Procedural + Manual paint | for landscape material

Hi, i have a procedural(automatic) paint material for my landscape depend on the slope of the landscape, but i also want to be able to manually paint the landscape,

i really couldn’t come up with any ideas on how to achieve it, you can see a little screenshot on my current material linked to the post,

it’s nothing special, just a LERP linked to two materials and get fed from WorldAlignedBlend to her alpha,

please give me some ideas on how to achieve this or show me some nodes, love ya <3

Hi. I was working on similar thing for last few days.
If you didn’t found the answer yet there are a few approaches that I found / figured out. This video might get you started:

What I do in my project is: one material function with makematterialattribute for auto-material + multiple material functions for manual painting. Creation of material functions is easy to do, but the hard part for me was to find a way to combine them. I tested a few approaches and for now I settled on the one attached. Hope that helps.