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John_Cillis

Sad News About FS2004- Please Read

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Hello All,Yesterday I directed people in this forum to a really important thread over on the developer's forum, regarding the changes just being discovered in the way MS2004 handles the simulation of flight dynamics. These talented people have looked beyond the new eye candy at the heart of how FS2004 works, and have found some very disturbing things.The thread seems to be coming to a conclusion, and its not a good one for anyone who thinks FS is more than a game. I've pasted the text of the main concluding post below, it is a long read but well worth the effort. I also recommend reading the entire thread, which can be found at this link:http://forums.avsim.net/dcboard.php?az=sho...&topic_id=12256Essentially, MS2004 does not take into account certain very important variables of flight dynamics that 2002 did, so aircraft in 2004 have taken a big step backward in terms of realistically simulating flight. Moreover, unless a workaround is discovered, Microsoft has eliminated the ability of aftermarket developers to create accurate flight models- and those which are so wonderful in 2002 will perform markedly worse in 2004. So you may not want to bother loading up that Dreamfleet Archer or Carenado 210, all the hard work that went into making them such good planes goes to waste when they're placed into the constraints of 2004. And for those of us who have commented about how "well" these planes fly in 2004, seems to be quite the opposite. Anyway, draw yourown conclusioons from the following but I am very upset to find that all we've gained in 2004 is eye candy, at the unecessary expense of accurate flight modeling. Here's the post word for word:______________________________________________Thanks to all of you for re-testing and to all others who have contributed.I believe we have all reached the same conclusion now with everyone eventually confirming my finding that both incidence and twist, together with their pitch and drag consequentials, default to zero at all times in FS2004. After giving this some thought I now conclude that this is not a mistake. It looks more like a a design time decision. I find it unlikely that the different variables relating to incidence and twist could go missing from the different equations in the flight model unless someone was instructed to go through the code and remove them everywhere they occur. Someone has. If this was an error some of the variables would still be working.Since the terms often get confused let me explain that FS2002 had an excellent flight model but dreadful default flight dynamics. The flight model is in the binary code of the product and is used by every aircraft. The flight dynamics belong to a particular aircraft and are coded in each aircraft.cfg and air file. The people who wrote the original flight model for Microsoft understood aerodynamics. The people who wrote their flight dynamics did not.Since there was nothing significantly wrong with the flight model and it had the capability to support realistic flight dynamics some of us who understand real world flight dynamics set about writing flight dynamics files for MSFS which exploited the capabilities of the flight model better than the proprietary default flight dynamics. By the middle of this year tens of thousands of Microsoft customers were downloading our work for free and enjoying the additional realism which we were able to unlock. Increasingly consumers were also buying payware aircraft because they were obviously superior to the aircraft delivered by Microsoft.What those who have contributed to this thread have just proved is that Microsoft have degraded the internal flight model equations just enough to ensure that realistic flight dynamics will no longer work in FS2004. We have been very careful to test with their SDK compliant default aircraft and at full realism. By carefully altering their proprietary code Microsoft have ensured that their commercial competitors, however small and insignificant, can no longer deliver products which are superior to their own. Some of you will have noticed for instance that Rob Young has posted elsewhere that Microsoft have removed the ability of the SF260 to spin in FS2004, whilst enabling spin within the Extra and Jenny FDE.This is entirely consistent with US law and entirely in accordance with the long term competition strategy of Microsoft as a corporation. Microsoft are perfectly entitled to react to competition by altering their proprietary code in ways which disadvantage others and make Microsoft look good.Opportunity, motive and modus operandi? You decide.The destruction of the pitch attitude and drag equations within the internal flight model stands in stark contrast to the impression which Microsoft conveyed prior to the release of FS2004. We have just proved that FS2004 is not compatible with any existing aircraft flight dynamics, even when they were fully compliant with all Microsoft SDKs. Destruction of the realistic pitch equation has ensured that FS2004 displays such aircraft at fake nose up pitch angles which preclude an appropriate view over the panel or VC. By removing the ability to process the drag correction from air file Section 1101-50h Microsoft have ensured that such aircraft suffer degraded performance in FS2004 because they always have excess drag. They become visually and dynamically incompatible with FS2004.FS2004 does not have an FDE converter. It just ignores key aerodynamic data from earlier SDK compliant FDE, degrading them so that they are no better than the new default FDE. Third party aircraft produced by experienced FDE authors, whether freeware or payware, always had significantly more realistic flight dynamics than MS default aircraft and are therefore degraded more. The Microsoft default FDE were so unrealistic that removal of the chosen aerodynamic variables from the flight model has hardly changed their attributes. I believe this points to careful selection and beta testing of the variables removed from the flight model equations.The implications for payware publishers whose expertise lay in producing realistic aircraft which exploited the internal flight model to the full are obviously grave, but they are not the only ones who suffer. The vast majority of MSFS consumers could never tell that the default aircraft had faulty flight dynamics and are therefore no worse off. The minority who could tell, including aviation practitioners and those who have invested hundreds of hours using the product to learn how to operate aircraft realistically from scratch, have been slapped in the face. The equations in question did not have to be destroyed for the eye candy aspects of FS2004 to work. Microsoft could have ensured that your favourite FS2002 freeware aircraft and your collections of FS2002 payware aircraft continued to work in FS2004, just by doing nothing at all to the flight model. Instead they made changes which ensure that all your FS2002 aircraft are degraded. We have proved that Microsoft have removed key aerodynamic variables from the flight model equations. Accident or design? You decide.Now I need to address a 'what if' that have come up in this thread suggesting that there is an FDE work around which can overcome removal of the variables.Ron, Bob and Douglas are talking about how substituting variation of AoA for AoI still 'works' and will have to be employed instead. Whilst this could restore realistic pitch it cannot restore realistic drag and will make the drag result even worse.Since Microsoft have ensured that FS2004 cannot process the drag data correction from Section 1101-50h the result of using an AoA rotation to substitute for an AoI rotation is a cartoon rotation which produces the wrong induced drag and a very distorted performance envelope. The drag consequences of +4dAoA and +4dAoI are very different. Picture a wing meeting the air and the bottom of the fuselage meeting the air in an aircraft where incidence = 4 and AoA = 4. The fuselage is level (aircraft has zero pitch) but the wing is four degrees nose up and is inducing substantial drag at 4dAOA. In FS2002 we could code the pitch and the drag for that aircraft differently and correctly. Now if we use an AoA rotation to remove the incorrect value of zero AoI which Microsoft have imposed for all aircraft in FS2004 we must make the wing have zero AoA to show the fuselage level again (zero aircraft pitch). Having reduced the AoA by 4 degrees to force the fuselage to zero pitch there is now also zero angle of attack and zero induced drag, producing a huge drag error.The proposal that AoA rotation substitute for AoI rotation ignores the fact that we have just proved that Microsoft have destroyed the drag equation as well as the pitch equation. The induced drag error cannot be corrected even though the pitch error can be corrected by the means proposed. This thread was never about data loading and reloading bugs in FS2004 real as they seem to be for some people. This is about the extent to which FS2004 is still a flight simulator at all.An FDE author can force FS2004 to display aircraft at the correct pitch but not with realistic drag. In FS2004 there is still a link between AoA and drag, but Microsoft have destroyed the link between pitch and drag. To make an MDL 'fly' at the right visual pitch it now has to be 'animated' like a cartoon. The MDLs are no longer 'flying' because in FS2004 as we have just proved they are not following the laws of flight. The consequence is that those who choose to produce FS2004 aircraft and updates will have to invoke a solution which is part video game and part flight simulator. Part cartoon animation and part dynamics code. The implications of this internal code change extend far beyond the world of FDE authors. Would be FS2004 MDL authors and painters of quality products have not understood yet. flight dynamics authors will have to explain it to them.When an aircraft is produced for use in any flight simulator, not just this one, the net flight incidence component of the flight dynamics equations is used by the FDE author to rotate the MDL to allow for wing incidence after it has been produced by the MDL maker. This FDE code also controls what can be seen over the panel or VC at run time. The FDE author then corrects any consequential drag error separately. That the FDE author can no longer do any of this in FS2004 is what this thread proved. For use in a video game which lacks wing incidence as a flight dynamic variable the MDLs have to be produced with their incidence rotation built in by the MDL maker at design time. We have just proved that the incidence variable is absent in FS2004.Let that sink in now and get ready to explain it to your project collaborators. That is what I mean by a *serious* bug in FS2004. The other new bugs are inconsequential by comparison.If producers have the goal of releasing FS2004 aircraft with even somewhat realistic performance envelopes which also fly at the correct displayed pitch attitude the only solution is as follows. 1) MDLs have to be rotated nose down by the net incidence of the real aircraft at design time to display correctly. 2) The MDL animations have to be prepared to match that nose down rotation.3) The textures also have to be rotated nose down in the paint package. 4) The FDE then have to be prepared with an 'overstiff' nose oleo which 'corrects' the nose down sit of the rotated MDL on the runway. Mainwheel oleos of tailwheel aircraft may be stiff enough already. I have tested and this works well.5) The MDL oleo animation may have to be written accordingly and not accurately. 6) The rest of the FDE then have to be written to match an 'equivalent aircraft' of zero incidence and zero twist but retaining the real world lift slope and consequential induced drag. Drag errors can then be 'somewhat corrected' using other data fields in Section 1101 which FS2004 can still process.If AoA rotations are used in lieu of the MDL rotation, as some have proposed, there is no way to correct the induced drag, (consider the zero case to understand why), and FS2004 is just a video game with animated cartoon aircraft. That seems to be the way this product is developing and I acknowledge that the majority of consumers who only use the product as virtual airport spectators and virtual passengers will be quite happy with that. The compromise above will therefore satisfy most FS2004 users, including most payware customers, but it is still a compromise with less accurate flight dynamics than FS2002. The comprise is largest for the fastest aircraft. Consequently I doubt that FDE authors whose expertise lies in creating realistic flight models will choose to spend hundreds of hours over the next couple of years producing or updating 'compromised' FDE for FS2004. They may decide to write payware FDE for FS2004 if the price is right, but their more demanding customers will always expect more realism than we now know is possible in FS2004. Those who have promised to produce FS2004 updates have a larger problem. Rotating pre existing MDLs is simple enough, but rotating all the animations and all the textures of a pre existing MDL may not be at all simple. It depends on the package used to create the aircraft originally. The FDE have to be rewritten anyway. All the other new FS2004 bugs also have to be taken on board and if possible fixed. The most important of these are the CoG bugs. Since I think I have now decoded them I will try to explain them later in a different thread. If anyone wants to design a Whitley for use in FS2004 the only choice will be an MDL rotated at design time, but I expect that most FS2004 third party aircraft will be displayed at fake pitch angles within the video game and most users will not notice. However since the fake pitch angles are always nose high you cannot obtain the correct view over the panel and you will wind up having to cheat in various ways to see where you are going, by scrolling the panel, or using a video game zoom factor, or some other video game cheat, to control the game. This has never been a requirement when flying with realistic flight dynamics.Due to removal of the incidence and twist variables the VIEW_FORWARD_DIR and SIZE_Y variables within panel.cfg, cannot always be used solve the view on approach problem in FS2004 in cockpit view due to ground / air mismatches previously solved by FDE code. There are no equivalents for the VC anyway. Setting the correct view over the VC 'panel' has to be resolved by MDL rotation in FS2004. All of which leads to my position on updating my own 'realistic' FS2002 freeware flight dynamics.My finding that FS2004 is unable to process three key aerodynamic variables essential to realistic flight simulation has now been confirmed by a range of experts. It is therefore not a question of how long it would take to produce FDE updates. FDE which are realistic in FS2002 cannot be updated to be realistic in FS2004. It cannot process the variables and equations which would allow real world inputs from flight manuals to cause the real world outputs. I cannot update my FDE for realistic first person flight simulation use in FS2004. The necessary code has been removed by Microsoft. Of course if the key variables were removed by mistake all Microsoft have to do is restore the old equations. They know where to find them. FSAviator

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FSAviatorWhatever anyone else might think I appreciate you taking the time to bring this to the communities attention.I have not migrated to 2004 and as dynamics/avionics are my highest priorities in FS this news is giving me food for thought.Eyecandy is just not enough.Please continue to keep us updated as this should concern us all despite what some folks might think or say.Best RegardsTed

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"Please continue to keep us updated as this should concern us all despite what some folks might think or say."This wasn't an update--it's a rehash of the post I copied the link for. Since I probably belong in the "some folks" you are referring to, what do we have to gain by reposting threads on the same subject, hours apart? I've released aircraft, and I'm mad as heck that Microsoft seems to have dumbed down the flight models. But it's like crying wolf--post about it too much, and soon the labels of "trolls" and whiner start getting thrown at you--and nothing ends up getting done.

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Guest Daniel Pimentel

Oh darn, MS has a full-blown conspiracy so that the 3rd party that makes their FS sell can't produce good stuff (Wow, I can especially see the reason to that considering they don't release any add-ons of their own) Sarcasm aside... Don't be foolish. MS won't try to kill the very market that makes FS sell so much. If anything, they must have done it by mistake. That's like saying "Oh, MS locked BGL's that don't use their buildings so that 3rd party sceneries don't look any better than theirs" MS is not making a true production effort to nail the planes... They WANT 3rd party to raise the bar. If they didn't, they'd be charging interesting royalties to anyone who tried to product payware, and they'd ban freeware. :-lol The whole POINT of FS is letting 3rd party complement their product to make it more desirable.Cheers,Daniel P.

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I am an FS-Zombie ..... everything is fine .... anyone who complains is a freeloading whiner who is clueless ... just look at those clouds ... if anyone thinks that the FS9 water is wrong, it's because they are freeloaders and whiners. I encourage freeware authors to go payware ( :-roll )... my freeware utility is now payware, and I'm going to make a fortune .... and yet everybody accepts the situation .... they too are FS-Zombies ..... and so are you. ( :-roll )WAKE UP PEOPLE!

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That ain't what I'm saying uh...FS-Zombie :). I am saying that there is no point to opening up a thread every few hours on the subject. That is whining, or as Daniel says, a heavy dose of conspiracy fears... Does anybody get that? What the issue is is neither here nor there--the style of informing is!

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Some one a while ago on this forum said that an X-Box version of Microsoft Flight sim was on the drawing boards.... Not sure were im going with this......then i will explainPerhaps its all part of MS master plan to down-grade the flight model enough in-order to make it work on the X-Box.....just a hunch!!!! Only Joking!!!!!!!OR was I !!!!!I must admit the first FS2004 flight i did using the Default B737 Didnt feel as good as the FS2002 Model (It Felt as if the simulator was on rails)Not much Slip during Turns sort of thing.....and to much trim required for take offs.I dont know much about MS flight dynamics, but a human can tell these things quite easily just by the way it feels(Novice or Expert User) I once had a dream that Microsoft Bought the UbiSoft IL-2 Sturmovik Flight Dynamics with its Buffetting Virtual Cockpit Cam for use with FS9........Then woke up and realised it was only a dream!!!!Good NightPS I wonder What would the Wright Brothers think of FS9 Flight Dynamics ?

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Guest Paul_W

Thanks for posting this information. It was very interesting to read what was for the most part an informed dialog among experts--and it will be interesting to read the input of others at a later point.

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Hi FSAviator,It may come as a surprise to you, but Microsoft Flight Simulator has never nor ever vill be more than a Flying Adventure Game.If you want a Simulator which give the name it


 

Staffan

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Actually, I have been following this thread and while 2/3rds of it went over my head (I can't even get a paper airplane to fly), it sounded convincing enough to zip over to the PSS forum to see what they had to say. It turns out, that they have been following this thread. They didn't sound pleased. Having said that, I don't expect much to come of this. If developers can patch their products enough so it can at least stagger through the air, most poeple will be happy. From following the various threads in this and other sites, it appears people are more concerned about water color and missing bridges than flight dynamics. I guess "eye candy" rules, which only makes sense in what is basically entertainment software for the masses (this remark should get a few people foaming at the mouth). It is indeed, sad news, but "dumbing down" is just the latest trend in many subjects. John Fitzpatrick

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Guest United

I can appreciate those in the FS Simming community who love the details of flight dynamics and how they are or are not emulated by Microsoft; however, let's keep in mind that such attention to flight dynamics only is important in real flight in real multi-million dollar aircraft and perhaps in million dollar simulators trainging real life pilots. If Microsoft somehow eliminated part of the hobby for the "flight dynamics" crowd, that is sad, but to 99% of FS simmers, it does not matter or impact their enjoyment of the hobby. I tried to read the original message of this thread and it was so far over my head, I couldn't even begin to finish it. Kudos to the writer, but........it's a $55.00 game so..........you get my point.Randy Jura, KPDX

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Guest James Banks

...If one ignores the FS graphic model, and rebuilds a visual model based on information described only in Microsoft's airfile and aircraft.CFG,( from any of their recent flightsims in the past decade )....you'll find yourself with a curious looking little flyer....Essentially...the fuselage will be a long, thin rectangle...maybe like a strip of thin cardboard, two inches high, a foot long....Same with the main wing. A similar thin wafer, placed flat at a ninety degree angle to the fuselage. ...Tailplane and rudder....more of the same, only smaller. ...Propellor (if it has one)...again....most simplied. I don't even want to think what the powerplant would look like....Behold now....the 3-D rendering of Microsoft's flightmodel...a thing not unsimilar in appearance to one of those fifteen cent corner-store balsa wood/rubber band powered toy planes we used to fiddle with as kids ....oh...so long ago....Find these bits of cardboard cut very plain. No tapering wing tips. No compound curves. No multiple wings or faired in fillets. ..I have yet to see an airfile section describing the compound dimensions of a NACA cowling for a radial engine, and it's aerodynamic effect....A late era WW-2 fighter's paddle-bladed prop may look just like the big square tipped unit from your recent short haul commuter turbo-prop. A few variables are described...but nothing to impress the eye....Biplane trainers and delta wing jet fighters all recieve but a single thin strip of cardboard to model their platform....A virtual Wright Flyer varies in visual only slightly from a virtual B.58 Hustler....and yet they perform so differently on the desktop........A few of us have become accustomed to relying on a few sections and entries to create seemingly "accurate" effects in FS flightmodels, and now a few of those entries have be deemed "redundant" and have been deleted by their creators...We find a "slightly simplified" flightmodel. Those who think outside the box have found that the box has a slightly different shape. This is not a tragedy. It's a bump. We'll simply have to work out new ways to orbit the box....Yes...I fly real world. Yes...I fly sims. Yes...I write/rewrite flightmodels. All spare time recreation....Compared to real life experience...desktop flightsims are just that...interactive television. A little virtual theatre where reality is suspended....Since most responsible adults are reluctant to hand me the keys to their real world Spitfires, Avro Arrows, Ford Trimotors, or Wright Flyers....therein lies the appeal. The enthuisiastic flight of "impossible" or "no longer existant" aircraft in crazy locations, enduring insane weather, or insane pilotage. ...The suspension of reality.....So....noting the removal of a few airfile entries by the Microsoft crew....and waiting for a few of us get over the shock, fear, and anger....it is with great certainty that I predict that we'll all come up with some clever new ways to suspend reality once again.....I submit respectfully....isn't that part of the game...?

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Guest PaulL01

"but........it's a $55.00 game"I think you may need to put a few more zeros after that figure so that it reflects reality a little more accurately. :_lol It is amazing to me how for some folks here that when some part of the sim is important to them they look or hope for support from the FS community, but when it is something dear to others some of those same people try to nock or berate it.Who here do not care if the airfile is accurate or not? Not? Then go play a frigen game that doesn

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Guest CargoMun

Now if Microsoft hadnt pumped up the game to be "..as real as it gets" the idea that certain realism features wouldnt be so life like was to overlook.. but since they chose otherwise, well you be the judge of that...p.s. why are there 2 exactly same threads going on about this? Dang confusing lol

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