A Story about shaders

Shaders are small programs that run on your GPU rather than your CPU. They are written in a language called GLSL (OpenGL Shading Language), which is similar to the C language.

While shaders are primarily used for rendering graphics, they are also widely used in other fields like AI, physics simulations, and scientific computing. This because the GPU is highly optimized for parallel processing.

The origin of the name

The term “shader” comes from its original purpose: shading objects in computer graphics. Shading refers to how light interacts with surfaces, affecting their appearance (color, brightness, shadowing, reflections, etc).

• Early computer graphics needed a way to determine how objects should look based on lighting conditions.
• Programs were written to calculate light reflection, shadows, and color variations, these were called shading algorithms.
• When these algorithms became more sophisticated and were moved to specialized GPU programs, they were named shaders.

The evolution of shaders

At first, shaders were fixed-function (predefined lighting and shading models). Later, they became programmable, allowing developers to write custom shader programs. Beyond simple shading effects.

Today, shaders do much more than just shading. They are used for:

• Vertex transformations (moving 3D objects, morphing geometry, etc).
• Post-processing effects (blur, glow, color correction, etc).
• Physics simulations (water ripples, cloth simulation, etc).
• AI and general computing (neural networks, cryptography, scientific computing, etc).

Despite this evolution, the name “shader” has stuck, even though modern shaders do much more than just shading.