  Interaction with virtual objects displayed in Optical See-through Augmented
Reality is still mostly done with controllers or hand gestures. A much more
intuitive way of interacting with virtual content is to use physical proxy
objects to interact with the virtual objects. Here, the virtual model is
superimposed on a physical object, which can then be touched and moved to
interact with the virtual object. Since it is not possible to use an exact
replica as a tangible proxy object for every use case, we conducted a study to
determine the extent to which the shape of the physical object can deviate from
the shape of the virtual object without massively impacting performance and
usability, as well as the sense of presence. Our study, in which we
investigated different levels of abstraction for a sofa model, shows that the
physical proxy object can be abstracted to a certain degree. At the same time,
our results indicate that the physical object must have at least a similar
shape as the virtual object in order to serve as a suitable proxy.
