Hi,

is there any trick to enable 4x AA in Voodoo4, via 3rd party drivers or tweaking? Just for 640x480-fixed resolution games, so fillrate/bandwidth won't be exhausted.

Thanks.

AFIAK, you need two VSA 100s to run 4x AA

wrote on 17.10.03 at 18:36:23:

AFIAK, you need two VSA 100s to run 4x AA

yes, get a voodoo 5 5500 if you really want 4xFSAA, you can usually find them on ebay for no more than $30 for an AGP version, PCI will run a bit more.

I know that, it's just I thought 4x AA absence was not a hadware limitation, but a driver limitation instead, to avoid very low framerates on high resolutions. VSA-100 implements FSAA via multisampling, so maybe Voodoo4 could make 4x AA forcing it to render the same scene several times  ???, obviously a driver hack would be a must.

In spanish eBay, it's impossible to find a Voodoo5 for less than 60 Euros;. Recently I saw a PCI one with an initial price of 80 Euros and Buy it now! price of 90 Euros; (not to mention that a Voodoo5 won't fit into my old AT case).

edit : symbol Euros

Hey, someone should fix international currency support on this server  ;D, that strange symbol means "Euros".

wrote on 19.10.03 at 04:07:18:

VSA-100 implements FSAA via multisampling

VSA-100 implements FSAA by SUPERSAMPLING (subjective it looks even better than multisampling). but it also needs a higher fillrate. 4x FSAA needs a fillrate you could only get with 2 VSA-100 chips. That' it!  8)

Not just a higher fillrate...but a wider memory bus as well... ;)

wrote on 19.10.03 at 13:20:56:

VSA-100 implements FSAA by SUPERSAMPLING

Take a look at this article:

http://www.nvworld.ru/docs/fsaa2-e.html

VSA-100's AA was officially named 'Rotated Grid Super Sampling', but technically it must be considered the first multisampling AA method.

Quotes from the article:


Let's examine this AA method closely. It is known by the name 'Rotated Grid Super Sampling' (RGSS). Based upon 3dfx T-Buffer technology which allows generating four frames at once and mixing them later to acquire wide variety of effects.

Voodoo5: is the first and only accelerator which supports T-Buffer technology, and therefore RGSS. The board has two VSA-100 chips, each of which can process and store one or two frames. Hence, we have two antialiasing modes: 4x and 2x.

4x Antialiasing mode: unlike standard supersampling, which is rendering one image in higher resolution, RGSS renders four identical images in a given resolution.

2x Antialiasing mode: another one antialiasing mode, which works faster but at the cost of quality. It processes only two frames to form final pixel using two samples.


This paper states that each VSA-100 can process and store up to a couple of frames, so a single chip would be unable to render the 4 simultaneous frames needed by 4x AA. But, is it actually a hardware limitation? With 32 Mb of RAM, a Voodoo4 has enough room to fit 640x480x16 quadruplicated front, back and z buffers, and still some free Mb for textures. That would be a very useful scenario for those graphic adventures or survival horrors which used static backgrounds and low resolutions. Performance will be downgraded to Voodoo1's, but those games were perfectly playable on Voodoo1.

T-buffer AA is Supersampling...this has been confirmed ages ago...
If they used multisampling, tell me why everything on the screen in Anti-aliased? If 3dfx used multisampling...anything that was not a polygon would be aliased...
Hence Elvis' screenshot using 8x AA on his 6k in Serious Sam: SE...notice how everything is "clear" and defined. If that was taken on a Radeon or Geforce, the leaves of the trees would be heavily aliased...

http://member.netmagic.net.au/tony/glide_20030707_222839.jpg

Quote:

This paper states that each VSA-100 can process and store up to a couple of frames, so a single chip would be unable to render the 4 simultaneous frames needed by 4x AA. But, is it actually a hardware limitation? With 32 Mb of RAM, a Voodoo4 has enough room to fit 640x480x16 quadruplicated front, back and z buffers, and still some free Mb for textures. That would be a very useful scenario for those graphic adventures or survival horrors which used static backgrounds and low resolutions. Performance will be downgraded to Voodoo1's, but those games were perfectly playable on Voodoo1.

I'd rather think it's a limitation of T-buffer, which scales nicely with multiple chips


4x fsaa on voodoo4 would be great.. it would mean 8x fsaa on my v5 5500 :)
but this won't be possible

and that would be as slow as 4X fsaa on a geforce2 MX, thus not very practicable, unless you want to play old glide game or get even better quality in quake 1&2 :)

wrote on 19.10.03 at 18:30:16:

T-buffer AA is Supersampling...this has been confirmed ages ago... If they used multisampling, tell me why everything on the screen in Anti-aliased? If 3dfx used multisampling...anything that was not a polygon would be aliased...

Ok, this is a semantic discussion ;) ... another quote about Rotated Grid Super Sampling: It is clear, that this method smoothes (using four samples) all of the screen pixels, not only aliasing effect (...) performance loss is comparable to one of the standard supersampling (Ordered Grid Super Sampling, supersampling using straight grid), but distant textures are improving too, like with OGSS. According to the technical description, it's not a supersampling nor a multisampling method; 3dfx went for 'something completely different'  ;).


wrote on 19.10.03 at 18:31:09:

and that would be as slow as 4X fsaa on a geforce2 MX, thus not very practicable, unless you want to play old glide game or get even better quality in quake 1&2 :)

That's the point :) , I love old skool, tested 4x AA on Geforce DDR and gave reasonable speed on ancient games. I wish that could be done on Voodoo4  ::).

you might have noticed that you even can't use other t-buffer effects (soft shadows, motion blur etc..) on your voodoo4. that's because ONE VSA-100 isn't able to do that --> lower framerate, lower bandwith (thanks Lecram25  ;D )
of course it would be cool to have 4x FSAA and the other effects on this card, but it wouldn't work well with most games..so -i state- it was just useless in the opinion of 3dfx.
my tip: buy a voodoo5  ;) try the german ebay site if your's is too expensive.

what are you people talking about, a GeForce 2 running 4xFSAA slow? I have a 32meg Geforce 2 GTS, I run midnight club 2 at 800x600 (for some reason I can't go any higher on 98, stupid nvidiots) with all the advanced in-game graphics on and at 4xFSAA. this game wouldn't even run on my V5 5500, due to lack of dx9 support, but it was almost perfect on the GeForce (only problem, at start of the race, with all the cars around you, it's like molassas).  I don't mean to stick up for nVidia in general, but this GeForce 2 GTS works pretty darn well at 4xFSAA. anyone got anything else they want to throw at it?

I believe the geforce 2 and below use software AA... I remember when the voodoo 5 came out with the first true hardware FSAA...So nVidia had to compete; so they enabled AA via software...
Don't quote me on that...

EDIT: Replying to amp_man.

Ok, but GF2 GTS wasn't mentioned here, Blazkowicz talked about GF2 MX... half the bandwidth and less than half the fillrate, I bet your GTS runs 4xFSAA much better than his MX.

Yes you're right as far as I'm aware.  3dfx FSAA is through the T-Buffer, wheras the Geforce equivalent was 'AA' and was based in the driver software.

As to the Voodoo4 4500 AGP I'm afraid I have to agree that this is a substandard card, and will never outperform even a Voodoo 5 5000 PCI.  Of course if someone has any evidence to the contrary I'd be definately interested to see it... ;)

Actually, the Voodoo 5 5500PCI is only marginally slower than it's AGP counterpart...2-3% I believe...

so would it be possible to create 4x anti ailsing through software for the V4? I don't own one, I'm just curious. It would be a lot of work to do if it can be done, but is it possible?

wrote on 19.10.03 at 23:42:51:

Actually, the Voodoo 5 5500PCI is only marginally slower than it's AGP counterpart...2-3% I believe...

Yea very true indeed my friend. ;)

3dfx worked quite a 'flanker' on the consumer with the 5500 AGP. :p

The FSAA is done by the VSA100 by jittering (the grid - of course  ;D), but has little to do with T-Buffer! You can get T-Buffer on Voodoo3 also! Yet no FSAA!  :(

Heck, that was one helluva confusing thing in the VSA100 documentation!  ;D

Anyhow, no VSA chip was multisampler! Multisampling looks nice for interior of a polygon, but is not good for intersecting polygons!

Well, that's from my memory! I have a friend who's FSAA filter encyclopaedia  ;D I _COULD_ scratch my docs about supersampling vs multisampling, though...