I've just found this guide on another forum, the name of which I think I'm not allowed to mention:
It is called: World to Screen method
"-> Get your characters actor
-> Use this actor to get every dynamic actor around your character.
-> Filter and get the desired actor.
Now with that you can get :
-> The coordinates of the BIP01_HEADNUB of the desired actor in the world
-> Get the coordinates.origin which is the position of the bone in the world ( vector )
~~After some testing I could get access to interaction class properly and unfortunately clients worldtoscreen function doesn't work.
SIDE STUFF THAT YOU NEED FOR
YOUR OWN WORLD TO SCREEN
-> Use your characters actor, get the level and then get the PlayerController
-> Use the PlayerCalcView which is inside PlayerController to get the camera location and rotation
-> Get the FOV of the game, which is 60
-> Also you will need to get the screen resolution, but you can do that easily from the given interface functions.
And now you have everything you need to create your own world to screen function.
Good luck with the maths!
Example of what you can do with that:
"
credits to "lulpogomega"