I am working on adding some visual cues to the player to help identify where each objects are in 3D. In many space games, there is usually an indicate on the edge of screen that reflects the direction towards that particular object. For example, an indicator in the upper middle edge of screen may indicate that particular object is straight ahead and an indicator in the lower middle of edge screen may indicate that object is directly behind.
If the game is mostly 2D, such as most FPS shooters, this would not be a difficult problem. Then the indicator is basically a top down radar. But with full 3D, Im unsure how to translate this inherently 3D information to 2D in a intuitive, yet meaningful way. If just using the 2D radar method, then I cant convey pitch/elevation information. For example, an indicator in the upper middle edge of screen can not differentiate between an object that is straight head in the same plane as the player versus something that the player needs to tilt 45 degrees upwards to see.
Is there something better than the top down radar method?