Tracks - Are you kidding?

[TurboHog]

Tracks are pointless and not a representation of what happened.

 

Skip the text below if tracks are not supposed to be an accurate representation of what happened in the mission... Then please tell me

 

So I wanted to help someone with a mission and I did so by providing a track (KA50 campaign mission). This is what happened in the mission and the track:

 

Mission

 

Me and my wingman shot many tanks and managed to keep some friendly units safe, allowing them to push forward. We never missed a vikhr. We were shot at multiple times by both laser beam riders and SAM's. I was hit one time by a proximity fused strela, doing little to no damage. In the end we couldn't protect the friendly convoy anymore. There were two tanks left that pushed forward into the enemy base. It was pointless to defend them with only a few vikhrs left. But they got quite far, as I said, nearly entered the enemy base. So, me and my wingman went back to base. During landing one of my engines stopped working because I didn't notice that the FWD fuel tank was leaking and I forgot to turn on crossfeed. We both landed safely on the helipad.

 

Track

 

The first five minutes show me excactly what happened in the mission. But then I suddenly fired a Vikhr into the ground a few meters next to the target I actually engaged in the mission. In the meanwhile, just like in the actual mission, I ordered my wingman to attack a target. In the mission I assigned a tank, in the track I slewed my skhval to a house and ordered to attack. Sure... I was quite surprised when my wingman also fired a vikhr into the ground, next to the target. But that certainly wasn't the last surprise. He got shot down! He went down, ejected, crashed. HUHHHHHHHH? He didn't receive a single hit throughout the mission. I stopped watching and restarted the track. Wingman was shot down again but not at the same position. Looks like these tracks are not a replay, but just another mission with you as AI. And the biggest surprise was the fact that I got shot down. YES, i got shot down in the track by a missile that was never fired at me in the mission. There was a laser warning and I was like: WHY am I not evading??? Moments later the missile destroyed me (well, I can hardly say 'me' anymore). Seriously WTF? As for the friendlies: because we destroyed about two tanks in the track instead of 10 tanks and some vehicles in the mission, the friendlies were crushed by some tanks that were supposed to be dead. They have been killed in the mission. Friendlies were all killed before they could reach the second line of defence.

 

These tracks are just pointless...

 

Here is the track I'm talking about, supposing that it would help. You can see me already talking about the tracks' mind of their own. Now, that is definitely confirmed. A track of a partially succesfull mission with a safe RTB that magically turned into a complete failure.

 

I hope one day these tracks become accurate...

Edited May 9, 2012 by TurboHog

[nomdeplume]

Tracks are known to have problems. When you playback a track, the game is actually running the mission again, with your aircraft's inputs being provided by the data recorded in the track file rather than by your controller. Pretty much everything else is re-calculated/re-simulated. There's two basic issues with this: sometimes the track doesn't properly record (particular?) events, so the track can diverge from reality - the longer the track is, the more likely you're going to run into this in a visible manner. Second, if you play a track back on a different version of the program than it was recorded on, different things may occur due to changes in the engine. For example, if the flight model changes then even if the track correctly applies precisely the same inputs at the same time, the aircraft's behaviour may be different.

 

The second problem is likely insurmountable, the first is I think just some bugs in the export and/or import functions. Issues have been known since the olden days though, so either it's something that's difficult to fix or it's way down on the priority list.

 

If you're wanting to be able to perform post-flight analysis, you might want to look into Tacview. This works by adding a script that export events etc. as you play, which can then be read back by the Tacview program. You don't get the graphics/sounds/etc. of the game, but it is an accurate record of what occurred in the flight.

[TurboHog]

This particular case has nothing to do with versions...

 

So it seems I'll have to accept that tracks are accurate for about 5 minutes... after that you start firing at the ground, you get shot down, your wingman dies, you lose the mission etc. etc. while in the actual mission you and your wingman survived and you won the mission. The original and the track can be eachothers opposite (what about failing a mission but winning in the track :megalol:). I think some optimization is needed here!

 

I know tacview, yes. Looks like I want to try that now...! But I have read something about negative FPS influence while running tacview?+

 

EDIT:

 

Could a moderator explain why this is now in the KA50 forum? It has more to do with the DCS world. Tracks are a DCS-wide feature, or should I say, failure? If I edit my first post and say A10C, you move it to the A10C forum. I change again into P51D and you move it to the P51D forum. Happy trolling for me... >.<

Edited May 9, 2012 by TurboHog

[Speed]

Could a moderator explain why this is now in the KA50 forum? It has more to do with the DCS world. Tracks are a DCS-wide feature, or should I say, failure? If I edit my first post and say A10C, you move it to the A10C forum. I change again into P51D and you move it to the P51D forum. Happy trolling for me... >.<

 

Where else would they put it? It's a bug/problem. And it doesn't involve the current beta version of DCS World. Hence it technically belongs under either Ka-50 bugs and problems or A-10C bugs and problems. Since you were flying a Ka-50... anyway, forum confusion like this should become better once we get an officially released, non-beta, unified core.

 

But yes, tracks are just not very accurate sometimes. I've seen them go a good 2+ hours and still be accurate, and sometimes, they only last 10 minutes. Known issue. Probably some things could be done to improve the accuracy, but a lot of the problem is how ED is trying to find a balance between not slowing down your computer, and recording accurate data. Track replay accuracy is something that a lot of games struggle with.

Edited May 9, 2012 by Speed

[TurboHog]

Where else would they put it? It's a bug/problem. And it doesn't involve the current beta version of DCS World. Hence it technically belongs under either Ka-50 bugs and problems or A-10C bugs and problems. Since you were flying a Ka-50... anyway, forum confusion like this should become better once we get an officially released, non-beta, unified core.

 

But yes, tracks are just not very accurate sometimes. I've seen them go a good 2+ hours and still be accurate, and sometimes, they only last 10 minutes. Known issue. Probably some things could be done to improve the accuracy, but a lot of the problem is how ED is trying to find a balance between not slowing down your computer, and recording accurate data. Track replay accuracy is something that a lot of games struggle with.

 

- That makes me want to assume that tracks are (going to be) significantly more accurate in DCS World ;)

 

I'm enjoying the benefits of Tacview now... It's ten times better than a track!

[PeterP]

to get a better understanding of the track-system please have a read here:

Better .trk editor

 

I have to admit - "well written" is something different , but it should give you a good oversight of the big-picture what is going on while a track replays, and why it is so hard to replay it correctly if things get more complex.

I hope you can warp your head around the example "playing a track backwards" - it is only a little bit easier forward.

 

We are scratching the surface to a level what you would call "scientific simulation in a controlled environment" - a thing that you do normally on parallel-CPU-mainframes to get a feasible solutions in the end.

 

So my question would be more like this:

Replaying Tracks - Do you rally want to simulate something complicated as this at a consumer-PC level ?! - Are you kidding?

though, communicating to the customer that a track can get FUBAR should be improved.

Edited May 9, 2012 by PeterP

[shagrat]

dynamic weather influences as well

 

It seems dynamic weather in a mission easily compromises a track as well.

Often you have a crosswind start. In the mission you record you take off adjusting rudder to compensate.

Playing back the track the crosswind is newly computed and a bit less.

After some 100 yards the plane crashes into the field beside the runway - end of mission :D

[Brisse]

Maybe it would be better if developers let everyone choose if to record tracks or not. Put another box under "game" tab in options that is called "record track". This way it allows to save up recources for the people that does not want tracks.

 

My overall feeling is that DCS is a very high quality product but this track functionality brings that feeling down a little since it's not working properly.

 

Tracks are very useful but if it's not working then maybe it should not have been included in the game.

[shagrat]

Maybe it would be better if developers let everyone choose if to record tracks or not. Put another box under "game" tab in options that is called "record track". This way it allows to save up recources for the people that does not want tracks.

 

My overall feeling is that DCS is a very high quality product but this track functionality brings that feeling down a little since it's not working properly.

 

Tracks are very useful but if it's not working then maybe it should not have been included in the game.

let's make that a "Start/Stop record track" hotkey to let the player decide when or what to record. Tha will save time and file space. I assume for beta issues this is also better. People can record the relevant issue even after a lengthy flight.

 

Additional suggestion for the DCS A-10C: there are these switches for recording HUD or TGP that are not used at the moment I guess ;)

[TurboHog]

Additional suggestion for the DCS A-10C: there are these switches for recording HUD or TGP that are not used at the moment I guess ;)

 

YES YES YES!

 

Gun camera on P51, skhval recordings and TGP/HUD for A10C... :thumbup:

[nomdeplume]

let's make that a "Start/Stop record track" hotkey to let the player decide when or what to record. Tha will save time and file space. I assume for beta issues this is also better. People can record the relevant issue even after a lengthy flight.

The problem with this is that it would require storing everything about the current mission when you start recording. Every single detail about every single aircraft, ground vehicle, weapon in flight would need to be stored (fuel, weapons remaining, damage, avionics settings, you name it). The entire AI state machine for every group/unit would also need to be stored, along with the state of all triggers/flags/etc. You get the idea.

 

So, I don't think that will make for smaller files, and it would probably incur a significant delay while all the data is written out. On the other hand, it would allow for saving/reloading the game mid-mission, which would be pretty nice to have 0.001% of the time.

[PeterP]

Hey guys - what you asking here (track on /off)for is really not worth the hassle,

as it is this will make no difference to the performance.

And a track has to be written any way - so triggers work,debriefing and so on.

A working mission relays on a accurate protocol, and why not backup some time-stamps at the end of the mission if the data is anyway already there?

[shagrat]

mainly I hope to have shorter Tracks since you can't rewind and e.g. converting part of a trak into a movie is taking time. I agree the performance impact might be irrelevant, but the option not to record some 40-90 sau msta fired grenade or m109 paladin hit building while starting up on the ramp might be nice.

during betas often read "...but the track is too long" so shorter tracks through swithing record on/off may be worth it ;-)

 

just my oppinion, though and perhaps easy to implement?

[winz]

This is a non trivial problem. The track is basically just a record of events and keystrokes that gets replayed. But for such system to work you need a simulation state that is indentical with the simulation state when you started to record those events.

Now, this state on the mission start. For split/rewind to work you need an ability to create a key-frame - store the state the simulation is in (a save/load functionality). This is where things go non-trivial.

 

On mission start, each unit is in predefined state (i.e. airplane can be on runway, on ramp, in air), with basic properties for each state defined in unit lua config files. Each trigger is in a predefined state, AI routines are predefined state...etc.

 

If you want to save the state during mission, then you have to extract all important properties, including those not defined lua files, but hard-coded in modules. So identifying and extracting all important information is one problem. Storing them is another, considering the complexity of DCS aircrafts the amount of parameters is huge (avioncs, electric system, hydraulic system, engine..etc) and you need them all if you want to recreate the aircraft state. The resulting track would be gigantic in size. And creating a key-frame every few seconds might even be a performance issue.

 

Creating such system would a big investment with zero-return value. You cannot sell it as a module, or as a major feature of a module.

 

That's the reason why very few games have a full rewind/skip feature in their replay system. And if they do, they most of the times work only on the parts you have already watched (they are creating key-frames on the fly).

[TurboHog]

This is old. Since world my tracks replay perfectly! Thanks ED!

[Tailgate]

I replayed a track of my P-51 -taxi and takeoff from Beslan. In the original I taxied down the runway and did a 180 at the end of the runway for takeoff, in the track, the plane turned 90 deg and proceeded to take off perpendicular to the runway, of course a wheel caught in the mud and cartwheeled. I didn't modify any views in the track.

 

For the most part, though, the tracks aren't too bad if I don't mess with the views too much, otherwise in several cases the plane augers in. It's like it skips a few frames, gets out of sync and the AI loses SA, particularly where the ground is.

[WildBillKelsoe]

I have tried something that always beats track faults.

 

Clear the temp folder in DCS, restart. disable all user processes after restart.

 

open the mission, play it, save track and log in one folder.

 

open C:/Windows/Temp/DCS/LastMissionTrack.trk

 

copy this track into the folder above with the other two.

 

Delete temp.

 

Restart computer.

 

Activate fraps,

 

open DCS

 

play track, and immediately before pressing fly button, activate fraps recording.

 

If you never changed view in the cockpit, I mean only F1 view and no other F2-12 views, it should play correctly. Have your friend do the same, and exchange avi files for editorial. How is that?

[cichlidfan]

If you never changed view in the cockpit, I mean only F1 view and no other F2-12 views, it should play correctly. Have your friend do the same, and exchange avi files for editorial. How is that?

 

You can skip all the other stuff and just don't change your view for the same results (or at least the same odds).

 

If you can't change the view it is of no value since you could have made that same recording with Fraps while you flew the mission in the first place.

[WildBillKelsoe]

You can skip all the other stuff and just don't change your view for the same results (or at least the same odds).

 

If you can't change the view it is of no value since you could have made that same recording with Fraps while you flew the mission in the first place.

 

I'm talking first hand, not replay play.

[Chippy]

This actually happened on a P-51 training track to me too, it was quite amusing to watch :D. He did a few barrel rolls off the runway and then continued to move the throttle and stick.

[ENO]

Being able to review the tracks for FRAPS and screenshots and to enjoy moments of a particular mission a second time is one thing- proper duplication of an issue you're trying to report with a track is another.

 

I suppose if you combine a track with a log, you get there- but quite often the bugs I experience and am asked to report occur in the multiplayer environment and me trying to get a track 5 minutes or less to preserve accuracy simply won't happen. Clearly supplying lengthy mission tracks is no better because they're obviously not accurate anyway.

 

I'm not making excuses about being a jerk about it once (twice I think) before- but it really does exacerbate the reporting process.

[Hamblue]

How often are track and log files written? Constant writing to an SSD drive is considered bad. At a minimum there should be an option to chose the location of the log and track files. This would allow those of us with SSD's to put the trk and log files on a secondary mechanical drive.

[PeterP]

How often are track and log files written? Constant writing to an SSD drive is considered bad. At a minimum there should be an option to chose the location of the log and track files. This would allow those of us with SSD's to put the trk and log files on a secondary mechanical drive.

 

 

A track is not constantly written just to give you the possibility to re-view it.

 

>> No, it won't higher performance >> ...

[Megagoth1702]

The few megabytes per session that are being written on an SSD are not that big of a deal.

[yodosha]

"...and then continued to move the throttle and stick."

 

:D