View Full Version : Lighting Question

12-19-2007, 02:04 PM
hello to all of you out there.
I hope you are all having nice time.
well, I do have a sily question for you my friends.
it has to do about lighting.
I'm working on a project of interior design.
I have a small apartment and I'm trying to light it.
I'm using mostly point lights and here it is the situation.
I'm having some point lights to light a single room and and when I 'm
satisfied with the result I go the camera to another room to continue to work.
And I see that this other room which is next to the first gets some kind of ilumination from the point lights there.
those two rooms don't have a common space. there are independed rooms just close to each other.
Is it supposed to act like that? I thought that the light rays do stop when they meet an object. then why does my point light rays go through a wall object and illuminate some object there.
I will go mad. I have read so many books regarding this thing and I still don't get it.
does anyone have any idea. any clues..????

12-19-2007, 03:11 PM
give it a falloff to fit inside the walls, you can see the falloff in your view (all light has falloff, it never goes on and on)



12-19-2007, 03:15 PM
Have you turned on ray traced shadows?

12-19-2007, 03:32 PM
turning on the raytraced shadows does make a difference
but only while I'm keeping the lights in low intensity.
when I use inverse distance or 100% intensity the light rays go through the
wall object and lit the other in the other room too.
and other than that the point lights are supposed to lit to any direction.
why in my scene, point lights affect only some walls and not all of them no matter distance they are????

12-19-2007, 03:36 PM
Post a render, it might be your geometry that has issues. What renderer are you using?

12-19-2007, 03:55 PM
Do the lights have shadows enabled?

As much information as you can give will be helpful.

12-19-2007, 04:04 PM
the geometry is very simple.
I made a box with the normal dimensions as a room have.
then I put a thin box to act as a thin wall to separate the box into two rooms.
very simple. (hope my english don't mess you up)
I lit the one room with a few point lights. I liked the result. ok.
then I went to the other room to see.
it was dark. to make an expirement I put the intensity of one point light to 100%
and then a wall from the second room got lit.
thats all. and I'm asking whyyyy???????

12-19-2007, 04:13 PM
still think you should post a render, its kinda hard to tell whats going on by just hearing it, might be the material of the wall, could be endless things. maybe you made the wall with normals flipped.. unless we actually see something its just guesswork really.

12-19-2007, 04:22 PM
ok I will post an image.
mmm how do I do that?
how do I post an image?

12-19-2007, 04:36 PM
first picture:the first room lit ok with the 4 point lights.
secont picture:the first room with the one point light intesnity at 100%
third picture:the second room in which the one wall is lit.

12-19-2007, 04:40 PM
I don;t think that wall is lit, I think you're looking through it. Most likely a normal facing the wrong way or something.

12-19-2007, 04:47 PM
what else could it be then?
and that scene its just a start.
if I go and use more lights in the first room the second would be lit more.
and not the whole room.just one or two wals.
I made the walls double sided and still the same problem.

12-19-2007, 04:48 PM
yeah both ground and floor arent lit, no falloff to detect in the second room, check normals , material, merge points

12-19-2007, 04:52 PM
and check if your geometry is planar (statistics panel in poly mode). triple your geometry if you doubt your model.

12-19-2007, 04:55 PM
all checked and are ok.
does that mean that my program works wrong??
maybe LW do not calculate the data of the light well enough and resulting to that problem.
what do you say?

12-19-2007, 04:56 PM
by looking at your renders my guess would be you set your walls to luminous, you can always post the object for one of us to check, i'm sure its nothing terribly complicated..

12-19-2007, 04:58 PM
i doubt lightwave works wrong or has a bug

12-19-2007, 05:01 PM
no nonplanar polys.
everything is good.
problem remains.I just got tired.
tell me my friend. is this happening in you too??

12-19-2007, 05:06 PM
looking at your renders, this is a simple setup, as basic as it gets..

i cant re-create your problem, and havent witnessed it. Dont know how clean you model and dont know your skill in lightwave. shoot me the model and i'll check it.

clumsycloudy 'at' gmail 'dot' com

12-19-2007, 05:08 PM
would you like to send you the object to test it?

12-19-2007, 05:09 PM
ok I'm sending

12-19-2007, 05:13 PM
you may check your mail my friend.
I'm looking forward your results...

12-19-2007, 05:51 PM
ok, you set ambient light to white color and gave it an ambient intensity of 3%, no falloff set to any of the lights

If you give the lights proper falloff the second room stays pitchblack

12-19-2007, 05:53 PM
sending you the scene now...

12-19-2007, 06:09 PM
okay made a fresh scene and all is fine now, second room stays black no matter if lights have falloff or not, placed one light without falloff in there to prove it

12-19-2007, 11:04 PM
I will study the scene you have sended me and see what I was doing wrong.
thank you...I will inform you regarding this.

12-19-2007, 11:13 PM
hello again.
I'm I missing anything?
I load the last scene you sended me and I still see the second room wall lit a litle.
of course that is without fallof as you said.
if I put light intensity to 130% that wall gets lit more.
is this normal? is it supposed to work like this?

12-20-2007, 01:31 AM
i sent 2 zipfiles, both have different object and scene files in them, so you have to make sure its using the right files. The scene calles "new.lws" has a light in it without falloff, lights the first room and second one stays black. I rendered using native and fprime and i am absolutely possitive the second room stays unlit, like it should.

Your scenefile seemed it wasnt good so i loaded the object (i remodeled to make sure) into a default scene, added light, switched on fprime and went through the wall to check if the second room was affected.



12-20-2007, 01:40 AM
i rechecked, cranked the light up to 1000%, second room is pitchblack

12-20-2007, 08:47 AM
hey my friend I'm back since I got to my work.
I took your mail and it looked that is working properly.
I do test it and its ok. I put the light to 1000% intensity and the second room its totally black.
but I don't understant. what was wrong? the geometry?

12-20-2007, 09:23 AM
dont know for sure, not the geometry, something in your scene wasnt 100% correct. I just remodeled to make sure it wasnt the geometry but only when i made a new scene i got correct renders. Maybe a corrupt *.lws file, sometimes files just messed up, i had a look at your original scenefile and it even looks wrong in opengl, no idea what caused it.

its working now, so be glad..



12-20-2007, 10:33 AM
thanks to you.
I made a few tests.
it is not the geometry to blame.
FIRST:the shadow type in the properties panel should be in raytraced and NOT to off.
SECOND:in the render globals panel raytraced shadows MUST be ON.
THIRD:I'm very stupid.
what was I thinking?
my friend with your help I realize that.
you see while I was trying to illuminate an interior scene I put all the lights with
the shadow type to off. because I was trying to achieve a soft ambient light with no shadows. I didn't think of getting any object's cast shadow to off.
I own you one pal....

12-20-2007, 10:39 AM
you may look at it.
you see I'm right.
now the fact with opengl IS an issue.
having the camera in the second room and through fprime is totally black nomater intensity has the light in the other room.
but the opengl does show some kind of illumination which is not getting to final render.I do not know why this is happening though.