In basic realistic art, whether it be drawing or painting, the fundamental essential is: knowing how to develop dimensional form by value. This is also known as perspective: the illusion of depth.The study of perspective as an organized method developed during the Renaissance. At that time Chiaroscuro (the study of light and shadow) was in high regard. The illusions of three dimensions on a two dimensional surface was broken into methods that can be used individually or combined… The five distinct methods are as follows: