In computer graphics, a shader is a type of computer program originally used for shading in 3D scenes (the production of appropriate levels of light, darkness, and color in a rendered image). This shader works by replacing all light areas of the image with white, and all dark areas with a brightly colored texture. The unaltered, unshaded image is on the left, and the same image has a shader applied on the right. Another use of shaders is for special effects, even on 2D images, e.g.
