Bug 327480

Summary:	Artificial sharp edges when using Color: Mix, Darken, Hue, Saturation, value in Wash Mode
Product:	[Applications] krita	Reporter:	vascoalexander
Component:	Brush engines	Assignee:	vanyossi <ghevan>
Status:	ASSIGNED ---
Severity:	normal	CC:	halla
Priority:	NOR
Version:	2.8 Pre-Alpha
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
URL:	http://i.imgur.com/WGnG9Dv.jpg
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Example: Same Brush compared Wash vs Buildup mode Soft Tip, Wash-Mode, Fuzzy Scatter, Fuzzy Colormix Artificial edges more visible.

Description vascoalexander 2013-11-12 08:05:33 UTC

Presets that use the Color Mix option set to Fuzzy are producing sharp edged artifacts when the Brush is set to wash mode. In Buildup Mode the Brush looks as expected.

Reproducible: Always

Comment 1 vascoalexander 2013-11-12 08:06:52 UTC

Created attachment 83511 [details]
Example: Same Brush compared Wash vs Buildup mode

Comment 2 Halla Rempt 2013-11-15 09:44:38 UTC

Hi,

Can you also add a preset that can be used to reproduce?

Comment 3 vascoalexander 2013-11-15 10:46:21 UTC

Created attachment 83580 [details]
Soft Tip, Wash-Mode, Fuzzy Scatter, Fuzzy Colormix

Created from the Default Airbrush; changed Opacity (0,2->1,0), activated scatter fuzzy, activated colormix fuzzy, changed spacing (20->10) and quality (1->3)

Comment 4 Halla Rempt 2013-12-10 13:42:38 UTC

I can confirm. I'm not sure how fixable it is, though...

Comment 5 Antti Savolainen 2018-06-27 21:08:40 UTC

This is ancient but according to boud it's still relevant. I'll bump it so it won't show as the oldest bug report that's open.

Comment 6 vanyossi 2019-05-30 02:14:14 UTC

Some updates as im close to fixing this:

This can be exagerated by picking a light colored foreground color and a dark colored background color.

It only happens in autoBrush

The artifacts are triggered on a strong change in Mix Strenght, which makes fuzzy dab the perfect mode to trigger it.

Comment 7 vanyossi 2019-06-01 05:45:54 UTC

Created attachment 120465 [details]
Artificial edges more visible.

Value set to pressure modifier. Both stroke blobs were made in a single stroke.

On the left: the first dab is made with almost no pressure and the surounding dabas are made at strong pressure. Notice the edge is marked for the original shape if there is a change in the sensor value.

On the right, eventually drawing over and over will remove the artifact as it only occurs on the "alpha" boundaries of the current stroke.