A pictorial convention designed to suggest spatial depth by placing objects drawn with diminishing size along and within converging sets of straight lines, all arranged to fix the illusion of a coherently receding space. Variously complex illusions of the viewer's point of view can be constructed depending on the number of "points" toward which lines within the picture plane "vanish," from one (in the simplest and perhaps most common case) up to six. Linear perspective is a species of anamorphosis. See aerial perspective.