Microsoft Flight Simulator 2024 had its second developer stream on the 2nd of October, where Jorg Neumann and the SDK team discussed the new SDK. The stream went over various areas of the SDK and answered some questions from the stream.
General Overview of MSFS2024 SDK
Starting off with backwards compatibility, the team confirmed most marketplace packages from 2020 will work straight out of the box. The new simulator will detect and handle them for you, however, there are a few exceptions which include biomes, UI and more unusual add-ons. The dev alpha build will be used to detect any potential issues, so new content will be signed off to appear on the marketplace.
There is no forward compatibility according to the SDK team, this means a 2024 package will not work on MSFS2020. Assets made in 2020 may have to be reworked to work correctly with the new simulator, as the system has been changed. The SDK team said this was due to changes aimed at improving performance and quality.
Content for MSFS2024 is mainly streamed, so all the data comes from the cloud, this means the client is a lot thinner than the previous simulator. Offloading more data onto the cloud allows for faster installation times and near-instant updates. Your simulator will only download what you need or what you will choose to use during your flight.
LODs have been changed slightly with a new LOD selection system. This will apply to all 3D objects like aircraft, airports, and sceneries, and it is there to preserve quality and performance. However, this will require some careful design of the LOD models of your 3D objects. There are still limits to your LODs as you can see below.
However, creating LODs is time-consuming and could take up to three months for an aircraft or half a day for scenery. There are tools which you can use to help you when creating your LODs such as 3DS Max or Blender. You could also use Simplygon which is integrated with their pipeline but requires a licence, or use other open source Solutions.
Q&A – General
Is there any improvement to the blending when multiple animations are applied to a single object? 3rd party scenery’s compatibility?
In terms of aircraft SimObjects, there is no improvement to the blending, and it is not exposed to the SDK yet. However, they do use a new system for facial animations, but this system is not open to everyone. They also confirmed that existing third-party sceneries will work in MSFS2024 and won’t need to be recompiled with the new SDK.
Can both SDKs from 2020 and 2024 be installed at the same time?
Both SDKs can be installed and supported at the same time without any issues.
SDK Overview – Aircraft
MSFS2024 allows multiple variations to be defined as “presets” which all share a common set of properties. Each preset will be able to use a selection of “SimAttachments” like instruments and parts. Extremely detailed models are now possible when in close range, with no performance cost when the part is far away from the camera.
Navigation graphs specify certain positions in an aircraft or airport and will also define the possible moves between each position. These nodes can be used to define the position of pilots and passengers in an aircraft or for specifying interactions at a specific node, such as during preflight. They contain sub-graphs, so if an airliner has multiple rows of seats that are similar, it defines one row and uses it multiple times.
The flight model for every aircraft has been significantly changed and improved. This means there are now new geometry sections in the flight_model.cfg file such as fuselages, wings, and htails. This allows for far more accuracy of the flight model and offers better flexibility for different aircraft like biplanes or twin-fuselages.
New core systems have been added to MSFS2024 along with previous systems receiving improvements, these include:
- Electrical (breakers, diodes, relays, transformers)
- Pneumatics
- Hydraulics
- Brakes
- Liquid dropping
For compatibility with career mode, there are various criteria an aircraft must meet. Each aircraft has to meet specified criteria to be fully compatible with an activity, and these criteria are listed in the SDK documentation. The SimObject editor will now include a compatibility tab which will tell you if your aircraft meets the criteria and what needs to be reviewed.
Q&A – Aircraft and Helicopters
With the new physics, will flight models on existing aircraft need to be redone to be compatible? Are there any improvements to the light system?
No, the SDK team says that they will be backwards compatible and wants these new features to be more optional for developers, so the flight model does not have to change. The renderer for lights already in use is the best it can be, so there are not many performance improvements.
Will the wear and tear feature affect the handling of the aircraft? What new features are exposed to the SDK?
Yes, however, there will be no visual damage but rather more internal. This means that aircraft systems may fail as a result of wear and tear, such as worn brakes, which would increase your stopping distance. At launch, gameplay features like banner towing and placing fires won’t be exposed to the SDK.
Will there be more parameters available for tail rotors? Will there be any differentiation between different types of rotor systems?
More parameters are still being worked on and are on the list to be done for the SDK release. As of now, there will be no differentiation between different systems as they don’t know enough, but they will look to see if this is possible.
SDK Overview – Airports and Scenery
MSFS2024 will introduce “SimPropContainers” which allow for library objects and SimObjects to be grouped in one single container. This means you can create them once and reuse them as much as you like, in other software you will find these being called “Prefabs”. These SimPropContainers will adjust detail as you move the camera closer or further away.
New biomes and geomes systems have been added to MSFS2024, which allows for polygons to be created in the scenery editor to adjust a range of parameters. You will be able to select the biome/geome, density, scale as well as individual tree placement. Biomes can no longer be created as the system is too complex.
New visual features have been added to make airports feel and look more like they would in real life, these new features include:
- Patches
- Cracks
- Tire Gum
- Ceiling
- Grooving
- Dirt
Archetypes are preset that can set any of the above features at once for any airport and can be tweaked through the scenery editor.
Q&A – Airports and Scenery
Will the drone camera issue with the collision material be addressed? Will double-sided taxiway signs be supported?
Yes, this issue has been addressed in the new simulator, so the camera is no longer affected by collision materials. Double-sided taxiway signs won’t be supported as it is not a feature the team have thought of adding, but it may come in the future.
SDK Overview – SDK & Dev Mode Improvements
WASM modules will no longer run on the main thread anymore, but these modules will remain single-threaded for now. New types of WASM modules have been added for MSFS2024, these allow the creation of system modules and modules for airports. System modules will no longer need a fake gauge to load the systems.
SDK Rollout Plan and Dev Alpha Build
A Dev Alpha build will become available on the 21st of October but only for registered Marketplace developers. In this build, only free flight will be available with two aircraft samples to help developers test their add-ons. The SDK documentation will be made publicly available on docs.flightsimulator.com and will also be downloadable from the build.
That was the end of the developer SDK stream, and you can watch the full stream on their YouTube channel. You can read more about the previous MSFS2024 Dev stream here and for more flight simulator related news, check out the rest of FSNews.
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