Shading is the term used to describe shading techniques that make the representation of surfaces and bodies in 3D graphics more realistic. Shading requires the illumination of a body. It is used to plastically emphasize body shapes and contours, as well as unevenness and curvature of surfaces.
The lighting effects available in graphics programs are calculated by shaders and take into account all realistic variants. These can be artificial light with one or more light sources for which the angle for the light radiation can be defined as well as their brightness and distance from the object. Likewise, seasonal and time of day dependent daylight can be used for object illumination, diffuse daylight and artificial light and many other lighting variants.
In addition, shading methods can be used to determine the reflection of light on the object surface. These include flat shading, Gouraud shading, Phong shading, the vertex shader and the pixel shader.