PS2 question

[Thowllly]

To help you save bandwidth I've crushed the VQ image too (without the black border):
laz-vq2bpp.png 174kB.
I'm too kind

 

[Squeak]

I mean, theoretically PS2 can do nice things, but realworld....unlesss we start to see something nice....

Are you implying there aren't nicely textured games on PS2? That's just ridiculous...

You have to admit though that they are few and far between.
But even in those few games there are buts. Jak and Daxter for example have some pretty detailed textures when you get close to them but from far away they just look cleverly tiled. You never see any large patterns done with textures.

 

[London Geezer]

I mean, theoretically PS2 can do nice things, but realworld....unlesss we start to see something nice....

Are you implying there aren't nicely textured games on PS2? That's just ridiculous...

You have to admit though that they are few and far between.
But even in those few games there are buts. Jak and Daxter for example have some pretty detailed textures when you get close to them but from far away they are just look cleverly tiled. You never see any large patterns done with textures.

WHAT do u expect.... u see tiling in pretty much every game although i must say it can be hidden a bit (at with good results) with multiple passes which is not such a big deal on modern consoles.... thats the curse of consoles, not a lot of memory...

 

[Squeak]

It’s not tiling as such I’m criticising, it’s the fact that they aren’t coupled with “macro-texturesâ€￾ (reverse of detail-textures). An old but good example of this is the paintings on the walls in Clocktown village in Majoras Mask.

 

[London Geezer]

It’s not tiling as such I’m criticising, it’s the fact that they aren’t coupled with “macro-textures” (reverse of detail-textures). An old but good example of this is the paintings on the walls in Clocktown village in Majoras Mask.

to be honest it leaves me puzzled as to why there are VERY few games that even TRY to hide those somewhat irritating effects on PS2 (blurred textures etc)... i mean, using detail maps (for example) wouldnt cut performance by much however the aesthetic gain would be quite large to say the least...

 

[Johnny Awesome]

This thread certainly proves the point about problems with the PS2 architecture. It's nice to see some mathematical proof of our subjective claims that DC has better texturing than PS2. It's pretty obvious from those images that 4bpp-CLUT just doesn't cut it for high-color textures, even when compared to 2bpp-VQ.

I'm curious about the use of IPU to save main memory though. Is this something that the PS2 has over the other two consoles, or is there some sort of substitute that would enable faster loading on GCN and Xbox as well.

It seems like you could do wonders with the PS2 by going DVD (jpeg) - > main memory (jpeg) -> main memory (4bpp-CLUT) -> GS.

Where is the bottleneck in this pipeline? Is main memory really the issue for streaming texture data or is the EE-GS bandwidth still the restriction?

 

[archie4oz]

I dont know but....the CLUT jpeg looks really depressing.

Well it's not a JPEG for one thing, however it is pretty ugly even for a 4-bit CLUT... This one is better...

4-bit CLUT

It's pretty obvious from those images that 4bpp-CLUT just doesn't cut it for high-color textures, even when compared to 2bpp-VQ.

Well considering that it's not even intended for that purpose to begin with, that kind've a pointless observation... I mean you're obviously going to use what ever format is suitable for the image whether it be PSMCT32, 24, 16, 8, 8H, 4, 4HH, 4HL...

 

[marconelly!]

Well, I was just trying to show the differences between 4bit CLUT and the alternatives

Of course, for a super-colorful picture like this, you would use 8bit clut and not 4 bit, to begin with.

It's pretty obvious from those images that 4bpp-CLUT just doesn't cut it for high-color textures, even when compared to 2bpp-VQ.

Don't forget that PS2 has 2x more memory than Dreamcast, so using 8bit clut in cases like this (which are super-rare btw, because when do you need a *texture* that looks like this picture?) is acceptable if you want to compare textures to Dreamcast. After all, proof is in the pudding - best textured games on DC are certainly no better textured than best textured games on PS2, like BGDA, J&D, Rygar, SH2 or SH3. Not to mention that some of the PS2 titles mentioned have multitexturing in abundance which is all but absent from any DC game.

 

[Johnny Awesome]

I still think that all of those games are limited texture-wise compared to games like Ecco, Shenmue, MSR, and Sonic Adventure 2 - all of which have multi-texturing. PS2 games are color-limited for a reason - the PS2 is poor at handling high-color textures. The proof is in this thread, if you remove your bias.

PS: Before anyone goes crazy on me - I believe the PS2 is more powerful than Dreamcast, but not for texturing. There are many good examples of particle effects and geometry on the PS2 that make the DC look dated, but not for texturing IMO.

 

[Ozymandis]

I don't remember Shenmue having much multitexturing. Did it use lightmapping?

 

[marconelly!]

I still think that all of those games are limited texture-wise compared to games like Ecco, Shenmue, MSR, and Sonic Adventure 2 - all of which have multi-texturing.

Ecco, Shenmue, SA2 are exactly the games I had in mind when I was making my previous post. They might be on par with those PS2 games I mentioned in texture resolution but have almost none of the multitexturing effects found there (Rygar and BGDA basically have scenes where animated 2, 3x multitexturing runs over almost every polygon on the scene, and both run at perfect 60FPS) Silent Hill 2 has visibly more quality textures than Shenmue (both 30FPS games), although it obviousy has an advantage of running mostly in closed quarters (But still, textures in closed Quarters in Shenmue look worse, not to mention the realtime shadowing effects in SH2 that are also texture based)

 

[Squeak]

I'm a bit surprised by your comments:

• You seem to imply that I have chosen images that would not be used in a game - I'm therefore bewildered as to what you think the "Unreal texture" is. Furthermore, I tend to collect textures/images sent to me from developers and I feel that my choice of images is fairly representative. (well with the exception of the last example which is deliberately chosen to show problems with all the methods!)

• 
  
  I realize that the test would have looked somewhat boring if you had picked pictures of grass or asphalt as test subjects but such textures is the most common kind in today’s games. This leaves headroom for 8bit and a few 16bit textures for special purposes.
  I’m not defending Sony’s choice to not include TC on the GS, nor am I criticizing it (I don’t know enough about the machine to do that); I’m just looking at the facts.
  I know the Unreal picture is from a real game, but it is a surrounded by much more dull textures (in the game) so it is an exception in that game (which of course makes it more interesting to look at).
  
  

  [*]As for textures with many colours - they do occur in games. As I said, I have a corpus of textures from various sources. Are you sure you're not looking at examples that are targeted specifically at systems which only have, say a CLUT system, thus forcing developers to restrict their art work? (BTW have you seen the colour ranges of Normal Maps!!)

Actually, I found your last statement a bit ironic given someone else wrote "And don't dig up those old 4- and 8-bit pieces of art - they had VERY limited colour ranges". It just shows that some people clearly see such 'near monochromatic' textures as somewhat bland. <shrug

Actually if my memory serves me right, I once read an interview with the developers of Unreal where they said that they actually deliberately chose to work exclusively with CLUT textures. I don’t remember the exact reason and it IS a old interview, but a bit curious anyhow.

I just think that on average (and that is what counts, right?) most textures in a frame from a modern videogame could easily be described with 16 colours. So the average bit count per texel in the frame would be somewhere around 6 or 7 bits if you only using CLUT textures for compression.

In the real world (what most games are trying to look like), multicoloured surfaces are also much less frequent than monochrome ones.

 

[Teasy]

Where is the bottleneck in this pipeline? Is main memory really the issue for streaming texture data or is the EE-GS bandwidth still the restriction?

AFAICS one of PS2's biggest problems with texturing is the main ram --- EE ---- GS setup. Specifically the 1.2gb/s EE to GC bus.

The system has 3.2gb/s main memory bandwidth, which is actually quite a lot, more then GC for instance. Yet only 1.2gb/s of that can be used for textures and geometry. You basically have 2gb/s bandwidth that can only be used for the CPU. I mean I know PS2's CPU is quite powerful and probably needs a good amount of bandwidth, but surely that's way over the top?

What if the CPU only uses 1gb bandwidth in a game? You still only have 1.2gb/s of the total bandwidth useable for textures and geometry. The other 1gb/s is just wasted. With GC and XBox whatever bandwidth the CPU doesn't use can be used for textures and geometry.

Basically PS2's problem with texturing is that its design is focused far to much on its CPU and not enough on the GPU. Were as GC and XBox are much more focused on the GPU, which is why they are so much better for texturing.

 

[ERP]

It's been said before and I'll say it again.
the 1.2GB/s bus to the GS is a red-herring, when it comes to performance bottlenecks on PS2. In most PS2 games the bus is very underutilised, because they bottlenecked elsewhere.

 

[andypski]

I just think that on average (and that is what counts, right?) most textures in a frame from a modern videogame could easily be described with 16 colours. So the average bit count per texel in the frame would be somewhere around 6 or 7 bits if you only using CLUT textures for compression.

Certainly not the case in the PC space, but pretty correct on consoles I guess.

Although at first glance many materials in the real world can look monochromatic this actually tends not to really be the case. They may have a fairly limited range of chroma, but certainly not one value. Looking at examples like woodgrain you will see significant variations in the colour hue and saturation, as well as the luminance. If you take away these subtle variations and pick a mean chroma value (as you would need to do if using only 16 colours) then the surface can become relatively lifeless and uninteresting.

A 'real-world' grass texture could mix various hues from saturated greens to unsaturated yellows, along with variations in luminance.

In the real world (what most games are trying to look like), multicoloured surfaces are also much less frequent than monochrome ones.

Agreed (with the caveats stated above), but it's not coincidence that people tend to believe that some PS2 titles have 'washed-out' textures. 4-bit CLUT is a horribly compromised format, and really should be a last resort due to the lack of anything better. 8-bit CLUT can do a fair job, but is still ancient technology as far as compression goes. If PS2 had DXTC textures 4-bit and 8-bit CLUT textures would instantly be dead formats for almost everything except some special effects achievable by palette manipulation. Sony no doubt had reasons to do things the way they did, but all their competition now use something much better for texture storage. In terms of quality/bit there is no comparison.

It does seem that good use of the PS2's resources along with well conceived artwork can still produce very good results. It's just harder than it would have been if PS2 had a good texture compression format.

 

[Panajev2001a]

Teasy the problem is another...

the EE's main bus has a 2.4 GB/s bandwidth... and since GS data passes onto that busyou have to take that 1.2 GB/s away and you get only 1.2 GB/s for the RISC core, the VUs and the IPU, etc...

The main RAM is 3.2 GB/s, but that is a theoretical figure that lowers to ~2.4 GB/s levels in real-world scenarios matching pretty much the EE's bus bandwidth...

if you increased the GIF-to-GS bus to 2.4 GB/s and you used it fully then you would starve the EE as it would not have enough bandwidth to feed its own execution units...

 

[Teasy]

It's been said before and I'll say it again.
the 1.2GB/s bus to the GS is a red-herring, when it comes to performance bottlenecks on PS2.

Overall performance yeah, but I was talking about texturing performance.

In most PS2 games the bus is very underutilised, because they bottlenecked elsewhere.

Yeah but in most PS2 games the texturing is quite average to poor, so of course that bus would be underutilised in those games.

 

[Teasy]

Panajev2001a

Ah yeah, I hadn't considered the actual efficiency of the main ram (although surely the EE to GS bus isn't 100% efficient either).

Still, wouldn't it'd be nice to have the ability to use more then 1.2gb/s for the GPU. If, for some reason, the CPU didn't need its full 1.2gb/s bandwidth. Although I suppose that may make the PS2 even harder to program for. Having to make sure you don't use too much bandwidth for the GPU incase you starve the CPU.

 

[ERP]

It's been said before and I'll say it again.
the 1.2GB/s bus to the GS is a red-herring, when it comes to performance bottlenecks on PS2.

Overall performance yeah, but I was talking about texturing performance.

BTW I thought the bus to the GS was 1gb/s not 1.2gb/s?

In most PS2 games the bus is very underutilised, because they bottlenecked elsewhere.

Yeah but in most PS2 games the texturing is quite average to poor, so of course that bus would be underutilised in those sorts of games.

OK let me try and phrase this another way.
There are a number of other bottlenecks you need to overcome before you get anywhere near needing to worry about the bus to the GS being a bottleneck.
You can throw a very large portion of your main memory over that bus every frame before you start to see it become a limitation.
IMO the PS2's biggest weeknesses from a texturing standpoint are the lack of some obviously useful destination blend modes on the GS, and the difficulty involved in implementing decent filtering.

 

[marconelly!]

and the difficulty involved in implementing decent filtering.

You mean trilinear / anisotropic, etc kind of texture filtering? How difficult is it to achieve trilinear filtering?