

Escher and the Droste effect – WebGL fragment shader - epsylon
http://birdgames.nl/2014/05/escher-droste-effect-webgl-fragment-shader/

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grovulent
I don't have anything intelligent to say about this - but this for me is one
of those moments where I feel positively in awe of how next level some people
are.

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ArekDymalski
I thought that this gif
[https://lh3.googleusercontent.com/-Izdubw7RJWk/URK2tZdqxzI/A...](https://lh3.googleusercontent.com/-Izdubw7RJWk/URK2tZdqxzI/AAAAAAAAASs/x0cXWbjrVLQ/s426/photo.jpg)
was already impressive, but this is just completely incredible.

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pmelendez
The gif is still very impressive. If I recall correctly the paper said that
they did this by finishing the white hole in the original piece so they could
do the conformal mapping completly.

More impressive is that Escher did this without a formal math training

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spacemanmatt
It actually took some reading of GEB before I understood how impressive
Escher's concepts were. I was fully taken by his illustrations, before even
considering the pure-concept material.

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irickt
Here is a mathematical reconstruction of the print with several fly-throughs:
[http://escherdroste.math.leidenuniv.nl/index.php?menu=intro](http://escherdroste.math.leidenuniv.nl/index.php?menu=intro)

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escherize
I've seen this painting before but didn't think much of it. Now that I can see
what's going on, I am dumbstruck with how abstract and novel this concept is.

This spacial reasoning ability is so amazing.

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cousin_it
Why is there visible angular distortion when you zoom in? It shouldn't happen
if you do the Droste effect correctly, like this:
[https://www.youtube.com/watch?v=9WHdyG9mJaI#t=0m43s](https://www.youtube.com/watch?v=9WHdyG9mJaI#t=0m43s)

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pmelendez
My bet is that he is using a continuos transformation and the guys who first
did this (at least as far as I know) reproduced and completed the original
transformation grid that Escher did.

[http://escherdroste.math.leidenuniv.nl/index.php?menu=symmet...](http://escherdroste.math.leidenuniv.nl/index.php?menu=symmetry)

The transformation is a conformal map so it should not deform angles. Other
explanation is that the fragment shader is losing information in the process
and that float numbers are not precise enough.

Still this is very impressive

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rogerallen
Bravo! I've taken a few runs at trying to put the Droste effect in a shader
and never got close to what you've done. Great job!

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bitL
Excellent! Thanks for sharing!

