indirect lighting ( Maya related )

[metal0130]

i'm not quite sure I know what you mean. you want the effect of the ceiling actually BEING a light source? indirect lighting would refer more to bounce light than a light "source"...

what is happening in this scene? is light hitting the ceiling and you want to fake the "bounce" this creates?

[Sefiroth]

What I want to create is something like this:
http://www.celestiallighting.com/images/home/h_circular_cove.jpg
If it was possible to emit light from an object it would be easy to get this result.
So first of all, how am I supposed to get such a lit surface like on this picture, and then like you say, how to fake the bounce of such a light.

I dont have experience in lighting, so maybe this is just basic stuff, but with this shape it is an oddity for me.

[metal0130]

have you thought about using a spot light with a negative intensity... I made a REAL QUICK setup in maya so bear with the cruddy quality... but I have an area light illuminating the surface evenly from directly below and then a spotlight pointing at the center with a high penumbra and a little falloff. with proper light linking to get rid of illumination on things you dont want it on... you could achieve the right look with regular only two lights. here is a quick render.
http://img.photobucket.com/albums/v712/metal0130/ceiling.jpg

if you really wanted to you could even duplicate a string of point lights around a circle, keeping them real close together and all with a real low intensity...

im sure there are more efficient ways of doing this but those are two down and dirty fast methods

[phix314]

I think I would create a faux light..

Have a torus with a surface shader on it to act as the "source" and create an area light to mimic the actual lighting it gives off. If you want the shape in there just do some creative light linking to keep things seperate.

[Sefiroth]

@ metal0130, thanks a lot. I think I will work with the multiple point lights. The picture show a circular shape, but for decorative purposes the shape can be very irregular. I will test both of them anyway, just to know how it feels and find out the possebilities of it.

@phix314. When making use of indirect lighting you will never see the light source itself. would kind of spoil the mood. But thanks for the advice.

[1armedScissor]

2 other ways; 1 - circular ramp (white exterior, black interior) into the color or intensity of a spotlight. Place the spot so it's pointing up at this shape & adjust the angle, penumbra & ramp until you get the effect you desire and place shadow lights as you need to. 2 - use textures to control the look & (again) place shadow casting lights as needed.

[Sefiroth]

I like the second one .You guys gave me a lot of ideas, thanks

[Rainroom]

why not use final gather...if the scene doesn't have serious render-time constraints?...u can add objects as light sources in final gather i guess...just my 0.2 cents...:).

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