Lighting

I have noticed when it gets dark in the sim ..well.. it gets dark. I've been playing around with the building tool but just cant figure out the lighting. Can anyone help me?

To use light prims to light things up you need Local Lighting turned on in your preffences (Ctrl+P in world)

But you can rise the sun by..

Activating Debug (Ctrl+Shift+Alt+D in world)

Then by going into the debug menu up top, choosing world, then force sunset

You might also want to check that your night time brightness slider is all the way up, and that your gamma is set to an appropriate level. (Edit -> Preferences -> Graphics)

If you're asking how to make a prim light up, it's done from the editor. On the object tab, there is a pulldown menu for material. Set the object to "light" and it will light up.

You might want to hold off for a few days though. 1.7 should be out some time next week, and it will feature a new way to do this that is much friendlier to our computers. Lights are a major source of lag in SL for anyone who has local lighting turned on because light objects cast rays. Put a few of them in the same area, and your poor little CPU has to process thousands more calculations per second than it normally would (That's right CPU, not GPU, go figure. Baaaad SL, bad SL. Learn to use the power of the modern graphics card already, would ya?). Anyway, 1.7 has a new feature on the texture tab called "Full Bright" which causes any or all sides of a prim to ignore local and world lighting conditions, and behave as if the sun were shining directly on it at high noon. That means the side(s) will glow in the dark without casting any resource-hogging rays.

I'll be turning almost all my lights off and replacing them with full brights the moment 1.7 goes live. Hopefully most everyone else will as well and we can finally enjoy local lighting the way it should be instead of letting it constantly abuse our poor little overworked and underpaid CPU's.

Or after the debug menu is available, go into mouselook, hit ctrl+alt+m, look up as high as you can, and hit ctrl+alt+m again. Voila, midday sun.

Here's a reverse question...how might one block the sun out? You know...for that scary haunted-house feeling...

There are two ways to achieve this:

1. Perpetual nighttime. You need a private estate sim to be able to set or freeze time for all people in the sim though.

2. You build your structure under water. This will tone things down and give a more eerie feeling.

Fullbright will make things easier to see. It also will make them look horribly ugly, if you set *everything* fullbright.

The first two pics here are a comparison of an area without and with fullbright

Fullbright is much more useful when you can set *parts* of a texture (which we can't do, judging by the description ... it would require a separate illumination texture or using the alpha channel to determine which parts were illuminated) or a model (which we can do with setting individual prims or their faces) to be fullbright. That makes them look like they are glowing. Like a plain red fullbright primitive in place of a robot avatar's eyes.

The basic difference is:

The current local lightning method actually lights up other primitives, and tends to look like a "real" light (compared to the normal lighting SL does).

Fullbright only removes the shading from a texture or surface, and does nothing to make the rest of the environment brighter. If that texture or surface is meant to be something that glows, like an LED, this looks great. Otherwise it looks ... bad.

Actually, just the opposite: set the slider all the way DOWN so it's pitch black at night--then lighting TRULY shines (contrasts).



Um, modern 3D video cards have HARDWARE transform & lighting (T&L) which is done on the GPU, not the CPU. But, yes, prelights (or "full bright" will greatly reduce lighting lag (with lots of polygons--twisted, hollowed tori/tubes/rings are the worst).



GPUs

Um, yes modern graphics cards have that, which is why I, um, said it would be nice if SL were made to actually use it. Um, Please read a little more carefully the next time you have the urge to correct somenone. Um, just because you have knowledge of how you, um, think something SHOULD work, doesn't mean that's how it DOES work.

You're absolutely right that the graphics card SHOULD be what handles local lighting calculations, but for some reason in SL it's not. I know this because I asked Lee Linden about how lighting works a while ago when the technique of turning side zero black to cut lag was first becoming popular. Read about it here. I have no idea why, but SL does indeed calculate local light with the CPU, not the GPU, which is why it's so slow.


No, CPU. If it were GPU, we wouldn't have so much to complain about.

Well, I don't think Lee Linden truly knows/understands how SL lighting works then. Even OpenGL uses hardware T&L so it's odd SL would be doing lighting in SOFTWARE (CPU) and not utilizing one of the very thing modern 3D cards were DESIGNED to handle: lighting (and vertex transformation--translation, scaling, and rotation). Reading that thread, For LL NOT to know how their own lighting model works is a bit pathetic. I will stick to the industy-standard method for dealing with lighting in 3D APIs like Direct3D and OpenGL until I learn otherwise.

is there an available (or plannable variation of 'full bright' as 'percentage bright' - set to a specific default luminance factor, say 0, 10-30% for shady areas at night (30-70 for more night-illuminated walls/object, 70-100 for fluor/neon/lightsources) - if local luminance/abient(sun)light drops below a certain level, the prim lights up that amount??

Just change the prim's color to a darker shade of grey if you want the prelight darker. Use a script to adjust it relative to sun direction, perhaps.

Gee, it must be nice to be so in touch with the universe that you instinctively know more about how a system works than the people who wrote it. That's really impressive. I especially like the part where you're able to use your awesome mental power to convince people that what they wrote isn't really what they wrote, and how you're able to persuade them to describe the workings of their system in a way that must be totally made up, because you KNOW, and they're pathetic. That's amazing.

I wish we had better internal control over simple brightness+contrast within SL. Would make a lot of difference with all the muddy, washed out nightshots that'd otherwise be a big splash on Snapzilla.

I'm also in favor of localized Gamma that doesn't affect other appies.