Halo 3 runs at 640p native XD

[sieanr]

kamekazai said:

selnor said:
Halo 3 runs at a lower resolution, not only to maintain a constant frame rate, but because it runs TWO frame buffers, that cover both the high dynamic range, and the low dynamic range. Hence why Halo 3 is possibly the most colourful game in a long time.

80 vertical pixels is a worthy sacrifice to not have a game that looks bland like Gears of Grey, and to have a steady frame rate during some of the larger battles (at one point in the game, there are 2 scarabs, about 8 ghosts, 20-ish brutes and grunts, 10 or 15 marines, and a buttload of aircraft having dog fights in the air. All in an area that is probably about 1/2 mile wide)

I am guessing that is the reason, it was probably possible to run the game at 720p and in fact without much difference, but bungie decided that the little extra framerate and dual lighting renders where worth it. So far I agree.

 

It also has to do with how halo is running two rendering passes, one on each buffer. This is where the EDRAM of the 360 gets into play. When the 360 was originally designed, the EDRAM was intended for handling 720p. However, there is no way bungie could fit two 720p buffers and get two rendering passes. So 640p is the highest resolution you could get out of this system. Also, there are various reports that Bungie was screwing around with MSAA until the 11th hour, but they just couldn't optimize it in time, or they couldn't justify the framerate hit - depending on who you believe.

And before MikeB pops in here to say the PS3 could pull this off, it cant. No PS3 game has rendered two different rendering passes, and likely never will for a variety of reasons. Halo 3 pulling off two completly different rendering passes is quite impressive and a really interesting use of the hardware. This is also a big reason why Killzone is using the relativly exotic method of deferred rendering as you can get most of the same things as you can with two rendering passes. However, deferred rendering has its own problems and benefits, namely blurry textures but great dynamic lighting.

@making music - that last pic is clearly a skybox, and the second is likely one as well.