Hey guys, here's my thoughts about brush managing (mostly editor) UX. For general improvements go here. https://forum.kde.org/viewtopic.php?f=288&t=141066
(Numbering compatible with general list, link above)
First there are my proposal of changes and then (additional) explanations and thoughts about them (for the sake of readability of the list).

Below the list there are screenshots from Krita 3.0 and 4.0 pre-alpha and also mockup for stacked brush UI.


A 1. Creating/deleting presets
It is the most important thing and fortunately it can be done without changing anything else in brush editor. Just a few more and few less buttons.
I think that creating and deleting presets is too important to be done in that implicit way that is available now. It's super confusing.

A.1.1 Create preset from template/enginge defaults
It would create a new preset with default settings for that brush engine. (Now you should click "Default preset" and then "Overwrite preset")

A.1.2 Create presets from current settings
It would create a new preset from settings set up currently (now you have to click "Overwrite preset", but remember to change a name)

A.1.3 Change/set thumbnail [new button]
Sets new thumbnail to the preset (from scratchpad, but could be extended to be able to set a thumbnail from file (because now it's hell ))
(There're could be a "[Save]" button somewhere)
The same reason as above: it's confusing and I've found myself with a lot of brushes with strange thumbnails (scraps) or even lack of them (blank white rectangle). Moreover now if you want to change only thumbnail it is impossible: you can't overwrite preset if you didn't change anything and scratchpad doesn't count.

A.1.4 Overwrite or Save changes [button]
It would overwrite settings in current preset. (Something like: deleting the previous preset and creating new with that settings, and I mean all: including name)
! Warning ! Expected result after changing a name and clicking "Save changes": no presets with previous name, one preset with new name.

A.1.5 Delete brush
It would delete the preset from the library.



Mockup:
http://i.imgur.com/6xijBfp.png
http://i.imgur.com/Z1QM1fa.png


A.2. Simplier ways to do simple things


A.2.1 Color abstraction - a lot of programs has only a slider or three slider to do the job. In our case there are three curves in three different tabs, which you have to set manually, which is hard. If you need only a small range of hues around a hue of your current color, you have to make something like this (with "fuzzy stroke" checked):

It's hard to set the curve symetric. And if you try it and decide "ok, I need smaller range", you have to get it right AGAIN. It doesn't make sense. My computer would be better at that job than me

It would be nice to have an option: curve OR range (when range would mean "straight line from A to B")
[Edit 1:]
I don't mean removing curve from preset definition, only allowing to choose the method to display/set it. So when user set the range from A to B, it would be translated to preset definition as a curve with two points: (min_x, A) and (max_x, B).






A.3.Other things

A.3.1 Painting mode somewhere else
Tt's hard to find, I mean, it should be closer to Opacity/Flow options, maybe above/below Blending Mode? I would even place it in other tab, because it's only one radiobutton with two options, and it has a lot in common with Opacity and Flow and seems quite important, even if you don't want to change it very often.

It could be instead of (or next to) Blending Mode right below Brush Tip, maybe?


A.3.2. Color and size options in scratchpad
When you try out blending brushes it would be useful to have more than one color... Size - because resolution of the scrappad and your typical canvas can be (and usually are) different.
But that option could be trickier to implement, so it's only a wish and not a deal breaker.

A.3.3 [done in 4.0] presets bar in brush editor is not very convenient


A.3.4 To think about: Why (choosing the source) you have to check something (like "Fuzzy Stroke") before you uncheck the previous one (like "Pressure", which is usually checked)? I mean it does make sense, but it's super annoying.

A.3.5 [done in 4.0] Search field for brushes in brush editor

A.3.6 Naming conventions: "Enable pen settings" and maybe "Strength" (settings in brush editor)
Maybe "Enable input" or "Enable curve" or "Enable dynamics" or something like that? "Fuzzy dab" doesn't seem like a pen setting at all...

A.3.7 Brush editor: don't exit after losing focus
- trying to pick different color in color wheel (to paint on a scratchpad, see A.3.2)
- checking message from a friend on facebook only to find out that you have to open brush editor again...
- taking a screenshot (with external program) to my post about UI improvements...

A.3.8 Brush editor in docker?
Tool options are in docker, grid/guides options are in docker, why not brush options?
I personally think that grid/guide options could be on toolbar instead of brush editor... It would make more sense for me.
(But see a "DISCUSSION" below, I talk there more about brush editor in docker)



[About A.1.1 & A.1.2]
Why? It's just easier to understand.
I think there should be one button: "[Create new]" and then a window with option: "from defaults (blank)/from current settings (exact copy of the brush you're using now)". That window should also contain the most important options:
- name of the preset
- brush tip
- size
- brush preset thumbnail (that little picture)?
- maybe tag(s)? It would be useful to organize it right away

Why size (and tip)? Well, I think the most use cases are:
- create new preset from existing with a little changes (like color abstraction or rotating with tilting), or
- create new preset from texture found online (don't ignore the fact that a lot of "brush sets" are not Krita bundles, but plain textures or abrs, so if someone want to use it, they have to load a texture and then create a preset around it)

So I think it would be useful to make it faster by letting to change the brush tip right away. And the size option is because when you create new brush, you know if this is sketch small brush or painting huge brush.

Of course in A.1.1. settings in the popup window would be from engine defaults and in A.1.2 they would be from current settings. Other settings (not available to change in popup window) would be from the same source.

About thumbnail: see A.1.3.


[About A.1.*]
I think it would help separate presets saved in your library and settings that you can change temporarily. It will make every change in brush library explicit and easy to understand.




DISCUSSION
The most confusing things in Krita brush editor is (for me) creating/deleting brush, seting thumbnails (preset previews) and searching for presets (which is done in 4.0). After that everything looks mostly fine, but... I'm still not very convinced. I mean I want all settings available, but I (and others artists, I think) don't change it all the time. It would be nice to have a simplier version of brush editor alongside with the extended/advanced version. Especially if it would be in docker - it could look like this: advanced/extended version *somewhere* and docker with simplier version (for example like in Artrage or Painstorm, but smaller than PSS (because we would have an advanced version somewhere else) and, please, more reasonable than Artrage).



BUT It could bring more confusion, so the extended version should be simply available somewhere around the simplier version, maybe a button (and extended version in popup window) or something?

(Like in color palette - you can click and then set up things. Yeah, there you can set up docker, not color itself, but the same philosophy remains).

We have to take under consideration that there will be the stacked brush engine, BUT in that case it would be in extended view and I think it could be the way the last mockup was done... And really, the last discussion about stacked brush was about "what it should be", so it isn't possible now to design every button if there's no precise design of available options.


All: http://imgur.com/a/KbJ5C

Screenshot of UI in 3.0
http://i.imgur.com/EgsQRIV.png

Screenshot of UI in 4.0
http://i.imgur.com/s1k95Li.png

Mockup of stacked brush
http://i.imgur.com/lvCjoY9.jpg

A 2.1 will break old presets if we remove the curve, keep that in mind.

I am completely neutral on everything else.

A.2.1:
I don't mean deleting it. I mean that in view user can choose: use curve or range, and in case they chose range, it would be internally translated to a curve with two points (so it would be straight line): one on the beginning of the range and one on the end of it.
The only problem would be: so if preset has curve with two points, how can we know if user chose range or curve? What should we display?
I think we can easily assume it was range* or have an option "do you prefer using curves or ranges" (which would be important only in case of straight lines in 'curve' field).
So it would not break anything.

* so users preferring ranges and simplicity would see ranges, and users who would prefer curves are technically advanced enough to forgive us