As the user moves the object in 3D space, she can track, by virtue of these shadows or silhouettes, how she is moving (or sizing) the object in each dimension.

• 当用户在三维空间中移动对象时，可以借助这些阴影或轮廓跟踪其在每个维度上是如何移动对象（或改变对象大小）的。