CrazyChris Posted July 13, 2004 Share Posted July 13, 2004 I know I've heard this before, but I can't remember? From a hardware standpoint why is the Jaguar not good at texture mapping? Please elaborate. Chris Quote Link to comment Share on other sites More sharing options...
Atari_Owl Posted July 13, 2004 Share Posted July 13, 2004 Because it is unable to do texmapping in phrase mode (64bit) and must do it in pixel mode unless the copy is a straight 1-1 copy (which in tex mapping is very rarely the case) In addition, since there must be a read for texture data as well as the pixel write, and since the ram is arranged in row/column pages, there is a page fault delay when texture and destination are not almost adjacent in ram. All this 1. Pixel mode not phrase mode (.25*speed) 2. Additional read 3. Additional page miss Makes texmapping a LOT slower than gouraud Quote Link to comment Share on other sites More sharing options...
justclaws Posted July 13, 2004 Share Posted July 13, 2004 Hello, In addition, since there must be a read for texture data as well as the pixel write, and since the ram is arranged in row/column pages, there is a page fault delay when texture and destination are not almost adjacent in ram. This explanation was really good. To clarify more though, for Chris, could I just add that normally (e.g. on a PC 3D graphics card) the graphics card has local RAM (as the GPU does) and so the texture is stored in that RAM, and required no read from main memory. If the blitter had had local RAM (e.g. 4K) then it could have been a different story, even with pixel mode writes, because the data for the textures would not have involved an external read + miss. The blitter does have a pattern register, but unless you want to create VERY boring textures, it's no help. The real purpose of the pattern register of course is to clear or fill RAM with known data. Cheers, JustClaws. Quote Link to comment Share on other sites More sharing options...
DracIsBack Posted July 13, 2004 Share Posted July 13, 2004 Also, for a layman's explanation ... in 1993, Texture Mapping was a relatively "new" feature in consoles. Quote Link to comment Share on other sites More sharing options...
Bryan Posted July 13, 2004 Share Posted July 13, 2004 Texture mapping requires fast access to RAM (textures), and the Jag's RAM is the slowest part of the system. -Bry Quote Link to comment Share on other sites More sharing options...
Atari_Owl Posted July 13, 2004 Share Posted July 13, 2004 JaguarII was intended to have both local Texture ROM (a few generic textures) and RAM (i think) to speed up tex mapping. And as Drac said, texmapping was pretty new in '93. Even Wolfenstein was very new and radical. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted July 13, 2004 Share Posted July 13, 2004 Also, for a layman's explanation ... in 1993, Texture Mapping was a relatively "new" feature in consoles. ..and the Jaguar was one of the first consoles (it and the 3DO)that was made for any kind of fast 3D (at the time), the 16-bitters needed added hardware to even come close to what the Jaguar could do (e.g. Genesis VR racing with SH1 chip in cart, SNES with the FX/FX2 chips in carts; StarFox. So, the designers put more thought into the then state-of-the art gauraud shading and light-sourcing, and less into texturemapping since it wasn't widely used then, even on the PC. The hardware of the Jag would have been capable, but Atari's stinginess with ram became it's undoing when compared to other next gen systems that had more extensive texturemapping hardware AND memory for it. The Blitter is a fantastic Processor, but no memory to take advantage properly. I think Atari didn't think the Next Generation consoles would be using 3D polygons with Texturemapping as extensively as they did; in the past consoles had always basically been a generation behind computers, and i think they thought it would be that way again. But it turned out that since Atari themselves and 3DO leap-frogged what would have been the next generation (consoles like Atari's Panther), so by the time the other consoles companies started designing their's, they had to one-up the Jaguar&3DO, so basically since that time new consoles have been on a par, more or less, with computers (at the time of release, computers always steadily advance where consoles take jumps). The Jaguar and 3DO, when released, were as powerful as the current PC's of '93-4. Dose that make any sense to anyone? Quote Link to comment Share on other sites More sharing options...
justclaws Posted July 13, 2004 Share Posted July 13, 2004 Hello, All nice points, by everybody, nice discussion, and no flaming. :-) Cheers, JustClaws. Quote Link to comment Share on other sites More sharing options...
CrazyChris Posted July 13, 2004 Author Share Posted July 13, 2004 Thanks for the great replies. I always enjoy reading stuff about the Jag. Chris Quote Link to comment Share on other sites More sharing options...
JagChris Posted July 14, 2004 Share Posted July 14, 2004 I know I've heard this before, but I can't remember? From a hardware standpoint why is the Jaguar not good at texture mapping? Please elaborate. Chris My understanding is it does ot have enough fast Video Ram to throw textures to the screen fast enough. Quote Link to comment Share on other sites More sharing options...
SteveW Posted July 14, 2004 Share Posted July 14, 2004 I remember reading something on Slashdot posted by John Carmack from id Software about the problem with texturemapping on the Jag. Something about scratchpad memory instead of real memory. I can't remember the details. Quote Link to comment Share on other sites More sharing options...
JagChris Posted July 14, 2004 Share Posted July 14, 2004 I remember reading something on Slashdot posted by John Carmack from id Software about the problem with texturemapping on the Jag. Something about scratchpad memory instead of real memory. I can't remember the details. Yeah, I remember someone reposting that on here somewhere. If my memory servers(it might not) he basically said not enough fast Video Ram. Something like if it had just a little bit more it would of been 3x faster at texture mapping. Then something about what a shame it was. Quote Link to comment Share on other sites More sharing options...
goatdan Posted July 14, 2004 Share Posted July 14, 2004 The Jaguar can't do texture mapping because, quite frankly it wasn't designed to do texture mapping. It can do 3D shading quite good, as that is what it was made for, but texture mapping wasn't a big deal until the Playstation really took it to a new level. Before that point, the best-looking 3D games had been stuff like Virtua Fighter and Virtua Racing -- both games based on shaded polygons and not texture mapped polys. Had Atari focused on making fun, polygonal games for the Jaguar instead of attempting to get it to do things it couldn't with texture mapping, I think we would've had a lot more hits on our hands like Battlemorph and a lot less duds like Fight For Life. Quote Link to comment Share on other sites More sharing options...
Stone Posted July 14, 2004 Share Posted July 14, 2004 I remember reading something on Slashdot posted by John Carmack from id Software about the problem with texturemapping on the Jag. Something about scratchpad memory instead of real memory. I can't remember the details. Yeah, I remember someone reposting that on here somewhere. If my memory servers(it might not) he basically said not enough fast Video Ram. Something like if it had just a little bit more it would of been 3x faster at texture mapping. Then something about what a shame it was. More? It doesn't have any Stone Quote Link to comment Share on other sites More sharing options...
agradeneu Posted July 14, 2004 Share Posted July 14, 2004 Lets out it so: The Jag can do Texmaps and it wasn't even bad in 1993 - compared to other systems like PC or 3DO. (BTW I wouldn't compare it to modern 3D cards, Justclaws) Iron Soldier II shows that the Jag can do a mix of shaded, source lighted and textured polygons quite well. I agree to Gunstar that the Playstation was the real breakthrough for fully texture mapped, source lighted 3D graphics. However, the Jag can do texs and not bad for its time. Otherwise explain games like BIWN, IS2, HS CD etc. BTW PCs did all Gfx by software and the CPU, no dedicated hardware for gfx or 3D rendering - and there were texture mapped 3D games like Doom, Descent, System Shock etc. The Jag was better than the common PC in 1994. Quote Link to comment Share on other sites More sharing options...
justclaws Posted July 14, 2004 Share Posted July 14, 2004 Lets out it so: The Jag can do Texmaps and it wasn't even bad in 1993 - compared to other systems like PC or 3DO. (BTW I wouldn't compare it to modern 3D cards, Justclaws) I agree, it wasn't bad at the time, but I think Chris was asking from the viewpoint of later systems, like the PS1 and N64, or even a modern PC. I'm certainly not comparing it to a PC graphics card, but it's good to explain what the difference is, I think, in a modern system like that. Iron Soldier II shows that the Jag can do a mix of shaded, source lighted and textured polygons quite well. Yes, but Gouraud shading was what the Jaguar was designed to do. I'm sure that Flare could have done better if texture mapping had been on the radar, I guess they'd have added blitter RAM as well. BTW PCs did all Gfx by software and the CPU, no dedicated hardware for gfx or 3D rendering - and there were texture mapped 3D games like Doom, Descent, System Shock etc.The Jag was better than the common PC in 1994. Yes, indeed, one could ask "Why is a 486 with an ISA bus VGA card not good at texture mapping?" That would be a fair comparison and equivalent question. Cheers, JustClaws. Quote Link to comment Share on other sites More sharing options...
Goochman Posted July 14, 2004 Share Posted July 14, 2004 The common PC in 1994 was Pentium based class PC's. This is right about the time the Pentium 60 and 90 came out. Quote Link to comment Share on other sites More sharing options...
justclaws Posted July 14, 2004 Share Posted July 14, 2004 The common PC in 1994 was Pentium based class PC's. No, the common systems were still 486, but Pentium systems were indeed definitely available! Your experience may be different though! This is right about the time the Pentium 60 and 90 came out. Absolutely, but not everybody can afford to replace all their systems just because a new CPU comes along! It was new PC, or a new Jag! I worked at a university in the UK, from 1992-1998. Trust me, we still had a good number of 486 based systems (even though IT was a major subject) running Windows 95, when I left there in May 1998. Anyway, I digress... In any case, a Pentium system still didn't have any 3D graphics cards like today, and texture mapping was certainly not common. Games like Doom was absolutely leading edge, and there were also complaints that it would not run on the average system, but it was a real incentive to upgrade, at least most people I knew could run Wolfenstein 3D. EGA PC games were still common as shareware! I respect your experience, but I'm sure of my own experiences! Regards, JustClaws. Quote Link to comment Share on other sites More sharing options...
agradeneu Posted July 14, 2004 Share Posted July 14, 2004 Plus till the arrivement of MMX there was no logic for gfx in a PC CPU, even if it was Pentium. BTW when i bought my Jag, a friend of mine bought a 486 PC and it was a big deal for him. But the Jag was quite a match, he was somewhat impressed, that an home video system could do so well with 3D gfx... @ JustClaws: Yes, agreed. Texmaps were definitely seen as the crop of the icecream when the Jag was designed; like this way: Oh look these fast polygons - and there are some little textures too! From what I heard and read and paying respect to my limited knowledge of hardware tech, I would say that the Jag was never designed for shifting big sized textures, which are inevitable if you want fully texmapped games. Just look at IS 2: they had really a hard time to implent these ground textures and they still are quite undetailed and simple blocks. Another thing is if the Jag could gain speed if the games would run in 256 colors instead of 16-bit color. By a close look to some games on the Sega Saturn I would assume that most of its programs are running in 256 color and low res. And that's despite the Sat is regarded as the better machine in 3d gfx! Quote Link to comment Share on other sites More sharing options...
JagChris Posted July 15, 2004 Share Posted July 15, 2004 I remember reading something on Slashdot posted by John Carmack from id Software about the problem with texturemapping on the Jag. Something about scratchpad memory instead of real memory. I can't remember the details. Yeah, I remember someone reposting that on here somewhere. If my memory servers(it might not) he basically said not enough fast Video Ram. Something like if it had just a little bit more it would of been 3x faster at texture mapping. Then something about what a shame it was. More? It doesn't have any Stone Right, and that seems to be the big problem. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted July 15, 2004 Share Posted July 15, 2004 Another thing is if the Jag could gain speed if the games would run in 256 colors instead of 16-bit color. By a close look to some games on the Sega Saturn I would assume that most of its programs are running in 256 color and low res.And that's despite the Sat is regarded as the better machine in 3d gfx! this is a GOOD point, and I'd also like to point out that most PSX games are in 256 8-bit color too! If you want to see what the Jaguar is capable of in 8-bit color depth (the devlopers FIRST attempt too), just look at Zero5. If more 3D Jaguar games did use 8-bit 256 color gfx instead of going with 16-bit 65,000 mode all the time some of those 3D games would be much faster and smoother. Quote Link to comment Share on other sites More sharing options...
Gunstar Posted July 15, 2004 Share Posted July 15, 2004 And just compare the Satrun's Alien Trilogy game to the Jaguar's AvP...it has a more advanced 3D engine (with stairs and different levels and looking up&down), but the texturing and overall graphic "look" with it's 256 color textures is terrible looking compared to Jaguar's AvP with much higher color depth 32,000+(?) Quote Link to comment Share on other sites More sharing options...
justclaws Posted July 15, 2004 Share Posted July 15, 2004 More? It doesn't have any Actually that's not quite right. It has 2MB!!! The Jaguar has a unified memory architecture, where all RAM is main/video RAM, this is what offers the enormous flexibility that offers programmers numerous options and choices for the games! If the system had only had a fixed frame buffer, like traditional systems, then the object processor concept could not have been implemented. Forget the mixed colour depths, unlimited parallax choices, dynamic scaling, dynamic object lists, enormous choice of resolutions, and limit yourself pages of video RAM. No way... Think differently, abandon the frame buffer, and be liberated... Cheers, JustClaws. Quote Link to comment Share on other sites More sharing options...
JagChris Posted July 15, 2004 Share Posted July 15, 2004 More? It doesn't have any Actually that's not quite right. It has 2MB!!! The Jaguar has a unified memory architecture, where all RAM is main/video RAM, this is what offers the enormous flexibility that offers programmers numerous options and choices for the games! If the system had only had a fixed frame buffer, like traditional systems, then the object processor concept could not have been implemented. Forget the mixed colour depths, unlimited parallax choices, dynamic scaling, dynamic object lists, enormous choice of resolutions, and limit yourself pages of video RAM. No way... Think differently, abandon the frame buffer, and be liberated... Cheers, JustClaws. Excellent, we will be expecting a game utilizing all of these concepts from you forthwith. Quote Link to comment Share on other sites More sharing options...
Stone Posted July 15, 2004 Share Posted July 15, 2004 More? It doesn't have any Actually that's not quite right. It has 2MB!!! Only if you abandon any speed of program execution... I was talking about dedicated video RAM - I remember reading the PSX only had 512KB, which would have helped the Jag hugely. Stone Quote Link to comment Share on other sites More sharing options...
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