>>5891572The deep theory is that sight is made up of rays coming from your eye. To create an illusionary drawing, you place things where they would intersect those rays if your paper were a window in front of the viewer. From there flow a couple of very obvious but very important points:
>things get smaller as the further away they are>lines that are parallel convergeLines that are parallel have the same slope, so they're travelling away from the viewer at the same rate, so the space between them shrinks uniformly and they all converge to a single (vanishing) point in the distance.
After tend to come a couple of things that are commonly covered because they're very useful if you're working out perspective by hand instead of with a computer.
The horizon line is a collection of vanishing points for every line parallel to an idealized ground plane. It also coincides with the viewer's eye level. It's very useful.
Things like 1 point are not special forms of perspective, they're shortcuts/conveniences where you set up a scene so that objects are flat on the ground and facing the same way so you can reuse the same vanishing point(s).
