How could I go about making radar glasses?

I'm working on a mod based off a story I'm writing, in the story there's a place called "The Void" that's literally pitch black and you can only see via goggles that will map out the terrain for you. I made a custom dimension for The Void, and it is indeed pitch black, but I have no clue how to make goggles that would allow the player to see the terrain.

I was thinking a pulse that gets sent out, maybe the fog color changes if you wear it, maybe something like a lidar scanner but I feel that would hurt performance real bad. Let me know if there are any ideas and how I would go about implementing something like that!