I have seen on some occasions in the past, that lasers were used to create a simple image (actually just a relatively simple shape of light) in real-time. It appears as if the image is 3D, although that may be an illusion. I hope you understand what I mean, because I'm not sure I could explain any better... I would like to know how that works, or at least how is it called (so I can do a search). Is there a screen of some sort, on which the image forms? If not, how is the image created? Thanks.