Thanks to Cory's explanation to me over Discord, I was able to deduce that this process is actually the same as what is described on the KRP Documentation as "Tyre Mark Overlay". The explanation there is a bit vague, so here's a better one (for Blender specifically):
Assign a texture to the alpha channel of the Principled BSDF of your shader you want to add the detail map to (ignore that color information is going to a scalar value, it still works as color)
- This texture, if it does not have an alpha channel, will be multiplied with whatever your diffuse color texture is
- If it does have an alpha channel, that will act as the mix control and it will be mixed between the diffuse color texture and the detail map
Create a second UV map on the object and scale it up (or whatever) to scale up the repetitions.
Name this UV map exactly the same as the texture you assigned to your alpha channel (without extension).
Export to FBX, FBX2EDF, and enjoy!
https://cdn.discordapp.com/attachments/913301511684108358/1070522670698999938/image.png
Assign a texture to the alpha channel of the Principled BSDF of your shader you want to add the detail map to (ignore that color information is going to a scalar value, it still works as color)
- This texture, if it does not have an alpha channel, will be multiplied with whatever your diffuse color texture is
- If it does have an alpha channel, that will act as the mix control and it will be mixed between the diffuse color texture and the detail map
Create a second UV map on the object and scale it up (or whatever) to scale up the repetitions.
Name this UV map exactly the same as the texture you assigned to your alpha channel (without extension).
Export to FBX, FBX2EDF, and enjoy!
https://cdn.discordapp.com/attachments/913301511684108358/1070522670698999938/image.png
