Bug 344108

Summary: Feathering option for Experiment brush
Product: [Applications] krita Reporter: David Gowers <finticemo>
Component: Brush enginesAssignee: Krita Bugs <krita-bugs-null>
Status: CONFIRMED ---    
Severity: wishlist CC: halla, tamtamy.tymona
Priority: NOR    
Version First Reported In: git master (please specify the git hash!)   
Target Milestone: ---   
Platform: Other   
OS: All   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description David Gowers 2015-02-13 10:11:58 UTC 
Experiment brush is currently limited to sharp edged results (either with or without antialiasing)
Providing a feathering option would allow it to be used also for effectively constructing a 'base image' for further airbrush-style work. Using Free select (with feathering) in GIMP followed by filling with FG color gives an accurate picture of the visual effect obtained. Among other things, it allows the quick and dirty construction of ad-hoc, arbitrarily shaped gradients.

I'm looking into implementing this. Any pointers at where best to begin integrating the existing gaussian-blurring (or box blurring ?) code with the plain rasterizing the Experiment brush currently does  would be appreciated.

I write this in somewhat of a hurry, but it seems to me that more than simply two options "[] feather"
and "Feather radius" are appropriate. From my experiments mocking the workflow up with GIMP, it seems that feather radius frequently needs to scale according to the size of the shape drawn. I am therefore considering that an additional option "Feather scaling" may be useful (a float value that may be set negatively, so that smaller areas are more feathered, or positively -- the usual --, so that larger areas are more feathered)

Reproducible: Always
Comment 1 Halla Rempt 2016-01-24 10:19:20 UTC 
WISHGROUP: Stretchgoal

(Note: we should group all experiment brush wishes and make a big project out of it)
Comment 2 Tiar 2020-11-03 14:27:15 UTC 
Possible workaround:
1. Select the area using the Outline Selection Tool.
2. Fill it with gradient tool, using the "Shaped" mode. If you use those gradients that have transparency on one side and a color on another one, it should work.