About splitscreen rendering

[AlNom]

Just a question that's been idling in my mind and I'd like to get a definitive answer (if possible).

Do developers typically render each of the players' screens at full resolution as the single player and just split-up how much space is taken on the screen (besides reducing other graphical effects)? Do they differentiate between rendered resolution and the view angle/aspect ratio ala Doom 3 in this case?

 

[robofunk]

Not an answer to your question, but related. Wouldn't Xbox 360 games get the best performance from rendering 2 player splits screen in their own tile. The added benefit would be taking advantage of the extra AA associated with tilling.

 

[see colon]

from games i've played i'd say that they aren't rendering at full resolution for splitscreen. but i would guess it depends on the game and the system.

 

[zed]

no u will render only into the half screen (twice) so effectivly the same number of pixels
split screen is more expensive to do that one screen
eg u have double the number of object vs frustum intersection tests which takes cpu, also (depending on the game viewpoint) but say its a straight shrink u will have 1->2 x the number of visable objects thus more objects will have to be animated / tranformed etc
( a possible slight benifit would be a smaller texture onscreen resulting in smaller mipmap levels being accessed )