hoverinc/ray-tracing-renderer

import * as THREE from 'three';

export function decomposeScene(scene) {
  const meshes = [];
  const directionalLights = [];
  const ambientLights = [];
  const environmentLights = [];

  scene.traverse(child => {
    if (child.isMesh) {
      if (!child.geometry) {
        console.warn(child, 'must have a geometry property');
      }
      else if (!(child.material.isMeshStandardMaterial)) {
        console.warn(child, 'must use MeshStandardMaterial in order to be rendered.');
      } else {
        meshes.push(child);
      }
    }
    else if (child.isDirectionalLight) {
      directionalLights.push(child);
    }
    else if (child.isAmbientLight) {
      ambientLights.push(child);
    }
    else if (child.isEnvironmentLight) {
      if (environmentLights.length > 1) {
        console.warn(environmentLights, 'only one environment light can be used per scene');
      }
      // Valid lights have HDR texture map in RGBEEncoding
      if (isHDRTexture(child)) {
        environmentLights.push(child);
      } else {
        console.warn(child, 'environment light does not use color value or map with THREE.RGBEEncoding');
      }
    }
  });

  const background = scene.background;

  return {
    background, meshes, directionalLights, ambientLights, environmentLights
  };
}

function isHDRTexture(texture) {
  return texture.map
    && texture.map.image
    && (texture.map.encoding === THREE.RGBEEncoding || texture.map.encoding === THREE.LinearEncoding);
}