Expanding the texture area

Hi guys and girls!
Sorry if this was already mentioned but I’ve searched and didn’t find anything similar.
Maybe it’s a dumb question, but I’m doing a procedural texturing of the terrain and I’d like to mix textures based on height. So, what I’ve done is separated the x,y,z location and mixed my textured based on z location. Now, the problem is, that, I’d like to have a little bit of area around the hole with the same texture as in the hole (like sand at the beach). How can I achieve that, because the mixing goes just till the edge, not over it?

You can try mixing it with vertex colours. Then you can paint where you want the sand to be. You can also blur the vertex paint to give a softer transition from sand to grass.

I’m trying to avoid vertex coloring since I need it to be fast and easy going because I’m preparing a file to be used for other people and I want it to be as easy as it can get :smiley: