A quick general question. If you had a first person car racing game and you put a rear view mirror in the HUD (linked to a rear facing camera) so you can see players coming up behind you, are you then essentially rendering two versions of your map at once? and if so, wouldnt this create lag? is there a trick to doing this? Or does two cameras at once not affect performance at all? TIA.
AFAIK older games only rendered a very smal potion of the game in the rear view mirror + reduced render resolution. You could try to render a bare minimum version without any fancy extras and use that as a base.