Second Life PBR Experiments

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As most people who are into second life know. Linden Labs, with the help of a Cabal of graphics engineers they hired and a Husky have overhauled the graphics backbone of Second Life and added support for modern Physics Based Rendering (PBR) which produces far more realistic looking light and color interaction then any previous second life model.

I have been aggressively changing assets used in my various builds and outfits to PBR and recently I started experimenting with skins. For a long while my skins looked like this:

As you can see, this is the bog standard Starlight Skin template with a pale skin tone thrown in. The starlight skin has a whole lot of shadow and highlight to make up for the fact that the SL lighting system didn't produce all that shadow and highlight.

But now we got PBR and that stuff is handled. We have ambient occlusion maps, roughness maps, and all that fun stuff. The roughness and light creates its own higlights. There's shadows cast and it all conflicts with the light/shadow reliaty that the skin template I was using generates. This was starting to rankle with me. One you notice it you just can't un-notice it. There's huge swaths of arbitrarily brightened and darkened areas of the skin conflicting with where the lights are falling.

So I decided to try an experiment to change all that up. I took the starlight template and changed the base color to pure white after disabling all the fingernail layers because we got mesh bodies with their own nails dammit we don't need skin-nails.

The result was what was going to be my AO map. It's not a perfect AO map but I figured it'd be good enough for a quick and dirty map.

An AO map tells the engine how much ambient light should reach any particular pixel. In the absense of direct light, a pure black area of the ambient map will show up pure dark in the engine. Ambient light comes from light reflected off of everything in the scene. Stuff buried in crevices, like your navel, don't get a good look at the outside world, and therefore don't get a lot of outside world light and appear dark. It'd be troublesome to make the engine calculate where all those crevices and stuff are. So instead we just make a texture that tells the engine where all that is.

I made a metal rough map using that. Feeding the AO Map into the red channel, and pure white into the roughness and metal channels (Always go pure white, even if you intend on it being non metallic. That way you got the option in case you want to do something fun in the future.

This gave me the resulting map. Which is again, quick and dirty, a more professional map might put a little more nuance into the roughness. But here we go:

But those dark crevices need some crevices to be dark in, so I hid all the layers in the Starlight template except the crevices of the knuckles and stuff and the navel and then threw that at a normal map generator (which uses dark for low and white for high) and got this.

So with all this detail shunt to other sides you might be wondering what I'm using for the base color.

The answer is practically nothing. Observe:
A swatch of pale skin tone

Yes, a 32 x 32 pixel swatch of pale skin tone.

I threw it all together in grid and looked at it and it was kinda decent. The knuckle creases were a bit intense and might need to be toned down (also Starlight doesn't align knuckles quite right to a reborn body) but here: