4 ms·

Escher and the Droste effect – WebGL fragment shader

89 points by epsylon 11y ago

grovulent 11y ago
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.
bitL 11y ago
Excellent! Thanks for sharing!
The_Brads 11y ago
This is really cool, since Portal I've been fascinated by the concept of creating optical illusions and optical phenomena with programming. While I believe that my mathematical knowledge is capable of comprehending this, I don't have any experience with the languages needed to program them. I'd like to though.
ArekDymalski 11y ago
I thought that this gif https://lh3.googleusercontent.com/-Izdubw7RJWk/URK2tZdqxzI/AAAAAAAAASs/x0cXWbjrVLQ/s426/photo.jpg https://lh3.googleusercontent.com/-Izdubw7RJWk/URK2tZdqxzI/A... was already impressive, but this is just completely incredible.
- pmelendez 11y ago
  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
  - spacemanmatt 11y ago
    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.
irickt 11y ago
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
escherize 11y ago
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.
cousin_it 11y ago
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
- pmelendez 11y ago
  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=symmetry http://escherdroste.math.leidenuniv.nl/index.php?menu=symmet... 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
- jameshart 11y ago
  There's a camera wobble effect he's applying that actually moves the camera slightly from side to side - might account for what you're seeing? On the shadertoy code (https://www.shadertoy.com/view/Mdf3zM https://www.shadertoy.com/view/Mdf3zM), remove the #define WOBBLE and you should see a clean zoom.
rogerallen 11y ago
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!

89 points by epsylon 11y ago

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.

bitL 11y ago

Excellent! Thanks for sharing!

The_Brads 11y ago

This is really cool, since Portal I've been fascinated by the concept of creating optical illusions and optical phenomena with programming. While I believe that my mathematical knowledge is capable of comprehending this, I don't have any experience with the languages needed to program them. I'd like to though.

ArekDymalski 11y ago

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

pmelendez 11y ago
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
- spacemanmatt 11y ago
  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.

irickt 11y ago

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

escherize 11y ago

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.

cousin_it 11y ago

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

pmelendez 11y ago
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=symmetry http://escherdroste.math.leidenuniv.nl/index.php?menu=symmet... 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
jameshart 11y ago
There's a camera wobble effect he's applying that actually moves the camera slightly from side to side - might account for what you're seeing? On the shadertoy code (https://www.shadertoy.com/view/Mdf3zM https://www.shadertoy.com/view/Mdf3zM), remove the #define WOBBLE and you should see a clean zoom.

rogerallen 11y ago

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!