get rid of some rocks

[Rich]

can i use some sort of a mask to get rid of some fake stones in the background? I only want the foreground one and they are underwater so i dont have to worry about it looking crappy, can i use a mask on the fake stones shader?

[Rich]

nevermind, fixed it
just made a big crater

[Oshyan]

You can indeed use masking on the Fake Stones shader. You would connect your mask into the Blend Shader input. You can use a procedural, image map, distance shader, or other node for masking. Easiest would probably be to use an Image Map with "Through Camera" projection and a mask based on a render of the scene.

- Oshyan

[Volker Harun]

That's right.
But beware of using a blending-shader on this distribution-shader.
The rocks on the shader's edges become messy.

Volker Harun