The human haptic system among all senses provides unique and bidirectional communication
between humans and their physical environment. Yet to date most human-computer interactive
systems have focused primarily on the graphical rendering of visual information and to a
lesser extent on the display of auditory information. Extending the frontier of visual
computing haptic interfaces or force feedback devices have the potential to increase the
quality of human-computer interaction by accommodating the sense of touch. They provide an
attractive augmentation to visual display and enhance the level of understanding of complex
data sets. They have been effectively used for a number of applications including molecular
docking manipulation of nano-materials surgical training virtual prototyping and digital
sculpting. Compared with visual and auditory display haptic rendering has extremely demanding
computational requirements. In order to maintain a stable system while displaying smooth and
realistic forces and torques high haptic update rates in the range of 500-1000 Hz or more are
typically used. Haptics present many new challenges to researchers and developers in computer
graphics and interactive techniques. Some of the critical issues include the development of
novel data structures to encode shape and material properties as well as new techniques for
geometry processing data analysis physical modeling and haptic visualization.This synthesis
examines some of the latest developments on haptic rendering while looking forward to exciting
future research in this area. It presents novel haptic rendering algorithms that take advantage
of the human haptic sensory modality. Specifically it discusses different rendering techniques
for various geometric representations (e.g. point-based polygonal multiresolution distance
fields etc) as well as textured surfaces.It also shows how psychophysics of touch can provide
the foundational design guidelines for developing perceptually driven force models and
concludes with possible applications and issues to consider in future algorithmic design
validating rendering techniques and evaluating haptic interfaces.
