Cafe Wall Illusion
This optical illusion seems to warp the straight lines as you move the slider. Port 1010 in Melbourne is a building that uses this effect, known as the cafe wall illusion.
The alternating rows of the squares are shifted to the left and right and because of this, the lines appear as if they are not parallel, even though they are.
 Wikipedia. "Café Wall Illusion." (Dec 8, 2014) en.wikipedia.org/wiki/Café_wall_illusion.
 Fermibot. "Illusions!" (Dec 8, 2014) fermibot.wordpress.com/2014/11/20/illusions.
"Cafe Wall Illusion"
Wolfram Demonstrations Project
Published: December 11 2014