model.js

import { GLTFLoader } from "three/examples/jsm/loaders/GLTFLoader"
import { DRACOLoader } from "three/addons/loaders/DRACOLoader.js"

const draco = new DRACOLoader()
draco.setDecoderConfig({ type: "js" })
draco.setDecoderPath("https://www.gstatic.com/draco/v1/decoders/")

export function loadGLTFModel(
  scene,
  glbPath,
  options = { receiveShadow: true, castShadow: true },
) {
  const { receiveShadow, castShadow } = options
  return new Promise((resolve, reject) => {
    const loader = new GLTFLoader()
    loader.setDRACOLoader(draco)

    loader.load(
      glbPath,
      gltf => {
        const obj = gltf.scene
        obj.name = "dog"
        obj.position.y = 0
        obj.position.x = 0
        obj.rotation.y = Math.PI / 2
        obj.receiveShadow = receiveShadow
        obj.castShadow = castShadow
        scene.add(obj)

        obj.traverse(function (child) {
          if (child.isMesh) {
            child.castShadow = castShadow
            child.receiveShadow = receiveShadow
          }
        })
        resolve(obj)
      },
      undefined,
      function (error) {
        reject(error)
      },
    )
  })
}