This 400x240 .psd takes any artwork--on multiple semi-transparent full-color layers with blend modes, masks, effects, or whatever--and does the following, in realtime on the the fly as you work:
Converts it to black and white for PNG export
Dithers it to grayscale with a 2x2 matrix--and you can adjust the dither alignment by dragging
I use it mainly for pixelart (zoomed in until the grid appears) but it also works with photographic or soft-brushed art. It exports a 5-level "checkerboard" grayscale using only the 3 grays that appear as nearly smooth solid colors on the Playdate hardware. It could easily be modified to use pinstripe dithering if you prefer.
It could even handle more than 5 levels (4x4 matrix = 17 levels) with some added work, although for that I tend to just let Photoshop's Export handle the dithering instead of doing it on the fly.
It seems to use some compositing that Affinity Photo doesn't support--although it does load in Affinity Photo (with an error message and the dithers mis-applied).
I have not tested the new Affinity Photo 2. That release seems to have new compositing features, so if anyone tests it, I'd be curious to know the result!
Is that's how it's supposed to look? I'm not quite familiar with APV2's new interface but this looks potentially right to me? Sorry I don't have PS to compare the original.
I can't actually... figure out how it's working in Affinity Photo. I'd love someone who understands it better to explain it!
Convert to grayscale (you can then add adjustments like Curves as needed to tweak the Posterize result)
Posterize to 5 levels (black—25%—50%—75%—white)
Three dither patterns replace the three grays, using "Blend If":
So in that screenshot, the 75% dither pattern is set to apply to anything from 70% to 90% gray. Those thresholds need not be precise—the posterization is already done—they just need to bracket the 3 gray levels. A range of 74% to 76% would have worked too.
(I had to move the grayscale/posterize layers out of their group, and add a Curves layer to compensate for Affinity's uneven/dark Posterize function vs. Photoshop's.)
