> consistent enough you want the opposite, if it's consistent, then it's more difficult to gauge it's motion just by finding similar zones. think on mouse on g

> consistent enough you want the opposite, if it's consistent, then it's more difficult to gauge it's motion just by finding similar zones. think on mouse on glass or metal, it's too uniform for the sensor to detect motion. anyway: paper https://dspace.mit.edu/bitstream/1721.1/6298/2/AIM-476.pdf https://dspace.mit.edu/bitstream/1721.1/6298/2/AIM-476.pdf lecture: https://www.youtube.com/watch?v=0BVZDyRrYtQ https://www.youtube.com/watch?v=0BVZDyRrYtQ usually circular motion is used, but linear works just as fine