anchor.diff:              //- 绑定窗口大小，自适应
               var threeexResize = new THREEex.WindowResize(renderer, camera);
   
  +            //- threejs 的控制器
  +            var controls = new THREE.OrbitControls( camera, renderer.domElement );
  +            controls.target = new THREE.Vector3(0,15,0);
  +            controls.maxPolarAngle = Math.PI / 2;
  +            //- controls.addEventListener( 'change', function() { renderer.render(scene, camera); } ); // add this only if there is no animation loop (requestAnimationFrame)
           }
           
           function animate() {
  
positive.code: extends threejslayout
  
  block content
  
      script.
          var scene,
              camera,
  
negative.code:             renderer.setSize( window.innerWidth, window.innerHeight );
              document.body.appendChild( renderer.domElement );
  
              //- 平面坐標系
              geometry = new THREE.Geometry();
              for (i = -size; i <= size; i += step) {
                  if (i == 0) {
  