[HN Gopher] Spirals, Snowflakes and Trees: Recursion in Pictures ___________________________________________________________________ Spirals, Snowflakes and Trees: Recursion in Pictures Author : nbaksalyar Score : 63 points Date : 2020-12-30 17:27 UTC (5 hours ago) (HTM) web link (learn.hfm.io) (TXT) w3m dump (learn.hfm.io) | babkayaga wrote: | i noticed a bunch if spirals demoed seem to kind of twinkle when | you scroll the page. is this a known optical illusion? | philo23 wrote: | A Moire pattern perhaps? | https://en.wikipedia.org/wiki/Moir%C3%A9_pattern | kroltan wrote: | It's called "limitations of display devices"! | | The high contrast of the pictures, modern smooth scrolling, | reveals the inherent ghosting (or overdrive) of most computer | screens. While decent monitors are usually not noticeable in | more regular use-cases, tightly-packed lines are very | noticeable. | | That means that there is a partially-faded copy of the previous | frame still visible for a fraction of a second, which your eye | sees, and the resulting image has Moire fringes because of the | mismatching angles. | | For example, my monitor shows the purple drawings pretty | sharply, but the green or white pictures are very artifacted | when moving. | jeremy_wiebe wrote: | Is it not due to the inexactness of mapping the image pixels | to device pixels? (Similar to what happens when drawing text | with antialiasing)? | kroltan wrote: | In principle it could be, but usually browsers snap element | rectangles to the pixel, thus protecting against that (have | you ever seen a blurry border on a box because its contents | had 0.5px size? nope, even though it is annoyingly common | in things such as game UIs) | | Plus you can see the same effect on the UFO tests, which | strictly uses integer positions so pixel misalignment is | not a factor. | kroltan wrote: | (me again) | | Which reminds me of this neat site to visualize these | limitations: https://www.testufo.com/ghosting | | On the top-right there is a drop-down, try all the options in | the "Tests" category! Note it has fast-moving imagery that | might trigger epilepsy if you're particularly sensitive. | ericslandry wrote: | Reminds me of https://mitpress.mit.edu/books/computational- | beauty-nature | nayuki wrote: | The lack of whitespace on the left and right sides of the page is | jarring. | nbaksalyar wrote: | Here's a better link: http://learn.hfm.io/fractals.html (can't | edit it anymore, sorry) | dang wrote: | Changed from http://learn.hfm.io/fractals/fractals.html. | Thanks! | 2xmm wrote: | If you like playing around with fractals, you'll love playing | around with images generated by context free grammars: | https://www.contextfreeart.org | jpcooper wrote: | Lots of ways of generating fun pictures in A New Kind of Science | (https://www.wolframscience.com/nks/) as well. ___________________________________________________________________ (page generated 2020-12-30 23:00 UTC)