From: Shifting Dreamscape
Chosen ... with regards to darkening the upper prim, thought about that, but then the problem becomes that in daylight said prim is darker.
That's why I said use a script to apply the darker color only at night. It's not foolproof, since if someone forces daylight, they'll see the two different colors, but most people will see it correctly (assuming that light is behaving similarly on their graphics cards to the way it behaves on yours).
From: Shifting Dreamscape
In regards to your suggestion for baking lighting into the texture ... sadly texture creation or detailed manipulation goes well beyond my skillset ... if I could do it in a script then great, but have no abilities or experience when it comes to image work.
Hmm. Well, you could always learn. That would be the best option. Or the second best would be to hire someone to texture the place for you. Neither is a quick and easy solution, and the latter could get expensive, but both are better than the alternatives, in my opinion.
If you want to go half way with it, one solution would be to fullbright both pieces, and then darken them both. Fullbright will make them immune to the effects of local lighting, so they'll both look the same. Darkening them will keep them from looking too washed out. It's not the best option, but if your main goal is just to make the two look the same as each other, that's the simplest thing to do.
Or you could add more prims, as 2K said. That's not ideal, obviously, but it could work.
From: Shifting Dreamscape
In any case ... wouldn't that though as well cause a problem in daylight?
Not at all. First, if you're going to use self-lit textures, it's best to fullbright everything, so that in-world lighting conditions can't mess with your pre-defined lighting/shading scheme. So the room will look the same all the time. Avatar appearances will of course still change throughout the day, but the room itself will not.
If the fact that avatars will darken at night, in contrast with the apparent lighting of the room, is something that bothers you, well that's where you can put your local lighting to good use. Just be careful not to overdo it. You don't want people looking washed out. Keep it subtle.
Second, if you're concerned about the fact that in RL, interior lighting schemes do change between day and night, I'd say you're over-thinking it a bit. There are certain things that are always constant, and those are the things you want your texturing to accent. Your overhead light, for example, is always going to cast a glow around itself onto the surrounding ceiling (unless it's turned off, which it never needs to be in SL). The ceiling will always cast a shadow onto the upper wall. The walls will always cast a shadow onto the perimeter of the floor. Furniture in the room will always cast shadows onto the floor. Etc., etc., etc.
Those are things that local lighting can never do, which is why it looks so fake. Accentuated shadows are what bring a build to life.
Third, if the idea of a static, never-changing, lighting scheme is too unrealistic for you, you could always step up the game by creating two (or more) schemes, and have all the prims switch textures at regular times, to show each scheme in accordance with the SL day/night cycle. Setting all that up is incredibly time consuming, of course, which is why it's not done very often. But if one has the time to do it, the results can be very cool.
In any case, the point is that local light doesn't behave much like light should. It's gotten better as SL has developed, but it's still got a long way to go. It's best not to rely on it too much.
