Post-Processing

Post-processing refers to effects that are applied to an image after rendering. Examples include tone-mapping, blurring, antialiasing, bloom effects, glitch effects, and many more. It typically involves rendering the scene to a render target The target’s texture is used as input to a separate fragment shader.

Clip-Space Covering Triangle

It is very common to render something that fills the canvas, screen, or texture. A simple trick to help with this task is to use a triangle that covers the entire clip space.

Notice how the triangle’s hypotenuse only touches the screen at the top right corner. Every fragment that is outside of the screen will be clipped.