The Freezing Rotation Illusion
Max R. Dürsteler

Winning contribution of the
"2006 Best Visual Illusion of the Year Contest"
   



IllusionContest2006SVCD.mpg 81MB
VHS-quality
IllusionContest2006.mpg 504 MB
DVD-quality

Description of the illusion
PDF document

The movies are based on original fish lens photographs taken in the green houses of the Botanical Garden of the University of Zurich. The virtual airplane is taken from Microsoft's DirectX 9.0 Software Development Kit. The movies are available either in TV quality (MPEG1 video codec, resolution 352x288 pixels, compatible with the Quicktime media player of Apple)or in DVD quality (MPEG2 video codec, resolution 720x576 pixels, compatible with most software DVD players). I recommend down-loading the movies by right-clicking on the hyperlinks and saving them on the disk.

 

Additional Movies
 

The freezing rotation illusion persists if surround and foreground object are in located different depth planes.

The following two stereo-pair movies demonstrate that the freezing rotation illusion still arises when the foreground object and the surround are located in different depth planes. Regardless if one is fixating in the depth plane with the foreground object or the depth plane with the surround, still intermittent freezing of the physically continuous foreground object rotation is perceived.

3D-Airplane rotation before swaying surround

Textured disk rotating behind swaying surround and fixation point


SVCD-quality 5.2 MB

The mean horizontal disparity of the continuously (12 °/s) rotating airplane is set to 1% of the width of the display. The surround at 0° disparity sways sinusoidally forth and back(frequency 0.2 Hz, amplitude 60°,maximal speed ~38°/s).


SVCD-quality 4.2 MB

The disparity of the continuously rotating (12 °/ sec) disk with the tree is set to 0.5% of the width of the display. The surround at 0° disparity (same disparity as the red fixation spot) is swaying sinusoidally with a frequency of 0.2 Hz and an amplitude of 60°.

Freezing Rotation Illusion web pages: 1 & 2
Freezing Motion in Depth Illusion