Landscape Layered Materials - Actual layering? Help!

So I am working on making a terrain material and plan on pushing it to the max with as many textures / terrain types as possible for the fun of it, however I am running into some issues.

First I have a few questions!

Is it possible to have actual layered materials that don’t erase the layer underneath? For example.

Dirt is Covered by Rock which is covered by Grass…
Can I have Dirt always there across the whole terrain so even when I paint over the terrian with rock and the dirt is now not visible it is still actually there? I then paint grass over the rock and dirt and that covers the rock and dirt, now when it covers the rock it is replacing its information but when placed over dirt it is just layered.

I ask this because I am having issues with white blotches on the terrain which seems to be due to the terrain having insufficient information when blending materials. All the layers are using height based blending some the edges blend nicely and have a stylized look. My issue is with these white blotches turning up usually in situations where 3 or more layers / textures are blending. I have no idea how to solve this but I did make some progress although it is really not idea. That is to set the bottom most layer (which is actually the top most in the UI) to no-weight blending which gets rid of this issue so long as this layer is covering the whole terrain. The issue is that you can see this layer under the other terrain at all times. Because I used dirt as this non-weight blended layer on rocks and sand you could see the bleed through of the dirt which I don’t want.

I am just looking for some advice on how to get my landscape material to work as intended.

This image is of 3 layers meeting causing the blotch issue.


This image shows me using the dirt layer as non-weightblended removes the blotching but them causes this opacity bleeding issue…

This image is what happens if I set the dirt layer as a weight blended.

I am using splatmaps to paint the terrain as well but even if I paint my hand these issues occur as well.

Any help would be appreciated!

Bump - Please help Q_Q

Haha so no one really knows how to solve this? Is this an engine limitation?

Right I have figured out how to have terrain with no black or white marks, pretty flawless close and distant tiling as well as height based blending between textures but that is also layer based as well so you can dig away the grass textures to reveal the dirt etc etc. Might do a video on it if I have time.