JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://threejs.org/build/three.min.js"></script>
<script src="https://threejs.org/examples/js/shaders/CopyShader.js"></script>
<script src="https://threejs.org/examples/js/postprocessing/EffectComposer.js"></script>
<script src="https://threejs.org/examples/js/postprocessing/RenderPass.js"></script>
<script src="https://threejs.org/examples/js/postprocessing/ShaderPass.js"></script>
<script src="https://threejs.org/examples/js/shaders/GammaCorrectionShader.js"></script>

<div id="d0"></div>

JavaScript

$(function() {

  let useComposer = true;

  // EffectComposer copied from https://threejs.org/examples/js/postprocessing/EffectComposer.js
  // with one line added in the parameters defined in the constructor
  /**
   * @author alteredq / http://alteredqualia.com/
   */
  THREE.EffectComposer = function(renderer, renderTarget) {

    this.renderer = renderer;

    if (renderTarget === undefined) {

      var parameters = {
        minFilter: THREE.LinearFilter,
        magFilter: THREE.LinearFilter,
        format: THREE.RGBAFormat,
        stencilBuffer: false,
        type: THREE.FloatType // line not present in original code
      };

      var size = renderer.getSize(new THREE.Vector2());
      this._pixelRatio = renderer.getPixelRatio();
      this._width = size.width;
      this._height = size.height;

      renderTarget = new THREE.WebGLRenderTarget(this._width * this._pixelRatio, this._height * this._pixelRatio, parameters);
      renderTarget.texture.name = 'EffectComposer.rt1';

    } else {

      this._pixelRatio = 1;
      this._width = renderTarget.width;
      this._height = renderTarget.height;

    }

    this.renderTarget1 = renderTarget;
    this.renderTarget2 = renderTarget.clone();
    this.renderTarget2.texture.name = 'EffectComposer.rt2';

    this.writeBuffer = this.renderTarget1;
    this.readBuffer = this.renderTarget2;

    this.renderToScreen = true;

    this.passes = [];

    // dependencies

    if (THREE.CopyShader === undefined) {

      console.error('THREE.EffectComposer relies on THREE.CopyShader');

    }

    if (THREE.ShaderPass === undefined) {

      console.error('THREE.EffectComposer relies on THREE.ShaderPass');

    }

    this.copyPass = new THREE.ShaderPass(THREE.CopyShader);

    this.clock = new THREE.Clock();

    // for VR

    var rendererSize = new THREE.Vector2();
    var scope = this;

    function onSessionStateChange() {

      renderer.getDrawingBufferSize(rendererSize);
     ...