How to build a projector with colored video?

Hi,

thanks for your reply!
This doesnt answer my question unfortunately.

I want to project with a spotlight and a light function a video or a image onto another textured surface.

My actual problem is, that i cannot project colored images and that the shape of the lightbeam is not square
I could use a texture on the , but thats not the way as we want to use the tool.(Prototyping projection mapping show)
Maybe this works with a world coordinate texture and a light?

Thanks for you reply!!