I want to do some projection mapping, because I have to adjust the perspective of my GEM output to the canvas I am projecting onto. I thought this would be as simple as having a rectangle with a texture on it that I can roteteXYZ until it matches the canvas. But as the projected content is a particle system, I don't really know how to map the particle syste onto the rectangle. Is there any way I can achieve that?

Thanks, that is what I was looking for. Great!