The use of pixel-shaders to apply filters to a scene to produce various effects.

Instead of rendering 3D objects directly to the display, the scene is first rendered to a buffer in the memory of the video card. Pixel shaders are then used to apply post-processing filters to the image buffer before displaying it to the screen.

Post-processing allows effects to be used that require awareness of the entire image (since normally each 3D object is rendered in isolation). Such effects include:

  • High dynamic range rendering
  • Bloom
  • Motion blur
  • Screen Space Ambient Occlusion
  • Cel shading
  • Crepuscular rays
  • Film grain simulation
  • Depth of field
  • Shadow mapping