Overlap comes to mind, plus you'll be guaranteeing a bind spot.
You readjust the display zone so what was "in the center" is now just outside the rim of the interior circle's rim. Then you tweak what remains of the original radar area and
adjust it to use the new outer ring's space. How can I say it... like taking a flat 2D picture and making it fisheye through a lens. The content is still there, just redistributed.
Ok, I see what you mean... your shifting the focus of the radar to be directly behind you instead of ahead of you.
Frankly if you're including the rear radar circle, then your rear deadzone will be eliminated. The blind spot directly ahead of you doesn't matter because you can see that area for most any purpose you'd use the radar for.
Not for the purpose of flying in nebulae, where you can't see more than 50m ahead of you. You can do as Angs suggested and highlight radar targets on the screen, but I really think some experimentation of the different ideas is needed.
Image the orb radar.
Now imagine that it is an actual physical ball.
Pretend you can take the ball, with the information displayed in it still active, and rotate it so that you can see it from different angles.
Now, if you want to cover all the bases, you can gently rock the ball back and forth, so that you can see, for example, if a fighter is dead ahead and would normally be masked by the player ship representation in the orb radar.
You can rotate the ball towards you (so the top is coming towards you and the bottom is going away from you) so that you can see 'over' yourself and see what's in front of you. Then rotate back.
If you keep doing this, nothing can remain hidden. Almost like purposefully pitching your fighter up and down to accomplish the same thing, except you don't have to move your ship, as your radar display is shifting.
Ok, I see what you mean there. That may be a bit more difficult than simply animating a texture, because you'll be wanting the relative xyz positions the same as you rotate the orb about, yes? You'd be wanting to make a particle (a 2D plane that always faces the player camera) for each of the radar objects and the radar orb will be a standard 3D orb.
Once the 3D orb is rendered correctly, the next step would be to make an interface to manipulate the orb... Sounds like a good project!
i thought about a holographic radar, kind of a third person view. you not only can see where all the ships are in relation to you but also their orientation and perhaps velocity as well. i had intended to use this for a newtonian flight model with a logarithmic scale and your velocity would be the primary frame of reference, the idea would have been to project your trajectory and your targets trajectory so that you could better engage your target, approach planets and do orbital maneuvers. using such a radar for non-newtonian flight would be a lot simpler, and it could be linear because the distances are shorter and just use the ship as a frame of reference. of course it might be information overload and thus be somewhat useless.
I think that style of radar would be good for capships or stations, when the commanders need to know what's all going on. But for a fighter in the thick of it all, I think the only thing they need to know is distance and angular position. Relative velocities can be estimated by the pilot and are not that important (at least from my experiance).