1. A method of manipulating a 3 -dimensional medical dataset comprising: translating a body part; receiving camera data of said translating the body part from a camera system; determining with a processor a translation distance and a translation direction from the camera data based on at least one of feature tracking and a focus depth of the camera system; translating a crop plane in the 3-dimensional medical dataset based on the translation distance and the translation direction; cropping the 3-dimensional medical dataset at the location of the crop plane after said translating the crop plane; and displaying the cropped 3-dimensional medical dataset using volume rendering.