These demos are real, you can click them! They contain the full code, too. 📦

#### Why postprocessing and not three/examples/jsm/postprocessing?

From
https://github.com/pmndrs/postprocessing

> This library provides an EffectPass which automatically organizes and merges
> any given combination of effects. This minimizes the amount of render
> operations and makes it possible to combine many effects without the
> performance penalties of traditional pass chaining. Additionally, every effect
> can choose its own blend function.
>
> All fullscreen render operations also use a single triangle that fills the
> screen. Compared to using a quad, this approach harmonizes with modern GPU
> rasterization patterns and eliminates unnecessary fragment calculations along
> the screen diagonal. This is especially beneficial for GPGPU passes and
> effects that use complex fragment shaders.

Postprocessing also supports gamma correction out of the box, as well as WebGL2
MSAA (multi sample anti aliasing), which is react-postprocessing's default, you
get high performance crisp results w/o jagged edges.

#### What does it look like?

Here's an example combining a couple of effects
(live demo).