I begin by establishing my eye level in relation to the scene I am drawing. This horizontal line will span the entire scene, and is nothing more than an abstract projection. This primary line will serve as a sort of foundation for the rest of the drawing.
If we define a vanishing point as the imaginary convergence of a set of parallel lines that are oblique or perpendicular to the picture plane, we will see that the intersection of the purple and yellow lines do not create a vanishing point.
Because the vertical lines in this drawing are parallel to the picture plane, in our construction, they will never converge. In physical reality we know that sets of parallel lines in fact never converge, but the decision to have some sets of parallel lines converge at vanishing points is what determines the type of perspective.
Had I chosen to have the vertical parallel lines in the drawing converge at an imaginary point above the drawing, it would result in a three point perspective drawing.What is occuring with the intersection of the yellow and purple lines is simply where the corner of the structure falls in relation to the eye level of the viewer. Most of the structure rises above, while a small portion is situated below. Within the drawing, this could also be considered a center of vision.
The center of my cone of vision where things are the least distorted by the flattening of the drawing.The number of vanishing points increases with the number of oblique planes in relation to the viewer. X point linear perspective simply refers to the number of dimensions we chose to distort (in our case a maximum of 3). 1 point linear perspective implies one dimension that is distorted while vertical and all other horizontal dimensions remain parallel and undistorted, and so on, and so forth.
I’ve highlighted the “key lines” that inform the construction of this particular drawing. I hope to repeat this exercise and go into more detail in future posts.
