Ghosting in DTD Arenas

[Jurassic]

Curious how many people get constant ghost ships in DTD? I get it 0% of the time in MMR these days, but 100% in DTD. I've always seemed to get it in DTD. I know other people I've asked have said the same. Does everyone get ghosting in DTD? Is there something wrong with the DTD arenas vs MMR arena? Have absolutely no idea what causes it.

[Kassius]

This is a good spot Jur, now that you mention it, ghosting is much more apparent in DTD. Yesterday I had 3 ships ghost across my screen at the same time towards me, I shot at one, then they actually turned up at a different trajectory and they had me.

[Rasaq]

Happens to me once or twice during TWDTD. Never happens during a lobfest, but if I'm chasing or regrouping I usually get the random ghost that I shoot at and then feel like a total idiot. Also, on rare occasions, shooting at the ghost results in a kill on the same named ghost player like 3 seconds later.

[Rab]

yep tons of ghosting

[Turban]

In before it is the massive past winners image top-left of the arena causing performance issues in that specific arena.

However one other explanation would be arena settings being slightly different, as an example Miscellaneous category has one which tweaks with position data and how frequently it is being updated to other players' clients. I believe that setting was changed in some competitive arena, but I can't recall whether it was for DT or TWL.

[qan]

Good catch that performance is different. I took a look at arena config differences. There are very few.

The only ones I could see that would affect net performance are:


TWDD: CloseEnoughBulletAdjust=8192
TWDTD: CloseEnoughBulletAdjust=512
Bullet packets sent further in DD to allow them to travel across the arena, meaning slightly more weapons packets sent overall.

TWDD: MapZoomFactor=7
TWDTD: MapZoomFactor=6
Slightly more radar packets sent in DD because the radar is slightly more zoomed out.

So from a network settings perspective, though the differences are small, all things being equal, performance should be slightly better in DTD.


The other difference is that there are more LVZs in DTD.



My hunch is that the number of players in the arena (at least, who actively receiving position/weapons packets, and not idle as are many in pub) has the biggest effect. Possibly something to do with how the server is choosing to send packets: buffering/clustering packets together, delayed ACKs (though IIRC weapons and position packets aren't sent reliably, not requiring an ACK), Nagle's algorithm, etc. Does this only seem to happen with a larger amount of spectators, or does it also happen with basically just the teams in the arena?

It's also interesting that it occurs in DTD more than, say, DTJ or DTB (correct?), because the players are spread out further. I would think that would mean fewer position packets needing to be sent in WB arenas.

WB does send more radar packets than Javs, from a quick compare. In WB arenas, every 3rd position packet is sent to radar. In Javs, every 4th packet is sent. This is probably because it's more important to see accurate radar in WB.

...But it could also just be something unexpected like the LVZ, as Turban said. Weren't the LVZ graphics only in ?go twdt at one point? They can affect framerate on older systems. Don't think they'd affect net performance, but you never know. SS is a mysterious, ancient beast.

Might be worth trying to host a few MMR games in DTD to see if it still happens with a small crowd.

[Kassius]

I'll say that the ghosting occurs even with minimal spectators in the arena.

[Jurassic]

I don't think it's spectator related as it happens immediately during DTD when spectators / players are spread out amongst the 4 arenas. Could it be 4 arenas running matchbots at the same time? Will have to pay attention if it happens late in games when other arenas are done playing and my team is still playing.

I did notice some minor ghosting in jav my first round this last weekend. But nothing like WB. Potentially because Best/Vys like to rush from off screen. Otherwise generally not a noticeable problem in jav. I think it does happen in BD with shifting sharks that are killed, but not to the point I've really thought about it. In all cases I believe shifting ships going at a fast speed are to blame. I think the shifting ships being off-screen is the difference in it happening so frequently in WB. What it looks like is 2-3 ships rushing you from off screen that blink out around the time you want to shoot them. Like Rasaq said above, I don't think it happens as much in lobbing games. More so when people are rushing around.

I believe it also happened in TWLD with the same frequency, but my memories a little fuzzy on that. Tripin pm'd me saying he experiences the same thing and happened during TWLD as well as DTD for him.

I don't think it's a hardware thing for me as I've changed to a new computer without change. I think I've become accustomed to what a ghost ship flying from off screen looks like, so I don't waste shots firing much anymore. But it's still an annoyance and definitive difference from MMR for me. I meant to post about it last season but never got around to it.

[MousE]

everything works fine for Racka this is just to hurt his opponents

[RageRitual]

I get this a LOT, and it's really tilting when I go to rush someone only to realize as I shoot, they are not actually there. Now that you mention it, it does not happen as often in MMR as in DTD/TWDD. I have also noticed it seems to happen more often when there is a lot of "shifting" around from players. It happens a lot less in lobfest type matches, maybe MMR is more lob heavy? I know TWDD certainly has more rushing in it.

[Rab]

+1 it's not spectator count related

can we just remove the lvz to see what happens? (I'd say we should do it anyway because of the silly download times, just stick the gif on the forum instead)

As for the other settings, I'm sick of repeating myself that all arenas for a division should have the same settings and map.

Make one change at a time tho to find out what the cause was.

[qan]

It could definitely be due to several matches running concurrently. Good to know that the spectator/arena count doesn't influence it. Rushing has always caused some issues. It could be prediction code.

Yes, all settings should be the same across a division, generally speaking. However, it's an old game maintained by volunteers. Mostly they're identical but sometimes a few surprises come up. The main issue is determining which of the conflicting settings are the ones to keep. Sometimes it's not clear when changes were made or why, though we do keep a changelog these days. A long time ago, we even had an incompetent and actively malicious sysop modifying settings for their own benefit.


It would certainly be worthwhile testing without the A1 graphics. For now, I'm moving them to just ?go twdt. There are still quite a few LVZ in there, but this is by far the largest, and it's always active. Please update the thread with how it goes next weekend. I'm not expecting a change but always happy to be surprised.

[Rab]

nice ty

[RageRitual]

I never really noticed ghosting with the old server, so if it is in fact related to the maps we are using, I assume it is something we have changed since the reset, that may help narrow it down some.

[RageRitual]

Today, I was having 0 problems with it, played 1 mmr dd, then the following game it was REALLY bad. I did change res from 1400x900 to 1920x1200.

If res change had nothing to do with it, I also when I relogged I noticed we had around 140-150 people on, which would mean we had almost exactly 100 people (around 40-50 bots give or take). We did have a surge of players log in due to DT starting up soon. This was around 1:30 pm sunday EST that I noticed the difference.