Holographic projector space map

For my space game I’m interested in doing a holographic space map projection system. Essentially, the player stands in a room, which darkens, and then a holographic map appears. The thing is, i’d like the size of the projection to exceed the room boundary, and it needs to work in VR. Any suggestions how I should approach this? Can I just force the map to be rendered after the room somehow? What else might I try?

Maybe there’s some clever render layer compositing tricks you can do if you mess with the source code? I have been looking for something like that but not found it in UE yet. It was easy to do in Unity but not sure how in ue.

An option you could look at is making your materials ‘Translucent’ and ticking the disable depth testing box?
That should draw those pixels over closer pixels.
Or maybe muck around with custom depth buffer things but I never tried that myself.