[ShootMyMonkey]

Originally Posted by Graham

wouldn't they flip anyway, if sharing the seam vertices?

Well, our exporters would make sure the seam vertices are duplicated when there's a flip like that or when using symmetry in modelling/texturing, so they don't really share the same verts per se. The mirrored UVs would mean that somewhere along the surface, the basis switches from right-handed to left-handed, but as long as you just let that happen and you duplicate the seam verts where the other copy has a different basis-space, things stay consistent appearance-wise.

In reality, we didn't run across that case as often as one might think (for instance, it would never happen on characters), but it did happen a fair bit on complex large pieces of architecture where various texture layers had different tiling factors.

binorm = cross(tangent.xyz,normal) * tangent.w; // where tangent.w is 1 or -1

Just the cross-product, actually. And yeah, if you were sharing verts, you would see a flip, or at least a kink right around the seam either way.

[RobertR1]

Joker,

Thanks for your very well written post. It is informative and not overly techincal so many can understand vs. just a few.

I think the RSX is being limited because it was not customized. It was an off the shelf product with minimal tweaks and was the best Nvidia was willing to do likely due to Sony's last min "oh crap, we need go out and buy a GPU." Wasn't the Cell all Sony needed at some point or they were going to design their own GPU of some sort before they went shopping for one? I believe reading something like that many moons ago.

Ati and MS however collaborated on a much deeper level and Xenos was produced. It probably doesn't hurt either that MS has the DirectX team behind them giving pointers.....

[nAo]

Originally Posted by ShootMyMonkey

Yeah, we ran into a few snags on this front when we considered shrinking or removing attributes. We tried dropping one of the basis vectors and recalculating it with a cross product in the shader -- unfortunately, that screws with you when artists start mirroring UVs and causes normal/parallax maps to flip at the seam, so that idea didn't last very long.

This problem is easily fixable, just store an additional bit per vertex that let you reconstruct the original tangent basis vectors. In HS we store a bit like that in the most significant bit of the w component of our position vectors so that we to reconstruct binormals we do something like that:

float4 binormal = sign(position.w) * cross( normal, tangent );

very cheap and effective.

We considered reducing the total number of UV channels coming into the vertex shaders, as well as double-packing them (two UV coords in each 4-vector, so you only use 1 attribute to get 2 UV coords)... that works out well for us, especially since 90% of our assets only uses 2 UV coordinate sets, all of which are 2d (even though having 10+ maps isn't out of the ordinary).

We do something like that either. Artists are free to use all the UV sets they want, then our shaders generator automatically detects how many unique UV sets are really needed and it packs them accordingly, in order to use less input attributes.
More clever optmizations could be done as well, as packing multiple UV coordinates per attribute components (the same trick could be also used to store your tangent+normal vectors in a single attribute at full precision) but we did not go that route cause our VS are so long and complex that in the end would have not made any difference (ie we are almost never attributes limited).
To speed up simple rendering passes as z pre passes or shadow map one just needs to split vertex data in at least 2 streams: one for position and the other one for all the rest..that way one can basicly achieve VS throughput wise some number pretty close to the theoretical capabilities of the chip.
So in the end I really don't understand all this complaining, it's not really that hard nor complex to overcome these 'problems'. ppl were complaining in the same way in the old PS2 days while on the PS2 you needed A LOT more work to make things work as expected and ppl did it anyway.

I'm not about to say that the attribute read rate of RSX isn't among the crappiest hindrances to progress, but you make it sound like having to free-climb over the Great Wall of China.

Exactly. I was almost laughing at the GOW comment..I wonder what's so impressive in GOW that RSX could not do. At this time I really fail to see how 360 titles are so much better that PS3 titles graphics wise.. (while devs have more experience on the former platform..)
GPU wise I think 360 and PS3 have more or less the same power; once devs will start to use SPUs to speed up RSX things will start to be even more interesting (and a few titles are already doing that..)

["Nerve-Damage"]

Originally Posted by nAo

So in the end I really don't understand all this complaining, it's not really that hard nor complex to overcome these 'problems'. ppl were complaining in the same way in the old PS2 days while on the PS2 you needed A LOT more work to make things work as expected and ppl did it anyway.

Exactly!!

Originally Posted by =nAo

Exactly. I was almost laughing at the GOW comment..I wonder what's so impressive in GOW that RSX could not do. At this time I really fail to see how 360 titles are so much better that PS3 titles graphics wise.. (while devs have more experience on the former platform..)
GPU wise I think 360 and PS3 have more or less the same power; once devs will start to use SPUs to speed up RSX things will start to be even more interesting (and a few titles are already doing that..)

[Tap In]

Originally Posted by joker454

Wow, this escalated fast. It's definitely exceeded my comfort zone though so I've used a new bogus email address to register here to make tracking me more difficult.

<skip>

This may very well be true! We'll have to wait and see. Spu's will help, I'll know more once I code for them in the new year.

thanks for your perspective and welcome!

BTW Mods.... perhaps thread title change?

[StefanS]

Originally Posted by Tap In

BTW Mods.... perhaps thread title change?

Changed. Hopefully that fits better now.

Anyway, guys, leave the GeoW discussion outside, will ya. This is the technical part of the forums and -nomen est omen- it should be a more technical discussion.

Anyway, devs keep feeding us nice infos. Anything else you found challenging, etc?

EDIT:
In case anyone is wondering what FKATCT means "formerly known as the Charlatan thread".

[Oninotsume]

I don't know what the situation is like abroad, but I work at a major Japanese publisher, and have friends also working at big name publishers throughout Japan, and NONE of them had PS3 devkits/tools anywhere near the same time as the 360. So, as far as the Japanese side is concerned there has/is a lot more further development going on on the 360 side.

In the end I don't really think it matters what game is using what type of work-around or hardware specific technology. If the game looks great to the player, and it's fun then it's a success.

I too was not totally blown away by Gears of War. Personally I think MotorStorm looks just as good, but that doesn't really matter because blowing guys away in Gears is just as fun as slamming a buggy into a cliff at 150mph!

[blakjedi]

I think joker explained himself completely and succintly in his post. And I find him to be honest especially as a MULTI-PLATFORM developer. Some of the comments since his response read kind of... strange.

Every dev has their own perspective... I find it interesting to see what comes across as lecturing from other folks who may/may not be devs or folks who may/may not be multi...

Can't we all just get along?

[scificube]

Originally Posted by blakjedi

I think joker explained himself completely and succintly in his post. And I find him to be honest especially as a MULTI-PLATFORM developer. Some of the comments since his response read kind of... strange.

Every dev has their own perspective... I find it interesting to see what comes across as lecturing from other folks who may/may not be devs or folks who may/may not be multi...

Can't we all just get along?

This is a technology forum. No one has been mean spirited in this thread. Ideas are meant to be shared here and position are meant to explored for the merit.

However, if no one else will say it I will say that just because a developer works with one platform or another this does not invalidate their assertions or color them as biased. What is said here is validated or invalidated based on it's merit not by whether one is a PS3 dev or a X360 dev or a Wii dev or developes on multiple platforms. It simply is not fair to the individuals that post here to give what they say any less credence than anyone else based on the what platform they work with. If what is said is meritous this all that should matter here.

The opinions of multi-platform developers do not belong to placed on pedestal above others out of hand. It should not even matter what kind of developer you are beyond having a perched view one can share from that others do not. Even then what is given/posited is judged by it's merit. If a multi-platform handheld developers posits that global illumination is a snap on the handhelds...just being a multi-handheld developer does not lend anything to the validity of that claim.

This is technology forum. Ideas are meant to shared. Positions are meant to be challenged based on their merit alone.

Nothing personal to you blackjedi. I simply think people should be respected for what they say not who they do or do not work for.

[Tap In]

good points scificube but it has been rare to hear from a dev that has any experience on both systems and is nice to hear a new perspective. I don't think one is valuing one over the other as much as pleased to see someone who can speak from experience on both.

I hope that continues and that joker can share some more (so long as nobody else tracks him down and tries to take him out)

[ShootMyMonkey]

More clever optmizations could be done as well, as packing multiple UV coordinates per attribute components (the same trick could be also used to store your tangent+normal vectors in a single attribute at full precision) but we did not go that route cause our VS are so long and complex that in the end would have not made any difference (ie we are almost never attributes limited).

We also have that reason for not going on with the sign-in-the-w component thing you mentioned and are still waiting out to see if we should pack tangent+normal in a single attribute*. The tools and the system we have in place for artists to modify pixel shaders with a graphical interface recently got in some features for them to be able to modify vertex shaders as well. Plus, there are still a number of vertex-level features which are planned, but yet to be written, so we don't know yet how complex vertex shaders will get or how much more we'll want to move out of vertex shaders and move into software. Plus, it also means that there may be cases where artists create vertex shader modifications which mean we can't get away with things like backface culling in software because we won't know which faces are backfacing until you get to the shader. I don't expect that but for a few predictable cases, many of which won't be subject to such scrutiny anyway. It's also generally harder for artists to start wrapping their heads around geometry modification.

As I said, we're not far enough along to decide anything with much certainty yet... especially not on the PS3.

* : I should add that the sign-in-the-w-component thing also would involve some changes to our exporters, which has a nice hefty task list lined up due to recent transitions from using MAX to Maya7, and now we're having to use Maya8 + ZBrush + Turtle... which is making life real hell.

[joker454]

Originally Posted by nAo

So in the end I really don't understand all this complaining, it's not really that hard nor complex to overcome these 'problems'.

I think part of my point was missed. Sure, theres a million tricks out there, using the sign bit is nothing new. My beef is that you have to do this on PS3 just to help rsx keep pace, you have to baby it. We do these tricks anyways because in many cases they not only benefit PS3, they also benefit 360 so why wouldn't we use them? So, clever tricks alone won't get you to 360 frame rate because the 360 usually benefits from the same tricks as well. Hence why I was saying the only way I believe to get rsx to complete is to use spus to help it deal with its inadequacies.

Originally Posted by nAo

I was almost laughing at the GOW comment..I wonder what's so impressive in GOW that RSX could not do.

Not sure why you'd laugh, its the most visually impressive console title to date. You need to play a few hours into it to see some of the best graphics though. Even if you assume that rsx by itself could do it, you then run into other PS3 limitations like less free memory available. Both boxes may have 512MB, but you have less to work with on PS3. Maybe only third parties like us are affected by this, but on our end the free memory difference is fairly large with 360 giving us lots more room to play. So, textures somewhere have to get cut down. This may be one of the reasons a common complaint on PS3 games is that "the textures up close are muddy", probably because they are cut down. For example, I'm guessing thats why the crowd in Fight Night looks all pixelated on PS3, but ok on 360. They may have run out of memory on PS3 and had to get memory from wherever they could.

Even barring that, you run into other PS3 limitations. A game like gears I don't believe will be doable in 1080p on either machine, I don't think they have the bandwidth for it. So you do it in 720p. But on 360, I can hardware scale it to 1080p free. You can't do this on PS3 because its 720-1080 hardware scaler is broken, so you'd have to scale it in software which takes up more of those precious cycles.

Originally Posted by nAo

At this time I really fail to see how 360 titles are so much better that PS3 titles graphics wise.. (while devs have more experience on the former platform..)

Both gears of war and resistance fall of man are first generation titles for their respective developers. Both were in development for roughly the same amount of time. No knock to Insomniac, they are a top notch crew, but gears looks way better.

I think the 'more experience on the former platform' isn't a valid argument. 360 games have all mostly been old gen ports. In other words, all shaders had to be written from scratch, and all new game assets had to be made. That's what happened to us, most of the time was not spent having fun with the 360, it was spent scrambling to get everything re-written. PS3 games on the other hand have mostly been 360 ports. Huge difference! Devs were able to save tremendous amounts of time since the same shaders can be used (I'm simplifying here, but you get what I mean), and they were able to use the same art assets. There still is a bit of a time advantage for 360 devs, but it's no where near as huge as people make it out to be.

Originally Posted by nAo

GPU wise I think 360 and PS3 have more or less the same power

I fully respect your opinion of course, although this is the first time I've heard a dev say that And I'm even talking about old school programmers that hate Microsoft with a passion! Even they, privately, give the nod to 360 in graphics. Although they will usually immediately follow it up with a lengthy discussion of the joys of cell

Originally Posted by nAo

once devs will start to use SPUs to speed up RSX things will start to be even more interesting (and a few titles are already doing that..)

Yup, totally true. Although nothing stops you from doing the same on 360. If you have a free 360 hardware thread, why not use it to precull? I'm certainly gonna try. Sure, it's no where near as suited to the task as spu's, but since I've gotta write the code on PS3 anyways, I'm gonna try leveraging it on 360 on the geometry that would benefit the most, solid models like characters that are usually half backface culled anyways.

The spu's are certainly the PS3's ace, but I'm wondering, will they let that box eclipse 360 performance, or just match it? I don't really know the answer to this so we'll have to see.

[Carl B]

Originally Posted by Tap In

good points scificube but it has been rare to hear from a dev that has any experience on both systems and is nice to hear a new perspective. I don't think one is valuing one over the other as much as pleased to see someone who can speak from experience on both.

I hope that continues and that joker can share some more (so long as nobody else tracks him down and tries to take him out)

Agreed, but remember that Joker doesn't have experience on both 'systems' yet as we might define them; his PS3/SPE coding will begin in the new year.

[joker454]

Originally Posted by xbdestroya

Agreed, but remember that Joker doesn't have experience on both 'systems' yet as we might define them; his PS3/SPE coding will begin in the new year.

Yes totally true. I'm certainly not the authority on console coding, I make mistakes here and there and I'm definitely still learning. That's the coolest part of being a games coder, you never really catch up because theres always something new to learn!

Likewise, being multi platform means I'll never be able to match what first parties can't do. Not because we don't do the same tricks (we do/will), but because our time is divided.

[Shifty Geezer]

Originally Posted by scificube

However, if no one else will say it I will say that just because a developer works with one platform or another this does not invalidate their assertions or color them as biased.

Indeed. Developers concentrating on a single system are likely to have a better understanding of how to do things on it, while those who are multiplatform are more likely to know the alternative system a bit better. With both perspectives, some good discussion could be got going.

[almighty]

Originally Posted by joker454

Both gears of war and resistance fall of man are first generation titles for their respective developers. Both were in development for roughly the same amount of time. No knock to Insomniac, they are a top notch crew, but gears looks way better.

Unreal Engine 3 was first revealed in 2004, and even then it was looking extremely polished and complete. So Gears, if truth be known was in development for atleast 3+ years, how much better do you think Resistance would of looked if Insomniac spent 3 years on a game engine before they starting creating game assett's?

Thats what annoys me when people compare PS3 game's to 360 one's that use UE3, UE3 is an extremely streamlined engine thats had years of work, 90% of PS3 launch game's use game engine's that id bet have'nt even had half of the time spent developing them as UE3.0 has.

[jonabbey]

Originally Posted by almighty

Thats a good point, he does'nt start on PS3 till after the new year and yet he's got his head set on 360 >> PS3

I think that's unfair. His comments have not been ad-machina as much as listing issues that he's had problems with in his cross-platform development on PS3. Whether or not single-platform developers can do things differently to take advantage of the PS3's strengths and produce a superior game takes nothing away from his insights.

And I say this as a reasonably hopeless Sony ******.

[Shezad]

Originally Posted by rounin

I'm also wondering if Joker's comments/evaluation on the PS3 are not rather immature, given that he has not yet become familiar with the platform yet.

Not Exactly, his comments are quite familiar inside the Ps3 development community.
I am a PS3 developer as well and unfortunately it is true that from a graphics point of view we need to help RSX with SPUs, and this means using CELL for something that the GPU should do.
In my very personal opinion, maybe worthless, the 360 GPU is better than RSX and Microsoft gave us better tools.

[scificube]

Originally Posted by Tap In

good points scificube but it has been rare to hear from a dev that has any experience on both systems and is nice to hear a new perspective. I don't think one is valuing one over the other as much as pleased to see someone who can speak from experience on both.

I hope that continues and that joker can share some more (so long as nobody else tracks him down and tries to take him out)

I'm glad for any developer that wants to converse here.

Sorry that page is gonna stay blank.

[thatdude90210]

Originally Posted by Shezad

Not Exactly, his comments are quite familiar inside the Ps3 development community.
I am a PS3 developer as well and unfortunately it is true that from a graphics point of view we need to help RSX with SPUs, and this means using CELL for something that the GPU should do.
In my very personal opinion, maybe worthless, the 360 GPU is better than RSX and Microsoft gave us better tools.

I'm wondering that given the timeframe of RSX, would R520 (obviously R580 was much later & G80 even later) have been any better? Just a theoretical question that if Sony had went to ATI instead of Nv for their graphic needs without regards for whether ATI even had the resource for another console.

[Mythos]

Originally Posted by Shezad

Not Exactly, his comments are quite familiar inside the Ps3 development community.
I am a PS3 developer as well and unfortunately it is true that from a graphics point of view we need to help RSX with SPUs, and this means using CELL for something that the GPU should do.
In my very personal opinion, maybe worthless, the 360 GPU is better than RSX and Microsoft gave us better tools.

Really....thatz lots of proof with just a stated oponoin (parroting joker)...care to elaborate?

[Pugger]

Lets be honest here the team nAo is working with will probably have more up to date tools and information from Sony and on a more regular basis than the 3rd party joker454 is working for. This doesn't for one minute undermine jokers viiew, it is just from a differnt prespective which nAo should have taken into account. Also nAo did you work on the 360 before moving to the PS3 as you seem to know a lot regarding development? On a personal level wherever the PS3 is going to end up on a graphical development level it seems quite obvious that 360 is going to rival it very strongly indeed and in somecases outdo it. For a machine released a year earlier (1.5 yrs in the UK) props must go to the design 360 team.

[Geo]

Sometimes I read these threads and get the feeling some people think its reasonable to expect that Sony or MS should have been able to produce a single console that had Cell, Xenos, BRD, HD DVD, 60 GB HD, HDMI, free online community, and cost $199 at release (including the 3-game AAA title bundle, of course). And, of course, that's *not* reasonable. Nor do devs, so far as I've ever heard, program for a component but rather a platform.

[nAo]

Originally Posted by joker454

My beef is that you have to do this on PS3 just to help rsx keep pace, you have to baby it.

I could easily construct tons of cases where exactly the opposite is true (rsx would run way faster than xenos) and I would have still proved nothing.

We do these tricks anyways because in many cases they not only benefit PS3, they also benefit 360 so why wouldn't we use them?

Sometime tricks benefit both platforms, sometimes they help a platform and harm the other one.
to say "everything we do to make RSX run faster help Xenos as well (or the other way around)" is imo naive at best.. Even in this case I could make a couple of examples related to vertex streams attributes..unfortunately NDAs don't allow me to do that.

Not sure why you'd laugh, its the most visually impressive console title to date.

Well..yes and no.. given the amount of stuff they have on screen I'm not really impressed...but I can see how very big normal maps can impress a lot of ppl

Even barring that, you run into other PS3 limitations. A game like gears I don't believe will be doable in 1080p on either machine, I don't think they have the bandwidth for it. So you do it in 720p. But on 360, I can hardware scale it to 1080p free. You can't do this on PS3 because its 720-1080 hardware scaler is broken, so you'd have to scale it in software which takes up more of those precious cycles.

I really cant find any logic in this argument. Why do you think that GOW would be bw limited at 1080p more than it's at 720p?

Both gears of war and resistance fall of man are first generation titles for their respective developers. Both were in development for roughly the same amount of time. No knock to Insomniac, they are a top notch crew, but gears looks way better.

Yes, GOW is prettier..so what?

I fully respect your opinion of course, although this is the first time I've heard a dev say that

Maybe you should check the internal ps3 devs forum more often than, you're not the only one that have worked on both platforms and you might be able to find ppl that agree with you and ppl that don't agree with you at all and that have the opposite experience.
I'm not really suprised by that cause every team has different engines..with different requirements..something that runs good on RSX can run not so good on 360.
Generalizing is not particularly smart..

And I'm even talking about old school programmers that hate Microsoft with a passion! Even they, privately, give the nod to 360 in graphics. Although they will usually immediately follow it up with a lengthy discussion of the joys of cell

The spu's are certainly the PS3's ace, but I'm wondering, will they let that box eclipse 360 performance, or just match it? I don't really know the answer to this so we'll have to see.

?! PS3 is already matching 360 now, with (probably) inferior tools and less experience on the system wrt 360, it can only get vastly better, no doubt about it. Non multiplatform titles are going to show this quite soon imho

[Tap In]

Originally Posted by nAo

I could easily construct tons of cases where exactly the opposite is true (rsx would run way faster than xenos)

just curious nAo.... have you coded for Xenos (360)?

thanks!