A method of manipulating a three-dimensional image file including a virtual object includes obtaining image information in a processing device of a non-instrumented physical object manipulated by a user, such image information including movement information; and causing virtual movement of the virtual object based on the movement information. A method of shaping a virtual object includes obtaining image information including movement information; and determining a shape of the virtual object based on the movement information. A method of modifying a virtual object includes obtaining image information including movement information; and altering a virtual surface appearance of at least a part of the virtual object based on the movement information. Systems and computer-readable media are also described.