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PSX + X-Plane for scenery

Started by mikeindevon, Tue, 8 Jul 2014 18:57

matchball

Hi Mike,

I appreciate this alot. Let me know if I can help you in any way (I am very fond of flying in IVAO ;) ).

Regards,

mikeindevon

Yes, you can help.  There are a few questions to save me doing the research.  How does X-Plane and IVAO interact: is there a plug-in for it?  What precisely are the variables you need?  If you know the datarefs for them that would be even better.

One problem that we may face is that some XP variables are read only.

Mike

matchball

Quote from: mikeindevonYes, you can help.  There are a few questions to save me doing the research.  How does X-Plane and IVAO interact: is there a plug-in for it?  What precisely are the variables you need?  If you know the datarefs for them that would be even better.

One problem that we may face is that some XP variables are read only.

Mike

The Software Developer is currently doing some ATC but once he has ended I will give him a call and ask the questions. Will report back during the day. :)

matchball

I have a problem that the X-Plane's aircraft hits the groun 10ft before the PSX and makes it very difficult for me to understand that the plane is still flaring without looking to the PFD. Is there a way to go round this? F.ex. disabling the gear extension so the plane would then "float" and never touch the ground?

matchball

So it seems that the problem is that X-Plane touches the ground at RA 0ft where as PSX around RA -6ft. Is there a way to solve this issue?

Hardy Heinlin

#225
PSX's main gear touches the ground at ca. 0 RA.

PSX's main gear is completely (untilted) on the ground at ca. -2 to -4 RA.

PSX's nose gear is on the ground at ca. -6 to -8 RA, depending on gross weight and strut compression.

mikeindevon

If you give me an ILS where this happens, I will have a look at it.

matchball

#227
It happens on all runways (at least where I have flown. EGLL 09L, ENGM 01L, LTBA 23). I think the problem might be that the animation of the main gears is not done in the X-Plane plane and the gears don't "bend"?

matchball

Also I have tried to disable sloped runways on X-Plane and it did not help.

Hardy Heinlin


matchball

Quote from: mikeindevonYes, you can help.  There are a few questions to save me doing the research.  How does X-Plane and IVAO interact: is there a plug-in for it?  What precisely are the variables you need?  If you know the datarefs for them that would be even better.

One problem that we may face is that some XP variables are read only.

Mike

I have now found the person who knows about X-IvAp (the interface between X-Plane and IVAO, and have sent him mail. But already now I can tell that X-IvAp indeed is a plugin inside X-Plane. I will come back when he has answered :).

mikeindevon

Hi Matchball,

Regarding the touchdown issue, have a look at the attached picture that was taken on the Basic 022 situation with the current version of XView..



When X-View detects touchdown it compresses the gear to the full up position with the wheels untilted.  This hasn't happened yet in this flight so XView is still flying.  The PSX RA is showing 2, which is more or less in line with Hardy's note above.  Also note that rollout has begun, so PSX has landed, but XView not quite.

Can you be more specific about the issue you are having.  What readings on the instrumentation are you using to say that PSX has touched down?

Note:  The PSX Plane gear does compress on landing by about one wheel diameter from the flying position.  This is done in one step: it is either uncompressed or fully compressed.  I could do the compression in stages, the gear model allows for that, but as it all happens so fast I didn't think it was worth the trouble.

Mike

Hardy Heinlin

#232
Hi Mike.

Quote from: mikeindevonAlso note that rollout has begun, so PSX has landed ...
PSX has not landed yet (not untilted yet). ROLLOUT engages at 5 ft RA in the air.

PSX has landed when you hear the click sound from the gear lock override solenoid (the speedbrake lever sound follows immediately).


Cheers,

|-|ardy

matchball

#233
Quote from: Hardy HeinlinHi Mike.

Quote from: mikeindevonAlso note that rollout has begun, so PSX has landed ...
PSX has not landed yet (not untilted yet). ROLLOUT engages at 5 ft RA in the air.

PSX has landed when you hear the click sound from the gear lock override solenoid (the speedbrake lever sound follows immediately).


Cheers,

|-|ardy

That sound is the one where I have based the idea of PSX touching down. :-)

Hardy Heinlin

"Touch-down" is really a matter of definition.

In an ideal case, the first touch occurs on 8 main wheels, i.e. the rear wheel pairs on each tilted 4-pack.

For most avionic devices that have an air and a ground status, the ground status is set when all 16 main wheels are on the ground; that is, when all 4-packs are untilted. That status I would call "the queen has landed". (And the nose wheel pair is still in the air).

matchball

One thing also where this can be noticed is at takeoff. Because the PSX plane already indicates positive rate but in X-Plane the plane jumps up fast after couple seconds.

GodAtum

I noticed that too, it always looks like a tailstrike.

simbro

I've also noticed this 'jump up' in FSX on occasions.

mikeindevon

#238
A bit of background detail.

X-Plane and PSX have a slightly different terrain elevation models.  In particular XP has sloping runways.  XView feeds into PSX the scenery elevation every few frames, but because of damping in PSX, this elevation data does not immediately affect the elevation within PSX.  When the plane is on the ground, this can lead to the plane's image in X-Plane ploughing into the ground especially on upward sloping runways.  This doesn't look good.

Also, although PSX is fed the elevation, it knows nothing about the slope of the terrain, either along the line of the plane or perpendicular to it.  This again can lead to problems with say the main wheels on the ground and the nosewheel below it.

The approach I took to avoid these problems was to set the plane's elevation to the XP ground elevation when I deemed the plane to have landed.  That is I ignored the elevation reported by PSX.  I also added the terrain's slope to the attitude (and roll) of the plane.  In this way the plane is always position correctly when on the ground and follows the slope exactly, although there is some small damping to smooth out XP's abrupt changes in slope. In fact you can taxi the plane up the side of a mountain and the wheels will remain on the ground whatever the slope.

So in summary, XView uses the PSX elevation when flying and the XP scenery elevation when on or very near (< 0.5m) the ground.  These slight jumps or early landings are a side effect of XView swapping between the two modes.

There is a setting within XView that specifies the distance between the base of the landing gear and the plane's centre of gravity.  To change this needs a recompilation.  If I alter it there is a risk that the plane will appear to plough into the ground.  When I developed XView I chose a compromise to ensure that this didn't happen.  The price we pay is some slight discontinuities.

I hope this clarifies the situation.

Mike

GodAtum

#239
Thank you for your detailed explanation. Unfortunately it does look odd on a full size flightdeck so customers wont get a realsitc experience. From my expereince, the landing seem to be OK but I'm not a real 747 pilot so cannot comment. Thank you very much for your efforts and hopefully there might be a workaround in the future.