> The Model 3 had limited bandwidth for sending 3D data. It operates on "models"
> which are collections of polygons (objects, essentially) which are all
> transformed by a common matrix and link to the next object to be drawn. I talked
> to someone who worked at Real3D and they claimed that initially all polygon data
> was fetched from VROM and that Sega was very disappointed with this so a couple
> megs of polygon RAM were added for dynamic vertex data (deformable car models,
> etc.)
>
> Still, the VROMs for most games are 32-64MB and they contain almost all of the
> polygon and texture data. It's an interesting architecture that worked extremely
> well for the time period (the CPU essentially only had to update matrices) but
> that sort of hardware has gone the way of the dodo.

That's actually very interesting info, Bart, thanks for sharing that with us. It seems in a way quite analogously similar to older 2D tile/sprite-based arcade architectures - the main CPU itself only manipulates some registers and some pointers, and the actual graphics tile/sprite data remains in ROM and is processed by the hardware to generate the display. Except in this case, the ROMs contain model/texture data, and the graphics hardware is a 3D rasterization pipeline. Adding RAM-based model storage, would be like RAM-based tile storage for 2D arcade hardware.

> The modern approach is to just throw geometry at the cards and have them render
> it (caching of polygon data as draw lists is also common, I believe.) It's a
> more flexible but resource-intensive approach.
>
> > It takes a Gamecube or an Xbox to rival & surpass the quality and performance
> of
> > MODEL 3, in practice.
>
> No way. By the time the Riva TNT hit the scene, Model 3 was obsolete.

That seems slightly a stretch. I've used a Riva TNT (16MB PCI) before, to play UT, and ... it doesn't even seem in the same world as a Model3 arcade game, as far as the graphics go. No way. Enabling AA would make it far, far worse in terms of comparative performance.

> Model 3 games definitely do not push around hundreds of thousands of polygons
> per scene. Try a few thousand. I remember Ville once hooked up a polygon counter
> to his D3D engine in Supermodel and in Sega Rally 2 there were around 9K polys
> per frame. And note that these are being fetched from the Real 3D board's local
> memory!

Well, that's not surprising. I think UT pushes probably around 10K poly/scene too, roughly, except that Model3 can add all kinds of nice texture-filtering and full-screen AA effects too, without any noticable slowdown that I can see. Try doing that on an TNT - bad idea.

Plus, you have to consider the fact that the TNT is limited in features, so much so that in fact UT multi-passes the rendering. (The reason being, that original game engine was designed for the Voodoo/Voodoo2 chipset, and utilizes some of those features in the graphics pipeline, that either have to be disabled or multi-passed on other cards such as the TNT, to get the same resultant visual effect. This is benchmarkable; the TNT gets half the frame-rate of a similarly-equivalent V2 card.) IMHO, the rendering chipset in a DC blows away a TNT, for the most part, especially with AA enabled.

> > MODEL 3 also has alot of texture space, so typically MODEL 3 games have more
> > texture variety even though DC can do higher res textures.
>
> Model 3 had 8MB of texture memory. Max texture resolution was 256x256.

Texture space in ROM or RAM or both? I wonder how / if they handled modifiable textures, or supported render-to-texture? I'm surprised at the limited texture resolution though, considering VivoNono and the Namco Sys22 stuff. (Voodoo2 hardware was also similarly 256x256 limited, of course.)

> > the proof is in the games. a lot of Dreamcast and PS2 games look like shit
> > compared to MODEL 3 games.
>
> You need to take another look. Model 3 games look nice because of nostalgia and
> because they're moving fast on arcade monitors but if you look at still shots or
> examine them closely, you'll see lots of billboards and simple geometry with
> relatively ordinary texture mapping.
>
> DC kicked Model 3's ass hard. Look at Naomi vs. Model 3, even. There's no
> comparison. None whatsoever.

I was always of the opinion that the Model3 was just ever-so-slightly higher-end than the straight-up Naomi or DC systems, although I think they could connect multiple Naomi boards in parallel to increase the rendering capability. (Doesn't HOTD2 or something use two Naomi boardsets? I'm not super-familiar with that hardware.)

Then again, I swear Outrun2 looks amazingly better than 99% of the home-console XBox games out there too, it's really hard for me to believe that it's running on what is effectively an XBox inside the machine. I guess that 512MB RAM / media-board really helps with that. One little thing that seemed strange to me though, when I first saw that game in the arcade, was that the attract-mode movies were some sort of MPEG or something, rather than rendered in realtime such as most other contemporary 3D racers, like Scud Race / Super GT was.