Room with only interior lighting?

I'm trying to build rooms that are NOT affected by outdoor or surrounding light, but I don't get it..
I even built a box around myself, and it was clear daylight in it. How can I make rooms that are only lit by the light sources I put in there?

You can't. Nor can you keep your interior lighting from escaping your house.

That's a bit confusing.. I'm certain that I at some point walked from a sunny outside into a very dark room, lit only by candles and torches... I can of course be mistaken.

You can make your interior textures dark. My "prim lab" is completely black on the inside, except for the grid lines, and it looks totally dark when you are in it. Except that your avatar appears fully lit, as is anything you build that is not very dark in color.

Also, if you just want to do photography...

world > force sun > midnight

and also adjust the nighttime lighting in your preferences.

Only you see these changes, though, so it's not a way to create a dark room for others to see.

I'm actually going for a "cave-like" room (or rooms, really) with only torches on the walls as lights.

No photo, no interactivity.. So any more tips would be really great.. I'd like to have stone walls, so just black won't do, there should be some "rock like" textures.

You could make your "rock like" textures very dark, except where the torches will go. Some more advanced texture artists already do this. Instead of making a uniformly-lit texture for, say, a floor, they paint in where the light falls. That's problematic for sun-lit spaces, as the sun moves, but for your caves it'd work really well.

Still nothing you can do about your avatar being lit.

not a perfect solution by any means, but some people have hung almost invisible black transparent phantom blankets areound here and there. They abosrb the light.

That makes moving the camera around a pain. Same with prim light beams. I hate those.

As others have said, light in SL cannot be blocked, so you can't make a room (or anything else) in which sunlight/moonlight will be absent. However, you can fake it pretty well. If you really want to make a project out of this, here's what I'd suggest.

You're doing a cave, right? Then presumably the wall surfaces will be rocky and irregularly shaped. This gives you lots of opportunity to apply baked lighting and shadow (heavy on the shadow in this case) in really interesting ways.

If you're not familiar with the term "baking", it means to create textures that have the appearance of light and shadow directly painted onto them. This can be done by hand in Photoshop, or it can be rendered in a 3D modeling application like Maya or 3DS Max. Either way, it's a VERY time-consuming process, but the results can be spectacular (or spectacularly bad, so make sure you have a good artistic eye for light and shadow if you're planning on doing this).

Think about precisely where you want your artificial light sources to be, and make sure the textures on all surfaces are shaded so that the highlights face the light sources, and the shadows face away from them. If you're planning on using torches, take a look at some photos of real rooms being lit by torches, or even by candles. Notice the flames cast a distinctive orange glow onto everything close to them, and then the appears increasingly more yellow and more faint on surfaces that are further away. Notice also that firelight casts intensely harsh, dark shadows, but there's also lots of subtlety to be seen once your eyes get used to the light. It takes a lot of work to pull that off convincingly with baking, especially since the light won't be "dancing" the way it does when you've got real live flames.

You'll want to turn on Full Bright for all surfaces, so that sunlight/moonlight will not affect them in any way. The ambient light will always affect your avatar when in or out of the room, no way around that, but Full Bright will stop it from being applied to the prim surfaces.

If you want to see a really good example of how what baked lighting can do, take a look at this video of Xenius Revere's chapel in Yule. Yes, that was filmed in Second Life, believe it or not, and that build does exist in-world. All surface textures were baked in Maya, and Full Bright was employed in SL to ensure that sunlight/moonlight do not show up to spoil the illusion. When you stand in the chapel, you can see of course that the lighting on your avatar is very different from the lighting on the objects around you, but by just looking at the chapel itself, it's hard to tell that the lighting isn't real.

If you want this particular project to look good, be prepared for a lot of work. There's no way around that. The ooh's and ahh's you get afterwards will be well worth the effort though. Just don't expect to build this in a day.

I'll check out the video, and also visit the place to look at it. But I already know that I won't be able to do that work myself, so I will hope that I can buy the service from somebody.

Anyone needs to be hired?