Basic Shaders, Local Lights, and Why We Don't Match

This might reasonably belong in the Texturing Tips section, but posting it here because the issue of matching prim body parts arises with some frequency. This may be old hat to serious texture folks, but it was amazing to me.

I wear these sculpty toes that I glued on some sandals I made; the toes came with a surface texture that's not much different from blank, so I painted them to match my skin tone, more or less.

A friend sent me a snapshot taken in fully saturated yellow local lighting; the toes were bright yellow! On my machine, in the same lighting, they looked fine. Experimentation revealed that the difference was the setting of Basic Shaders: turned on, a blank-textured surfaced painted some color looks the same as a white-colored surface to which the same color of texture has been applied. Without basic shaders, the painted on color is almost completely washed out by the local lighting, whereas the texture-applied color looks normal:

With Basic Shaders:


Without Basic Shaders:


For more detail on how to reproduce the effect, see https://wiki.secondlife.com/wiki/User:Qie_Niangao/Basic_Shaders_Local_Lights_and_Why_We_Dont_Match.

Anybody who makes (or wears) body part attachments may want to be aware of this difference.

My question is: Could this be useful somehow, or otherwise something upon which existing content depends? (Otherwise I'm inclined to think that rendering of color tinted surfaces under local lighting is just wrong without basic shaders, in which case I'd file a jira.)

File a Jira. They were supposed to have fixed this several versions ago.

Thanks, Argent. Done: https://jira.secondlife.com/browse/VWR-15690

I've noticed this effect also. It's seems that the basic shaders, or lack of, is a real killer to things people have spent a long time getting just right. Environmental shaders also have some effect, but not nearly as drastic. One trick to minimize the effect is to deliberately make the base texture you're using a fair amount brighter, or with more positive gamma, then use the tint function with base grey shades... Darken it to match when all the shaders are on. The result when the shaders are turned off is that the differences between the 2 isn't that bad at all.. and in some cases you can't even tell. Not exactly sure why this trick works, but usually it does (depending on the source texture of course).

Linden Lab will probably "fix" this by not letting you turn off basic shaders anymore.

Bad idea, that would kill off a lot of low-end machines.

That would be a mercy killing.

Kidding aside, sometimes I turn off basic shaders for snapshots, so I'd like to see this fixed.

there are other graphics glitches that need fixing badly, like VBO not being usable on some videocards because it messes up the screen with triangles