This paper describes a novel method for digitizing the 3D shape of an object in real-time, which can be used for capturing live sequence of the 3D shape of moving or deformable objects such as faces. Two DMD (digital micro mirror) devices are used as high speed switches for modulating and demodulating light rays. One DMD is used to generate rays of light pulses, which are projected onto the object to be measured. Another DMD is used to demodulate the light reflected from the object illuminated by the light pulses into intensity image that describes the disparity. A prototype range finder implementing the proposed method has been built. The experimental results showed that the proposed method works and video sequences of disparity images can be captured in real time.