Before a cartographer can start designing a shaded relief, he has to compile the necessary basic data. This includes contour lines, river networks, aerial photographs, pre-existing maps and other information describing the form and appearance of the terrain.
The river network and the contour lines serve as a framework for the following steps and must be visible during the whole shading process.
Which Shadows Should One Depict?
A shaded relief depicts the brightness of a terrain's surface under oblique illumination. Three-dimensional shadow effects very similar to a shaded relief are observable in nature, if the landscape is of a uniform color.