What is "shader"

Shader \Shad"er\, n. One who, or that which, shades.

n. 1 One who, or that which, shades. 2 (context computer graphics English) A set of software instructions used to calculate rendering effects on graphics hardware.

In the field of computer graphics, a shader is a computer program that is used to do shading: the production of appropriate levels of color within an image, or, in the modern era, also to produce special effects or do video post-processing. A definition in layman's terms might be given as "a program that tells a computer how to draw something in a specific and unique way".

Shaders calculate rendering effects on graphics hardware with a high degree of flexibility. Most shaders are coded for a graphics processing unit (GPU), though this is not a strict requirement. Shading languages are usually used to program the programmable GPU rendering pipeline, which has mostly superseded the fixed-function pipeline that allowed only common geometry transformation and pixel-shading functions; with shaders, customized effects can be used. The position, hue, saturation, brightness, and contrast of all pixels, vertices, or textures used to construct a final image can be altered on the fly, using algorithms defined in the shader, and can be modified by external variables or textures introduced by the program calling the shader.

Shaders are used widely in cinema postprocessing, computer-generated imagery, and video games to produce a seemingly infinite range of effects. Beyond just simple lighting models, more complex uses include altering the hue, saturation, brightness and/or contrast of an image, producing blur, light bloom, volumetric lighting, normal mapping for depth effects, bokeh, cel shading, posterization, bump mapping, distortion, chroma keying (so-called " bluescreen/ greenscreen" effects), edge detection and motion detection, psychedelic effects, and a wide range of others.

Shader is the twenty-first album by electronic musician Vektroid under the alias of Sacred Tapestry. The album features more drone-y sounds compared to other Vektroid works.
A remastered version of the album, titled Shader Complete, was released in 2016. Changes from the original album include different titles, altered song lengths and structures, and the addition of two tracks recorded during the Color Ocean Road sessions.