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virtuali avatar image
virtuali asked FlyingRaccoon answered

Scenery editor extremely slow with large airports

While it's very nice the crash when editing nodes has been finally fixed, the scenery editor is very slow, and it seems to become slower and slower the more nodes it contains.

What used to cause a crash before (moving nodes), now results in several seconds of the editor being very stuttery and almost unresponsive. See the attached (unlisted) video, showing the problem:

When the fps is in the red, everything is lagging, including moving around with the gamepad. The problem doesn't happen just when moving nodes around, but even when changing a property, for example the name of a taxiway.

This makes editing a large airport extremely slow but, in addition to that, makes almost impossible to use any function that has the "One click" placing, because in that case the stuttering is constant and the frame rate never settles down to normal.

During the stuttering, the CPU usage goes up, and GPU usage goes to almost zero. The system it's an i9-11900K with 64 GB/Ram and RTX 3090.

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virtuali avatar image
virtuali answered virtuali commented

Further information, the problem seems to be almost fixed, if there isn't a copy of the scenery being edited in the Community folder so, it's working acceptably ( the pause is there, but it's way shorter ), if the scenery is temporarily mounted only when the project is loaded.

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FlyingRaccoon avatar image FlyingRaccoon ♦♦ commented ·

Hello Virtuali.

This is happening on SU5?

I've not been able to reproduce this kind of freeze yet. On a way less powerful machine, editing heavy airports, my framerate is low but consistent. (also tried copying the edited package to community)

I've noticed the lines you're manipulating are not refreshing the yellow taxiway lines. Are you editing your airport on top of an already existing airport without removing it or on top of another 3rd party airport?
Or are you using project meshes and if so in what quantities?

The fact I can't repro can also come from the fact you might be using a lot of features we don't use a lot like ProjectedMeshes for example.

I know I sound repetitive but can you provide a link to your package sources as a private comment please?
If you end up being in a very specific case, I should be able to repro using your package.


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virtuali avatar image virtuali FlyingRaccoon ♦♦ commented ·

I'm using SU6, and I had this problem when I had a copy of the same scenery I'm editing in the Community folder, which didn't used to be a problem before ( at least, I never noticed )

As I've said in my subsequent post, if I remove the scenery from the Community folder, leaving only the one I'm editing that is mounted on the fly by the Scenery Editor, the problem is almost entirely gone.

The reason I needed a copy of the scenery in the Community folder, was due to the other bug of the Terraforming I reported in another post: the terrain keeps going up/down if there's some terraforming used.

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leonardomoreira avatar image
leonardomoreira answered

I have exactly the same problem, only with a copy of the current package inside of the Community folder, in my case, I'm using symbolic links.


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devmode_player avatar image
devmode_player answered virtuali edited

I can confirm the same issue for complex projects, and this is directly linked to the large number\overall complexity of projected mesh items used in project.

In my tests I even got the critical number of projected meshes which caused the complete hang of the Sim on loading\editing project in developer mode.

It's still not clear about the link between the complexity of project and total number of projected meshes.

Overall it would be interesting to hear more info on limitations of the projected meshes especially in case of upcoming LODs optimization process

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virtuali avatar image virtuali commented ·

In my case, I only had 3 Projected Mesh, but the airport is quite big and it contained lots of TaxiwayPath/TaxiwayNodes (over 2000) so, maybe it's not necessarily the number of Projected Meshes, but the number of objects included, regardless of their types. But I guess the complexity of the objects that makes up Projected Mesh will be a factor too.

Not sure why not having a copy of the same scenery in the Community folder too seems to improve the issue quite a bit (although some lag while dragging nodes is still there, but it's acceptable) but, I had to do this because of the *other* bug which will be hopefully fixed in time, that Terraforming doesn't work well in the editor, not just editing it, but even the visualization is a problem, with the terrain going up/down when moving over different parts of the airport, requiring either zooming in/out a lot, or press the "Load this asset group" for the airport, which seems to "refresh" the elevation for the area around the Developer Camera.

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FlyingRaccoon avatar image
FlyingRaccoon answered


SU6 has seen an optimization of the projected meshes but this may not be enough.

We are optimizing based on our own heavy airports and airport designers feedback but that doesn't cover all use case.
We are willing to have a look at those issues but we need the package sources to identify the bottleneck in your case.


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