$ npm install postprocessing

// Attention: Three is not yet an ES6 module!
import { WebGLRenderer, Scene, PerspectiveCamera } from "three";
import { EffectComposer, RenderPass, GlitchPass } from "postprocessing";

const composer = new EffectComposer(new WebGLRenderer());
composer.addPass(new RenderPass(new Scene(), new PerspectiveCamera()));

const pass = new GlitchPass();
pass.renderToScreen = true;
composer.addPass(pass);

let lastTime = performance.now();

(function render(now) {

	requestAnimationFrame(render);
	composer.render((now - lastTime) / 1000);
	lastTime = now;

}());

import { Pass } from "postprocessing";
import { MyMaterial } from "./materials";

export class MyPass extends Pass {

	constructor() {

		super();

		this.needsSwap = true;
		this.material = new MyMaterial();
		this.quad.material = this.material;

	}

	render(renderer, readBuffer, writeBuffer) {

		this.material.uniforms.tDiffuse.value = readBuffer.texture;

		if(this.renderToScreen) {

			renderer.render(this.scene, this.camera);

		} else {

			renderer.render(this.scene, this.camera, writeBuffer, false);

		}

	}

}