在Autodesk Forge中围绕模型旋转相机

Question

我创建了一个扩展程序，该扩展程序可以使相机围绕Revit模型旋转，该Revit模型是在存储桶中上传的，但是如何在单击工具栏上的按钮之后使相机不断围绕模型旋转。 另外，如何再次单击同一按钮停止旋转？ 下面的代码是单击按钮后我用来旋转相机的代码。

var _this = this;
var _viewer = _this.viewer;
var turnTableToolbarButton = new Autodesk.Viewing.UI.Button('turnTableButton');
turnTableToolbarButton.onClick = function (e) { 

    const nav = _viewer.navigation;
    const up = nav.getCameraUpVector();
    var pos = nav.getPosition();
    const axis = new THREE.Vector3(0, 0, 1);
    const speed = 10.0 * Math.PI / 180;

    const matrix = new THREE.Matrix4().makeRotationAxis(axis, speed * 0.1);

    pos.applyMatrix4(matrix);
    up.applyMatrix4(matrix);

    nav.setView(pos, new THREE.Vector3(0, 0, 0));
    nav.setCameraUpVector(up);
    var viewState = _viewer.getState();
    _viewer.restoreState(viewState);
};

Answer 1

我认为您在这里需要使用requestAnimation，而您的按钮将停止或启动对新框架的请求：

  let started = false;

  let rotateCamera = () => {
      if (started) {
          requestAnimationFrame(rotateCamera);
      }

      const nav = viewer.navigation;
      const up = nav.getCameraUpVector();
      const axis = new THREE.Vector3(0, 0, 1);
      const speed = 10.0 * Math.PI / 180;
      const matrix = new THREE.Matrix4().makeRotationAxis(axis, speed * 0.1);

      let pos = nav.getPosition();
      pos.applyMatrix4(matrix);
      up.applyMatrix4(matrix);
      nav.setView(pos, new THREE.Vector3(0, 0, 0));
      nav.setCameraUpVector(up);
      var viewState = viewer.getState();
      // viewer.restoreState(viewState);

  };

  turnTableToolbarButton.onClick = function (e) {
      started = !started;
      if (started) rotateCamera()
  };

根据您的代码段和现场插图，查看我的扩展库回购以获取完整代码。