Only 5 years after we're all sick of it, "Bullet Time" is do-able in MMOGs.

[Shockeye]

Matrix-style ‘bullet-time’ in multiplayer gaming

19:00 20 July 2005
NewScientist.com news service
Duncan Graham-Rowe

In a strange example of the cyber-world imitating Hollywood imitating the cyber-world, Finnish researchers have developed a way to achieve the “bullet-time” effect of the movie The Matrix in real-time multiplayer games.

The effect combines slow motion with dynamic virtual-camera movement to seemingly allow a character to slow down their environment, giving them more time to respond to game events.

The challenge had been to achieve this with real-time online multiplayer games, says Jouni Smed at the University of Turku. So far the closest anyone has come to it is by speeding up the player, instead of slowing down the environment, he says. “It’s not the effect one wants because the player has even less time to react.”

Smed’s solution is to exploit something called a local perception filter (LPF). This is software that compensates for the natural communication-time delays which occur in networked games by rendering objects and players at slightly out-of-date locations.

In locally networked games, time delays can be as much as 10 milliseconds, while transatlantic games suffer a latency of around 60 milliseconds. However, the use of LPFs means players do not notice any time lag because events are ever so slightly slowed down until the game catches up with itself.

Using a test-bench game called MaxMaze Demonstrator, Smed and colleagues found that they could also artificially introduce delays of up to a few seconds, allowing one player to slow down their environment and gain a strategic advantage, while game-time appeared normal to their opponent.

Without LPFs or similar techniques, networked games would appear more jerky, with characters jumping from one position to another as the system hangs waiting for updates, says Smed. But the downside of these conventional techniques is that sometimes characters are not where they appear to be to other players. This is why players may occasionally think they have shot an opponent in a game and are surprised when their target refuses to die, he notes.

Journal reference: Computer Networks (DOI: 10.10.16/j.comnet.2005.04.007)

What would be great is if they could put this into a game based on the Matrix.

[Samwise]

Something like this would be wasted on MMOG-style combat.  Gimme multiplayer Max Payne.

[Biobanger]

Ah, so you slow down yourself while the server keeps going at a normal pace... and how will this give you an advantage over the guy on the server strafing around you?

"Dude! Check out my bullet-time headshot!"
"Oh, I missed... and died, nevermind."

[Kail]

I'm not sure how this would work; maybe someone with some more technical knowledge can clear this up?

As far as I can tell, he's suggesting using lag to simulate bullet time, right?  But lag is, like, a fraction of a second.  If you slowed down "time" to half speed for five seconds, wouldn't it look to the other players like their pings suddenly all jumped up to 2500 or something crazy like that?

I mean, I swing my sword, and 400ms (or whatever) later the computer tells me if I hit or not.  If this bullet time stuff is supposed to let the player dodge my attack, I don't see how that would be possible by slowing down time for 400ms.  So you have an extra half-second in which to act; this is going to change something?

[Samwise]

An extra half second is more than enough time to dodge a bullet.   :-D

[Venkman]

If you see it coming.

I thought MxO bullet-time was passable, but that was mostly possible because of the overtly turn-based combat system. Otherwise, based on Smed's (heh) description, it really sounds like just adding that 0.5 seconds, which isn't really bullet-time as much as not-quite-so-instant time. If they coupled that with a, say, game that moved 10% slower across the board (except run speed dammit!), then maybe they could do some interesting martial-arts system.

Otherwise, I don't see it mattering as long as MMOs rely on target locking anyway.

[Fabricated]

Uhhhh...I thought this was done already.

[sinij]

Correct me if I'm wrong here but did they not just reinvented speed hack from good old UO days? Exactly same thing was done with Gear by pushing more updates per set interval of time than your fellow non-cheating players resulting in faster actions.

[Samwise]

Correct me if I'm wrong here but did they not just reinvented speed hack from good old UO days? Exactly same thing was done with Gear by pushing more updates per set interval of time than your fellow non-cheating players resulting in faster actions.

The challenge had been to achieve this with real-time online multiplayer games, says Jouni Smed at the University of Turku. So far the closest anyone has come to it is by speeding up the player, instead of slowing down the environment, he says. “It’s not the effect one wants because the player has even less time to react.”

[Murgos]

I think it would be cool if when you activate it it just lags out everyone around you and leaves you normal.

Heh, now that would be fun.

[eldaec]

Correct me if I'm wrong here but did they not just reinvented speed hack from good old UO days? Exactly same thing was done with Gear by pushing more updates per set interval of time than your fellow non-cheating players resulting in faster actions.

No, speed hack speeds you up on your screen and on everyone else's.

They are suggesting they can speed you up on other people's screens, at the same time as slowing both you and everything else down on your screen.

Basically your slow-mo player screen image and game range/LoS/aim/collision checks get based on everything else's position some amount of time behind right now, wheras full speed players get to see a server extrapolation of where you probably will be by the time your client catches up.

Planetside uses the same technique to deal with lag spikes.

People use it to cheat.

These are most assuredly not the droids you are looking for.

[Pococurante]

I have the recipe for it so haven't gotten to that level yet, but this is all the bullet-time I need:

[Trippy]

Paper (in PDF form) is here.

[Pococurante]

Otherwise, I don't see it mattering as long as MMOs rely on target locking anyway.

Exactly.  It's a wasted effort if the only real effect is the non-BT'd player just thinks he's gotten another lag spike.  In further news papers must be written, thesis presented, doctorates confirmed.

The alternate approach is perception sphere (PS) using a similar game mechanic as WoW's duel circle implementation.  I don't have time for a real spec but this is a useful thumbnail for discussion:

Implementation Entities

Tri-state perception flag:  attribute of player object
     -1  Slowed reactions
      0  Normal reactions
      1  Enhanced reactions
Perception timer: attribute of player object
BT object:  world object, binds the player IDs within its range.

Implementation Events

OnPSActivate
OnPSDecayed
OnPSEnlist
OnPSNegative
OnPSNeutral
OnPSPositive
OnPSResist
OnPSTransition

Implementation Rules

Activating Player
Attribute flag on PSO identifying owner player.

Affected Player
Attribute flag on PSO identifying enlisted player.

BT Resist
Skill-based.  Calculation to be determined.

Tri-state perception flag (PF)
Negative State debuffs movement speed and attack frequency only. Debuff is applied as final value modifier to calculation to reduce after all other buffs.
Neutral State defines normal game play, no modifiers. Players can accumulate abilities to resist a BT effect.
Positive State buffs movement speed and attack frequency only.  Buff is applied as final value modifier to minimize percentage bloat of intermediate buffs.

Perception Timer (PT)
MinValue six seconds.  MaxValue 10 seconds.  See OnPSEnlist

Perception Sphere Object (PSO)
Sphere effect radius is equivalent to a WoW duel circle.
BT effect timer = PT.MaxValue
OnPSDecayed transition shock player list, de-enlist player list, destroy self

Transition Shock Event (TSE)
Pacing mechanic to minimize unintended consequences of stacked player BT requests.
Occurs when:
  OnPSDecayed
  OnPSTransition

Scenario

Player activates BT ability (OnPSActivate) :
If within range of existing perception sphere they simply roll to activate effect. If so PF goes positive and PT is set to existing BTO decay timer less lag.
Else drop PSO, PSO enlists players within range

OnPSEnlist players perform saving roll.  Successful save hardsets PF to neutral and sets PT, failed save goes negative and sets PT.  PT is always set to BTO decay time less lag difference from the enlist event packet's timestamp.

Enlisted player engages their BT ability, see OnPSActivate
Enlisted player flees circle, see OnPSTransition

Anyway that's the general idea.  The timers need to be played with to minimize affect.  But basically this is just a mechanism to impose radius-based buffs/debuffs that is coupled with client-side animations that render accordingly to give the same effect.