Replay track issue/bug?

[Mike Busutil]

I did a flight with the P-51 where I chased down and successfully killed the AI aircraft.

 

After watching the replay to record some shot's, I noticed the replay shows me break off from the fight and start randomly shooting at nothing until I crash into the ground...

 

I know for a fact 100% I did not break off from the fight and I did not crash.

 

At first I was thinking maybe the AI aircraft was not properly showing itself in the correct position in the replay but then this does not explain why the replay file shows that I crashed.

 

I later watched the replay file again from a different view and this time I did not see my plane break off from the flight or crash. Instead it showed just as I played it, AI aircraft was successfully shot down.

 

Are their any reports of this happening?

Edited September 16, 2013 by Mike Busutil

[Picksplitter]

Yes, there are other reports of this.... somewhere. Will try to find them....

 

This has also happened to me.... the trk has very little in common with the flight flown... not certain as to why or what to do about, except stop trying to save trk's :music_whistling: (at least that's what I did....)

[Mike Busutil]

Thank's Picksplitter!

[Picksplitter]

found one link... read it thru a bit of it... all I saw was a bunch o' stuff I don't understand :cry: and there doesn't seem to be a fix for it...

http://forums.eagle.ru/showthread.php?t=95416&highlight=incorrect+track+file

Edited September 16, 2013 by Picksplitter

[AUS_Twisted]

It's because the game does no record proper replays like you see in other games/sims, it only records the control inputs and replays that back which ends up giving different results at times. Patches also make older replays completely useless also :(

[cichlidfan]

It's because the game does no record proper replays like you see in other games/sims, it only records the control inputs and replays that back which ends up giving different results at times.

 

I have always suspected that the replay feature is largely carried over from ED's Digital Training system. That application is really only concerned with the control inputs made by the trainee. It probably works great in the classroom, but in a flight sim...not so much.

[Luzifer]

I have always suspected that the replay feature is largely carried over from ED's Digital Training system. That application is really only concerned with the control inputs made by the trainee. It probably works great in the classroom, but in a flight sim...not so much.

 

I'm pretty sure Il-2 tracks worked the same way, as do other games. There is a good reason for that which does not involve training systems: track files are small and require little resources to create while running the game. Additionally track replay does not need special code, just running the normal simulation with the track file providing input in place of the user.

 

If the simulation is fully deterministic, this will work fine. In practice, if the simulation is not very carefully coded for just this purpose. numerical instabilities will cause large deviations. Even if it worked perfectly, you still couldn't rewind (simulation can't run backwards) or skip forward (everything between now and the later position needs to be fully simulated).

[HiJack]

It is strange really beuse all the information on where the different units are on the map is in the track file. I wish we had a "replay" tool that played tracks regardless of version used to record the track. And that could fast forward and fast reverse.

[Luzifer]

A better format could be modeled on video compression. Most motion compression consist of building a frame by modifying previous frames (move that block of pixels from there to there, change a couple of pixels there) and so has the same dependency on previous frames. That has the same potential problems, i.e. errors propagate forward and amplify, no seekability. The solution there is that regularly full frames without interdependencies are inserted, which limit error buildup and allow skipping to those frames.

 

Something similar could be done for a track format, i.e. every few seconds a full state is saved for the same benefits. This would limit drift to at most that which can accumulate in the time span between full states and allow skipping forward and backward.

[Mosley]

The track system in Dcs World does have its fair share of problems. Some work great others don't. Personally after watching my a10 do gun runs into the ground I have given up on the internal track system.

 

I have noticed that while playing a mission if you use time compression and speed things up this can create all kinds of problems with the tracks. Also the longer the track is the more it gets messed up toward the end. Sometimes... With just recording user inputs this doesn't supprise me.

 

If you are wanting to watch the replays to learn from mistakes and what not Tacview is a better option. The tracks for tacview are much larger and I have yet to see something happen that I didn't do in sim.

 

IMO the internal track system is only usefull for submitting a 3-5 min track for bug reporting purposes. Its just a little to squirly for me.

[Mike Busutil]

Has there been a ED dev confirm this is being addressed?

[Tone71]

Rise of Flight lets you start a recording mid-flight, for as long as you like, and you can later fast forward and rewind that track to your hearts content, with zero issues (that I've ever encountered). I wish DCS had this system, as it's so much easier to make videos this way.

[cichlidfan]

Has there been a ED dev confirm this is being addressed?

 

I am fairly sure it is on the bug list, since it been discussed many times in the past 2 plus years. Beyond that there is no information.

[Fishbreath]

Rise of Flight lets you start a recording mid-flight, for as long as you like, and you can later fast forward and rewind that track to your hearts content, with zero issues (that I've ever encountered). I wish DCS had this system, as it's so much easier to make videos this way.

 

RoF fast-forwards by playing the track sans graphics, and 'rewinds' by playing the track sans graphics from the beginning to the point you picked to rewind to. As I understand it, DCS's simulation engine is tied so closely to the graphics engine that it can't be decoupled like that (which is why we don't have a dedicated, no-graphics server, either). Among other things, EDGE, I think, is supposed to fix that.

[AUS_Twisted]

I think iRacing probably has the best replay system of any game, records proper movement of the cars and has every replay and camera view setting you could ever ask for. File sizes are of course a lot bigger but it's worth it when replays work exactly as it should, they don't get messed up with patches either.

[White Owl]

Well, at least I know I'm not alone in my struggles with track playbacks. This is so frustrating... Here I am, trying to demonstrate the P-51D module for Youtube, trying to talk up the DCS WWII kickstarter, and I've had six failed tracks in a row!

 

At least reading here, I know there's nothing more I can do about it. Time to go back to external recording tools, and enjoy that reduced frame rate and poor image quality. Blech.

[Hamblue]

Just having the ability to turn tracks off would be fine with me.

The tracks folder gets pretty big if you forget about it

[cichlidfan]

Just having the ability to turn tracks off would be fine with me.

The tracks folder gets pretty big if you forget about it

 

You mean on a server? No track gets saved in SP unless you specifically save it.