I found a watercolor software expresii, and found related papers published by the author. Can krita also achieve such watercolor effect?
Related links： MoXi - Digital Painting Redefined - NATURAL and ORGANIC Finally!! (ust.hk)
3 Likes
Krita currently doesn’t have any simulation based engine. Last time I saw this question being answered the devs also had no current plans to implement it - though I believe if a volunteer came and added it to the program there probably wouldn’t be problems.
When it comes to expresii I believe Krita also doesn’t have a GPU based brush engine - though devs have spoken they would be interested but it’s a tremendous job that introduces a lot of difficulties.
I hope you will get an answer from someone who is actually related to Krita, not like me 
.
4 Likes
Krita can get pretty close to the end results, i remember the Digital Atelier brush set has pretty good water color brushes that look realistic enough for most needs. However what Krita can’t do is an actual physical simulation on pigments, materials and liquids (like how wet is the ink, or the canvas at a location). This is no small request it would probably fundamentally change how Krita needs to work. It would need a new brush engine and layer types minimum, and even more (for example in real life ink flow would be depend on incline and distortion of the paper).
That said physical painting simulators are a whole other category of painting software and Krita currently doesn’t aim to be one.
3 Likes
Just out of curiosity, ould this be offset be having a separate library/engine running in bg with krita basically just displaying the result and providing mouse/pen events or something similar?
Does Krita even have some hooks for things like this?
Krita doesn’t have the capabilities right now but it could probably be done. G’mic filters already do that kind of (Krita is using an external program for image manipulation). However then you could just as well use a dedicated water color program and import the saved image from there or put it in as a file layer. Blender already can do something similar with Krita (or any other software). It basically works like that: Blender renders an image, exports it to Krita, your paint the texture on the still image and then it gets reimported to blender and blender translates this as a texture to the 3D model.
If there would be an actual library that could do the heavy lifting of physics based painting simulation ready to use (and with a fitting license) than you can just as well build it into Krita and I bet if there were an open C/C++ library available Krita and many others would already have this. Just building the user interface into Krita is trivial compared to implementing the whole simulation thing.
But it probably still feels wacky and out of place. I remember when I tried another software that had this capability, I think it was Corel Painter, it was a bit weird to use too. You could only use the water color brush on special water color layers, half of the blending modes were disabled and transparency didn’t work as expected too. That probably would be the case in Krita too.
And there are additional issues with color spaces and color mixing that would come into play too, when I think about it.
2 Likes
Well export/import might work with blender, it certainly wasn’t what I had in mind ;0 I think that’s just too clunky.
Out of place I also dont’ see that as much of an issue, after all krita already has different layers which have these issues you mentione anyway.
When it comes to other parts with blendir, … I assume this can be worked around, one thing is just because the other program had it doesn’t meant it would have to work the same way and who knows how far the programs now are compared to when you tried it in corel painter.
You could probably work the color spaces out too.
Sure I don’t think this is coming to Krita but was just wondering from the tech stand point how feasible it would be .
Thanks.
Sure a lot of things can be worked out but it takes a ton of work. You probably remember the discussion from Hardmode - Manually Mix Colors where realistic color mixing is discussed and the issues there are. You will have this in addition to the whole material simulation. That’s quite a lot. Having an external program, sort of as a plug-in, could kinda outsource the issues to another program but this program as well has to exist and allow the mode of operation you described i.e running as a background process that can communicate with other processes. It’s not trivial. I could think of a lot of plot stoppers and I think the Krita devs can think of even more.
However since Krita is open source, there is always place for hope that someone who is realy into this topic and has a solution will add their part.
1 Like
We used to have this in the 1.x days. The whole hog: simulating flow, realistic color mixing. Watercolor layers as a separate layer type. But it simply wasn’t all that interesting and though I was really interested in it back in the day, these days I think that digital art is a different thing from traditional art and should be approached on its own merits.
5 Likes
I hope one day somebody will wrote free color-mixer in Corel Painter-style, etc.
For Photoshop is for example this: https://www.mixoos.com/
What I mostly mean is that “freeform”, “liquid” color selection from painters’ dock. 
There is news about this topic: Huawei’s “gopaint” recently added that fluid brush in its update.
Gopaint is a software used on Huawei tablets to benchmark Procreate. Therefore, unlike previous simulation software, it does not serve the “minority” more. This has certain reference value
In gopaint, this feature is a “tool” (which should be able to be combined with any brush), with two parameters (water content and paint amount) and a fan (used to dry and prevent diffusion)
Videos on Bilibili (Chinese)： 【天生会画新版本】流体笔刷，可以风干的笔刷_哔哩哔哩_bilibili
2 Likes