The animations aren't as nice-n-smooth as the David Whyte ones which inspire this. Is it just framerate (easy to fix) or is there something deeper causing this?
It's not just the frame rate; David Whyte is doing 4x temporal supersampling too, so for each output frame, 4 frames are rendered, accumulated into an integer buffer (lines 20..29) and the output is their average (lines 31..35).
In addition, interestingly the color mapping is done afterwards (lines 38..41), based only on the red value of the original image. (One could do HDR and other tone mapping here, too.)
