Drawing perspective is a method of portraying objects on a flat surface so that the dimensions shrink with distance. Each set of parallel, straight edges of any object, whether a building or a table, follows lines that eventually converge at a vanishing point. Typically this convergence point is somewhere along the horizon, as buildings are built level with the flat surface. When multiple structures are aligned with each other, such as buildings along a street, the horizontal tops and bottoms of the structures typically converge at a vanishing point. When both the fronts and sides of a building are drawn, then
Parallel projection central or perspective projection, in which the rays pass through a fixed point called the "center" or "viewpoint", as this point is moved towards infinity. Put differently, a parallel projection corresponds to a perspective projection with an infinite focal length (the distance between the lens and the focal point in photography) or "zoom". In parallel projections, lines that are parallel in three-dimensional space remain parallel in the two-dimensional projected image. A perspective projection of an object is often considered more realistic than a parallel projection, since it more closely resembles human vision and photography. However, parallel projections are popular in