In anticipation of the proliferation of micro-projectors on our handheld imaging devices, we designed and tested a
camera-projector system that allows a distant user to point into a remote 3D environment with a projector. The solution
involves a means for locating a projected dot, and for adjusting its location to correspond to a position indicted a remote
user viewing the scene through a camera. It was designed to operate efficiently, even in the presence of camera noise.
While many camera-projector display systems require a calibration phase, the presented approach allows calibration-free
operation. The tracking algorithm is implemented with a modified 2D gradient decent method that performs even in the
presence of spatial discontinuities. Our prototype was constructed using a standard web-camera and network to perform
real-time tracking, navigating the projected dot across irregularly shaped and colored surfaces accurately. Our tests
included a camera-projector system and client on either side of the Atlantic Ocean with no loss of responsiveness.