Fragment Shader (Fragment shader) is a technical term that is extremely important in rendering and optimizing game graphics (technical art). After processing the vertex shader, a program that uses lighting, textures, and color composition to determine the final color to paint on each pixel (fragment) on the screen.
Real-world analogy: A top-notch painter who colors inside the borders of a coloring book using ``precise gradations and special paints''
Fragment shader is a ``painter that uses a spray or brush to apply color with ultra-precision within the borders (polygons) of a 3D model assembled by vertex shader''. Rather than just painting with one color, we paint every pixel on the screen with beautiful textures and shadows that capture the human eye, such as, ``There's strong light here, so let's make it shine golden,'' and ``The area in the back is in shadow, so let's make it dark blue and muddy,'' without making any compromises.
Illustration: Fragment Shader (Infographic that clearly illustrates the basic processing flow and mechanism of fragment shader) in Japanese notation
Detailed mechanism and operating principle
Edit the Fragment shader (or the Fragment stage of Shader Graph) to calculate specular reflections and environment map reflections in high-definition pixel units from the normal vector and light direction.