Editing Computer mouse (section)

==== Transfer function ====
The virtual motion is connected to the 3D mouse control handle via a [[transfer function]]. Position control means that the virtual [[Position (geometry)|position]] and [[Orientation (geometry)|orientation]] is proportional to the mouse handle's deflection whereas velocity control means that [[Translation (geometry)|translation]] and [[Rotation (mathematics)|rotation]] [[velocity]] of the controlled object is proportional to the handle deflection. A further essential property of a transfer function is its interaction metaphor:

* Object-in-hand metaphor: An exterocentrical metaphor whereby the scene moves in correspondence with the input device. If the handle of the input device is twisted clockwise the scene rotates clockwise. If the handle is moved left the scene shifts left, and so on.
* Camera-in-hand metaphor: An egocentrical metaphor whereby the user's view is controlled by direct movement of a virtual camera. If the handle is twisted clockwise the scene rotates counter-clockwise. If the handle is moved left the scene shifts right, and so on.

[https://www.semanticscholar.org/paper/Exploration-and-virtual-camera-control-in-virtual-Ware-Osborne/8be4773bb1bb658e3f7b1b3947a1fc578f276be8 Ware and Osborne] performed an experiment investigating these metaphors whereby it was shown that there is no single best metaphor. For manipulation tasks, the object-in-hand metaphor was superior, whereas for navigation tasks the camera-in-hand metaphor was superior.