Difference between revisions of "Lag compensation"

From Team Fortress Wiki
Jump to: navigation, search
m (Exceptions)
 
(35 intermediate revisions by 27 users not shown)
Line 1: Line 1:
Team Fortress 2, being built on the Half-Life 2 engine, is generally configured to use '''Lag Compensation'''. [http://developer.valvesoftware.com/wiki/Lag_Compensation]
+
{{Quotation|'''The Soldier'''|Stop lagging and start tagging, men!|sound=Cm soldier pregamelostlast 02.mp3}}
  
This is the technical reason behind cases where players may believe they were "shot through a wall" (especially by Snipers), and may also explain a majority of perceived [[facestab]]s.
+
''Team Fortress 2'', being based on the [[Source Engine]], is generally configured to make use of '''lag compensation'''. Lag compensation is most commonly the technical reason behind cases of kills or actions that would otherwise seem infeasible in given circumstances; for example, when players perceive themselves to have been "shot through a wall" by a [[Sniper]], [[backstab]]s being performed at the incorrect angle (known as ''[[Backstab#Issues|facestabs]]''), or otherwise missing entirely (known as ''[[Backstab#Issues|failstabs]]'').
  
In a nutshell, when a high-latency (high-ping) player attacks, the server temporarily "rewinds" its copy of the action in order to compensate for their lag. For example, the enemy Sniper shoots when he sees your head, at that moment you and most other players may believe you successfully ran behind a wall. When the server receives the fire message from the Sniper, it "rewinds", finds out you ought to have been hit, and then deals damage, leading to the appearance of being "killed through a wall".  
+
When a high-latency (high-ping) player attacks, the server temporarily "rewinds" its copy of the action in order to compensate for their lag. For example, the enemy Sniper shoots when he sees your head, at that moment you and most other players may believe you successfully ran behind a wall. When the server receives the fire message from the Sniper, it "rewinds", finds out if you had ought to have been hit, and then deals damage, leading to the appearance of being "killed through a wall".  
  
This is an intentional engineering and design decision, a tradeoff to enhance the realism of attacks at the expense of the realism of taking damage. Were lag compensation disabled, many players would have cause to complain that they shot the enemy without inflicting any damage.
+
This is an intentional engineering and design decision, a trade-off to enhance the realism of attacks at the expense of the realism of taking damage. Were lag compensation disabled, shots that look like they hit the enemy without inflicting any damage, which is still an issue due to [[Hit detection|hit registry]] and which is more of an issue with melee weapons, would become more common.
  
 +
== Exceptions ==
 +
Projectile weapons such as [[Rocket Launcher|rocket]]s, [[Grenade Launcher|grenade]]s, [[syringes]], and [[Flare Gun|flares]] are not lag-compensated. The [[Pyro]]'s [[compression blast]] and [[Flamethrower]] are also not lag compensated, despite the effects appearing immediately after firing on a player's screen. This makes Pyro an increasingly difficult class to play at higher latencies.
  
==Exceptions==
+
Spectators do not have lag compensation. If you are spectating someone in first person, you are not seeing exactly what they are seeing, rather you are looking at what the server is seeing. This is especially noticeable with high-latency Snipers, where you should expect to see unusual shots that may appear to miss or jerk about from your perspective.
  
Projectile weapons such as [[rocket]]s, [[grenade]]s, and [[flare gun|flares]] are not lag-compensated. It is not clear whether the [[Syringe Gun]] or [[Flamethrower]] are lag-compensated. The [[Pyro]]'s [[compression blast]] is also not compensated, making it increasingly difficult to use at higher latencies.
+
== Update history ==
 +
'''{{Patch name|7|7|2022}}'''
 +
* Fixed lag compensation when [[Weapons|melee]]-ing teammates
  
Spectators do not have lag-compensation. If you are spectating someone in first person, you are not seeing exactly what they are seeing. This is especially noticable with high-latency snipers, where you should expect to see unusual shots that may appear to miss or jerk about from your perspective.
+
== See also ==
 +
* [[Backstab#Issues|Backstab issues]]
 +
* [[Source Engine]]
 +
 
 +
== External links ==
 +
See the following links for in-depth technical explanation of how lag compensation works in the [[Source Engine]]:
 +
* {{vdc|Lag compensation}}
 +
* {{vdc|Latency_Compensating Methods in Client/Server In-game Protocol Design and Optimization}}
 +
* {{vdc|Source Multiplayer Networking}}
 +
* {{vdc|Prediction}}
 +
 
 +
{{Mechanics Nav}}
  
 
[[Category:Gameplay]]
 
[[Category:Gameplay]]

Latest revision as of 15:11, 11 August 2024

Stop lagging and start tagging, men!
The Soldier

Team Fortress 2, being based on the Source Engine, is generally configured to make use of lag compensation. Lag compensation is most commonly the technical reason behind cases of kills or actions that would otherwise seem infeasible in given circumstances; for example, when players perceive themselves to have been "shot through a wall" by a Sniper, backstabs being performed at the incorrect angle (known as facestabs), or otherwise missing entirely (known as failstabs).

When a high-latency (high-ping) player attacks, the server temporarily "rewinds" its copy of the action in order to compensate for their lag. For example, the enemy Sniper shoots when he sees your head, at that moment you and most other players may believe you successfully ran behind a wall. When the server receives the fire message from the Sniper, it "rewinds", finds out if you had ought to have been hit, and then deals damage, leading to the appearance of being "killed through a wall".

This is an intentional engineering and design decision, a trade-off to enhance the realism of attacks at the expense of the realism of taking damage. Were lag compensation disabled, shots that look like they hit the enemy without inflicting any damage, which is still an issue due to hit registry and which is more of an issue with melee weapons, would become more common.

Exceptions

Projectile weapons such as rockets, grenades, syringes, and flares are not lag-compensated. The Pyro's compression blast and Flamethrower are also not lag compensated, despite the effects appearing immediately after firing on a player's screen. This makes Pyro an increasingly difficult class to play at higher latencies.

Spectators do not have lag compensation. If you are spectating someone in first person, you are not seeing exactly what they are seeing, rather you are looking at what the server is seeing. This is especially noticeable with high-latency Snipers, where you should expect to see unusual shots that may appear to miss or jerk about from your perspective.

Update history

July 7, 2022 Patch

  • Fixed lag compensation when melee-ing teammates

See also

External links

See the following links for in-depth technical explanation of how lag compensation works in the Source Engine: