Size of Eye Textures

I've been tinkering a little with making eyes (well, recolouring the eye template, anyway), and I was looking at tweaking the texture a bit more to better fit the eye-size of my avatars. I am not quite sure (other than trial and error, of course) how to work out what a good size is, though.

Does anyone have any guidelines for size of the eye in the texture in relation to the avatar eye size? For example, I've got my avatar's eyes set to size 40 with a 40 for the eye slit as well. That seems more realistic to me, but the standard eye size looks too big with it.

I've noticed that some eye designers provide eyes in two sizes, does anyone know what size the eye in the smaller texture usually is?

Whatever size you make the texture, it's gonna get baked to 512x512 when SL composites your avatar's outfit, just like every other outfit texture component. The physical "size" of your eyes in SL has no bearing on this. When you resize the avatar's eyes (or any other body part), the texture that's on them does not change. It will of course appear to get bigger or smaller as you increase or decrease the size of the body part, but that doesn't mean you're actually changing the measurements of the texture. So just use the template size as is.

However, if you're talking not about the size of the whole canvas but about the relative size of the iris and/or pupil within it, that's entirely up to you. You can paint over that canvas any way you want. Just remember to keep everything centered unless you want your avatar looking cross-eyed or wall-eyed. Feel free to experiment.

Yes, I meant the size of the iris & pupil. Sorry for not being clear on that.

I guess I was mainly wondering if there are any standard diameters that people know work well for more realistic eye sizes.

I don't know of any standards (maybe people who specialize more in eyes than I do will chime in on that), but here's what I'd suggest. Make an image with with a ton a graduated concentric circles. Color code them so you can tell which is which. Apply the image as an eye texture, and then pick which circle you think looks the most proportionate on the actual eyeball.

Oh, that's clever. Much better than having to upload several textures to test.

Great idea, thanks.

After making some eye textures with irises that are considerably smaller than the standard size, I've run into an issue that I am not sure its possible to work around.

Whether or not I have a background for the eye or just the iris itself, I get a bit of a ring around the eye when the texture is applied to the eye in second life. This ring seems to match the standard size of the iris, and I would guess that it is some kind of bevel shadow that is applied when the texture is added to the eye.

Is this correct? If so, is there a way around it?

There's not much you can do about that. I suppose turning the avatar bump mapping off (if that works correctly at all) might have some effect, but there is also a shine that gets applied to the eye as well. All of that is controled from peoples individual clients, so you as the creator have little control over how others set up the graphics on thier systems. BTW, I think the texture size for eyes is baked at 256x256. This is the resolution of the eye white on the client side. It makes sense to render the eye at this resolution because the surrounding texture of the face is then a closer match. Upon closer examination the eye will look more natural when viewed against the surrounding skin which inevitably has that harsh edged look to it because of overlapping polygons. The closer match in texture resolution helps to ease that harsh trasition a little.

Ahh, thanks. I suspected it was something along those lines. Guess I just have to put up with it, then.

The eye texture as you prepare it will be rotated 90 degrees when it gets applied to your avatar. Elsewhere in the Content Creation Forums here, someone (Robin Sojourner?) discusses this in more detail. I think it's 90 degrees CCW (counter-clockwise) so that if you put a reflective highlight at 3 o'clock, it will show up on your avatar at 12 o'clock. It's one of those lovely (and idiotic) gotchas that fill a designer's life in SL, keeping us in good practice in our employment of expletives.
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After a little experimentation in wireframe view, I think it's safe to say that the "ring" is not a bump mapping issue. It seems it's built into the actual geometry of the eye. I guess the eye is actually modeled better than I had thought. Like a real eyeball, the avatar's eyeball is not a perfect sphere. The iris area protrudes outward, almost like a nipple. You can see it here:



So yeah, looks like you'll just have to live with it.

Ah-ha, the wireframe does make it clear how it works. Good attention to detail, I suppose, to have it rendered that way. But annoying that it means only a certain size of iris will work perfectly. Especially since that size is way too big to be realistic.

Good observation, Chosen. The raised effect on the eye never really bothered me all that much, which is probably why I never investigated the ghost pupil/iris. I hardly notice it once the eye is textured realisticly. It might be kind of cool if there was an eyeball shape slider we could manipulate.