Xbox gpu Nv2a

[ERP]

NV2A is capable of more of VS1.1 and PS1.3 (but it's NOT PS1.4 o PS2.0 compliant), actually on the VS side it can do things you can't do even on a SM3.0 part.

oh my. like what?

dare we suggest that NV2A can do things that you can't do on R500 / Xbox2?

that would be beyond funny.

To be honest I've never found the additional VS functionality all that useful (The costs are just too high), I doubt very much R500 or anything else would implement it in the same way. But you should be be able to get similar functionality out of it.

 

[Nappe1]

NV2A is capable of more of VS1.1 and PS1.3 (but it's NOT PS1.4 o PS2.0 compliant), actually on the VS side it can do things you can't do even on a SM3.0 part.

oh my. like what?

dare we suggest that NV2A can do things that you can't do on R500 / Xbox2?

that would be beyond funny.

not as funny as Pyramid3D able to do texture reads (or in fact, using any other data available on Unified Memory as data input.) on Vertex Shader in 1997... (while X800 can't do it yet, GF6800 is at last capable of doing this.)







sorry I could not resist.

 

[Ostsol]

Is there a technical document out there that details the hardware and graphics API specifications for the XBox?

 

[LeGreg]

Is there a technical document out there that details the hardware and graphics API specifications for the XBox?

Yes. But you have to be paying the cost of the SDK first and have an approved publisher in order to be able to do that. (in some case, the concept of your game has also to be approved by Microsoft).

 

[nAo]

To be honest I've never found the additional VS functionality all that useful (The costs are just too high), I doubt very much R500 or anything else would implement it in the same way. But you should be be able to get similar functionality out of it.

I agree with you..performance hit is too high and I never found something worth it, moreover I work on the PS2 most of the time

 

[DegustatoR]

To be honest I've never found the additional VS functionality all that useful (The costs are just too high), I doubt very much R500 or anything else would implement it in the same way. But you should be be able to get similar functionality out of it.

I agree with you..performance hit is too high and I never found something worth it, moreover I work on the PS2 most of the time

So it's vertex texturing then? 8)

 

[nAo]

So it's vertex texturing then? 8)

No, it's not. You have a pm. (sidenote: pm notifies do not work )

 

[AlNom]

May I be pm'ed about it? (unless it's something else... )

 

[Akumajou]

Are there any documents that list what the xbox is cable of in terms of Direct X features? (I know its 8.1 using shader 1.1 with some 1.3, but some stupid fan boys are arguing how the xbox is cable of dx 9 via "programing" and will be able to do half life 2 well )

Sufice to say they are driving me up the wall while I try to explain to them how its not possible and I want to shove some common sense down their collective throats.... not that they will believe me.

I think that what those fanboys were referring to was how way back in the days the SEGA Genesis was not capable of doing the SNES "mode 7" effect and later SEGA, with their custom assembly level programing was able to do mode 7 with skilled programing software.

Again SEGA proved this again with Saturn since that console lacked the PSX's hardware lighting effect, Sega's AM2 team again used custom assembly level programing and produced games with lighting effects (Fighting Vipers, Fighter Megamix) and later other SEGA depts put out games with lighting effects like Sonic Team, Team Andromeda and others.

I believe that the fanboys were referring to "if" a highly skilled game developer were to program a game on XBox using assembly level type code, said developer could produce a game with custom effects that would exceed the known capabilities of XBox and look almost like first generation XBox2 games just like console history has shown.

However the way you can answer those fanboys is that it will never happen because using a low level assembly like custom code on XBox would take development times into too many years since the XBox is so much more complicated as an architecture in comparison to N64, PSX, PS2, DC and Saturn all of whom have had games programed in such a way.

In other words a game would take more than 3 or 4 years to develop keeping in mind the time it took Sony's Polyphony Digital to have Gran Tourismo 1 running on PSX, or the time it took Sonic Team to make Nights into Dreams and Burning Rangers and Team Andromeda's Panzer Dragoon Saga.

Plus there is no reason for any development team to do it because its just better to get to know the SDK in XBox2 as soon as possible to game games ready by launch date.

 

[Fox5]

"I believe that the fanboys were referring to "if" a highly skilled game developer were to program a game on XBox using assembly level type code, said developer could produce a game with custom effects that would exceed the known capabilities of XBox and look almost like first generation XBox2 games just like console history has shown."

That's a pretty big jump to say it would look like xbox2 games. Genesis approached snes, and gamecube can approach xbox, and saturn approached psx, but none ever surpassed the capabilities of the next most powerful console(well...rebel strike often runs at 60 fps and I don't know how many bump mapped xbox games do that).

BTW, why is xbox too complicated to program in assembly? Certainly the x86 cpu doesn't prevent it, so would it be harder to write assembly code for the shaders on xbox than writing assembly for any other system?(wasn't all the early xbox shader code in assembly?) It would probably take a long time, but it takes a long time on any system.(a future rare game on xbox could possibly use assembly...though based on their current offers they seem to be high level, conker doesn't look much better than starfox adventures and is launching 3 years later) Does microsoft even let devs write 'to the metal' code for xbox?

 

[crystall]

However the way you can answer those fanboys is that it will never happen because using a low level assembly like custom code on XBox would take development times into too many years since the XBox is so much more complicated as an architecture in comparison to N64, PSX, PS2, DC and Saturn all of whom have had games programed in such a way.

Believe me, X-Box is not even vaguely as complex as PS2 or the Saturn from a developer point of view. Writing an entire game in asm on the X-Box would be an easy task compared to programming the Saturn, that was a really convoluted machine.

 

[Mintmaster]

Unless the per phase means something really significant it doesn't seem like ps1.4 added very much, at least not compared to ps2.0.

Heh, the "phase" feature is huge. With PS 1.0-1.3, if you wanted to look up a texture there are several pre-defined ways to do it, which is why there are a whole crapload of tex___ instructions.

In ps1.4 you replace all those instructions with just texld, and you can do whatever you want before the phase marker (well, whatever fits in 8 math instructions and 6 ordinary texture instructions), and look up a texture using any value from those calculations. If I'm talking to technical for you, think of it this way. With a PDA, you can write memo by selecting characters from the virtual keyboard, but you only have a certain selection of pictures. The other option is to make a memo in a bitmap/paint program, using the stylus to draw any character or picture you want.

That's why ps1.4 can do that virtual displacement mapping technique, also known as offset mapping or parallax mapping. In ps1.0-1.3, you're confined to a box of ideas.

 

[Mintmaster]

XGPU aka NV2A is capable of VS1.1 and PS1.1 or 1.3, not sure which, so in those terms it matches either GF3 or GF4Ti, and matches either DX8.0 or partial DX8.1 (yes, some will argue this, I'm sure, but I'm still saying less than PS1.4 = partial DX8.1 )

From what I've heard, HL2 in DX8 mode looks pretty close to DX9.

I'm pretty sure the XBox will look pretty good running HL2, and with the low resolution, I doubt speed will be much of a problem either. Remember, 640x480 has only 16% of the pixels of 1600x1200.