Grass Tool Height Restrictions & More

Hey all! I’m working with a quite large tiled landscape and just finished using the grass tool with my various material layers. I’m using weightmaps from World Machine and layer blending to determine where my materials are applied. I also have multiple biomes. To save resources, my beach/ocean floor material is the same as my Desert material, so the weightmaps were combined in world machine. Now however, when coupling the grass with that desert material, I of course end up with grass all over the beach and the ocean floor. I’d like to somehow limit the grass application to within a certain height bounds (and also perhaps slope bounds), but I’m not quite sure how to go about that.

Also, how might I go about creating a mask for a tiled landscape to prevent the grass tool from being applied to certain areas of the terrain? For example, even though I have the same grass material applied for grasslands as I do for a rainforest, I’d like them to have different types of grass.


Another thing I’m trying to figure out is how to automatically delete the grass when using the Landscape Spline Tool to create things like rivers and paths, I don’t want the grass to be poking through those. The map is too large to hand paint everything, and I don’t see a way to manually delete the grass in certain areas.

Bump. Still cant figure out how to limit grass tool to certain landscape heights

Made a thread about this too and didn’t get an answer either. So I want to know too.

Yeah its tough. I tried to use this tool to add trees and rocks to the landscape as well, just to get a procedural base across the map. My map is extremely large, so this seeemed convenient. Unfortunately it seems the grass tool removes collision from the meshes, so it won’t work for my purposes.

You should use the Grass Output node in your landscape material which defines the landscape layer type to spawn grass over the selected terrain layers. You can make it so grass meshes only spawn on the grass layer, and when you place landscape splines down you can make them automatically paint a landscape layer onto the terrain which would remove the grass.

Right, the issue though is that in World Machine my weight maps that correspond with those landscape layers have too much falloff. It’d take me a week or so to re-render it, as this is a huge tiled landscape. I dont think a mask would work well with a tiled landscape either.

Something that would really help with this is a feature like in the procedural foliage tool that allows you to only spawn foliage on a certain layer, and it allows the user to set the minimum layer weight percentage. So the place has to be at least, say, 50% grass material in order to spawn grass. If anyone could show me how to set something like this up in blueprints with the grass tool, I’d be really appreciative!

Anyone have any ideas on how I would go about adding a minimum layer weight percentage to the grass tool? Something like the feature in the procedural foliage tool.

Update: figured it out. I assumed the constant input had to be between 0-1. Making the input value on layers you don’t want to receive foliage a negative value will make that layer actively remove grass. A value of -1 it will remove 100% of the grass even if a specific area is only 1% that material. Hope this helps people with the same problem.