I’m looking to create a 3d radar, similar to the one in Elite Dangerous.
Idea being my pawn is in the middle and I will use my “sensors” to detect and render enemies / allies on the radar (location and vertical distance (above / below)). The radar will sit in the players UI, so could arguably be a render target of an actor of some description, I’ve been also wondering whether using some of the HUD draw primitives would be useful?
Any thoughts on where to start on this?
Built a bunch of these. Short on time for an in-depth response, but here’s 2 quick starting points… And a WARNING too… 3D Radar can take longer than an entire game to make… So look at the MARKETPLACE first, and see whats available… A lot will come down to how you intend or NEED to interact with the RADAR (not the HUD display part that’s easy as there’s lots of UMG examples around to help). Suggestion: Become an expert with the WIC and its limitations, benefits and bugs. 
Thanks - I think currently, just a read only display is ok. I’ll look into WIC, as I might need it for other things
FIrst I’d decide - are you doing it as a 3D hologram or 2D images on the HUD?
Both involve the standard of all radars: translating an object’s world coordinates to local radar coordinates around your player. Then drawing either a static mesh or an image representing the object at the computed location.
In the 3D version you get the perspective effect “for free”.
In the 2D version you’ll have to fake the perspective. I’ve never done it, but assume it involves “smushing” the coordinates on one axis of the radar based on your player forward vector.
I think 3d makes the most sense.
Would you use a flat mesh, a camera that could rotate around it, and some sort of “adding / moving mesh” logic to represent the “returns” on the radar? Then use a render target to show it on the UI?