Virtua Fighter 3(Shenmue) on Sega Saturn

Actually, if my math is correct and I understand the way frame buffers work at all the Saturn would never be able to render more than that 196k polygons per second figure I mentioned at 40bytes per polygon. I don't know exactly how the rendering process works or if any compression can be involved in making the final image or anything like that. I do know that the 3D VDP1 sends its 256KB frame buffer to the 2D VDP2, which combines its 256KB frame buffer with VDP1 for the final image sent to the display.

I do not know for a fact that each polygon must weigh ~40 bytes in the frame buffer. Perhaps Druid II or somebody more into the actual rendering side of things than myself can say otherwise. It is interesting that 40byte polygons would fill up 256K before reaching 200,000 polygons per second though. That was Sega's own spec limit for texture mapped polygons, with 500,000 being the theoretical limit which I would suppose was purely taken off the MIPs performance of dual SH-2s.

 

My understanding of how the Saturn can layer frame buffer outputs rendered by its two VDP chips isn't brilliant, though analysing footage of Burning Rangers definitely helped me figure out the exact process on a cycle-by-cycle level. Of course, that's just one game and there's no way of telling if VF3 would have used a similar technique. Would it even be possible to combine the results over several frames, such as how early tape recordings could be built up using overdubs? I realise this is a rather obscure analogy, but it's the best way I can put into words the theoretical process that I'm thinking of - does that make sense to anyone, and would it even work at all? Maybe the programmers at AM2 were able to build up layers over four cycles rather than the two of titles like Burning Rangers, which would mean that figures in the region of 750k polygons per second might be possible? If this could be done, I reckon the floor would be drawn first, followed by any 3D objects surrounding the fighters and then the actual characters last, one at a time. This way, everything could be layered without there being too many z-buffering issues, not that the Saturn natively supported such a feature (or did it?)...

 

What that sounds like is some kind of multipass rendering, which would lower the framerate and therefore not increase the polygons per second. Burning Rangers does some sort of voodoo with overlaying lower resolution polygons for the translucent light beams. I've seen this described as a VDP2 effect being overlayed over VDP1 graphics before. That was just to get transparency though, not for increasing the polygon counts of any models on screen.

 

My theory involves rendering a first pass (floor geometry) in the frame buffer, then layering over this any 3D walls or additional foreground polygonal background data such as walls. Finally, the characters are drawn and placed on top of all this, which remains in memory somehow. Would that kind of "multipass" processing even be technically possible on the Saturn, as it's far more advanced than what Burning Rangers was doing?

 

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The 40byte figure is just a standard weight for a polygon in most to all rudimentary 3D rendering discussions. I've seen it as low as 32byte, but I toss out the high end hoping somebody has looked into the memory usage side of polygon rendering. I haven't been able to find any significant difference between the VDP1's native quadrilateral rendering, which included the options of "pinched" quads making triangles, and a "true" triangle based rendering system from this time. Quad based rendering is definitely a hold over from tile based 2D rendering and blitters like those in the Sega CD or Amiga, I just don't see any practical limitation to it for this generation of hardware. The characters and objects are usually made up of squares and rectangles anyway.

My impression has always been that the VDP1 was more limited than the SH2s alone could generate coordinates for. I also haven't seen any confirmation that the DSP could contribute significantly to polygon rendering. It seems much better suited for offloading system tasks from the SH-2s, like direct memory access.

 

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From my analysis of Burning Rangers footage, the system of alternating processes doesn't always work as sometimes the whole cycle takes three frames rather than two, resulting in a less than smooth update when viewed at full speed (naturally, this effect is even more pronounced when advancing in slow motion). However, I did that using video recordings of the PAL code, so it's possible this might not be the case if tested with the original NTSC version. In the future I hope to do a similar technical breakdown with Panzer Dragoon Saga and Shining Force III, as I've also heard these utilised some kind of framebuffer combination technique that I'd love to learn more about...

 

I haven't noticed any glitches in the Burning Rangers effect. Here are some shots and videos from the US version.

 

To notice the instances where there's slowdown you have to really view footage - preferably direct feed - recorded at 50Hz (or 60, if the material is sourced from the NTSC version) and check it on a frame-by-frame basis. I definitely recall there being plenty of instances where I spotted each cycle taking three frames, with the last two normally being repeats. Is this a result of the PAL speed difference or some kind of slowdown/delay, because I remember it happening randomly as opposed to being regularly patterned? Also, you can really see the result of transparent elements being rendered in a lower resolution if you place your character over an area with this effect present, such as a large fire.

 

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Incredible! So there really was no excuse for Virtua Fighter and Virtua Racing not being arcade perfect conversions - or even superior to their Model 1 counterparts? Then again, I guess this kind of capability wasn't discovered until much later into the Saturn's life...

 

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Interesting. How does texture mapping and lighting affect these numbers? Is it all on the SH2s/DSP to manage calculations or does the VDP1 handle some of it?

SCU and SCU DSP, I did not know that. I can't seem to figure out where I put the white papers just now, but I don't think it makes a clear distinction between them.

 

The Daytona car in high resolution IS REAL!! I could bet my entire home on that since I've seen it with my own eyes. All the demo featured was the Hornet driving around on various bitmap floors. On floor was the Daytona logo Thee car was far higher in polygon count than the car used in the final game. In fact it was pretty close to arcade spec. Everything looked high resolution and ran at a very smooth frame rate. I own this clip on VHS stored at my parents home in the UK but I can name one other guy who will have this clip as long as he kept the video. He lives in Birkenhead, UK. I haven't spoken to him in 10 years or so since he took a hissy fit over some Goemon game that I never sent him. this guy is a hoarder though so I would bet he still owns a copy of the VHS I sent him. It also includes early demo Virtua Fighter work NOT shown on the Dreamcast VF4 network disc or whatever it was.

 

The only right thing to do for posterity purposes is record that video and send it to somebody who can do a quality digital capture.

 

I have about a dozen screenshots of the Saturn Daytona USA tech demo that come from various scanned publications, so I'm in absolutely no doubt it exists. As for video footage, I believe there's some Japanese tape including highlights from the 1994 Tokyo Toy Show, where this prototype was first revealed to the public - wasn't it a direct feed version of the same sequence that later ended up being passed around to certain people within Sega Europe (which may also have been the source of images printed in the UK's official Sega Magazine)?

P.S. Yakumo, do you by any chance remember what exactly was featured on that VHS tape relating to Virtua Fighter? Any descriptions at all would help, as I'd love to know more about what didn't make it onto either the VF4 History disc or that much shorter movie included with VF3tb...

 

I would be happy to host these things if anybody is interested in making sure they are available online. Just let me know.

 

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If there wasn't any plan for an upgrade for the saturn, Vf3 would have been a though work. Still "Saturn Shenmue" looks fantastic...even if it's a complete different genre and max. 30 frames.
I agree the implemantation of "rotating and zoomin 2D playfields" in Last Bronx was fantastic(great 3D illusion), in VF2 and Fighting Vipers it still wasn't all that impressive!
Still i don't understand why in vf2 the fighters and the background are High-res and in Fighting Vipers and Megamix only the Backgrounds seem Highres but the fighters look quite poor in terms of resolution....can someone explain that phenomenon?
i don't think there was any VF3 stuff on saturn, after all these years there would have been leaks and pictures in the net.
If VF3 would have been released on saturn(without upgrade), it would have looked like VF2 perhaps with a better Background implementation (last bronx-style). On a technical standpoint vf2, panzerdragoon2, virtua cop 2, sega rally, nights, daytona cce were the peak of saturn 3D programming, after that there were reports and a strong impression that sega reduced their support of the hardware(people and money) and people where relocated to other projects(arcade,DC..). There is no other explanation analyzing the lower graphic quality of the following 3D saturn games and the outsourcing of the development(ManxTT, Touring Car Championship..). Suma sumarum, i think saturn wasn't exploited entirely, i think with the necessary money, bigger teams and projects, those games i mentioned could have been toped on a technical standpoint...not by far but quite a bit....

Shemue on Saturn looks very promising and very far developed.....looks like Panzerdragoon saga(cities) on steroids! I can imagine that AM2 with their huge talent could have realized such an 3D engine at the end of saturns life maybe even without any hardware upgrade but probably with a poor framerate! What an achievement that would have been!!!!