I have a underwater scene that I have rendered in different passes. rendered the main object and sea environement in vray, with particle passes (particle flow) some fake caustics and volumetric passes too using the scanline. Pulling this all together using combustion.
right problem is I saved out a vrayzdepth pass too to use for creating fog. I did a mock up of the final composite in photoshop and it all worked well, though I was using the zdepth info as a selection colour fill to and the fogging and blueing you get underwater. I cannot figure out how to achieve this effect in Combustion using thevray zdepth layoffs.
Two choices - either make a solid blue / green layer and use your zdepth as a matte - make sure the matte is set to be white in the distance and black close up to give you more blue as it falls away. Alternatively use it to control a hue / saturation where everything is colourising to blue.
Well, just make a solid blue layer in combustion and use a channel swap filter on the blue layer so its alpha channel is set to the luminance values of your vray zdepth render - pop the blue layer above the main 3d render and you’re good to go.