2D computer animations typically evolve from primary sources, including prints and drawings. These images are derived from various other disciplines, including cartography, typography, advertising and technical drawing. Although the final images produced using 2D computer animations take the shape of common objects such as animals, humans and popular characters, there is a complex process that is followed to replicate those images on a computer screen. Graphic artists rely on computer and mathematics skills to produce these pictures. This involves establishing coordinates, such as position, size and orientation of the original object or objects that are being replicated and then transforming those coordinates to fit the dimensions of another surface, which in the case of 2D graphics, is usually a computer screen.