I want to emulate the effect of this image without having to resort to using a slide-projector, is this something that can be done with software? I know I can just overlay a bunch of graphic light effects, but what about articulating the random curves of shape and form?
[Image edited to PG rating]
Paint a pattern on a layer, set the layer blend mode to mutiply, change the opacity as needed.
It's not an exact simulation (because it ignores the 3D nature of the surface being projected upon), but it's close.
Also, I would think that one could do a Displacement Map, from the original Image w/ but a little processing, to get a bit of the 3D.
Years ago, I did a shot with a projector for the full facial "wrap," and then, some years later, repeated that in Photoshop. It was a close call, which did the better job.