postprocessing

Post Processing

CI Version Peer dependencies CDN

A post processing library that provides the means to implement image filter effects for three.js.

Demo · Sandbox · Documentation · Wiki

Installation

This library requires the peer dependency three.

npm install three postprocessing

Usage

Post processing introduces the concept of passes and effects to extend the common rendering workflow with fullscreen image manipulation tools. The following WebGL attributes should be used for an optimal post processing workflow:

import { WebGLRenderer } from "three";

const renderer = new WebGLRenderer({
	powerPreference: "high-performance",
	antialias: false,
	stencil: false,
	depth: false
});

The EffectComposer manages and runs passes. It is common practice to use a RenderPass as the first pass to automatically clear the buffers and render a scene for further processing. Fullscreen image effects are rendered via the EffectPass. Please refer to the usage example of three.js for more information on how to setup the renderer, scene and camera.

import { BloomEffect, EffectComposer, EffectPass, RenderPass } from "postprocessing";
import { Clock } from "three";

const composer = new EffectComposer(renderer);
composer.addPass(new RenderPass(scene, camera));
composer.addPass(new EffectPass(camera, new BloomEffect()));

const clock = new Clock();

(function render() {

	requestAnimationFrame(render);
	composer.render(clock.getDelta());

}());

Output Encoding

Simply set WebGLRenderer.outputEncoding to the desired target color space and postprocessing will follow suit. Built-in passes automatically encode colors when they render to screen and internal render operations are always performed in linear color space. It’s recommended to enable high precision frame buffers when using sRGBEncoding:

import { HalfFloatType } from "three";

const composer = new EffectComposer(renderer, {
	frameBufferType: HalfFloatType
});

Performance

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.

Performance Test

Included Effects

The total demo download size is about 60 MB.

Custom Effects

If you want to learn how to create custom effects or passes, please check the Wiki.

Contributing

Please refer to the contribution guidelines for details.

License

This library is licensed under the Zlib license.

The original code that this library is based on, was written by mrdoob and the three.js contributors and is licensed under the MIT license.