How to get grass to not spawn on cliff in Auto material with Grass Output node

I have a auto material for my terrain. I wanted to start using Grass output node for easy grass generation on my terrain. It works how it should besides the fact no matter what i do i cannot figure out how to get it to not spawn grass on my rock texture. If i paint any other texture over the grass it goes away. Does anyone know how to fix this?

The grass node samples a given layer, and will put the meshes there. I assume you’re not sampling the rock texture?

Im using the sample grass node and plugging it into the grass output

Yes, but which layer are you sampling?

I’m using the Layer sample with “Grass” layer from my Layer blend. It works with everything but the rock texture that forms when i sculpt high enough. I even tried having a empty layer sample for “Rock” in grass output with no foliage in it and that didnt work.

Here is my cliff Height

my slope is basically the same thing.

Here is my Output and Layer samples and blend.

Right, but you’re sampling the rock. That’s why you’re getting grass on the rock :slight_smile:

( I might have missed a meeting )

It spawns the grass if i dont sample the rock also,

This is how it looks without the rock layer sampled. it doesnt change.

You aren’t “sampling” anything. Unless you paint grass where grass goes and rock where rock goes nothing will change in the way you have it currently set up.

Now I’m confused. This is landscape grass type, not foliage tool.

It will put grass where you take the sample layer from:


If you paint it, yes. But there’s nothing making either of those a layer in the graph shown.

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I just saw ‘auto material’ and went from there… :wink:

Oh ok that makes sense. Im not sure how to specify the grass material. Would it just be a Multiple with the sample? Ill have to mess around with it when i get to my computer tonight.

I would just use the same mask the material is using directly.
Maybe multiply x 10 and clamp to get it clearer.

That worked thank you.

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