Xbox2 hardware: good, yet disappointing at the same time [from a developer]
- Thread starter doncale
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The Abominable Snowman
Member
I hope that, next gen, we can see Dead or Alive 4 on par with the CG movies from Dead or Alive 2.. or even 3wunko said:
Pug said:
The problem is that 10MB is too small for a framebuffer with AA at HDTV resolutions.
1280x720p x 8Bpp x 0xFSAA = 7,372,800 B
1920x1080i x 8Bpp x 0xFSAA = 8,294,400 B
1280x720p x 8Bpp x 2xFSAA = 14,745,600 B
1290x720p x 8Bpp x 4xFSAA = 29,491,200 B
1920x1080i x 8Bpp x 4xFSAA = 33,177,600 B
1920x1080p x 8Bpp x 4xFSAA = 66,355,200 B
So if you like your games to be full of jaggies the 10MB of eDRAM is for you. Otherwise, it's too small.
DCharlie
And even i am moderately surprised
am i being retarded or something?
10 Meg _Bytes_ of video ram
8 BITS per each pixel
aren't you calculations a factor of 8 wrong?
if that's the case, then surely that means we can have 4 FSAA on a 1080p image in a 10 Megabyte frame buffer (ignoring the fact that you'd probably render a couple of frames at least)?
10 Meg _Bytes_ of video ram
8 BITS per each pixel
aren't you calculations a factor of 8 wrong?
if that's the case, then surely that means we can have 4 FSAA on a 1080p image in a 10 Megabyte frame buffer (ignoring the fact that you'd probably render a couple of frames at least)?
DCharlie said:
With 32-bit color precision, a 720p, 4x FSAA frame wouldn't fit. But as others mentioned, the whole frame doesn't have to fit, it just won't be quite as fast if it doesn't. I think some were also thinking the 10MB was the only memory the GPU could access (ala PS2?), i.e. for textures, vertices etc. but this obviously can't be true - the 10MB is just for screenbuffers, everything else would be accessed from main memory.
HyperionX said:
64-bit color?
Also the fact that Xbox 2 has a hardware video scaler... 720p up and down. Excluding Z-buffer... a 720p framebuffer of 32 bit color would take 3.5 megs.
720p framebuffer + 2xFSAA and Zbuffer = fits in 10 MB = scaled up and down to users desire
DopeyFish said:64-bit color?
Also the fact that Xbox 2 has a hardware video scaler... 720p up and down. Excluding Z-buffer... a 720p framebuffer of 32 bit color would take 3.5 megs.
720p framebuffer + 2xFSAA and Zbuffer = fits in 10 MB = scaled up and down to users desire
Huh? A zbuffer is 4 bytes per pixel too, so it's 8 bytes per pixel and 720p with 2xFSAA is 15MB.
gofreak said:
Yes, the Z-buffer is the same resolution as the frame buffer. It can be a lower precision, but 16-bit tends to cause ugly artifacts, and 24-bit tends to be bad for hardware to deal with, so in practice almost everyone uses either 4 bytes for color, 3 bytes for z, and 1 byte for stencil or they cut 2 bytes off the color and get ugly banding artifacts.
edit - speaking historically of DirectX and Xbox. I will not comment on any potential future Xbox consoles
gofreak said:
Yes. http://www.firingsquad.com/hardware/multisamp/
You could, but the z-buffer is accessed heavily when using AA.
Close to it at least. You'd probably want a 24-bit zbuffer and probably 32-bits + stencil to prevent rendering artifacts AFAIK.
Jesiatha said:
no no what he's saying is that the Z-buffer is redone within the FSAA and that's incorrect. The FSAA reads off the z-buffer seperately, it not doubling the space required for the z-buffer, just increases the bandwidth toll on the edram -> gpu.
which is going to be really really fast anyways.
Dopey, he was referring to the idea someone else suggested about leaving ZBuffer in main mem. Obviously that would defeat the purpose of using edram in the first place.
Anyway, with frontbuffer in mainmemory, you don't HAVE to fit the entire screen into eDram at the same time, things can be rendered in parts.
).
Anyway, with frontbuffer in mainmemory, you don't HAVE to fit the entire screen into eDram at the same time, things can be rendered in parts.
Actually he meant 8Bytes per pixel (hence the capital B, I guess writting the french way with their octets or whatever they call them is less confusingDCharlie said:
).DopeyFish said:
I think what he's saying is that when you use 2x FSAA, you double the frame buffer size and double the z-buffer size. When rendering, you need fast access to both of them, so putting one of them in a distant slow memory and the other in a very fast local memory is probably a bad idea. And lastly, that a 1280x720x8Bpp (frame+z+stencil) buffer with 2xFSAA will not fit in 10MB.
super-heated plasma
Member
From IGN:
Sakaguchi gave Hirokazu Hamamura, president of Famitsu publisher Enterbrain and one of the most respected names in the Japanese videogame scene, a private first look at a video of the game in motion.
During a speech given at the Asia Online Game Conference 2005, Hamamura had this to say about the experience: "It's such a realistic video that with just one look you'll know that you're looking at a next-generation system. It's something that cannot be realized on today's machines."
Going into more details, Hamamura offered an example of what's possible on the next generation Xbox: "It's possible to show a camera outside the Earth's atmosphere approach a forest on the Earth's surface, then show leaves on a tree one at a time." Hamamura wasn't clear on if he'd seen this specifically in the Mistwalker footage, or if he was just giving an example of his own.
Sakaguchi gave Hirokazu Hamamura, president of Famitsu publisher Enterbrain and one of the most respected names in the Japanese videogame scene, a private first look at a video of the game in motion.
During a speech given at the Asia Online Game Conference 2005, Hamamura had this to say about the experience: "It's such a realistic video that with just one look you'll know that you're looking at a next-generation system. It's something that cannot be realized on today's machines."
Going into more details, Hamamura offered an example of what's possible on the next generation Xbox: "It's possible to show a camera outside the Earth's atmosphere approach a forest on the Earth's surface, then show leaves on a tree one at a time." Hamamura wasn't clear on if he'd seen this specifically in the Mistwalker footage, or if he was just giving an example of his own.
super-heated plasma
Member
gofreak said:
Alas, I am only a junior member and not allowed to create threads.
Doom_Bringer
Banned
super-heated plasma said:
WOW!
alejob said:
To clarify, when judging the output of common DVD players, I find it quite impressive, be it on a SDTV or HDTV. Why then would the Nextbox, or PS3 need to offer 32-bit internal precision, when a common set-top DVD player only offers 12-bit output precision at best?
First of all, the video data on a DVD isn't even stored with more than around 8 bits per channel precision or so so anyhting more than that in the DAC is pointless unless you want to do some sort of non-linear transformation there, like gamma correction. 10 bit is fine for gamma correction though so even 12 bits is a bit overkill, anything more is completely pointless, the precision isn't there in the source data to begin with! However when he is talking about 32bit color precision he is combining four channels (r g b and destination alpha) of 8 bits each for a total of 32 bits and your 12bits is per channel. So his 32bits were actually lower than your 12 bits.
Tea Master
Banned
Monk said:
Somebody get this guy a copy of HL2.
Hiro_Kunimi_80
Member
i agree... FSAA is totally useless @ high res better deserve power to others things
uhm amped2 @720p or dragons lair @720 OR 1080i are virtually "aliasing free" (and they don't use any kind of FSAA
uhm amped2 @720p or dragons lair @720 OR 1080i are virtually "aliasing free" (and they don't use any kind of FSAA
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