I’m currently working on porting my brushes to Krita and I have a quick question regarding the stamp creation settings, specifically when I do animated brushes:
Is there ever a reason not check the options for “preserve alpha channel” and “create mask from color” options?
I couldn’t find a concise explanation for it on my own, but it seems that it “preserve alpha channel” allows the brush the maintain both foreground and background (black/white) color for the tip, but not checking it will only maintain the line art (foreground color) and effectively ignore the background/white color. If I enable those options I can turn them off in the settings, more or less, but if I fail to enable them it’s permanently greyed out.
Now I’m not entirely sure when you would choose NOT to have that option enabled, and it’s making me unsure if I understand what it does.
Sorry if I’m not explaining this well enough, I’m porting from CSP so I’m unfamiliar with the terminology used for Krita.
The option to preserve the alpha channel is probably to keep transparent areas; if you uncheck it, the areas where there is transparency will be filled with color.
But it might be easy to see the difference: save a version with the option checked and another version with the option unchecked… and see the result.
I’m not familiar enough with the normal brushes to know if it is different, but in the case of the animated (hose) brushes it automatically keeps transparency regardless of whether those sub options are enabled or not.
In my current case my tips are effectively white blocks outlined in black on a transparent background. No matter what option I choose after turning on the animated brush setting they all maintain the transparent background.
Testing them is how I’m getting frustrated.
If you opt to not enable anything and proceed to the brush editor, the brush mode selector is enabled. You can choose alpha mask, color image, lightness mask, and gradient map.
Back at the brush stamp creator, if you enable the first box “create mask from color” then the brush mode selector is disabled and it defaults to alpha mask setting.
Again, back at the stamp creator, if I enable preserve alpha channel I wind up with literally the same options for brush mode as disabling both options, and they act the same as well.
My confusion is with why having those two options enabled have literally the same results as having both options disabled. It feels redundant, like an oversight. But I don’t know enough on whether or not it’s an oversight, so that’s why I’m asking if it makes a difference for animated brushes.
In “Regular” Brush Style, when “Create mask from color is enabled”, the stamp is greyscale with no transparency and only “Alpha Mask” can be used. Adding “Preserve alpha channel” keeps the transparency. When neither are enabled, the image is unmodified (keeping color and transparency).
But for “Animated” Brush Style, the stamp preview always shows mask+alpha. I guess either it’s a bug, or it only supports that and the options weren’t disabled.
