Considering the tricks of palette shifting [1] and stuff that old computer and console games used to make computationally cheap animated backgrounds, does anyone know if there were computer games that used optical illusions for "computationally super-cheap animations"?
I was thinking the same thing - my guess is that these illusions rely on particular visual patterns and colors that don't lend themselves well to video games.
One thing I'm interested in is getting video games to take advantage of eye tracking and foveal vision for perf gains. I thought I saw a prototype somewhere that did this but I can't dig it up at the moment...
Really cool! Just to make sure there was nothing funny with the web page (not that I thought so, but still), I printed the Rotating Snakes picture on paper. Sure enough, they still appear to rotate, even on paper.
Absolutely superb. And I'm doing an optical illusions special with my students this week too so this goldmine is perfectly timed. Thanks!
My favourite are the colour ones. I stare and stare at them trying to isolate the bit that - for example - is actually grey but looks red, to see its "true" colour. That level of concentration...not really ever seeing the grey, but perhaps objects behind me in the room flying around Matilda-style.
The linked research only describes phenomenological characteristics of illusions, so it doesn't strike me as an explanation. But it points to research that does attempt to explain the peculiarities of what conditions these illusions arise. For example, it seems to explain the effect of the brightness of the background on these motion illusions :
First, an optimised stimulus can induce motion aftereffect on a stationary sinusoidal grating, which provides evidence for the activity of the visual motion mechanism. Second, perceived direction can be altered by background luminance. The local mean luminance seems crucial. On the basis of these findings, we propose that asymmetric responses of motion detectors to the jittering luminance gradient are the source of this illusion. A gradient model of motion detectors, which takes the image velocity as local temporal gradient over local spatial gradient, can predict such asymmetric responses if we assume imbalance in the positive and negative parts of temporal derivative filters. The asymmetry then depends on the DC offset of the stimulus, which explains the effect of the background luminance.
[1] http://www.effectgames.com/effect/article.psp.html/joe/Old_S...