  This paper identifies and confirms a perceptual phenomenon: when users
interact with simulated objects in a virtual environment where the users' scale
deviates greatly from normal, there is a mismatch between the object physics
they consider realistic and the object physics that would be correct at that
scale. We report the findings of two studies investigating the relationship
between perceived realism and a physically accurate approximation of reality in
a virtual reality experience in which the user has been scaled by a factor of
ten. Study 1 investigated perception of physics when scaled-down by a factor of
ten, whereas Study 2 focused on enlargement by a similar amount. Studies were
carried out as within-subjects experiments in which a total of 84 subjects
performed simple interaction tasks with objects under two different physics
simulation conditions. In the true physics condition, the objects, when dropped
and thrown, behaved accurately according to the physics that would be correct
at that either reduced or enlarged scale in the real world. In the movie
physics condition, the objects behaved in a similar manner as they would if no
scaling of the user had occurred. We found that a significant majority of the
users considered the movie physics condition to be the more realistic one.
However, at enlarged scale, many users considered true physics to match their
expectations even if they ultimately believed movie physics to be the realistic
condition. We argue that our findings have implications for many virtual
reality and telepresence applications involving operation with simulated or
physical objects in abnormal and especially small scales.
