Editing Blendweights Textures

Blenweights textures combine several masks into one texture. Commonly, 12 or 16 different masks are packed into the R, G, B and A channels of a texture, which is then repeated 3 or 4 times in an array.

In JWE, each of these masks controls the distribution of one type of normal map texture for scales and skin details.

To edit them properly, we must decompose the RGBA images into separate grayscale layers, with each layer representing one mask.

Gimp

1. Open blendweights PNG file.
2. Make sure that Gimp stores the PNG's transparency as an alpha channel, not as a layer mask. By default, no need to worry about this if you opened an existing PNG file.
3. Colors > Components > Decompose. Color Model = RGBA. A new image will be created that has each of the channels as one layer.
4. Edit the layers to your liking.
5. Colors > Components > Compose. Color Model = RGBA. Do NOT use Recompose, which is supposed to do the same thing as Compose, just without the dialog, but is broken at least in gimp 2.10.
6. Export to PNG, make sure that Save color values for transparent pixels is checked if you're asked.