Lastly, an interestingÑand usefulÑaddition would be a mechanism to adjust the faceÕs direction of gaze as
it appears to the viewer; research has shown that factors such as face curvature, pupil placement and screen curvature
ToonFace: A SYSTEM FOR CREATING AND ANIMATING INTERACTIVE CARTOON FACES LEARNING AND COMMON SENSE SECTION TECHNICAL REPORT 96-01 11
interact in determining where a two-dimensional projection of a face seems to be looking, from the observerÕs point
of view [Anstis et al. 1969]. The same would apply to head motion. This is especially important for systems that
track a userÕs line of gaze [Bers 1995a, 1995b, Koons & Thrisson 1993] and thus allow for reciprocal behavior
from the machine.