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FSX MCX Aircraft Conversion Results in Backwards Prop Rotation

tgibson

tgibson

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Hi Arno,

Just to let you know - when I convert any FS2004 piston aircraft to FSX format, the prop rotation ends up backwards from the FS2004 model.

What's interesting is that in MCX the prop rotation is in the correct direction if you move the slider from left to right, but the result in FSX is the other direction.

For now I've been reversing the rotation of all the props in MCX and that fixes it.

Hope this helps,
 
Hi Tom,

That's weird, of you import the mdl file back in MCX it is also reversed I assume?

Does this happen with any prop plane?
 
Hi,

Yes, it is still reversed when I import the FSX format plane into MCX (well, it displays the same animation as it did when I first imported the FS2004 aircraft - remember the animation appears reversed if moving the slider from left to right). I didn't realize this and thus have lots of FSX planes with reversed props, so I just Imported one again, reversed the still, slow, and blurred prop parts' animation, and Exported again. Then all was OK.

If I then import *that* plane back into MCX, the animation in MCX is reversed, just as I Exported it. So there is no reversal when you Import an FSX aircraft, only when I Import an FS2004 aircraft - at that point the props will be reversed upon Export.

I hadn't converted a turboprop, so I did that. The FS9 aircraft had props that rotated clockwise, after export they rotated counterclockwise.
 
OK, I'll try to check. Sounds like some FS2004 transformation is not exported to FSX right.
 
Keep in mind that the prop animation in MCX is consistent between the two sims, so it must be the import that is the problem, not the export.

An explanation.

If I import an FS2004 aircraft with clockwise props, in MCX the props rotate clockwise when I move the animation slider from left to right. Upon export that plane has props that rotate counterclockwise.

If I import an FSX aircraft with clockwise props, in MCX the props rotate counterclockwise when I move the animation slider from left to right. Upon export that plane has props that rotate clockwise.

Hope this helps,
 
Hi,

I'll try to check tonight. But since MCX does show the FS2004 MDL correct after import, I don't think it is an import issue. That's why I think the FS2004 representation is somehow mingled up when going through XtoMDL on export.
 
Well yes, but then using your logic it displays the FSX MDL file *incorrect*.
 
Hi Tom,

I tried to reproduce it here with a couple of FS2004 prop planes I have as MCX test models, but I'm afraid I can't reproduce it yet.

What I did is load the FS2004 model, observe the prop rotation direction, export to FSX MDL, import the FSX MDL, observe the prop rotiation direction again.

For all the models I tried, the direction does not change. Did I miss anything compared to your workflow?
 
Yes you did. The difference is in the sim, not in MCX. In MCX the direction of the rotation will always remain the same before and after conversion. It's the results in FSX that are wrong.

EDIT - I had the sequence incorrect.

1. Import an FS2004 model. The rotation direction in MCX will be the opposite direction as in FS2004.
2. Export to FSX. In FSX the rotation is the same as in MCX, which is the opposite direction of the FS2004 model.
3. Import the FSX model back into MCX. The rotation animation is the same as in the FS2004 Import (which is incorrect), and any export causes the prop rotation in FSX to be the opposite direction of what is desired.
4. Import the FSX model into MCX and choose Reverse Rotation for all prop still, slow, and blurred parts/nodes. Now the rotation in MCX is the way it was in the FS2004 model. Export the model and the rotation in FSX is now correct.

PS. The rotation in MCX I describe here is when you drag the animation slider from left to right (i.e. from keyframe 0 to keyframe 100). Obviously things are the opposite when dragged from right to left. But the key thing here is that when I import an FS2004 model and immediately export it to FSX, the prop rotation has been reversed by MCX. Intuitively this is not expected behavior.
 
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EDIT: The direction of prop rotation in MCX is the direction you get in the sim. It's just backwards when you import an FS2004 model.
 
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Hi Tom,

Ah, sorry, missed that bit of information that it is only in the sim. As I'm not an aircraft developer I also find it hard to test aircraft in sim (I'm a scenery guy used to slewing around).

Maybe you can try one thing. In the latest development release you can enable the option to "Remove mirror transform" in the ObjectModel3D settings. Can you try to set that to true and see if it makes any difference?
 
Hi,

I tried it both ways and I don't see any difference in behavior.

But please note that I have edited the two posts above - I had the location of the error in the wrong place.

The prop rotation as displayed in MCX is the prop rotation you get in the sim. But upon importing an FS2004 model the prop rotation has reversed itself in MCX. Importing an FSX aircraft and then exporting it does not result in this reversal.

I assume reversing the prop rotation as you import an FS2004 model will result in the correct rotation in FSX.
 
Hi Tom,

Thanks for the update. This sounds a lot easier. In that case I should probably just inverse the rotation when reading from FS2004 MDL. I have to double check, but I think the prop animations are not stored in the MDL as keyframes, but made by MCX.
 
I assume that is true, since FS2004 prop rotation is one of those "built in" animations that does not need keyframes in GMAX. Just the part name and the pivot point are required.
 
Hi,

I have reversed the direction now. It was indeed an animation for which MCX makes the keyframes on import. It will be in the next development release.
 
Yes, I can put this fix in the soon to be released stable release as well.
 
Thanks. I just tried it with the latest development release and it works fine.
 
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