edit v.0.6   Shader Fundamentals and Rendering Pipeline Shaders are small programs (with a “.shader” extension in Unity, and .usf/.ush in Unreal) that determine how surfaces interact with light . They perform mathematical calculations and execute a set of instructions (commands) to compute the color of every pixel covering an object . In essence, a shader tells the GPU—whose thousands of small, efficient cores are optimized for parallel processing—how to render objects based