertex accuracy by using some other tool. From this, clearly everything he discusses is specific to Maya's exporter. Thus, any criticisms of his post must also be specific to Maya's exporter.


ADDITION: Also, as far as his wish that someone does a vertex-accurate exporter for Maya, maybe I'll do that if I have time this weekend...
_____________________
(Aelin 184,194,22)

The Motion Merchant - an animation store specializing in two-person interactions
1 2