SDK News – 12.4.0 | Fast and Furious

With X-Plane 12.4.0 now available, let’s take a deeper dive into some of the changes concerning X-Plane developers!

I am unusually tardy with this post, so I would first like to apologize for the delay. I chose today’s title mostly because of multi-threading… but also because I’m all about family. And the X-Plane family has certainly come together over the holidays with our latest release.

12.4.0 is out now – Introducing some significant performance upgrades, A330 Improvements, Tobii integration, new art assets, and much more. We’ve been furiously working on this for quite a while in the latter half of 2025, and we are happy to see such a well-received reaction. I personally frequent Discord, Reddit, the Org forums, AVSIM, and other Facebook groups, and we want to make sure users are feeling more heard.

One thing that has impressed me of late is the amount of creations going on. RealOps is breaking ground with its ground-handling plugin. The wonderful scenery innovations by X-Codr. New career mode plugins. More people are trying out aircraft development. New developer tools/pull requests from XP2B. The community has been cooking lately!

More importantly, we’re focused on giving you guys and gals more features to create in X-Plane. This is going to be a big focus for some upcoming updates of ours. (No, that isn’t a reference to scenery… that comes later). But more on that another day!

So let’s get into what’s new for this update…

SDK Changes

SDK 430

SDK 430 is now available and compatible with X-Plane 12.4.0 or newer.

Warning: the 4.3.0 SDK incorrectly identifies itself as version “421” in the version included in X-Plane 12.4.0. Despite this, all entry points are present. The version number is corrected to 430 to match published docs as of X-Plane 12.4.1.

Official Changelog

• The new XPLMInitFlight and XPLMUpdateFlight APIs in XPLMPlanes provide complete control over creating and editing how the user’s flight starts.
  
  These APIs supersede and expose deeper functionality than the previous XPLMPlaceUserAtAirport and XPLMPlaceUserAtLocation APIs.
  
• The third MDCU is exposed in the avionics API.

Other Noteworthy Changes

• Fixed an error where users might get the message “The sim destroyed an instance during the dag!” when using add-ons (XPD-17441)
  
• Improved documentation of XPLM_MSG_DATAREFS_ADDED (XPD-17317)
  
• Fixed return value of XPLMGetVirtualKeyDescription (XPD-17397)

Future SDK changes

We will/should be adding access to additional basemaps/terrain data in a future update.

What happened with plugins during 12.4.0?

The short story here is, we found quite a few plugins calling X-Plane functions before it was fully loaded, which is a big no-no. I’ve asked Ben to make a blog post in his free time about further details on this, and how you can best avoid such incidents in the future.

Can you improve documentation on this?

Short answer: Yes
Long answer: I don’t think it’s any secret that we’re in the middle of a large documentation revamp, so there will be plenty of forthcoming changes. When we’re ready to communicate more, we shall!

Performance Improvements

The glorious future is here! Or at least, partially. X-Plane now takes advantage of multi-threading for scenery only. I strongly encourage you to read Sidney’s post about it here, and make sure you understand performance here. But here are a few Q&A’s

Should I expect massive amounts of increases?
It depends on your hardware and what the bottleneck was in the first place. If you’re GPU-limited (which is your GPU Compute time taking longer than your CPU), you are unlikely to see any benefits

Is this the end of multi-core/threading improvements?
No! Please see Sidney’s post for a full outline. Additionally, 12.4.1 will have additional performance improvements.

Will this help my multi-monitor setup?
Not inherently, as this is geared towards the scenery system. We have plans to address multi-monitor displays and further parallelize that work. This is not a short-term item, and I would suggest you read Sidney’s article.

Are you working on device losses?
Yes, but with caveats. We know it occurs disproportionately more with AMD devices. However, we found user feedback to be particularly poor. Throughout 12.4.0 beta, we decided to enable a “partial flavour” of AMD aftermath by default, and this should help us get one step closer to diagnosing these issues.

For the bug trackers here, we have XPD-17857, if you want to follow along.

How can I help?
Contact us via support, and they will give you further instructions. And be prepared to submit Aftermath reports!

New Assets

WED artists, we won with this update. Petr and Justin have created a brand new round of assets, fulfilling some long-requested items.

Segmented Circle
lib/airport/markings/segmented_circle

Wind Tees (Currently Not Animated)
lib/airport/markings/wind_Tee

Signal Square (Common for small EU airfields)
lib/airport/markings/signal_square

New Glider Models: ASK-21 & Ventus 3
lib/airport/aircraft/gliders

Animated Cranes
lib/vehicles/static/tower_crane

Construction Material Objects: Cable Wires, Wooden Pallets, Steel Pipes, Concrete Pipes, Cement, PVC Pipes, Concrete Blocks, Steel Beam
lib/industrial_area/construction

VHF Dipole Antenna Tower
lib/airport/radars/VHF

RV/MotorHomes/Trailers
lib/vehicles/static/RVs

Camping Equipment: Tents, Chairs, Tables, Coolers
lib/public_area/camping

Completely Revamped Modern Cars
lib/cars

New Taxis
lib/cars

Pavements: Asphalt, Concrete, Grass, Mosaic, Tiled, Mulch, Grates (Pavements are 0.15m AGL, if you wish to place objects on top)
Documentation Here
lib/airport/ground/sidewalk_15cm

Planter Objects: Grass, Bushes, Rock Shrubs
lib/vegetation/planters

Fences: Mesh, Metallic, Stone Wall, Wooden
lib/vegetation/planters

Road Bumps
lib/airport/ground/roads/speed_bumps

We’ll certainly be back with even more assets in future updates (for those who attended our Discord Developer Stream over Christmas, if you know… you know). But my personal thanks to Petr and Justin for knocking these out of the park.

A Note On Grass…

Some of you will be looking at that grass polygon with a swooning desire to place large swathes of it over your airfields…

PLEASE, PLEASE, PLEASE…. DO NOT DO THIS!

This is a one-way track to performance degradation, and we will block gateway submissions that abuse this! We have also dreamed that one day the world will be filled with lush grass to touch. But this is not the device to get there. Keep your grass planter objects in small, localised areas.

Gateway Update

Finally, we have our latest round of Gateway airports by our incredible WED artists. I’m working with Julian to get more updates to you, but I’m in awe at some of the work being done by the artists lately.

Don’t forget that Worldeditor 2.7 Beta is also available to try (although you will not be able to submit gateway airports with this). This provides the ability to flatten the default mesh (default mesh only!)

(Note: This list is not a complete representation of all changed/added airports)

That’s all from this update. Catch you next time!

About Dellanie Byron

No-one quite knows who he is, or where he came from. However this happy little Quokka exhibits a passion for design.

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