Visualizing a subset of SDF data
The signed distance field of a sphere, for example, is simply the distance of an arbitrary point in 3D space from that sphere's center,
minus the sphere's radius. By using an alternate convention to define a distance from the sphere's center, such as the cross product of two
vectors associated with three points including the sphere's center, information can be extracted from the same SDF formula in a different way.

For example, imagine that the 2D screen that displays a shader is in the z = 0 plane, placing a point S on this screen at coordinates
(x, y, 0). A virtual camera at point C, which has coordinates (xc, yc, zc), where zc > 0, is located in the space in front of the screen.
Next, define another point P located behind the screen at coordinates (xp, yp, zp), where zp < 0. Next, define vector SC as (x-xc, y-yc, zc)
and vector SP as (xp-x, yp-y, zp), noting that the sign conventions for these vectors' components are intentional. Finally, define a new
vector that is the cross product of vectors SC and SP, and use this new vector as an input into 3D SDF calculations.

This is a key process that I use in this assignment, i.e. after the "Preliminary Test Etches" section. Combined with a few other steps,
some of which add complexity to the visuals, I simulate parallax like effects using a basic 3D SDF structure as a starting point.