Projecting a 3D hologram to a wall

[UE4] I have an issue. how would you set up a hologram if it were to collide with a wall and the hologram would project on the wall like a movie projector?

What do you mean by a “hologram?” Is it a volumetric effect?

It’s pretty easy to set up a film projector effect by attaching some video (or a render target) to a light function. And if you add some exponential height fog, you can get volumetric effects of the light projecting through the fog.

Is that what you mean?