Qarl Linden's Maya export script

NOTE: Steps 1-4 here are the setup steps for Maya itself. You only have to do them the first time. After that, the actual sculpty export begins on Step 5. So do 1-4 now, and then every time you export a sculpty hereafter, you can skip 1-4 and star directly on Step 5. Just don't skip them the first time, or it won't work.

1. Find the sculpty exporter script at http://wiki.secondlife.com/w/index.php?action=raw&ctype=text/javascript&dontcountme=s&title=LlSculpt_mel/sculpt.mel. Copy the text of the script from your browser window to a text file. Save the file as llSculpt.mel.

2. In Maya, open the Script Editor. You'll find the button for it all the way at the lower right hand corner of the screen. It looks like 3 stacked rectangles, a black one on top of two gray ones. Click the button, and the script editor will open.

3. In the Script Editor window, go File -> Open, navigate to wherever you saved llSculpt.mel, and open it. You can now either run the script directly from the editor, or save it as a button on the shelf, and run it from there. I'd suggest the latter. Step 4 explains how.

4. On the main menu bar (not the script editor's menu bar, the one at the top of the main Maya window), go Window -> Settings/Preferences -> Shelf Editor. The Shelf Editor dialog will open. Click on the Shelves tab at the top of the Shelf Editor dialog, and then click the New Shelf button near the bottom. In the Name field below, name your new shelf Second Life and press Enter. Then click on Save All Shelves, and close the Shelf Editor.

You should now see a new shelf tab near the top of your Main Maya window called Second Life. Click on that tab now. You'll see it has no buttons yet. We're about to add one.

Go back to the Script Editor. In the Mel pane, se|ect all the text from llSculpt.mel by pressing ctrl-A. At the top of the script editor, go File -> Save Script To Shelf. In the dialog that pops up, name your new shelf item llSculpt and click OK. You'll now see that a button as appeared under your Second Life shelf tab, called llSculpt.

Now, whenever you want to run the sculpty exporter script, you can just click that button. You'll never have to worry about performing steps 1-4 (unless a new version of the script becomes available, and you want to upgrade).

5. In your Maya scene, se|ect the sculpty object you want to export, and perform the following steps:

Edit -> Delete by type -> History
Modify -> Freeze Transformations
Modify -> Reset transformations
Edit -> Delete by type -> History

If you don't perform these steps, your sculpty will come out messed up. Its imperative that none of your objects for export have any transformations or history records on them. Maya must believe that the state they're in now is the state they've always been in.

6. Click the llSculpt button to open the Export Sculpt Texture dialog. Click the Browse button on the dialog to choose where you want to save your sculpt map(s), and to assign a name for the file(s). Set the X & Y resolution both to 64. Check the boxes for Maximize Scale and Correct Orientation. When you're ready, hit Export. Your sculpt map(s) will now be in whatever directory you specified.

7. In SL, upload the sculpt map(s) you just exported from Maya. Make sure you have it set to upload small textures losslessly. Otherwise compression artifacting will make your sculpt prims will come out lumpy.

8. Create a cube, and then on the Object Tab, change the prim type from Cube to Sculpt. Notice most of the numeric parameter fields on the object tab disappear to be replaced by a texture picker. Use that picker to assign your sculpt map to the prim.

If you did everything right, your object in SL should now look like your object in SL.


A few things to note:

1. If the sculpty doesn't look right in SL, either you didn't follow the above instructions properly, or you made the source object wrong in Maya. Remember, for sculpties, the best way to work is to make every object by deforming a NURBS sphere, torus, cylinder, or plane. Arbitrary objects won't work. Everything must have perfect topology, meaning each object must be a singular contiguous surface, unfoldable into a perfect rectangle. You can deform the shape to become anything you want, but don't tear the surface, and if you're using a sphere, don't open the poles. For best results, the surface should have 16 sectons and 16 spans.

2. The default topology for sculpties is spherical, but there are some other options, accessible in SL via the pulldown menu, just below the sculpt map field in the editor. These are torus, cylinder, and plane. If you plan to use them, your source object must match. In other words, a toroidal sculpy should start out as a torus in Maya. A cylindrical sculpty should start as a cylinder in Maya. A planar sculpty should start as a plane in Maya. Again, you can deform the shape as much as you want to become anything at all, but don't make any changes to stitching or opening/closing. The topology must remain intact. In all cases, 16 sections and 16 spans is the best resolution to work with.

3. As you start making more and more complex items out of sculpties, it won't be uncommon for one project to contain many different sculpt prims. It quickly becomes time consuming to upload all the maps, and apply them one at a time to each prim, and then try to place all the prims by hand so everything lines up. There is a more advanced sculpty exporter, which will generate baked textures and a script to instruct a program how to assemble the objects in SL.

You can find the advanced script and the assembly program at http://wiki.secondlife.com/wiki/Importprimscript

Be aware that the script makes use of the Maya software renderer to bake the textures, which is just about the worst renderer there is. I recommend allowing it to do its thing, just to make rudimentary placeholder textures, and then replace those textures later with ones baked by a better renderer. The best renderer on the market for this type of work is Turtle. If you can't afford Turtle, Mental Ray is will do a decent job. It will give you better results than the Maya software renderer, anyway.

4. Keep in mind that because the maps are generated by translating XYZ positional data to RGB color data, the precision is somewhat limited. The maps are using 8 bits per channel per pixel, which means there are only 256 possible values between zero and whatever maximum you're using, for each vertex. The larger the distance between vertices, the greater the margin for error. A sculpty in-world will almost never be an exact mathematical duplicate of the model it was sourced from. It will be a very close approximation, close enough that no one will likely notice the difference, but it won't be totally identical.