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IL-2 Sturmovik The famous combat flight simulator.

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  #11  
Old 05-29-2011, 02:41 PM
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ACE-OF-ACES ACE-OF-ACES is offline
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JtD
It does not need any data conversion to make a plane that goes 600 under standard conditions real life go 600 under Crimea conditions in game.
No that is not correct..

If you want to compare apples to apples you have to convert non std atm performance values to std atm performance values. With that said, the Crimea map is NOT std atm conditions, therefore you can NOT compare the performance values obtained on the Crimea map to real world data, in that real world data performance values are relative to std atm conditions, unless otherwise noted.

That is the reason why I re-tested all the planes in IL-2 on the 'Flight Test Map', because the 'Flight Test Map' is std atm conditions, which enables the user to make direct comparisons to real world data without having to convert it first.

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JtD
It's also not a matter of capability, just a matter of having been done that way and why not.
As noted above the 'why not' is because you can not make a direct comparisons between Crimea performance data and real world data, it is apples and oranges. You have to covert the Crimea performance data to std atm, or, covert the real world data from std atm to Crimea atm conditions to have an apples to apples comparison.

Maybe a graph will help you 'see' what I am saying?

Below is the summary graphs from IL-2 Compare, where I included a copy of the A20C performance data from the Crimea map and compared it to the A20C performance data from the 'Flight Test Map' which is std atm conditions. As you can see in each graph, there 'is' a difference, thus you should now 'see' that your initial statement above of 'It does not need any data conversion' is not correct. As you can see there is a noticeable (read to the naked eye) difference in each performance values listed



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JtD
Just pointing it out to you,
Trust me your not telling me anything that I didn't already know!

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JtD
because as you will acquire real life data, you'll find that many planes are slower than their real life counterparts if flown in standard conditions.
As I pointed out above, and can be seen in the TAS graph, when you 'convert' the TAS data from Crimea atm conditions to std atm conditions the TAS values are lower. On that note, that is exactly what they did in real life! In that they could not sit around and wait for a day that has std atm conditions, they had to test on the day of the test (within reason), but they took note of the atmospheric conditions so they could convert the data from the conditions on test day to std atm conditions.

But know this, most of the difference you will 'see' between in-game data, be it Crimea or not, has more to do with the fact that the in game planes are configured differently from the real life data. That is to say you will be hard pressed to find real world data that is of a plane exactly like the in-game plane. Even though they may both say P-38J, upon a closer inspection you will find there are 'differences' in the real and simulated plane configurations that is causing most, if not all of the differences in the performance data.

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JtD
As for the "myth", consider my statement proof.
Clearly you do not understand the meaning of proof!

For example, above I 'said' something.. that being your initial statement was not correct. But I did not stop there, I did the work to provide 'proof' of what I was saying where I provided graphs showing the difference in the A20C performance data on both maps

That is what I mean by providing 'proof' thus your statement will have to remain in the 'myth' column, sorry.

Last edited by ACE-OF-ACES; 05-29-2011 at 02:52 PM.
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  #12  
Old 05-29-2011, 03:46 PM
JtD JtD is offline
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Originally Posted by ACE-OF-ACES View Post
No that is not correct..
I wouldn't say it if it wasn't correct. I don't want to compare apples to apples, and the game has never tried to do that. All plane performances have been tuned so that standard values are being achieved in Crimea atmosphere, give or take a small margin for many planes and give or take a large margin for a few.

This is why I have pointed out that you'll often see too low speed values if you use il2-compare data from the flight test map - hardly problematic, considering that planes generally are modelled to match best historical data found, 5% give or take. As an example, TSAGI values for the La-5FN: 590 on the deck, 645 at altitude. Crimea 584, 644, FlightTestMap 575, 633. This tendency is there for a large number of planes. Now the 2% between Crimea and FlighTestMap are not that much, well within the variance of real life data and inside the limits of the game, so eventually it doesn't matter.

The impact of using a non standard atmosphere as in game standard has zero impact on the relative performance of planes, and Crimea has been used because it was one of the first maps existing. So tests could be made on it.

Anyway, I'm not going to publicly discuss details of flight model making, so that's all from me. No matter what, you've produced a valuable set of data and hopefully you can deliver more real life reference for the interested audience.
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  #13  
Old 05-29-2011, 08:05 PM
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Originally Posted by JtD View Post
I wouldn't say it if it wasn't correct.
Well sorry to disappoint you but your statement is in error

Allow me

Based on Oleg’s past posts it is clear to all that he understands what standard atmospheric conditions (std atm) are, and that performance data collected under ‘other’ conditions (maps) can be converted to std atm.

It is also clear that Oleg said to use the Crimea map for testing.

What is not 100% clear is if Crimea map was std atm conditions at one time in previous versions of IL-2 and was later changed.

The reason I say that is if you go back and look at Oleg’s statements over the years, initially he was somewhat cryptic as to what the atm conditions of the Crimea map were, He referred to it as ‘normal’ and/or ‘ideal’ atm conditions..

But in his later posts he flat out says the Crimea map is std atm conditions, but what with the advent of mods we now know that the current and previous (4.xx) versions of the Crimea map are NOT std atm conditions!

Yet Oleg did say the Crimea map is std atm conditions!

But who knows, maybe it was at the time he made that statement?

In either case I give Oleg the benefit of the doubt, that one, he was savvy enough to take into account the performance differences due to the non std atm conditions of the Crimea map when comparing the results to real world data, or two, that he was savvy enough to convert the real world data to Crimea atm conditions when comparing the results to real world data.

So in light of all that confusion and what we know now due to mods I decided to use the mod ‘Flight Test Map’ which we know is std atm for testing!

In that Oleg himself said that test results are only valid if they are done under the same conditions as the data you are comparing to.

Hope that helps!
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