直接上代码，

<canvas class="webgl" type="webgl" id="gl" bindtouchstart="onTX" bindtouchend="onTX" bindtouchmove="onTX" style="width:100vw;height:90vh"></canvas>

const common_vendor = require("../../common/vendor.js");

Page({

  onLoad() {
    const query = common_vendor.index.createSelectorQuery().in(this);
    query.select("#gl").boundingClientRect((x) => {
      this.win = x;
    }).exec();
    common_vendor.index.createSelectorQuery().select("#gl").node().exec((res) => {
      const canvas = this.canvas = res[0].node;
      this.platform = new common_vendor.WechatPlatform(canvas);
      common_vendor.PLATFORM.set(this.platform);
      const scene = this.scene = new common_vendor.Scene();
      scene.background = new common_vendor.Color(16777200);
      scene.add(new common_vendor.AmbientLight(16777215, 1));
      scene.add(new common_vendor.DirectionalLight(16777215, 1));
      const camera = this.camera = new common_vendor.PerspectiveCamera(75, canvas.width / canvas.height, 0.1, 1e3);
      camera.position.set(0, 7, 15);
      const renderer = new common_vendor.WebGL1Renderer({ canvas, antialias: true, alpha: true });
      renderer.outputEncoding = common_vendor.sRGBEncoding;
      renderer.setSize(canvas.width, canvas.height);
      renderer.setPixelRatio(common_vendor.$window.devicePixelRatio);
      const controls = new common_vendor.OrbitControls(camera, canvas);
      controls.enableDamping = true;
      controls.dampingFactor = 0.25;
      controls.enableZoom = true;
      var textureLoader = new common_vendor.TextureLoader();
      var texture = textureLoader.load("https://files.ifok.cn/m2photo");
      texture.minFilter = common_vendor.LinearFilter;
      var bump = textureLoader.load("https://files.ifok.cn/security_sign/design_fabric_skin/fabric004.png");
      const loader = new common_vendor.OBJLoader();
      loader.load("https://files.ifok.cn/m2_obj/x.obj", (object) => {
        object.traverse((child) => {
          child.material = new common_vendor.MeshStandardMaterial({
            color: 11119017,
            side: common_vendor.DoubleSide,
            map: texture,
            bumpMap: bump,
            bumpScale: 2
          });
        });
        object.scale.set(0.1, 0.1, 0.1);
        object.position.set(0, -10, 0);
        scene.add(object);
        this.clo_object = object;
      }, () => {
      }, () => {
      });
      const axesHelper = new common_vendor.AxesHelper(10);
      scene.add(axesHelper);
      this.raycaster = new common_vendor.Raycaster();
      this.mouse = new common_vendor.Vector2();
      const render = () => {
        if (!this.disposing)
          this.frameId = common_vendor.$requestAnimationFrame(render);
        controls.update();
        renderer.render(scene, camera);
      };
      render();
    });
  },

  onTX(e) {
    this.platform.dispatchTouchEvent(e);
  }
})

我使用的是three-platformize，可以通过npm install的方式直接安装的，小程序原生的npm我还没有试过，加载进去后用THREE替换掉common_vendor即可，加载器那里需要导入OBJLoader，然后就可以直接用了