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Guest Patrick_Waugh

Additional virtual engines

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Hi,just a thought: I was thinking how to break the 4-engine-limit. Since this is hardcoded in the simulator, there seems to be no clean solution to this.It's not quite a problem to code a thrust-gauge that will split the engines power up into 2 or more "pieces". Let's say, lever 1 is at 35%, lever 2 is at 20%, and the "real" engine is set at 55%. I tried that, and it works. But it end up in very unrealistic engine-behavior,Could one code a gauge in C++ that can read an unused section from the airfile and then modulate power-output along a curve given there?And could that gauge also control the engine-sounds, giving each virtual engine its own sound?

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>Could one code a gauge in C++ that can read an unused section>from the airfile and then modulate power-output along a curve>given there?You can do anything you want in C++, but "power-output" of what?You would be doing much the same as what you did in your first version, setting the true engine based on your "sub-engines", with similar results.You don't need an .air file to take values you calculate and then turn them into the power setting for an engine, but your results are not going to be realistic as 50% power on an engine is %50 power, even if you call it 100% because you are using 2 of them to sim the engine. And doubling the real engine power is not likely to get you what you want, as it is much more involved.>And could that gauge also control the engine-sounds, giving>each virtual engine its own sound?Nope, not with the in-game sound engine. You could program your own sounds with DirectSound.

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1st: The power-output of the engine - should I have said thrust instead?2nd: I know it's not realistic, that's what I said in the "I tried that"-part.3rd: I thought of using a "flat" power-curve for the "twin-engines" in the air-file and then use another curve - read from a section of the airfile unused by the simulator - to modulate power-settings along the thrustlevers travel.4th: I read from one of ur previous postings that u had a similar "problem" and solved it using DirectSound. I did not take that as undoubted proof that the simulator cannot do anything else.5th: In general, I dont like solutions that do not allow a max of customization without changing and recompiling code. That's why I wanted to stay as close as I could to the way FS does it's things. Like use external sounds, read the curves from the airfile and so on.I'll take your kind reply as a general "no, nay, never, not this way" and will tinker with the stuff a little more when I'm deeper into FS-gauge-programmig. As I said before, I'm an old guy and it takes some time to lear new stuff.Best regardsKai aka OneDownOne2Go

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>3rd: I thought of using a "flat" power-curve for the>"twin-engines" in the air-file and then use another curve ->read from a section of the airfile unused by the simulator ->to modulate power-settings along the thrustlevers travel.>Hi,Actually you don't need to read anything extra from the .air file; instead use polinomials to relate engine data retrieved from FS Vars with proper thrust lever positions. And it can be done entirely in XML, indeed. Thing like a Thrust Commanded Vector/pointer can be perfectly modeled (though not being an easy task) besides other specific engine control systems-all in XML, or C++, as you prefer.If your a/c has 8 engines in pairs of two, I think it should be possible to obtain fair results if you have good info on performance parameters and true relationship between thrust,fuel comsumption, and flight scalars (lift, drag,etc) for a 4-engine system (.air tables) with similar technical data. Very fun for sure :-)Tom

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>4th: I read from one of ur previous postings that u had a>similar "problem" and solved it using DirectSound. Yes, again you can program anything you want with C++. I just stated above that you cannot do it with the in-game sound engine.With DirectSound you can do anything you want with sounds.>I did not>take that as undoubted proof that the simulator cannot do>anything else.I have no idea what this sentence means. Take what? Do what else?>5th: In general, I dont like solutions that do not allow a max>of customization without changing and recompiling code. That's>why I wanted to stay as close as I could to the way FS does>it's things. Like use external sounds, read the curves from>the airfile and so on.I agree.>I'll take your kind reply as a general "no, nay, never, not>this way" and will tinker with the stuff a little more when>I'm deeper into FS-gauge-programmig. As I said before, I'm an>old guy and it takes some time to lear new stuff.Or a LOT more. =)

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When I did the B-47E last year, I finally settled on the simplest practical solution, even though it's not totally realistic. To get six engines, I doubled up the inboards as a single FS engine, i.e. real world engines 2 & 3 were linked to FS engine 2. In the same vein, 3 & 4 were FS 3.Obviously, that means engines 2 & 3 start and shut down simultaneously, as do engines 4 & 5, but that's the only unrealistic effect. Adjusting the power coding is boringly simple: Add up the total power output of the real world six or eight engines, divide by four and assign that value to the engine coding.I'm sure you have already considered this approach. It ain't rocket science, but AFAIK it's the best of a bad lot.Cheers,Glenn

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>I have no idea what this sentence means. Take what? Do what else?Well, maybe this is a kind of "lost in translation"..I did not take the fact that u did it with DirectSound as proof that it cannot be done in a different, more "simulator-related" way.

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>When I did the B-47E last year, I finally settled on the>simplest practical solution, even though it's not totally>realistic. To get six engines, I doubled up the inboards as a>single FS engine, i.e. real world engines 2 & 3 were linked to>FS engine 2. In the same vein, 3 & 4 were FS 3.>>Obviously, that means engines 2 & 3 start and shut down>simultaneously, as do engines 4 & 5, but that's the only>unrealistic effect. Adjusting the power coding is boringly>simple: Add up the total power output of the real world six>or eight engines, divide by four and assign that value to the>engine coding.>>I'm sure you have already considered this approach. It ain't>rocket science, but AFAIK it's the best of a bad lot.>>Cheers,>>Glenn>>Yeah, already tried that. I used the "startes" to control if the virtual engines gauges display data or not and to cause some delay like on a real startup. Using the v-e's trhustlevers as "multiplier" for the engine-data, I even got independent gauges. Disadvantage: Setting engine 2 (real FS-engine) to 0% and engine 3 (virtual FS-engine linked to engine 2) to 100% will result in engine 3 showing data like it's in idle. Not to mention that virtual engines have no effect on the total thrust this way. Anyway, best that can be done quick just to get the needles moving.

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Ah.All I did with DirectSound was allow myself to do any sound effect, whenever I want without needing to trigger any FS variable or use the in-game engine.Good luck doing that with the in-game engine. =)

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