import { GodraysPass } from 'https://unpkg.com/three-good-godrays@0.7.1/build/three-good-godrays.esm.js';

import { EffectComposer, RenderPass } from 'postprocessing';
import * as THREE from 'three';
import { GodraysPass } from 'three-good-godrays';

const { scene, camera, renderer } = initYourScene();

// shadowmaps are needed for this effect
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap;
renderer.shadowMap.autoUpdate = true;

// Make sure to set applicable objects in your scene to cast + receive shadows
// so that this effect will work
scene.traverse(obj => {
  if (obj instanceof THREE.Mesh) {
    obj.castShadow = true;
    obj.receiveShadow = true;
  }
});

// godrays can be cast from either `PointLight`s or `DirectionalLight`s
const lightPos = new THREE.Vector3(0, 20, 0);
const pointLight = new THREE.PointLight(0xffffff, 1, 10000);
pointLight.castShadow = true;
pointLight.shadow.mapSize.width = 1024;
pointLight.shadow.mapSize.height = 1024;
pointLight.shadow.autoUpdate = true;
pointLight.shadow.camera.near = 0.1;
pointLight.shadow.camera.far = 1000;
pointLight.shadow.camera.updateProjectionMatrix();
pointLight.position.copy(lightPos);
scene.add(pointLight);

// set up rendering pipeline and add godrays pass at the end
const composer = new EffectComposer(renderer, { frameBufferType: THREE.HalfFloatType });

const renderPass = new RenderPass(scene, camera);
renderPass.renderToScreen = false;
composer.addPass(renderPass);

// Default values are shown.  You can supply a sparse object or `undefined`.
const params = {
  density: 1 / 128,
  maxDensity: 0.5,
  edgeStrength: 2,
  edgeRadius: 2,
  distanceAttenuation: 2,
  color: new THREE.Color(0xffffff),
  raymarchSteps: 60,
  blur: true,
  gammaCorrection: true,
};

const godraysPass = new GodraysPass(pointLight, camera, params);
// If this is the last pass in your pipeline, set `renderToScreen` to `true`
godraysPass.renderToScreen = true;
composer.addPass(godraysPass);

function animate() {
  requestAnimationFrame(animate);
  composer.render();
}
requestAnimationFrame(animate);