lights in raytrace

**abby** · 03-22-2006, 06:07 AM

When I put lights on it looks very strong but in raytrace the room is totaly dark. Why? What to do?
And why some of the lights when I put them higher don't work at all? I'm a newbie with all these so if someone can help me..

**Chiefdoggydogg** · 03-22-2006, 06:14 AM

When you open the light make sure use in both is checked

**abby** · 03-22-2006, 06:27 AM

Use in both is checked but nothing changes

**cgirerd** · 03-22-2006, 07:49 AM

Not knowing the details of your plan, I can't guess exactly what the problem is, but maybe this info will help you figure it out - you may already know this, but just in case...

When you are in render view, part of the light is the effect of the "interior ambient" slider in the 3D dbx. In a new plan, if you had a closed room (no windows, no doors) and did not put any lighting in, it would be partly lit by the interior ambient "generic" light. But interestingly, if you slide that all the way to 0, there is still some light anyway. Now if you went to raytrace that room, it would still be somewhat light if you left on the "create default light" toggle on the raytrace dbx. But if you uncheck that, the raytrace will be completely black.

What gets trickier is once you have even one little light you've added (wall sconce, "add light", ceiling light, lamp...), the raytrace will only use light from that source and not generally light the scene with the "default light". So if that light is very weak (low intensity) or hidden (the height is off so it's "in" the ceiling or the floor or in a cabinet (hey - it's happened to me!), it won't show in raytrace. Something else I do to try and solve lighting problems is to change the color of the light I'm trying to figure out to bright pink or blue - then the light from it is more obviously separated from general light or other regular lights I have in the scene.

Good luck.
Christina

**lbuttery** · 03-22-2006, 08:01 AM

change the color of the light I'm trying to figure out to bright pink or blue - then the light from it is more obviously separated from general light or other regular lights I have in the scene.

Nice idea !!!

Lew

**jsimanyi** · 03-22-2006, 08:48 AM

This may sound stupid, but a large number of my quickie raytraces require me to turn up the brightness via the image adjust slider. They work fine, it just seems that the default is quite dark. Have you played with that (admittedly limited) tool?

Also, just render a single room without windows at first, and place lights one at a time to get a feel. Everything about Chief takes a while to understand, but it's worth the time testing in small versions to feel more comfortable when it gets complicated...ya know, like on a real job...

John S.

**abby** · 03-22-2006, 08:59 AM

I put windows, create default light is on.. (I retrayce using night not daylight)
I used ceiling light but it's too low (it almost touches the table) so i raised it and it's not working now(intensity is high!)

I'll try changing the color maybe it will help. thanx Christina!
I tried that with brightness, it helps a littlebit but not always..
Will try placing lights one at a time, maybe i'll learn soon. Thanx John

**jsimanyi** · 03-22-2006, 09:07 AM

It takes a while to find settings that work for you, and it's a bit frustrating at first 'cause the renders are sooo easy.

But it's worth it. Keep playing around - you'll get there.

John S.

**abby** · 03-23-2006, 06:22 AM

But still don't know why ceiling light doesn't work

**abby** · 03-23-2006, 08:46 AM

Half of problem solved... Shadows make room looks darker than i wanted

When I turn off shadows it looks better...

Thax for helping everybody

**jsimanyi** · 03-23-2006, 09:56 AM

Check your offset value in the light dbx. The pretty looking light assembly is a different "thing" than the light source for rendering and raytracing. Likewise, you need to make sure you actually HAVE a light source selected in raytrace (the Light 1/Light 2 stuff in the dbx).

Really the light "source" is just a point that radiates. There is a chance you have it buried above the room, so the ceiling planes are blocking any light from getting in.

It's a long shot, but take a look.

John S.

**Elmware** · 03-23-2006, 05:06 PM

I have the same problem when raytracing with lights in a room, and if there isn't a light, it's too dark. So I tried doing it without the radiasity, and it seems to be much better.

**mcqueenhomes** · 03-23-2006, 05:25 PM

Yeah I get better interior traces without radiosity.

**Chiefdoggydogg** · 03-23-2006, 06:01 PM

i think it is the OCD in me but i have to crank up the quality all the way no matter how long it takes...it seems to me lower settings of radiosity give blotchy results maybe its just me?

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