HDTV games won't work online?

[wco81]

Supposedly, ESPN MLB 2K4 for the Xbox won't work online with 720p mode enabled. They have to disable 720p mode before going online.

What is that about? They can't be sending graphics over the connection so why should it make a difference if you're HD or not?

PC gamers play online running games with much higher resolutions than NTSC TV. So it can't be about different sync modes between the players can it?

I sure hope it doesn't mean that in the next generation, when HDTV support should be more common in games, that you have to disable HDTV mode to play online.

 

[AlNom]

it might be due to gameplay balance? 720p is widescreen so maybe the devs felt that it would be unfair? I don't know beyond that.... there is 480p widescreen though, isn't there? that would make my point moot then.

 

[wco81]

I play Madden online all the time on my HDTV with the PS2 set in 16:9 mode. Don't think there is actually more resolution tho.

Maybe it's a Sega-only problem.

Most console games have a disclaimer that online experience may be degraded compared to offline. Maybe they're cutting down details but not necessarily the resolution?

In any event, you would think PC online games would have all kinds of problems since people are running different hardware and different settings from each other.

 

[AlNom]

yeah that is weird...

I guess it is a sega thing then since you mentioned that other games work fine.

 

[zurich]

Different screen sync means messing up the physics and other stuff that is tied to that refresh figure?

 

[ERP]

Different screen sync means messing up the physics and other stuff that is tied to that refresh figure?

Possibly.... but I can only see it being an issue if the game runs at a different framerate in HD (say 30 vs 60). Even then it's soluble, you just lock to the lower rate.

You are probably right in that it is something to do with a loss of determinism betweeen the two versions (HD and Non HD). Most console online titles rely on being able to evolve in lockstep between data packets.

 

[pcostabel]

It's probably just a matter of memory/performances. Either that or the programmers are lazy

 

[zurich]

Different screen sync means messing up the physics and other stuff that is tied to that refresh figure?

Possibly.... but I can only see it being an issue if the game runs at a different framerate in HD (say 30 vs 60). Even then it's soluble, you just lock to the lower rate.

You are probably right in that it is something to do with a loss of determinism betweeen the two versions (HD and Non HD). Most console online titles rely on being able to evolve in lockstep between data packets.

Hah cool!

So how will it be fixed next gen with games varying betwen 480i and 1080i with everything inbetween??

 

[ERP]

Different screen sync means messing up the physics and other stuff that is tied to that refresh figure?

Possibly.... but I can only see it being an issue if the game runs at a different framerate in HD (say 30 vs 60). Even then it's soluble, you just lock to the lower rate.

You are probably right in that it is something to do with a loss of determinism betweeen the two versions (HD and Non HD). Most console online titles rely on being able to evolve in lockstep between data packets.

Hah cool!

So how will it be fixed next gen with games varying betwen 480i and 1080i with everything inbetween??

Well it shouldn't really be an issue even today....

But determinism is a real pain to maintain, you can waste a lot of hours (I've personally spent 100's of hours on a single determinism related bug) trying to track down issues.

Disabling Network play between HD and non-HD seems like a quick fix to me. Or possibly a way to avoid a problem that was percieved to exist. Obviously I'm just speculating.

 

[wco81]

If the problem is between HD and non-HD, then why don't PC games have problems connecting online?

There are far more differences in HW configurations and probably SW settings for resolution, detail settings, etc.

Like I said, most console online games have disclaimers about performance being lower online but I'm not sure if that refers to lower frame rates, lag and so on or whether they actually turn down detail settings. Perhaps it's a blanket disclaimer to cover everything. If there are graphic differences other than perhaps choppy frame rate from lag, it's hard to tell.

 

[nAo]

Probably it's a memory issue..

 

[DeanoC]

Its probably a decision made early on and couldn't be corrected, so came back to haunt them later on.

They likely assumed a determinstic system would be o.k. as every console we have identical framerate, later on in the project the realised they had the RAM and speed to add HDTV.

Without time to redo the network code, there left with 2 choices.

A) No HDTV support for single or multi-player
B) HDTV support single player only.

 

[jvd]

couldn't it also be the heartbeat ?

On mmorpgs they cap the framerate at 30fps so all games are sync up.

Perhaps they messed up and capped it at 60fps and in hdtv res it doesn't run at 60fps and so they screwed them self

 

[Ty]

They likely assumed a determinstic system would be o.k. as every console we have identical framerate, later on in the project the realised they had the RAM and speed to add HDTV.

But even in consoles, framerates on one console can differ from another box and thus throw the system off, right?

 

[ERP]

They likely assumed a determinstic system would be o.k. as every console we have identical framerate, later on in the project the realised they had the RAM and speed to add HDTV.

But even in consoles, framerates on one console can differ from another box and thus throw the system off, right?

Yes it varies, but not by very much. As long as each game tick elapses the same delta T it doesn't matter.

The idea is that you transmit all non-deterministic data over the network and nothing else. On something like a football game that would be a clock time and an associated joystick packet. You then run the simulation and it evolves the same way on both machines. You hide the latency by predicting the future on the machines.

Determinism is a really nice thing, and really easy to break, and the problems can be extremely subtle, involving sideeffects of multiple unrelated game parts.

 

[Ty]

Yes it varies, but not by very much. As long as each game tick elapses the same delta T it doesn't matter.

The idea is that you transmit all non-deterministic data over the network and nothing else. On something like a football game that would be a clock time and an associated joystick packet. You then run the simulation and it evolves the same way on both machines. You hide the latency by predicting the future on the machines.

My bad for not being clearer (either that or I'm too simple minded to understand your post). You and I are facing each other. Behind me (what you see) is a much more complex scene (perhaps a crazy amount of explosions and other alpha) than what I see behind you (a white quad). Does this cause problems? I mean, IF any dependency is based upon syncs, I presume it would. But then again, I'm a moron.

 

[ERP]

The destinction is between game frames and visual frames.

You can accomodate varying visual framerate by elapsing multiple gameplay frames. The other option is to artificially limit the framerate on the faster system, this sort of automatically happens because your sending the clock in your network packet.

 

[wco81]

One other thing to mention. There are examples of games which work across platforms. Like FFXI and NFS Underground, which support PC vs. PS2 online games.

Then there are games which support multiple consoles, like the various racing games and others which permit 4 or more different players from different consoles. Of course SOCOM supports 16-players and this fall, there are suppose to be even 24-player games I believe.

So in context, you would think HDTV to non-HDTV games wouldn't be as difficult a problem as it would first appear.

Among console online games, the tools most commonly used appear to be Gamespy and of course whatever APIs MS uses for XBL (probably a port of Direct Play?). Not sure if Renderware has tools to enable online play (i thought Rockstar licensed someone's online tools but apparently isn't making San Andreas online).

EA uses their own and it seems pretty reliable (some of the older PC games like Madden 2001 for the PC was pretty unreliable online) but limited. Little or no multiple console support as most of their games are one-to-one. But they did put out a product which networks between the PS2 and PC versions of NFSU.

Sega also seems to use their own tools, called SNAP I believe, with offer of infrastructure. But their PS2 implementations have been poor with a lot of "divergence" errors (they actually echo that term). Apparently, there are problems with their XBL-compatible games as well.