Underwater lights at night?

[stayinwonderland]

Been trying to set up a scene with spot lights underwater at night and not sure I'm heading in the right direction. The water is a solid block with a fog gizmo in it plus a bit of fog set up in the vray material.

 

Here's my light set up:

 

Sunlight sytem set to 0.03 or thereabouts to give a general moonlight ambience.

Dome light also set to low and with a blue hue to act as an ambient fill

Underwater lights - vray lights, spheres (6 inches), with no decay.

 

* the one by the palm tree is sat in a little cup so act as a spot light.

 

Issues:

 

Should I have no decay set on those lights? This doesn't seem very professional but if i don't, they only illuminate a tiny space around them. There's no attenuation parameteres to tweak?

 

The lights don't seem to be reaching to geometry outside the water? I would expect the tree trunk and poles to be illuminated.

 

Here are some renders. First is with no decay where the lights can be dimmed a little to around 30:

 

[ATTACH=CONFIG]46823[/ATTACH]

 

This is what it looks like with decay enabled and an increase in light multiplication to around 50:

 

[ATTACH=CONFIG]46824[/ATTACH]

[BrianKitts]

there's only two uses for a light with no decay..... 1 is for a sun, and 2 is for ambient fills. Beyond that I would never use them.

 

Why don't you use a standard omni light so you can shape and control it's attenuation. Just because you're in vray doesn't mean you can't use standard lights.

[stayinwonderland]

hmm, I did wonder about standard lights in vray. Well, what i did try was to use decay on some but ramp the multiply up to 1500. But maybe I should try the omnis. I also increased the exposure which helped see the effect of the lights.

 

Question though, should one expect caustic refractions by underwater lights on the geometry they're hitting that's above the water? I don't seem to be able to get that even with caustics turned on.

[Ismael]

Some good things:

 

http://www.cg-blog.com/index.php/2011/12/27/vray-caustics-setup-tutorial.htm

http://sketchupvrayresources.blogspot.com/2011/07/tutorial-underwater-lighting-using-vray.html

http://www.cgpinoy.org/t7907p15-share-your-simple-pool-render

[stayinwonderland]

Yeah, i've read the first two. The 3rd one though showed an interesting set up of using a spot light with a procedural smoke shader as the projector map to fake caustics. Nice.

 

Here's what I got so far:

 

[ATTACH=CONFIG]46836[/ATTACH]

 

Just working on a high quality render. Taken 5 hours and it's two thirds through calculating light cache. Sheesh. Some lights have decay and some don't.

Edited January 21, 2012 by stayinwonderland