turns out that by looking at each channel individually:
red varies a lot
green seems to be either at 255 or 0
blue is almost always at 128
and by that, i can conclude:
red: glossiness (inverted roughness)
green: metalness
blue: specular
greyscale specular maps seem to be glossiness btw, and alpha is the same as all other channels
red varies a lot
green seems to be either at 255 or 0
blue is almost always at 128
and by that, i can conclude:
red: glossiness (inverted roughness)
green: metalness
blue: specular
greyscale specular maps seem to be glossiness btw, and alpha is the same as all other channels