Rendering Masks

[Stormlord]

I have a question regarding rendering of masks.

When I need for instance a mask of only the water in a scene (Lake or sea). How do you render just the a mask of the water?
Or how do you render the terrain only to have a mask for further manipulations in Photoshop?

STORMLORD

[Dune]

You need a mask as seen from the render camera? I've done that to decrease rendertime once or twice as a test. You just add a totally black surface shader at the end of the landline, and add a totally white luminous surface shader at the end of the waterline. Turn of the sun and render.
For a topdown mask you can use a ortho camera position.
What do you need it for?

[Stormlord]

Thank you Dune
I need sometimes masks to manipulate a certain area (water slightly more blue ect...) in Photshop.

An for all, who run into the same issue, here is a quick example for masking water and/or terrain.

[attachimg=1]
Masking Water

[attachimg=2]
Masking Terrain

[attach=3]
Screenshot of the scene

STORMLORD