visual cues
We perceive depth as a result of the arrangement of objects in the
environment, the
capacities of the eyes, and the interpretation of the object(s) by the
brain itself. There are
a number of cues, or characteristics that cause us to perceive depth.
Cues are either
binocular or monocular, depending on whether two eyes, or one, are
required. The two
binocular cues are binocular disparity and convergence. Binocular
disparity is based on
the difference between the images each eye receives, due to the fact
that our eyes are
separated. Convergence relies on the tension of the muscles that
control our eye’s
movements, and allows us to gauge distances of objects that are very
close to our eyes.
There are several monocular cues, and we will explain a few of the more
relevant ones. Motion parallax is a depth cue based on the rate of movement
between objects and
our head, i.e. looking out of the window of a moving car. Elevation is
a cue based on
how high the object is in one’s vision; there is a tendency to interpret
them as being farther
away than other images. This cue is especially important to artists,
because it presents
them with an excellent way to simulate depth. Another important cue is linear
perspective, which states that lines appear to converge as they move
farther away.
Some other important cues are
interposition,
aerial perspective,
texture gradient, and
relative brightness.
Go to our demos page to see some examples of visual cues.
