One-point-, two-point-, three-point-perspective and beyond
Fig. 1: One-point perspective refers mostly to a situation of a set of lines perpendicular to the Picture Plane (PP) and a set of lines parallel to the Horizontal Line (HL).
Fig. 2: Two-point-perspective refers commonly to a situation of two sets of parallel lines with both Vanishing Points (VP) located on the Horizontal Line (HL).
Fig. 3: Three-point-perspective refers e.g. to presentations of buildings where not only the horizontal side-lines but also the vertical lines converge as shown in figure 3. Such presentations are unlikely to be based on real - retinal - images, and best considered as free artistic creations.
Fig. 4: Neither “one-point-” nor “two-point-” nor “three-point-perspective” appear to be terms with much practical or theoretical impact, but rather obscure the very obvious and important fact, that even very simple images, such as the scenery presented in figure 4, exhibit easily up to four or more Vanishing Points (VP).