threejs纹理加载三（视频加载）

threejs中除了能把图片作为纹理进行几何体贴图以外，还可以把视频作为纹理进行贴图设置。纹理的类型有很多，我们可以用不同的加载器来加载，而对于视频作为纹理，我们需要用到今天的主角：VideoTexture。我们先看效果：

 我们直接看代码：

<template>
    <div>
    </div>
</template>
<script  setup>
import { ref } from "vue";

import * as THREE from "three";
import { OrbitControls } from "three/examples/jsm/controls/OrbitControls";
import * as Dat from "dat.gui";
const gui = new Dat.GUI();
const scene = new THREE.Scene();
const camara = new THREE.PerspectiveCamera(
  75,
  window.innerWidth / window.innerHeight,
  0.1,
  1000
);
camara.position.set(0, 0, 10);

const Gemertry = new THREE.BoxGeometry(5, 5, 5);

//视频加载器
let video = document.createElement("video");
video.src = "/src/assets/819.mp4";
video.load();
video.crossOrigin = "anonymous";

document.addEventListener("click", () => {
  video
    .play()
    .then(() => {
      render();
    })
    .catch(err => {
      console.log("err:", err);
    });
});
// video.play();
let texture = new THREE.VideoTexture(video);
texture.minFilter = THREE.LinearFilter;
texture.magFilter = THREE.LinearFilter;
const materials = [
  new THREE.MeshBasicMaterial({ color: "#f90" }),
  new THREE.MeshBasicMaterial({ map: texture }),
  new THREE.MeshBasicMaterial({ color: "#63a" }),
  new THREE.MeshBasicMaterial({ color: "#e2d" }),
  new THREE.MeshBasicMaterial({ color: "#c57" }),
  new THREE.MeshBasicMaterial({ color: "#f00" })
];

const cube = new THREE.Mesh(Gemertry, materials);
scene.add(cube);

// 将网格对象添加到场景中

const renderer = new THREE.WebGLRenderer();
document.body.appendChild(renderer.domElement);
renderer.setSize(window.innerWidth, window.innerHeight);

const control = new OrbitControls(camara, renderer.domElement);

const render = () => {
  renderer.render(scene, camara);
  requestAnimationFrame(render);
  if (video.readyState === video.HAVE_ENOUGH_DATA) {
    texture.needsUpdate = true;
  }
};
render();
</script>
<style scoped>
</style>

这里特别要注意：对于视频而言。很多浏览器禁止了默认播放，所以这里我们通过给文档对象添加点击事件来实现，然后在加载成功的回调中我们要重新调用我们的render（）函数。