1. A method of merging a real image and a synthetic image in real time, comprising: providing a first signal containing depth and image information per pixel about said real image; providing a second signal containing depth and image information per pixel about said synthetic image; comparing said depth information corresponding to said real image and said depth information corresponding to said synthetic image for each pixel; selecting one of said image information corresponding to said real image and said image information corresponding to said synthetic image in response to said comparison step for each pixel; combining the selected information to produce an output signal; calculating an interaction between images in the first signal and the second signal, wherein said interaction is selected from the group consisting of occlusions, collisions, shadows, and reflections; and generating output signals based on said calculated interaction.