Note: In versions 2.83 and earlier, Alpha was not premultiplied.
Short description of error
Erasing the alpha on float images erase the RGB channels as well.
Exact steps for others to reproduce the error
- Open the attached file. (Left image is a Non-float while right image is Float, both have Alpha channel. We are seeing only the RGB channels).
- Use the brush "Erase Alpha" to erase part of the non-floating-point image (on the left).
- Use shift-click to sample the pixel-values of this image. The RGB channels have NOT actually been affected and the image only appears to have been premultiplied.
- Use the brush "Erase Alpha" on the floating-point image (on the right).
- Use shift-click to sample the pixel-values of this image. ALL channels were erased!
It may look like the same bug as T86866 but it isn't! The brush works as expected; it's the RGB display that's wrong.