Broken replay tracks in DCS in 2021

[alphagamer4]

I'm new to DCS. I believe it's an outstanding flight sim.

 

But my perspective on the game took a major hit when I loaded up a REPLAY track and discovered to my horror that the replay does not reflect my actual gameplay (i.e. I crashed in the replay when I did not in the original playthrough).

 

For a game like DCS with its relatively high price points, the lack of a fully functional replay track is an embarrassment.

 

After conducting a due diligence, I was surprised to learn that this replay bug has been around for years, not months or even days, but years.

 

In light of this, I cannot recommend this game to my friends or colleagues in good conscience.

 

The devs should know better. The devs should be better.

 

Do your customers and community better and fix the broken replay system once and for all. Thank you.

[dorianR666]

There are two separate issues here:

 

1) The track file only records inputs, the rest is independently resimulated. So as time goes on, the imprecision increases. This isnt really a bug, just a tradeoff. Recording changes of all states of all objects several times a second would be problematic and track files huge. If it worked this way, someone else would complain about 2GB files.

 

2) There is a bug that some inputs sometimes arent recorded into the track file. Its annoying but it happens quite rarely. Not as big issue as it sounds. (Though yes, it needs to be fixed).

 

 

Many new players dont know about this: there is a free app called tacview, which allows you to record and analyze your flights in DCS. You dont see the ingame graphics, but it gets the job done.

Edited January 10, 2021 by dorianR666

[jwflowersii]

So I discovered the issue with replays is that the input file is generated per frame.  The best way to get reliable tracks is to lower you graphics settings to have high framerates.  It is more likely to record correctly the higher the frame rates.  If you have any stutter, this is when it tends to get "unreliable".

[alphagamer4]

On 1/10/2021 at 2:19 AM, dorianR666 said:

There are two separate issues here:

 

1) The track file only records inputs, the rest is independently resimulated. So as time goes on, the imprecision increases. This isnt really a bug, just a tradeoff. Recording changes of all states of all objects several times a second would be problematic and track files huge. If it worked this way, someone else would complain about 2GB files.

 

2) There is a bug that some inputs sometimes arent recorded into the track file. Its annoying but it happens quite rarely. Not as big issue as it sounds. (Though yes, it needs to be fixed).

 

 

Many new players dont know about this: there is a free app called tacview, which allows you to record and analyze your flights in DCS. You dont see the ingame graphics, but it gets the job done.

 

 

I have TacView Advanced. It's great for tactical analysis (it's intended function) but terrible for creating cinematic gameplay footage from a recorded battle.

 

What is the point of having a track replay if it is incapable of 100% replay accuracy (from either a gameplay or input perspective)?

 

Thanks to the limitations of the DCS Track Replay system, it is nearly impossible to record cinematic footage of a air duel after the fact. And it is close to impossible to create such recorded cinematic footage "live" as the battle plays out the first time around (at least, not if you do not want to get shot down).

19 hours ago, jwflowersii said:

So I discovered the issue with replays is that the input file is generated per frame.  The best way to get reliable tracks is to lower you graphics settings to have high framerates.  It is more likely to record correctly the higher the frame rates.  If you have any stutter, this is when it tends to get "unreliable".

 

I experienced the opposite.

 

With an average of 190 fps in-game, my DCS track replays did not turn out accurate at all.

[rayrayblues]

Another combat game that I used to play uses the Widelands Replay format (not the Widelands game) which stores the battle partly on their server and your input commands are stored on your machine as a .wrlp file.

When you replay the battle it puts them back together to re-create everything that happened including all other units.  Replays are automatically saved, so you don't have

to remember to hit the "save Track" button. Server side replays are also available. The replays don't deteriorate over time except: see below.

 

There is a downside though.

Every time the game updates to a new version, the files are on their side get deleted and you can no longer replay that battle. If you are planning to make a cinematic video,

You have to do it before they change to a new version, which is about every 2 to 3 months or so. They do let you know when an update is coming though.

 

On 1/10/2021 at 12:19 AM, dorianR666 said:

1) The track file only records inputs, the rest is independently resimulated. So as time goes on, the imprecision increases. This isnt really a bug, just a tradeoff. Recording changes of all states of all objects several times a second would be problematic and track files huge. If it worked this way, someone else would complain about 2GB files.

 

The typical file size of a .wrlp file on your machine is 2 to 5 MB each, a tad more than our tracks, but certainly not in the ~Gb range.

 

21 minutes ago, alphagamer4 said:

I have TacView Advanced. It's great for tactical analysis (it's intended function) but terrible for creating cinematic gameplay footage from a recorded battle.

 

 

I, like many others are more interested in using tracks to create cinematic videos of our greatest battles and sharing them on YouTube.

TacView is great, but like you said, virtually useless for us content creators.

 

The DCS track system is buggy at best. Shorter tracks are more reliable, but if a great battle moment occurs in the middle of a long track,

odds are that you will not be able to find and record it. I am hoping dearly that ED does something to improve their track replay system.

For now, us content creators have to rely on short tracks;   also, IDK how BigNewy and others can diagnose problems using this unreliable system.

[fudabidu]

Played a very small mission trying to track down some bugs and all my TRK files desynced almost immediately.
Sensors not tracking, missiles going crazy, AI behaving completely different ... completely useless if you want to report any bugs.

[J-1775]

On 1/11/2021 at 5:42 PM, rayrayblues said:

Another combat game that I used to play

I assume I know what 'flightsim' you're speaking of. It's the one that introduced flex wings to WWII aircraft. And after months of void promises finally managed to be the first 'flightsim' to have working DLSS for VR! Which not only brings an incredible boost in VR FPS, but ─ with the need of AA gone ─ brings unbelievably nice and steady pictures with almost all 'shimmering' removed.
The DCS recording system probably needs a complete overhaul. Who'd wonder after almost ten years? What I don't understand: Why doesn't DCS realize that a good support for the cinematic addicts is best FREE marketing. With YT and social media ANY effort put into that would pay back in cash within the shortest time...
Well, obviously they consider the accuracy of a missile path under all weather conditions as more important than a new customer base? I REALLY start to wonder what MAC may bring in terms of overcoming old quirks and focusing on user friendliness (input system, skins, cinematics...).

[Rhino1980]

How does Glowing Amraam put these moves together without blowing his God damned brains out from frustration?  He must record it live with help from some people flying for him.  I don't see how it would be possible with this retarded replay system.

[dorianR666]

26 minutes ago, Rhino1980 said:

How does Glowing Amraam put these moves together without blowing his God damned brains out from frustration?  He must record it live with help from some people flying for him.  I don't see how it would be possible with this retarded replay system.

server-side tracks probably. they dont replay inputs.

[LithiumR]

I've noticed that my MP tracks play fine. SP tracks often desync so I've started hosting my own missions as MP even though I fly them as SP and I haven't had any desync issues. I have no idea if this is a thing or I'm just getting lucky. I noticed though that my replays from GS and other servers always seemed to be fine but even a simple 1v1 in SP desynced after just a few moves. That's what put me on to this. YMMV

[Hiob]

MP-Servers most probably don't record player-inputs but meta data in form of xyz coordinates or vectors for any given object.

I don't know why it's handled differently in SP but there is a reason for sure.

 

Can you replay "inside cockpit" views alongside button and switches being operated when recording a MP session?

Edited August 9, 2021 by Hiob

[LithiumR]

1 hour ago, Hiob said:

MP-Servers most probably don't record player-inputs but meta data in form of xyz coordinates or vectors for any given object.

I don't know why it's handled differently in SP but there is a reason for sure.

 

Can you replay "inside cockpit" views alongside button and switches being operated when recording a MP session?

 

I’m not using the replay from the server as I don’t have access to that. I’m using the replay recorded in the saved games/DCS/tracks/multiplayer folder.... which if I host a session (not dedicated server) records a track (records a track there regardless of if I’m on my own server or if I’m on a remote server).  That’s how I make my own tacview files from multiplayer sessions also.... just let the replay run and then check the tackview folder. 
 

Again, idk if it’s recorded differently and therefore accurate or if I’ve just gotten lucky with “hosted” tracks playing better than SP “non hosted” tracks. 
 

Edit: I realize I didn’t totally answer your question. Because it’s a replay that’s recorded locally on my end (client) all of the head movements and clickity clicks are there. Even if I host my own local server for myself the .trk file is saved in /multiplayer folder leading me to believe it’s recorded as a MP.trk vs a SP.trk. Hope that helps clarify what I’m trying to explain. And again, idk if MP tracks recorded locally are recorded differently than SP tracks or if it’s just been coincidence that they have been accurate. 
 

Example: If I do instant action dogfight the replay is desynced... but if I instead go to multiplayer and create my own server (whatever that button is labeled) and load the same exact instant action .miz the replay is NOT desynced. 
 

This is a combination of replay and live recording from GS server easily 2 hours in... replay is perfect. So far replays from PvE servers like Through the inferno with AI also record perfectly. That’s what made me wonder if I hosted my own local server for SP missions if the replays would be just as accurate and so far they are. 

 And perfect replay against AI here... hosted as a MP server instead of as a SP mission. Perfect replay...

 

someone with more .lua knowledge than me could probably verify or disprove this theory that MP.trk’s record differently than SP.trk’s. It makes since though (I think). In a SP replay just inputs are used and the mission isn’t a replay exactly but really “played again”. In MP there has to be some kind of x,y,z coordinates sent to the server and/or other clients so that clients can render objects in the correct place. So maybe MP tracks are recorded with that additional x,y,z info that makes the replays more accurate. But idk... I’m just guessing and might not know what I’m talking about haha. 

Edited August 9, 2021 by LithiumR
To add info again and again haha... and then fixed spelling

[Hiob]

Thanks for the clarification.

Now, if that's a functioning workaround, I'm happy. Will try.

@BIGNEWY

Perhaps this should be made aware to the devs. Maybe it gives them a hint to solve the issues.

[Rhino1980]

I notive problems in server side tracks too though.  Particularly if you speed up time for a portion.

[Oban]

I really wish they would sort these replay tracks out, I just did the recce mission with the F18 on the Normandy map, and completed it, rarely getting about 500' and wanted to watch it in the replay, but every time I try to watch it, doesn't match the actual mission, even getting shot down 2-3 times.. which simply didn't happen..

If you can't fix this ED, REMOVE THE FEATURE!!!

[Nealius]

On 8/9/2021 at 10:37 PM, LithiumR said:

I've noticed that my MP tracks play fine. SP tracks often desync so I've started hosting my own missions as MP even though I fly them as SP and I haven't had any desync issues. I have no idea if this is a thing or I'm just getting lucky. I noticed though that my replays from GS and other servers always seemed to be fine but even a simple 1v1 in SP desynced after just a few moves. That's what put me on to this. YMMV

 

Most likely single-player AI filmed live. Multiplayer server tracks do not sync overwing vapor, and their control surface animations are very choppy. Neither of which make for good videos.

 

Modules that are broken in single player tracks will also break in multiplayer client tracks. The above examples of client tracks (Viper, Anton) are modules that are not known to easily break during replays. 

[chlywly]

I was very excited about filming in DCS and although the cameras are great the replay system is completely non-functional... Just not sure what I am supposed to do? Single player replays are totally corrupted, multiplayer replays don't work either. Nothing seems to work right. Am I missing something, is there some way to improve them?

How does anyone film anything if not by using accurate replays?

[rayrayblues]

On 11/22/2021 at 12:22 PM, chlywly said:

How does anyone film anything if not by using accurate replays?

I've been wondering that for years. So many good YT vids. How do they do it?

As @Rhino1980 said above; "without blowing his God damned brains out from frustration."

[Nealius]

On 12/1/2021 at 12:45 PM, rayrayblues said:

I've been wondering that for years. So many good YT vids. How do they do it?

As @Rhino1980 said above; "without blowing his God damned brains out from frustration."

Basically the tricks are:

1. Pick a module with reliable replay tracks

2. Do a short, simple mission with few triggers

3. Nerf the AI so they basically don’t engage you or anyone else

4. Use a server replay track and editing magic to work around all the animation bugs and warping, desync, etc

5. Pray

 

[rayrayblues]

On 12/1/2021 at 11:19 PM, Nealius said:

5. Pray

[Str][ker]

This has been a great discussion covering things I am interested in.

Two questions:

1) Can a track recorded on a server be used to see the replay from inside an aircraft? I am trying to record a good track in VR so that I can replay it with my wife wearing the headset to see what it's like in the game. Each time I make a track, it becomes desynced at some point. I could run a server, record to it and then copy the track file to my PC and then see if it works. I will try it but wanted to know if anyone would know an answer first.

2) Someone mentioned it's a frame rate issue which I can confirm through experimentation (the track is more reliable as my framerate improves). Is it the recording of inputs or the playback that requires good framerates? If it's the recording, I could drop a lot of settings, take off, fly around and lad and then bump up settings for the playback. If it's the playback, well I guess I am out of luck. I can get some tracks to last pretty long but eventually they fail and my plane crashes.

I'll try to reply here with my findings.

[Nealius]

1) No, only client tracks will show the replay from the cockpit.

2) For VR incentive rides I pick a module that reliably works, typically from an air start. The three times I consistently see a track desync it's with tire/ground interaction, tire/carrier interaction, or high-speed dives. The framerate theory doesn't seem plausible to me, as I never had issues with the Hornet while doing VR in absolutely terrible framerates on a 2070. Replay both in VR and 2D. 

[Showtime112]

I would like to share my views and opinions on this topic, I hope someone from ED will read it. I'm a YT content creator, currently with about 12.000 subs and over 3 million views on the channel. I use DCS as my platform. And sure, I think this is the best military flying simulation ever made. I've been playing them since the 80s and I have to commend the efforts that go into continuous improvement of DCS. And if there's one thing I could change, that would definitely be the replay track. It's one of the weakest spots of the whole game. And it's not just something that content creators use, I think. I've always enjoyed using replay track in various flying and driving simulations long before I started producing videos. That's why I think fixing it would mean much more to many players than some new helmet display alignment procedure or a new radar mode (not that realism isn't important).

As someone already wrote here, content creators are excellent free propaganda for any game. I've had so many comments with people asking, 'what is this game' (even though I always include it in the title ), 'where can I download it', 'is it free to play' etc. I can't say how many new players my channel brought to the game but I'm sure the number is not small.

I haven't found any connection between level of details and replay track. One connection I found was that certain models are extremely prone to it. I've tried Mirage 2000 and F-14 with intention to buy both of them. I haven't bought them and I will not. Why? Because replay tracks on those two break EVERY SINGLE TIME. And it's not just the usual, 'AI does something different'. The player's airplane starts to deviate from the very start and in a few minutes, it just crashes into the ground (or sea). Every time, without exception! I managed to do a couple of videos with the Mirage but I was restricted to live cockpit recording and AI. Yes, those models are third party but I'm sure they can't fix that without ED. Other Razbam modules such as MiG-19 and Harrier don't seem to be any worse than ED modules.

To sum up, replay track is one thing that deserves to be put on some 'to do' list for a complete redesign. The concept of allowing AI to make different decisions makes no sense. Il-2 Great Battles has an excellent replay that works and you can even rewind it. I think DCS deserves to have one at least as good. On the long run, it would seriously contribute to the game's success.

[Flappie]

10 minutes ago, Showtime112 said:

The concept of allowing AI to make different decisions makes no sense.

Yes, it makes perfect sense as a debugging tool. We testers use it every day to reproduce bugs, then test bug fixes. Without this tool, we'd be at a loss.

I agree with you: video creators -such as yourself- really need a new trusty replay tool, one which would record every single player/AI event and AI decison.

[BIGNEWY]

Hi all, 

Our current track replay system is old, and only replays inputs, AI can behave differently for example, or turbulence maybe slightly different which can create problems, large MP track replays or replays with heavily scripted missions also present challenges. 

We have long wanted to redo the track replay system but its a huge task and we dont currently have the resources to take on this task, it has to be something for the future. 

As a tool for bugs it still works well enough for us to reproduce and report issues, I use track replays all day long.
We are aware of the limitations it has for video recording, but I think we can all agree our videos look pretty cool. 

My advice, It is best to keep track replays as short as possible to show a problem for bugs or prepare a scene for video creation, this will give you the greatest chance of a good replay.

thanks