What You're Seeing
The Kanizsa Triangle is a optical illusion in which the brain perceives a triangle that isn’t really there. Discovered in 1955 by Italian psychologist Gaetano Kanizsa, this illusion illustrates how our visual system fills in gaps, constructing complete shapes from partial or missing information.
Your visual system uses modal completion to fill in the missing edges of the triangle. The three black circles with wedge shaped cutouts (called “Pac-Men” or inducers) are arranged so that their missing sections align precisely. As a result, your brain interprets the image as a white triangle lying on top of the circles, even though no actual triangle exists.
How to Use
Show Triangle Outline: Draws a red outline along the percieved triangle to help visualize the illusion. Press the button again to hide the triangle.
Reset: Reset the illusion.
Spacing: Use the slider to adjust the distance between the Pac-Men and observe how it affects the strength of the illusion.