Participants used four different travel techniques for their virtual
walkthroughs. By technique, we mean a particular combination
of an input device, a number of hands used to control the
device, a number of DOFs, and a device-to-avatar movement mapping.
Each technique moved the avatar and viewpoint together,
such that the avatar’s viewpoint always faced in the same direction
as the avatar’s forward motion. For all travel techniques, collisions
between the avatar and objects of the scene (obstacles or walls)
were slippery, so that the avatar did not get stuck in a corner. In
all cases, a rate control algorithm controlled the translations of
the viewpoint in the VE. A pilot study helped us select speed control
mechanisms for each travel technique to optimize user
performance.