Self Lit Prims!!!! The Way!

alright folks, I've posted on a few feature request threads now, requesting self lit prims. We have light prims but these have the pesky habit of actually radiating light. Well duh you might say, that's what you want them to do isn't it? NO! Self lit prims are prims that aren't effected by the surrounding light, lit from within, AND also do NOT cast light on things around them. That last part is useful for signs, are anything you want to be visible in the dark without it making things around it washout, or change color. And not least it also keeps mid range to slower video cards from dying with local lighting turned on.

So, here's the secret. The light that shines from an object is the color of side 0. so you can use every other side as long as you set side 0 to BLACK. because black turns off the light source. It will still be very visible in the dark, but it will no longer cast any light around it.

For example, the top of a cube is side 0, so set the top and bottom if you like to BLACK and you can put signs on the other four sides. Make the prim type light, and walla, a sign that's visible in the dark with none of the dissadvantages.

Another use for this is jewelery. I've seen many a diamond that's set to light so it shines at night. Looks wonderful but with local lighting on it also makes funny lights on your avatar, doing things like making the underside of your hair glow. Make side zero of the gemstone black and hide it in the setting, or in the middle of the gemstone if the stone is many prims. Now your gemstones shine in the dark without hurting anybody or making your av glow in strange places.

Please Please consider using this. It speeds up everyone who likes to have local lighting turned on, and lets things around them that are supposed to shine with light do so.

if you're not sure how to figure out which side is 0, create a new script and replace all the code in it with the following script:

default
{
     state_entry()
     {
          llSetColor(ZERO_VECTOR, 0);
     }
}

As soon as you save this script side 0 should turn black.

If you want to turn side 0 of EVERY prim in an object black use this code.

default
{
     state_entry()
     {
          llSetLinkColor(ALL_SIDES, ZERO_VECTOR, 0);
     }
}

Also remember that in things like jewelery things like the chain do not need to be light, and that you can set individual prims as light rather than the whole object.

Thanks

Excellent suggestion!

I'm working on something that needs this exactly. I want it to to be highly visible at night, but I don't care at all if actually radiates light.

This is also great for things like animated fire: you want it to cast orange light but you don't want to tint the prim completely orange.

This is great stuff. I look forward to incorporating this technique.

Rick, once again I am humbled before your genius. Great suggestion!

farking hell that's a great trick.

ty ty ty!

/me claps.

Thanks!

Aw, we vixens get no respect...

WTG Cross good job I didnt see yours!

also thanks for this thread keep the free flow of information!

*giggle* Rickard's much better at explaining ideas sensibly than I am.

Very nice. I'm curious if this still requires some CPU time in the client, even though the effective light cast distance is nothing. Very nice observation, either way!

Cool. I'll put this to use in my new vendor right away.

While it's a good hack, we STILL need to separate light emittance and bright apearance. This trick is useless on shapes where side 0 must be visible, such as spheres and tori.

I tested it, at my house with 16 lit boxes. With the trick it was about 4fps faster than without the trick. So I think it helps. Not a huge difference, but there wasn't much around to actually light either.

cutting causes one face exposed by the cut to be side 0, so if you can hide the cut it works for spheres and tori.

but you're right we still need an official way rather than a hack .

OK I like that but could you explain in little baby steps again now to do that.

Or sell me one.