Buffer shadow effect question

Hi,
A gearwheel mesh is placed in front of a spot lamp and animated.(Please see the attached video)

A question:

            Could this effect be created using real people instead of the gearwheel ? Some green-mat video clips  containing real people would be helpful ? 

            I just want to create a "morning-ray effect" involving real people(For example a boy and a girl are walking in the background of morning sun) Is it possible in blender? Your suggestions/advise please.

Thank you.:slight_smile: