OOF2: The Manual
Axis2HSV (Axis2HSV) — Map Axis orientations to HSV values.
The direction of the orientation's axis of rotation is represented
by a declination θ and an azimuth φ.
Axis2HSV maps the cosine of θ into the
value, so that an orientation with θ=0
is bright and θ=180 is black. It maps the azimuth φ
into the HSV
hue, so that φ=±180 is
red and φ=0 is cyan.
The orientation's angle of rotation about the axis, ψ, is
mapped to the HSV
saturation, so that ψ=0
is fully unsaturated (white, gray, or black), and ψ=1 is
Note that this isn't a great way to convert orientations to angles, because small changes in orientation can result in a large change in color, and black represents more than one orientation (all orientations with ψ=0 or θ=180).