Masking a default shader

[Djb3000]

Hi,
I have used a default shader to add texture to a terrain using a Filter Forge filter filter with a diffuse map and a bump map etc. Is it possible to overlay another default shader texture masked with a bitmap in an Image file shader? I cant find a way of doing this as the default shader doesn't seem to have a mask input.
Is this possible?

[gregsandor]

You can atttach it as a child of a distribution shader or surface layer and mask that.

[Djb3000]

Of course. Why couldn't I see that?

Thanks 

[gregsandor]

Of course. Why couldn't I see that?

Thanks 

Stronger coffee