A method and apparatus for providing force feedback to a user operating a
human/computer interface device and interacting with a computer-generated
simulation. In one aspect, a computer-implemented method simulates the
interaction of simulated objects displayed to a user who controls one of
the simulated objects manipulating a physical object of an interface
device. The position of the simulated object, as provided within the
simulation and as displayed, is mapped to the physical position of the
user object. This mapping can be broken under conditions that are
effective to provide force feedback to the user which imparts a physical
sensation corresponding to the interaction of the simulated objects.