a 4k exe-gfx released at Tokyo Demo Fest 2021



Earlier in 2021, NuSan mentioned the Kuwahara filter in a discord server I'm in. The filter was originally invented to reduce noise in photos without making them look blurry, but it has the pleasant side effect of making images look a bit like paintings if the filter is applied with a sufficiently large kernel size.

I started by making a simple tree in a fragment shader. The code for this isn't very elegant or efficient, it pretty much just iterates through all branches for every pixel to find the closest branch, but this shader is only run once so it wasn't worth optimizing. The leaves are just cyclic noise which is faded out depending on the distance to the nearest branch.

The result from the first stage doesn't look that pretty, but that's what the filter is for! Here is the canvas first without and then with the filter.


For the final touch, I made a very simple SDF for a canvas on a wall and textured it with the painting. The scene is rendered using a heavily simplified path tracer, mainly to make sure the final render has proper MSAA, but also for those perfect soft shadows.

Here are some close-ups.

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This entry ended up winning 3rd place in the compo. I even got a little trophy for it, which was made in Japan and shipped halfway around the globe. The package it arrived in is completely covered in layers of shipping information in 5 different languages, and I cherish it almost as much as the trophy itself.

My one regret is making the background and the canvas itself too boring. I gave the entry a Japanese name and went for a Japanese-style painting, complete with a Japanese-style logo stamp, but then I did not commit to the bit enough to place it in a more Japanese scene.