Feedback Fade to black on wall collision with head

Hi,
I've been thinking all day about how to implement a fade to black when the player steps out of bounds into a wall.

Ideally, I would like there to be an indicator for where they can step to get back in bounds. However, with a fade canvas/mesh involved, I'm not really sure how any indicator would be visible, at least with how I currently have things implemented.

So my theory for implementation is this:

• The player steps out of bounds
• A screen fade to black transition happens
• A camera layer culling swap happens that shows an outline of the room and the indicator, normally on a layer invisible by the main camera.
• The normally visible layers are set invisible until the player steps back into bounds

I'm worried that this is overcomplicating things, however. I was hoping someone out there could provide feedback and maybe improve upon the suggestion on how to actually go about implementing it. Unfortunately, I'm not a shader guy, otherwise I feel like that would probably be an efficient way to do it.

There could also be other obvious solutions to this implementation that I'm over looking, so I would greatly appreciate feedback and ideas. The concept is widely implemented in VR games, but I haven't really seen a whole lot on the actual implementation.

Thank you!