Shading The gradation from dark to light in a single color according to specific principals for the purpose of creating a three dimensional effect is called shading. In contrast to the metric accuracy of contour lines, hill shading is primarily used for its visual effects. Slope shading operates on the principal that the steeper the slope - the darker the shade. Oblique shading or hill shading is based upon the effect of an oblique light source on a terrain surface. Combined shading combines the effects of slope and hill shading.
Additional displays are possible using shading techniques.
Numerous visualizations have also been produced by combining a hill shades digital terrain model with orthophotos or satellite imagery. 5.1 Slope Shading Slope shading, as mentioned above operates basically on the principal of the steeper - the darker. The same is true for landforms in nature, on the model and in the map. All of these examples are very appealing visually. The of computer generated hill shading combined with our inherent fascination with the map produced ensures continued use of this method.