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
- Motion blur
- Screen Space Ambient Occlusion
- Cel shading
- Crepuscular rays
- Film grain simulation
- Depth of field
- Shadow mapping