Pixel shaders are computer programs that run on the graphics card and are responsible for calculating the final color of each pixel in a 3D scene. They are written in a shading language, such as HLSL or GLSL, and are compiled into machine code that can be executed by the GPU. Pixel shaders can be used to create a wide variety of effects, such as lighting, shading, and texturing.
To check if a pixel shader is working correctly, you can use a graphics debugging tool, such as RenderDoc or NVIDIA Nsight. These tools allow you to visualize the output of the pixel shader and identify any errors.