Doodling with Harmony Keymod

blue flowery stuff
blue flowery stuff

I am definitely no artist but some people liked this image – I wonder why, no joke.

The Original is about 4000*3000px and was created with “Harmony Keymod”, a heavy modified version of Mr.Doop’s Harmony, a procedural drawing tool, in less than 15 minutes.

I’ve put the tool online on my personal webspace, if you want to give it a spin – here you
Site down, I’ve changed the link to point to the last online version on You can download it and remove the stuff added by archive org from the source code.
you can open the resulting self contained HTML file completely local on your file system. It does not need nor dues it open any connections to the internet.

Try one of the “easy” brushes like “shaded” with the settings “offset-scale” 80, “brush-size” 30 first.

The global composite setting needs some experimentation on your side, especially with the transparency settings, because some work better with low opacity and some with high. Hint: You can erase with destination-out too. The description of what the composite settings and some other things do is linked in “HELP”.

The modifier keys for brush size and opacity can be pressed while drawing to change the brush behavior dynamically.

Save is self explanatory. Save+Alpha lets you re-import the image for further drawing, undo and redo should be pretty straightforward too.

Yes, some of the other options are not quite as self explaining as I would like, but *sigh*, it is a fun project and I add stuff as I see fit.

Everything is self contained in one file, you can even download the page and use it offline, everything you do on that page stays on your computer, no data is send to any place in the interwebs, no tracking etc. pp.

Please write in the comments if you like it or not (How dare you! And, what’s more: Why not?! 😀 ) need more instructions, can provide hints how I can improve it etc. etc.


PS: There is a chromium bug which causes a massive RAM explosion with one of the Javascript commands I used for undo and redo on some hardware – see – which hits Vivaldi too in combination with some hardware. If you did overwrite chrome://flags/#ignore-gpu-blacklist please consider to disable the overwrite. If you didn’t overwrite it and are still hit by it, you sadly have to wait until the chromium authors have fixed the bug.

4 replies on “Doodling with Harmony Keymod”

  1. Done 😀

    btw. I have added some extra brushes and started to build in some other settings.
    The settings are not not yet functional, I was a bit too busy over the last weeks, but the stuff will get in as soon as I can carve out an hour or so without distraction …

    Basically it is still a big experiment and I will see where it takes me.

  2. Some more code changes – removed the Fur and the Chrome brushes and added an “offset-scale” setting when Shaded is active. This allows to smoothly transition from Fur over Shaded and Chrome to Sketchy.
    I really need a better name for that.

  3. Looking for a name for a new setting, which configures how many lines are drawn between the points of the new shaded brush. Any suggestions?

    Additional planned stuff:
    – Dynadraw can have 4 settings – something like elasticity, weight, velocity and if the angle is fixed or not. The code is ready for that, but I have absolutely no clue how to integrate that into the UI without making it too complex.
    – Combining stringy, curvy and web to one brush. I did not yet check how compatible they are to each other, but I believe it should work in some way.
    – And then there is the next big thing, a flood fill. Sadly not as easy to implement as I would like because of all the different opacity levels, it still needs a lot of work to get right. I think I need to brush up my math knowledge a bit for that.

    I would really appreciate if someone who knows UI graphics stuff – meaning design – can help me with some mock-ups and ideas for a design rebuild. I am running out of space with the new settings I am planning.
    A native English speaker who can help me to find the best fitting words for the settings would be welcome too.

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