bloom |
When you see a shiny object in very bright light, you will often perceive a glow or "bloom" around the brightest highlights, and this shader aims to simulate such an effect. Adding bloom to a sunlit scene can really add some impact - it softens up the result just enough. You would want to set the trigger color to very nearly white.
You can also use it to apply scene-wide glowing effects keyed to a specific color - bloom looks at every pixel in the scene, and if it is higher than a certain target color, applies the bloom.
Examples: