In the second session of the Light, Space and Perception workshop/work group, hc gilje offers a hands-on exploration of how to use one projector as many smaller projection areas: How to position and mask video images on different surfaces and objects in a space, and do simple transitions between scenes.
downloads applications for mac and pc, plus documentation:
http://hcgilje.wordpress.com/resources/video-projection-tools/
hc gilje is a research fellow at Bergen National Academy of the Arts