Motion/Pursuit Law on Invariant Circles (Visual Depth Perception 4)

fixate distance f

100.

symmetric depth d

10

ϕD

10

time t

3

scale

125

This Demonstration computes the motion/pursuit law in the two-dimensional horizontal "fixation plane" of the eyes. The observer is looking mainly at F on the vertical axis, but also sees D as she translates to the right at 6.5 cm/sec (interocular distance per second). The distractor can be moved off the

d

1

axis around the time zero invariant circle.

We do not know a theoretical explanation for the rough approximation of the peak motion/pursuit law by the 2D relative distance, but this Demonstration compares

dθ

dβ

(0)

,

dθ

dβ

(

t

c

)

, and the 2D signed relative distance,

±

|D-F|

f

. It also lets you vary time and compare the motion/pursuit law at other times.