Hi guys, so for my building to look derelict and wanted the stone bricks to look mossy and worn. i found a way of doing this while browsing the internet and thought i’d share if anyone else wanted to do this. (sorry in advance if i do not explain this very well i’m no teacher)
ok so what i essentially did is set up two principled bsdf s with pbr materials the same way @Grant_Abbitt did in the lectures (in my case a moss and stone texture). Connected them together with a mix shader, created a new image texture node with a new image which i plugged into the fac of the mix shader. i then selected the new image i created and went into texture paint, if you paint all white it adds one texture with all black adding the other. i dont know if this is the most efficient way of achieving this result but i found it easy enough.
Hope this was helpful 