Flat (undistort) projection on several 3D surface


I can’t understand one thing.
example: i have got flat wall and one box near, and projector over my head or some where else. i making 3d model in vvvv box and quad. Now i want to make flat (without distortion for my point view) projection on wall and box. but i don’t understand how!

i can make normalized projection on flat surface using textured quad.
i can make projections on different sides of one real cube, using one projector.

But how can i make undistort projection on several 3d surfaces?

how to project on 3d geometry


thanx, but i know this.
and i understand that “A projection onto an arbitrary surface looks undistorted (ie. exactly as being projected) when seen from the point of view of the projector.”

But i don’t understand how to make it.
How make projection on virtual 3d objects, like light from some point, point of view. Than i can make render for real projector (placed in another point).

or i must make many renders for each side of 3d object? but if i making projection on 10 objects * 3 sides = 30 renders. i think it too much.

Another example:
in path
ProjectionMapping_SimpleSetup.v4p tiki-download_file.php?fileId=1842 in “How To Project On 3D Geometry”
autor use node “Ligth” flying over the boxes. How change this node to virtual projector looking at boxes?

Have a look at the Projected Texture.fx inside girlpowers(slideprojector)

Also this might come handy :