The interactive and shared surface technique described herein employs hardware that can project on any surface, capture color video of that surface, and get depth information of and above the surface while preventing visual feedback (also known as video feedback, video echo, or visual echo). The technique provides N-way sharing of a surface using video compositing. It also provides for automatic calibration of hardware components, including calibration of any projector, RGB camera, depth camera and any microphones employed by the technique. The technique provides object manipulation with physical, visual, audio, and hover gestures and interaction between digital objects displayed on the surface and physical objects placed on or above the surface. It can capture and scan the surface in a manner that captures or scans exactly what the user sees, which includes both local and remote objects, drawings, annotations, hands, and so forth.