Networking, Lag Compensation, and Hit Detection

[adw1983]

As the host -- I have experienced both the following scenarios:
1: Godliness beyond all reason:
Going 26-0 when I should have died multiple times: Opponents CANNOT hit me while I move while using the PDW.
Going 33-0 when I should have died multiple times: Opponents CANNOT hit me while I move while I use SMR.
(I got hit several times in both games -- but never thrice in a row.)

2: Going severely negative versus opponents who are worse than me, shooting 20 rounds on target with the SMR then 5 out of 8 pistol rounds on target with only two hit detections -- one of them off target on my screen, apparently hitting the opponent through a wall while he was not there yet.

...

Most of the time, the latter applies:
I rage-quit Black Ops 2 over 40 times because of lag -- compared to only 5 times in MW3.
I played MW3 a whole lot more than BO2.

By "lag" and rage quit, I mean and only mean: When I can't hit opponents that are in my sights to the point beyond frustration.
(I do not mean; Going negative, losing gunfights, losing the game or getting "flanked".)

The five last times I quit because I could not hit anyone, including the last time I played Black Ops 2 -- which was when I did not get hit detection with my SMR -- I was hosting.

Black Ops 1 was extremely wonky when hosting too.
Both feels less precise than MW3, where I used to have 27% accuracy with the Mk14.
It's as if the characters are smaller than in MW3.

...

Simply put: I feel schizophrenic when hosting in Black Ops 2.
Quite literally:

What I see on my screen does not even come CLOSE to what happens ingame when hosting.
Bodies of enemies I kill TELEPORT 10 feet forward to their final resting place: They die instantly when I get hit-detection -- but not instantly, because hit-detection isn't instant, and not where I actually shot them.
There seems to be absolutely no rollback what so ever for my shots; no lag comp to compensate for the artificial delays.

HOWEVER, I get kills instantly with my dragonfire:
It's as if the dragonfire is allowed to hit instantly -- while I'm just another client in the network when wielding a normal weapon as the host.

Another wonky thing when hosting is that the dragonfire, with instant hit detection, still misses if you target a running enemy from above: You have to lead the target, even though the projectiles hit absolutely instantly, without travel time, when the target is standing still.

I can't help but suspect they've Foxtroted up the host's data, using the actual events on the host for hit detection while the "client" running on the host machine is denied hit prediction -- or hit prediction can be screwed up, not counting the artificial delay between what you see on your screen as the host compared to what happens in the game world at that very time.

Hosting in Black Ops 2 most often feels like playing CoD4 against an american host, from europe.

[42]

Sounds like your problem is more your connection than how BO2 hosting functions.

[Pentaza]

Apr 2, 2013 19:15:47 GMT -5 adw1983 said:

I can't help but suspect they've Foxtroted up the host's data, using the actual events on the host for hit detection while the "client" running on the host machine is denied hit prediction -- or hit prediction can be screwed up, not counting the artificial delay between what you see on your screen as the host compared to what happens in the game world at that very time.

Yes, this is my guess too, that the hit detection and visuals sometimes aren't lined up correctly when host.

Mousey's comment regarding packet loss - this still shouldn't change the concept of shooting where you see them on screen. The problem that packet loss can cause is the characters jerk around the map so you can't track them with your aim. But even with that, if you're on target, aiming down sights, when you pull the trigger it should still register a hit. You shouldn't need to aim ahead (unless using a ballistic knife or crossbow, of course).

And I don't seem to ever have a problem when I'm client, irrespective of whether I'm playing against players who have low or high latency. I'm located in Europe and have played with bros in the US, on US-hosted games, and it runs fine.

[Pentaza]

Apr 5, 2013 17:31:03 GMT -5 Mousey said:

well to be fair we are kind of iffy on whether or not hitmarkers still register client side. I can only really check in cod4 since I can drop into a server @800 ping, but it may have been changed somewhere along the line and I'm pretty sure it has.

This is an interesting point as to where the hitmarkers register, because there's a downside with each in the face of latency (and also packet loss).

If the hitmarkers register host side, you have to wait the full round-trip time before you get the hitmarker feedback locally. Beyond a certain threshold (based on human perception, and I don't know what the key threshold is), this would make the game feel imprecise, particularly as the latency increased. And with high enough latency and a fast enough firing weapon, you'd be landing the second hit before you got the first hitmarker, which I expect would make the game feel very off.

If the hitmarkers register client side, then given that the host makes the decision about when someone has been killed, with a fast enough firing weapon and high enough latency, you could quite easily get, say, 7 or 8 hitmarkers when only 3 or 4 hits are needed to kill. This would also make the game feel very off.

Due to the way we perceive that there's a bullet travel time between firing and hitmarker (even though in the game the hit detection is instant), I'd say some delay between hit detected and hitmarker would be acceptable.

If the hitmarkers are host side, then this could explain how sometimes pulling host seems to feel like God-mode. If player latency conditions mean that zero artificial ping is added to the host, then hitmarkers would be instant, and would make the game feel super sharp (this in addition to the kill-registering advantage in close gunfights).

Note, however, that the significant host disadvantage that I sometimes experience, with hits failing to register, isn't explained at all by any of this, because it should be no different to playing as client. In fact, it should be better as host, because there's no possibility of packet loss resulting in skipped hits (unless they've tried to simulate packet loss for the host, and in my opinion that would be really stupid). I suspect, as has been mentioned previously, that something very fucking stupid is going on, and they've put the artificial ping in the wrong place, such as e.g. the hit detection doesn't take artificial ping into account, but the rendering on screen does. (Artificial ping should only be applied to the information sent from the host's player to the host's server, not the other way round, etc.). If this were the case, then it would explain the intermittent nature of the host disadvantage, because when zero artificial ping is added, the hit detection and on-screen rendering would be aligned properly. But this is, of course, complete speculation, based on an attempt at reverse-engineering an effect that is itself based on subjective views (albeit from a number of bros), not yet proven with slow-motion replays, etc.

[LeGitBeeSting]

Why is Urbane always host.

[bucket415]

Here is Tmartns attempt at this thread

[Slick]

Wasn't worth 10 minutes in my opinion. He could've used less time and simply explained how client side hit detection worked and how it effects you. Would've been easier to follow for most people. It feels like he tried to cram too much excess info most people won't understand anyway.

He also offered almost no actual tips. "Get better internet" is not a good tip, bandwidth is only an issue if you have packet loss resulting from heavy internet usage. Gaming takes very little bandwidth, so he should've talked about ping more.

[bucket415]

I agree, it was the worst video I have ever seen in try to explain lag comp in COD. I only got through maybe 4 minutes of it.

[the1jeffy]

So, Drift0r's video. Go.

Thoughts: He pretty much nailed it, with some cool video clips (while obviously staged) that demonstrate the effects we've all seen in game. He is rather vague on the methods that the host uses to make decisions, i.e. the time stamping, but I suspect the devs didn't want to get into that or asked him not to, as I believe that's where some of the true hacks go to do what they do. Also, his insistence that host is preferential is also probably something that the devs are trying to drive home (to stem the tide of "I'm host! Time to dash!), even though it doesn't tell the whole picture. In a more perfect world, the host DOES (or should) have a slight advantage, however, I believe that hosting drives the Xbox's networking/processing capacity to it's limits so wonky things seem to happen.

That's my take. I am open to redirects if I've been led astray.

[the1jeffy]

Thanks, I didn't catch that. It's just about what I thought -- that any omissions/slight inaccuracies were intentional.

Dedicated servers don't solve lag issues, but they certainly are more consistent. Gears 3 multi has them and I still got lag related issues on occasion. However, the character movement rate and TTK is much much lower in Gears than CoD, so the comparison isn't 1:1.

That being said, I would be completely flummoxed if they didn't go dedicated for the PS4/Xbox720 version of CoD. If they are going to take the time to write a new engine, it only makes sense -- dedi's (to use your parlance) give the devs a level of control over matchmaking/glitching/hacking/boosting that they've not had, not mention the IP control, and I believe that from a development standpoint those things are more important than 'lag comp' as it's largely out of their direct control.

[lackingdamage]

Apr 11, 2013 8:57:52 GMT -5 Mousey said:

we discussed that slightly in his other thread.

denkirson.proboards.com/index.cgi?action=display&board=general&thread=6218&page=1#147881

a few things are off but its deliberate and for the most part harmless.

If you ask me, the host just needs a hell fo a lot more bandwidth than everyone else which can give the impression of "host disadvantage," especially if they increased the networking rates.

Dedi's are the best way to solve it but idk how practical that is from a business standpoint.

Not very
Dedicated servers only work when you have one close to all popluation centres. Millions of COD players means it unlikely to happen due to the high cost from it.
Reason why they went with the client server system in COD was due to the fact anybody could be a server. I know a couple of people over the years who when they game on PC no server close to them.
"BUT BF3 HAS SERVERS" I know but only 2 locations within the whole of the EU on console. Result can be a times very iffy hit detection mixed with how they model lag to cope with that fact.

What they could do is harsher matchmaking like in LP which god knows it not rolled out across the normal matchmaking system.

[tiesieman]

BF3s console server system doesn't work because there's no 3rd party servers. Hopefully, the next game will expand on it and show that community-run dedis even on consoles are a great solution.

[lackingdamage]

Apr 13, 2013 6:02:38 GMT -5 tiesieman said:

BF3s console server system doesn't work because there's no 3rd party servers. Hopefully, the next game will expand on it and show that community-run dedis even on consoles are a great solution.

It does not work due to the lack standardized server settings in ranked. Which is one reason I don't game on PC.
Give me Standardized server settings be on that within a heartbeat.
3rd party is a small issue compared to that problem.

[adw1983]

Apr 2, 2013 19:36:49 GMT -5 Mousey said:

Bodies of enemies I kill TELEPORT 10 feet forward to their final resting place: They die instantly when I get hit-detection -- but not instantly, because hit-detection isn't instant, and not where I actually shot them.

That absolutely sounds like packet loss.

Every single game I host feels like this.

[adw1983]

...

Problem:
Demonstrably, hit-detection is WAY OFF in Black Ops 2, even when hosting:
Running my TV in game mode, my controller wired and reducing the resolution on my 360 to 720p just to minimize any input lag -- I cannot hit a sprinting target by aiming directly on that person;
People's hitboxes are misaligned with what's going on in my game even when hosting.


Problem:
Very often, targets that are killed can damage their attackers after their death.
This can also be observed in theater mode:
The person who is killed continues to fire after his death, and these bullets cause damage if they hit -- for as long as they would not kill the target.
We can only assume that IF those bullets dealt enough damage to kill, he would be awarded the kill instead -- and that the combat-winning hit detection would have been dropped in favor of the delayed shots hit detection and kills.

Is this behavior exclusive to the 360?

=======

If I develop "client hit detection - host hit determination / host hit prioritization" -- would they employ the coding in their games?

[pachiderm]

Neither have I

Sure, every once in a while I'll shoot right at someone and not hit them but I've never had a consistent problem hitting someone if I was actually shooting at them. I've also never seen any bullets coming from dead bodies in this game.

[anthraxx]

Best post 2013 NA.

[riggsmurtaugh]

Hey Bros,

Long time lurker, first time poster. There's some great info here already, but I came across a thread over on the Respawn forums that I thought might interest you all. It's great getting some info from the source for a change.

www.respawn.com/forum/viewtopic.php?f=16&t=2375

You are my bro, bro.

[otisman666]

Interesting reading there Riggs, thanks.

[markopolo]

All I know is whatever they did in the most recent update on PSN, they effed it up.

Tons of moonwalkers, teleporters, and matrix-like bullet dodging there.

It's like MW3 again, and I effing hate it.

[markopolo]

Yea, but I'm not one of them.... I fight through it thinking I've had a bad connection day.

Except it's been a bad connection week

[markopolo]

I hope it'll swing back to normal for me... other than this past week, BOps2 has been a very lag free experience that has been really fun.

Probably the Connection Gods punishing me for playing hardcore

[wings]

How much of an issue, if any, do routers influence the smoothness of gameplay? I'm thinking of upgrading my router and it's handy to have a spare just in case. Current router is the D-Link 615.

[statix]

Feb 18, 2013 23:22:28 GMT -5 Mousey said:

I mentioned on the front page that a lot of the "MW2 and CoD4 have godlike netcode" bullshit can be attributed to how much stronger weapons were. While in BO1-BO2 you tend to live juuuuust long enough to start to react but not long enough for it to matter across a network. I mean come on,

They're literally killing you in two bullets in mw2 so it seems normal. half the guns in the game can kill in two bullets ffs. Placebo doesn't even begin to describe this crap.

I have the call BS on the old "MW2's weapons were stronger" argument/excuse for why things feel laggier in later COD's. All the top AR's in MW2 -- Tar-21, SCAR-H, ACR, Famas -- took 3-4 bullets to kill, with the exception of the ACR, which took 4-5 bullets. This is in-line w/ many of the weapons in MW3, Black Ops, and Black Ops 2. The Famas in Black Ops, for example, was 3-4 hit kill, not to mention being ridiculously accurate in bursts, having super-accurate hip fire, and having a ludicrous fire rate. It was arguably a more effective weapon than the AR's in MW2! Even considering Stopping Power.

Stopping Power in MW2 did make the aforementioned AR's take one less bullet to kill at close-range and long-range. But at mid-range, the aforementioned weapons were still 3-hit kill. The fact of the matter is, unless you're sniping or being sniped, mid-range is the vast majority of gun fight encounters you'll face in MW2 and COD in general.

Plus, MW3 and Black Ops 2 also have overpowered, 2-hit kill rifles of their own; Type 95, anyone? Not to mention you can turn those 2-hit single-fire guns in Black Ops 2 into full-auto weapons with a simple attachment.

Thus, the whole "MW2's higher damage creates the illusion of better hit detection" argument doesn't really wash.

Addendum: Regardless of the above, my problems with Black Ops 2 aren't even with its hit detection. My bullets generally register fine (with the exception of when I die despite shooting several bullets into an enemy, which I attribute to network latency/delay). My main problems with Black Ops 2 is the high incidence of instant deaths (dying by one bullet or sometimes no bullet), dying a second later after running behind cover, and dying by some opponents who seem to have incredible reflexes -- players who pop out and kill me before I have barely any chance to react. In the last case, you would think I'm playing with a lobby of MLG pros, when in fact, they're just average players or noobs. However, you wouldn't know this by how fast they pop out from behind cover and kill you with lightning speed. You'd only know by looking at the killcam replay, and seeing that they actually took 2-3 seconds to come into the room, look at you stupidly standing there and staring into space, and finally shoot you with average skill/speed.

That's the look-ahead factor that's inherent in the substantial extra delay of Black Ops 2 (about twice the added lag/delay of MW2) to which I attribute the symptoms of "instant death syndrome" that frustrate me on such a frequent basis. People who lag more have much more of a sight-advantage over everyone else, to the tune of hundreds of milliseconds -- a not-so insignificant number in COD time.

Actually, the argument that MW2 has more powerful weapons than Black Ops 2 is actually an indictment against Black Ops 2. Since the weapons are supposedly so much more powerful and fast-killing in MW2, it's amazing that players (myself included) seemingly complain less about dying instantly, dying behind cover, and dying with little-to-no chance to react to enemies moving into view -- issues you would expect to experience more in the game with deadlier weapons.

[daftpunk]

@ statix , you're experience of BO2 mirrors mine almost exactly..B01 was the same ...

[Deleted]

I'm probably gonna sound really dumb for saying this...but would turning off voice chat in options help lower ping?

[adw1983]

May 9, 2013 8:17:27 GMT -5 Mousey said:

Keep in mind that their advantage only exist when theyre coming from cover or when they're shooting you as you run behind cover. If you're the aggressor in either of those situations, or in a fight where cover isn't involved, then the delay works in favor of the least lagged player.

In how many out of 100 cases do two player round a corner simultaneously?

One player is very likely to round a corner before the other player, receiving a disadvantage.

[fearsomepirate]

Hi, first time poster.

I live in southern Mexico, so my connection is generally crappy enough to have a some valuable input, I think.

First, yes, higher DPS hides lag. Simply put, with low DPS, more stuff happens between you first getting shot at and the kill finally registering. You will move farther, fire more bullets, etc, so you'll feel a lot more "unfair" deaths. For example, if you are running behind cover, the odds of you making it to the cover from your POV before you die increase with lower DPS weapons. You are less likely to have fired 15 bullets before you die. I find that in general, the best way to compensate for my laggy performance is to switch to guns with a very high DPS (and, in COD4, WaW, and MW2, use Stopping Power).

Second, a *huge* difference is matchmaking. MW2 searches only low-ping matches. This is nice because it means you usually get good connections. But it's bad if you live in Central America, because it means that you will never find a connection, period. I plain cannot play MW2 now. Similarly, I cannot find a match if I set BlOps2 to "best." By contrast, the Treyarch games and COD4 will all put you in pretty crappy matches if that's what they find first, as will BlOps2 if you set it to "any." So it's not directly comprable, because most of your experiences with MW2 were probably lower-ping matches than what you experienced in BlOps.

Third, rose-tinted goggles. COD4's netcode is horrible. There's lots of glitching, jumping, insta-freezing, denied kills, etc. It's really bad. That should be no surprise, since WaW uses a lot of COD4's code, and the netcode didn't seem to be changed much for BlOps. If you haven't played COD4 in a long time, then you are probably remembering it as being better than it was, because it didn't have much competition at the time. Its badness is more obvious without Stopping Power (see the first point).

[oTradeMark]

Mousey, I've read this thread in the past and I appreciate your contribution to informing people about the technical details of COD networking. My question for you or anyone else reading this thread as we look forward to next gen consoles & future COD iterations is: What solutions do you propose to increase the connection experience in Call of Duty?

It seems like increasing the snapshots & client updates per second would be a good place to start right? Assuming the clients are sending & receiving more updates per second than in past games interpolation would not have to wait as long as it does to render a new snapshot and packet loss would not be as detrimental as it was in past games as well.

Dedicated servers remove issues like dashboarding & lag switches and should hopefully improve the consistency of matches that a player experiences but lag compensation is still required to combat latency issues.

So I'm curious as to what you guys think are the most pressing connection issues and the solutions that need to be implemented to give the best experience to the users.

[oTradeMark]

Jul 31, 2013 9:00:36 GMT -5 Mousey said:

I don't have any. The models being used for everything in cod are absolutely archaic and if they really wanted to improve it, the resources are available.

keep in mind increasing network frames puts more stress on players' connections (especially host), and also puts more stress on the hosts console in addition to that. Unless console players get dedis in ghosts you shouldnt expect any improvements there at all regarding connection since the PS3 and 360 are still getting versions and they cant afford to have the game fall apart because the host cant handle it.

Besides, increasing the network frames wouldnt help with much except let them lower interpolation a bit (or hiding packet loss better).

What do you mean the resources are available to improve their models? Is there a fast paced FPS game out there that has superior networking code to COD and how is it superior?

It will be interesting to see what Respawn does with Titanfall... On one hand I'm excited and think they might make some major improvements because of the staff they have and yet on the other hand I'm worried that since they are the ones that utilized the same networking code for years in COD4/MW2 they might not make many improvements at all.

In regards to updates/stamps is there a reason that the amounts are different? Clients send 30 updates per second but only receive 20 stamps. Wouldn't it make more sense to make those numbers the same? 30 updates sent and received per second for example? I don't quite understand why stamps are so low unless it's just because they are trying to limit the amount of information sent from the host, ie upload constraints.

I also am not holding out for many improvements in COD ghosts because as you said they are developing it for both current and next gen consoles so unless they all get dedicated servers it is pretty unlikely that they would change the netcode for next gen consoles and leave it the same on current gen.