Sculpty exporter for Wings 3D

Good to hear, just FYI, you should use the Sculpted Sphere option under the more menu to create them, the LOD value is the power of two of the size (so LOD 6 = 64 pixels)

This doesn't sound like a Mac-specific problem. The {badmatch,"Unsupported mesh shape"} error says that you had something other than the 32 section, 31 slice sphere mesh that my exporter expected. (31 sections, 32 slices, perhaps?) Strife's exporter is less picky. But I just tried exporting one with 31 sections and 32 slices, and the exporter was happy to do it, but the resulting file wasn't a valid bitmap. Even if it did result in a valid 31x33 bitmap, you might not like what SL does with it. So check out your bitmap in SL before you put too much work into it.

*snickers* That it does, I should probably add a warning about file sizes that SL will eat. I wanted the ability to edit odd sized images.

There's 31 vertical faces/sections (including poles) on a Wings 32x31 sphere. Yet there's 32 vertical faces/sections on a SL sculpty prim.

Maybe something is amiss?

OK so i managed to make a sphere and have actually imported it into sl but when i try to change the shape of the sphere using extrude it wont export. I take it that extruding changes the number of verteces etc.

My question is how do I make something other than the standard sphere

Hi Hurly!,

You're right, extruding is naughty. Instead, to change the shape of the sphere, you must rearrange its vertices/points. This is done by simply selecting them and manually moving them around. Let me know if you need more detail.

That's an interesting observation, 2k. I have never actually counted the faces in SL. That would seem to imply that Qarl is doing something less obvious than a 1-1 mapping between bitmap values and vertex coordinates.

If you're going to verify it, I suggest that you count a sculpty that's been made in another program. Because a Wings sculpty will only have 31 sections when taken into SL. It's odd because I can't see where the lost section is. The northern and southern poles of a Wings sculpty seem to be mapped just fine. So there must be a double somewhere.

Can you post a 32 x 32 sculpty bitmap that produces a 32 slice sphere?

The default sculpties in the Library folder should be fine. The banana's faces are quite easy to count. Also, enabling full bright makes them easier to see.

I just looked at the blender template here. Their sphere also uses 32 sections.

Are you sure? I counted 32 sections (so 33 vertices from north pole to south pole), using the wireframe view and a black and white checkerboard texture to be sure.

Well I counted 31. But even so, you've verified that an SL sculpty has 32 sections and not 31 as Omei's plugin requires.

I checked out a couple of the bitmaps at http://wiki.secondlife.com/wiki/Sculpted_Prims:_Sculpt_Maps_and_Textures. They are 128x128 bitmaps. It seems that you can get an extra row of vertices in the SL-rendered sculpty if you use a larger bitmap and let SL do the interpolation. This makes me wonder what SL would so with 33x32 bitmap. I'll try it and post the results.

It's been a long time since I used Wings 3-D and it was even for use in a different 3D game. But I do remember a part of Wings where you can, in essence, flatten all the faces onto what amounts to a 2D texture map. The 256x256 texture map is then imported into something like PS or PSP where you "color" each of the individual faces, staying "within the lines" of each face with whatever color / texture you choose. Once you are satisfied with the "map" you then bring up your wire mesh, incorporating the newly colored texture map as an overlay of sorts, and voila! a completely textured object is born.

My question (finally) is this. Can this process be done to create textured sculpties in SL?

Thanks in advance...
Bartiloux Desmoulins

Bartiloux, that's what I want to do, too. It's clearly feasible. I'm investigating the details.

I just found this tutorial...

http://homepage.mac.com/ycarry/Wings/Pencil/Pencil3.html

It seems to encompass many, if not all, of the steps I remember from my days creating objects in that "other" 3D game. Give it a look and see if this might make life easier when it comes to texturing sculpties.

Bartiloux

I modified my exporter to export a cube of 32 slices (i.e. a 33x32 bitmap). SL accepted it fine. But here's a comparison between 32x32 (left) and 33x32 (right) bitmap files. In each case, I raised every other vertex to create spikes. It looks like in both cases, the sculpty is sampled on a 32x32 point grid, just as Qarl has said. So a 32x32 bitmap (i.e. 31, not 32, slices in Wings 3D parlance) is still the best way to control the SL shape seen at maximum LOD.

If you really want to explore this in more detail, it wouldn't be hard for me to generalize the exporter to generate a sculpty file from a sphere with arbitrary section and slice counts. Let me know if you think that would really be valuable.

Yes, that's the idea. In fact, Wings has gotten even better since that tutorial was written. Now, you can interactively color the texture map (using your favorite 2D paint program) and see the texture applied to the Wings model. (You do need to save the image in the paint program and refesh the image in Wings, but that's just a couple of clicks.)

Thank you for the pointer to the VRML plugin, Bartiloux. It should be helpful in working out how to export the baked texture directly from Wings.

Okay... so that was going to be my next question. Just because you can texture something in paint using that technique, will SL "know" what to do with a textured sculptie? Is the export different, or are there additional steps, when exporting a pre-textured sculptie into SL?

My goal is that when you export from Wings, you will get two bitmap files -- one with the sculpty shape (currently implemented) and one with the appropriately mapped texture, ready for uploading into SL (yet to be done).

Wish me luck!

*seaches for the hat being passed around to contribute to "the cause."

Nope, nothing is amiss. I think what's happening is you're confusing Vertices with Slices (Which is why I mentioned the fencepost error). The exporter calculates the sculptie map based on vertices but Wings3D asks you to size your sphere based on slices/segments.

This is why you might get unexpected results if you create a sphere that isn't nsegments with n-1 slices. You'll end up with an extra pixel in one dimension that the SL importer will then sample down, giving the odd results in Omei's post.

Maybe this picture will help this to be more clear.

BTW, if the means you were offended, I apologize. I didn't intend to do that.

The above pictures are not how sculpties actually work in SL. The attached image shows a sculpty sphere in SL, with the object detail slider all the way down and wireframe on, at about 700m altitude. There are 8 segments and 9 vertices vertically.

If the sculpty texture is, say, 64x64, then the pixels are sampled vertically at positions of 0, 8, 16, 24, 32, 40, 48, 56, and 63. To get a full detail 33 vertex sculpty, it samples at 0, 2, 4,..., 60, 62, and 63.

I think it has to be this way, in order to get nice effects when changing between levels of detail: if we go from 16 edges to 32 (so 17 vertices to 33) then we only add vertices, the existing vertices do not shift around to new positions.

A SL sculpty has 32 slices, not 31.

It's all a little messy. I think it's a result of the the "Approximation" approach that LL understandably wanted to take. But they may have underestimated our desire for total control over each vertex.

Or maybe it's just me that's a control freak?