This demo implements kind of a visual version of the Shepard tone
illusion. This is an infinite zoom, by use of an OpenGL technique called
“Spectral Texturing”, a clever way of blending multiple textures
with each other by use of alpha-blending…
You can find more information about the technique and stimulus at:
The “Spectral Texturing” method was published as a sketch at Siggraph 2003:
It was also demonstrated at VSS demo night 2004.
Feel free to use the stimulus for experiments, but please kindly tell
Daniel Berger how you use it: firstname.lastname@example.org
The original code for this demo has been written by Daniel Berger in 2003.
The code has been adapted for use with the PsychToolbox by Mario Kleiner