Wings 3D Exporter

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Revision as of 07:27, 12 August 2009 by Zai Lynch (talk | contribs) ({{Help|Misc=*}} Category:Sculpted Prims)
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An exporter is a plugin for Wings that creates an SL compatible texture file from the .wings model. In the case of Wings 3D, the exporter plugin is also an importer. This allows Wings 3D to read sculpty files created in specialized sculpty programs like Rokuro, Tokuroten or Sculptypaint. Wings 3D can then be used to add additional details not possible in these simpler programs.

The Wings 3D plugin is written by Omei Turnbull. You can get the most recent release of the plugin from

Initial templates

To create a model, start by opening one of the .wings template files from the plugin zip file. These templates are named according to the number of segments and slices, and whether faces are represented by triangles or quadrilaterals.

For most models, 32x31tri.wings is a good choice. There is very little advantage to modeling with a 64x63 mesh, and there are significant disadvantages. Of the almost 3000 additional vertices in a 64x63 mesh, only 32 of them will actually have any effect on the sculpty in SL. Unless you know exactly which 32 vertices these are, you just risk being disapppointed because the details of your model rely on some of those 2950+ vertices that are going to be ignored once they get into SL. As for triangular vs. quadrilateral faces, the triangular faces allow Wings to better match the way SL will render your model. The only disadvantage of triangular faces is that it makes the model look a little "busier".

The big benefit of starting with one of the templates, rather than creating a sphere with the Wings command, is that the templates contain UV maps (provided by Hypatia Callisto -- thanks again, Hypatia) that allow you to create and preview sculpty textures using just Wings and any 2D paint program. (For more details, see below.)

Other topologies

In the original release of sculpties, SL only supported sculpties with a "spherical" topology. (That is, the surface has no breaks and the solid has no holes.) As of this writing, SL has incomplete support for the planar (one surface break), cylinder (two surface breaks) and torus (no surface breaks but one hole in the solid) topologies. The Wings 3D plugin fully supports all four topologies.

Import/Export options

The exporter and importer now have a number of options that allow the SL sculpty to better match the Wings model (or vice versa). To access these options, click on the box on the right side of the File/Export/SL Sculpties menu. If you click anywhere to the left of the box, Wings will export with the default option values.

Exporter options
  1. Bitmap size. The size of the sculpty bitmap is not strictly tied to the size of the model. The main reason for this is that for quite awhile after Sculpties were introduced, using a 128x128 bitmap was the best way to minimize compression artifacts created by SL, regardless of the resolution of your model. At this point in time, however, a 64x64 bitmap, combined with the lossless upload option, is generally a better choice.
  2. Allow recentering? Without this option set, if your model is not centered on the intersection of the major axes, accuracy can suffer due to quantization error as floating point values are mapped into the 8-bit integers required by SL. Recentering does not change your Wings model; it simply allows the exporter to choose a better coordinate system center for generating the sculpty. The default is to allow recentering. But if you want to make very small sculpties, you can do this by creating your model off-center and then un-checking this option. You might also use this option if you want the sculpty shape to be offset from the center, say to alter the movement when the prim is rotated.
  3. Allow rescaling? Without this option set, models that are long and skinny are very prone to quantization error, so this is an important option for those models. However, the default value is for it to be disabled. If it is enabled, the exporter will created a "compact" sculpty, i.e., one whose length, width and height will all be equal. After the sculpty is rezzed in SL, you will have to stretch it back to its original shape. The extra step makes this an "advanced" technique, but the increased accuracy of the result makes it very worthwhile.
Importer options
  1. Topology. The sculpty bitmap format does not include any indication of the intended topology, so importing gives you the choice of specifying one. Spherical is the default. Changing a sculpty from spherical to planar topolgy, for example, won't change its overall shape at all -- it will just create a gap along the sculpty's seams.
  2. You now have a choice between creating triangular or quadrilateral faces. The default is triangles. As mentioned above, triangular faces allow Wings to better match the way the model will look in SL.

Texture previewing

If you start with one of the provided templates, you can use Wings in combination with any 2D paint program to texture your model. The steps to do this are:

  1. From the Window menu on the Geometry window, select Outliner. The Outliner window shows you all the components of your model. Left-click on the item "Default Sculpty Texture". Release the mouse button, left-click on the texture line again and then drag and drop it onto the "Sculpty Material" line. When prompted, choose "Diffuse". (There is a quirk in the Outline window that requires separate actions for first selecting an item and then doing something with it.) Your model should now be wrapped with a pattern of black lines and colored squares labeled with letters. This is the default texture, with the required Sculpty UV map. The pattern will guide you as you are painting your texture.
  2. Have Wings create a new file for the texture bitmap by right-clicking on the "Default Sculpty Texture" and choosing Make External. (Remember, when using the Outliner window, the context menu refers to the item that is selected, not the item your mouse is over. If the context menu doesn't contain the options you expect, it's probably because you forgot to first select the line with a left click.) Name the texture file whatever you want, but be sure to choose a name that distinguishes it from the sculpty bitmap file.
  3. Open the file you just created in your favorite paint program. You should see the texture that is wrapped around your model in the Wings window. To help orient yourself, select your whole model in Wings and open the UV Editor window from the Windows menu. You should see the same texture bitmap you see in your paint program. Now put both the Wings Geometry and UV Editor windows in face selection mode. (That's the third icon of four in the middle of the icon bar at the top of the window.) Now, when you choose a face of your model in the geometry window, the corresponding area of the texture in the UV Editor Window will also be highlighted. Use this as a guide to where you should paint with your paint program. Proceed to paint your texture. Wings will not reflect your painting as you work, but when you want to update Wings' view, save your file in the paint program, right click on the texture line in Wings' Outliner window and choose Refresh.
  4. When you are satisfied with the results, you export the sculpty bitmap file from Wings. The texture file you painted is ready for use; it is not processed by Wings.

Other changes in this release

  1. Export Selected: Useful if you have have multiple objects open in Wings at one time. In that case, select the one object you want to export and choose the Export Selected command instead of Export. Beware, though, that Wings will easily shift from the (commonly used) Export to the (rarely used) Export Selected if your mouse passes over the Export Selected line as you move to the Export sub-menu. If exporting gives you an "Unsupported mesh size" error when you know your mesh is OK, it's probably because you executed Export Selected by mistake.
  2. Texture orientation in SL: The sculpty bitmap is rotated so that you shouldn't have to rotate the texture in SL when you apply it to a newly created sculpty.