X-Plane 11.0 Beta 14 and the State of Various SDKs

X-Plane 11.0 public beta 14 is out. This one is a bit of a two-steps-forward, two-steps-back. Some notes:

  • You won't need a ton of thrust to start moving anymore - Austin was able to remove that hack from the tire model based on some new ideas for modeling low speed tire physics that get around a years-old problem.
  • The Cessna apparently wanders around the runway like a drunken moose.
  • Max's new cloud art is in. Under some views and conditions, you may get significantly better performance.
  • Under other views, they may kill your GPU. I'm looking into this.

Most importantly, I broke Plane-Maker, so public beta 15 will be out in 24 hours, and I'm going  to sit in the corner and have a time-out for a few minutes. If we have a fix for the Cessna in that time frame, we'll ship both, otherwise I'll get a patch out to fix Plane-Maker and we'll get to tires soon.

The State of Various SDKs

SDK stands for software development kit, but the term is now used more generally for the various interfaces, tools, and file format standards to make add-ons of any kind for X-Plane, even if there is no program (software) involved. I've been getting a lot of questions about what's safe to start developing on top of, and what's going to be ready for third parties. Here's a quick update on the status of some of the V11 SDKs.

FMOD + Sound

FMOD-based sound is one of the biggest new features for third party developers in X-Plane 11. Here's the status:

  • FMOD support is feature complete in public beta 14. Therefore we expect to have X-Plane sound "third party ready" by the time we go final with 11.0.
  • There's a lot to document about FMOD. I have already started the beginnings of full documentation, but it will take time to get it on paper. I'm hoping to have draft FMOD docs that you can use shortly after we go final.
  • There's a lot of details to get right in making an FMOD-enhanced aircraft; please do not ship an FMOD-enhanced aircraft before the docs come out - there's a very high chance of doing something wrong if you're just trying to guess how the system works from our Cessna project.*

When we ship, we will have bare bones tools for working with FMOD, but we will publish everything we had when we did the Cessna, and this setup is adequate for creating production aircraft. Fortunately, most of the work is done in FMOD Studio, a rich, full featured sound editing environment. It's great to use.

The 'thin' side is X-Plane support: the sound attachment file (.snd) that links FMOD events to your aircraft has to be built in a text editor. We also have some graphical debugging and it is possible to attach a live mixer to X-Plane while you fly.  All of this will be covered in the docs.

In the long term, we'd like to make the sound attachment system visual and have it run inside X-Plane while you fly.

What you can do now: learn how to use FMOD!  Download the FMOD studio editor (it's a free download) and start working with its sound design tools.

Graphics - Aircraft, Scenery and Modeling

I still have a list of graphic artifacts, but I think the overall operation of the new lighting system is as it will be for shipping 11.0. You can start using the new material model now; until the exporters have direct support, you can always add the NORMAL_METALNESS directive by a text editor or add it to a PNG comment.

Probably the biggest weakness of the new lighting model right now is the lack of detailed control over the interior of aircraft; I expect we'll have new techniques to cope with this in future updates, but they won't be mandatory aircraft changes. Unfortunately I don't have good work-arounds right now for aircraft where the interior lighting is unacceptably weird.

What you can do now: tune the brightness and alpha levels of translucent textures - they need to be adjusted for X-Plane 11's linear blending. Fix any panel problems introduced

Aircraft Physics and Systems

One of our biggest pushes right now is to try to get to "done" on the aircraft physics and systems code. The engines should be done - we don't have known open bugs. The tire modeling is still problematic as of public beta 14; Austin has a fix for the bad behavior of the Cessna in beta 15.

What you can do now: test your aircraft's physics model with X-Plane 11. If you have a fleet of aircraft, pick one particular aircraft and carefully update it for X-Plane 11. If you find out that there's a physics problem after we go final, we're going to have a lot less flexibility to fix things.

We run the physics engine on our own fleet (and we don't use plugins to modify the physics) but that's a limited set of aircraft. If you have good data about how your aircraft doesn't work right with our flight model and good input data in Plane-Maker, we'd like to hear about it.


The weapons SDK is the one area where we have moved temporarily backward from X-Plane 10. X-Plane 11 features a new unified weapons system that takes technology from both X-Plane 10 desktop (for physics) and X-Plane 10 mobile (for multiplayer simulation). Unfortunately, we haven't had time to create an appropriate dataref interface to these weapons.

Getting the interface to weapons finished is on our short list for after 11.0 ships; I do expect that the list of datarefs may be different for 11.xx than it was for X-Plane 10. The new system has new capabilities that make the old "fixed index of weapons" model not a great fit.

Unfortunately, this means that if your add-on depends on plugin-controlled weapons, you're stuck in a holding pattern until we can post a new interface that we can maintain.


As of public beta 14, plugins should just work - we've closed the remaining plugin API and major dataref bugs. There are a few areas of fine print:

  1. You can't use drawing callbacks in the map in X-Plane 11 - the totally rewritten map doesn't use the same coordinate systems, so there is no way we can make old code work.
  2. Some datarefs and commands are not available in X-Plane 11. This is a normal part of the evolution of the sim.
  3. Multi-monitor support has a pile of bugs when you put X-Plane's menu bar on the second monitor. If your plugin works normally except in this condition, it's probably an internal X-Plane bug you're seeing.

Note that to control toe brakes in X-Plane 11, you now need to set an override. Once you do, you completely own the toe brakes - you can look at the raw joystick input datarefs if you want to write a plugin that "processes" toe brake inputs to create some kind of effect.

What You Can Do: Check the command and dataref lists that are in Resources/plugins. If you need a command or dataref that has been dropped (and is not weapons related), contact us to discuss your use case and we'll figure out what to do. If you are still seeing plugin bugs, file them now!

What we will not have done for 11.0 is entirely new plugin functionality to expose new X-Plane 11 specific features. We will need to do a major API revision to allow plugins to undock windows (like our GPS and map does), to expose some of the new FMS capabilities (expect a limited API) and to restore map customization functionality.

Particle FX

The particle system SDK is kind of done, mostly. We use it in the shipping mobile product, and the editor is available in the desktop product now. I still have two features left to do that Austin considers "must-have"; I expect to get them in shortly after we go final, at which point we can start providing documentation. (One of those features is the ability to control aspects of the particle system from multiple datarefs - that will change the UI enough that it's not worth writing docs now and then changing them.)

My suggestion is to stand by on this - it won't take that long to get the system to a "tinker with it" stage.


* I am quite impressed with how far some people have gotten without docs! But shipping an add-on that "seems" to work but violates the SDK rules makes a compatibility mess later.

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About Ben Supnik

Ben is a software engineer who works on X-Plane; he spends most of his days drinking coffee and swearing at the computer -- sometimes at the same time.
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42 Responses to X-Plane 11.0 Beta 14 and the State of Various SDKs

  1. Sebastian says:

    I`m getting zero to none frames anytime I add Overcast, used to have Little Impact on my System (steady 34-40 fps with my Settings before). The Clouds look fantastic, but apparently make my sim unplayable! Are you sure you don`t want to reintroduce Cloud Detail in some form? 😉 Anyway, would like to give you Feedback so if I can help in any way...

    • Ben Supnik says:

      Changing your visual FX setting now DOES change the cloud cost! It sounds like something seriously borked is happening. I have to investigate a lot re: clouds.

      • Sebastian says:

        Okay, the Problem disappeared, back to good Frames! I dont know why but after lowering the visual fx and aa Settings and experimenting with different overcast Levels, I am now back to everything on high and just works and Looks beautifully!! I don`t know why I had only 13 fps before and now on same scenery in Switzerland at least 30...?

      • Sebastian says:

        I guess something with visibility range? just notice it was at 15 miles now...Still with 30 miles and overcast @22fps... But the `mood` is so amazing I can`t really describe it 😉

  2. RD says:

    "Under other views, they may kill your GPU. I’m looking into this."

    I've already filed a bug on this yesterday, but it seems to be related to day time. While getting almost 0.100 gpu time at day, it drops to 0.030 at dusk... (same conditions)

    There are some advanced users/devs claiming could be something related to shadow size or view distance, maybe?

    Anyway, this update has blown my mind, excellent job on the new clouds! Keep rocking, everybody!

    "The engines should be done – we don’t have known open bugs."

    I assume this is related to the general sim code, right? I've filed two bugs on the default C90 engines that are not fixed in pb14, yet.


  3. AlfaMike says:

    Ben, thank you very much for the update.
    You wrote this:
    "Some datarefs and commands are not available in X-Plane 11. This is a normal part of the evolution of the sim."
    Is it possible to have a full list of datarefs and commands no longer available in X-Plane 11 as well as possible workarounds for them?
    Maybe you just removed datarefs that are older and/or been 'duplicated' by new ones, but it would be useful for us to know it for sure (doing a manual search in the dataref txt file in order to check if some of the hundreds and hundreds of datarefs used in a plugin are no longer available is not the best way to check it).
    Thank you in advance.


    • Ben Supnik says:

      I'll get the website updated, but the datarefs.txt and commands.txt file that ships with the sim is pretty much always current.

      My hope is that add-ons that use commands and datarefs check for whether "find" succeeds and, in a debug build, log failures so developers can detect problems. (In shipping plugins, I encourage developers to not have their plugin completely explode into pieces due to datarefs or commands missing unless it's absolutely critical. In particular, plugins should not freak out if an array dim gets BIGGER.)

      A few other bits of dataref and command excitement:
      - Commands can have aliases to make old command paths work, so missing commands might actually be working - try XPLMFindCommand...I'll try to post an alias list soon.
      - Datarefs can have multiple types...for example, if we list a dataref as "double" in the docs, it will read/write as float and expose to the SDK as float AND double. So we can promote from float to double without breaking your add-on.

    • Steve.Wilson says:

      Winmerge is your phrend on Windows. There are text file compare tools for Mac and Linux as well. Just compared PB14 DataRefs.txt to 10.51 and confirmed that none of the drops affected my plugins. Took about 1o minutes, tops. Some of the additions are quite intriguing.

  4. Saso Kiselkov says:

    Great job on everything, Ben, even with the occasional regression that creeps in. The new cloud drawing is an especially welcome change.

  5. Günther Wittwar says:

    For me beta 14 is a huge step forward.
    The new clouds a really looking good!
    Only the color of the clouds during sunrise is a little bit strange, dark greenish.
    If needed I can offers links to pictures.

    I like that sim more on every day.
    Congrats to the team.

  6. Tom Knudsen says:

    Hi Ben

    Beta 14 looks good at least on my end. Getting good frames with range in the upper part of the 35-40's. This is very good for XP11 at least for my hardware setup (Nvidia 1080, i7 3770K and 16gb ram). Reading through the known bugs list, I see you guys are going to improve it additionally (awesome and thanks).

    So over to the important thing and I quote:
    "You won’t need a ton of thrust to start moving anymore – Austin was able to remove that hack from the tire model based on some new ideas for modeling low speed tire physics that get around a years-old problem."

    Aircraft is still moving right of the bat, especially when booting up the airplane with engines running it rolls away like there is no tomorrow. No parking brake is applied (off position). Makes me wonder if its normal to leave the airplane between turn with either chocks on, parking brake on or both?? Ok, so we discussed this before but never got an answer from you. Remember you asked if I had the Saitek Flight Yoke controls? Did not get an answer after that though.

    Anyway, strangely there is no options to assign button for setting the parking brakes in game via the EDIT, seems to me you guys do not like to call it parking brake. I find two references in this list when searching for "brakes". Either "Toggle brakes Max effort" or "Hold brakes maximum". Both makes no logical sense to me, it is even called "Parking Brakes" in real life, so why not have an option called "Parking brake toggle" or like you have with the lights "Parking brakes on" and "Parking brakes off" each three options should have been in the gui.

    Anyway, filed a bug report about it.

    Last but at least a question about graphics: Will PB15 or 16 included a fix for the sky artifact rings in the sky originate from the skycolor_ png files? Noticeable especially in the night sky. PS.. Bug is filed I believe on this too, if not let me know and I file it again with images as examples.

    For what it is worth, I for one wish you guys port the app "X-Plane Control Pad" over to Android too, that program is just pure genius.

    • Ben Supnik says:

      Ringing in the sky is on my short list. We're still discussing brakes on startup internally. If you care a lot, email Austin.

      I think there's zero chance of us porting control pad to Android. Android development is a significantly bigger PITA than iPad development, and control pad doesn't bring in revenue. Austin doesn't do Android dev himself either, so it's going to be IOS only.

      • VK says:

        good that sky banding is on your short list.. wanted to know if the stripes in the water/sea is also on your list? the water in XP10 looked much better.. so what changed in 11 that puts stripes on water?

    • sqrt(-1) says:

      Completely agree on "X-Plane Control Pad being pure genius. I just don't understand why it's a 2GB download. Sounds a bit big. No?

  7. Matt Rauch says:

    Along the lines of Plane Command. In PB13 if I checked the boxes for altitude alert on the default 172, there was no sound. It worked in previous versions prior to PB13. Will this be addressed in the PB15 fix/update?

    • Ben Supnik says:

      If this check-box works for all other aircraft, then this is _not_ a bug. The c172 is done with FMOD, and therefore it is a requirement of the aircraft author (of the C172) to do _every_ sound in the C172 with FMOD. Therefore you can't get back some of the sim's default sounds by check-boxes.

      We do not allow mix & match for FMOD and legacy sound - it's one or the other. When using FMOD, only sound from radio beacons and communications (e.g. ATC, ATIS) are outside the author's control.

      If this check-box fails for the Baron or kingair please file a bug - they're "normal".

      • RD says:

        On that subject, are you guys planning to get all the default fleet with FMOD sometime or C172 only?

        • Ben Supnik says:

          We plan to roll out FMOD over more and more planes over time. We don't have another FMOD plane coming for 11.0, but in the long term, FMOD is our sound solution.

  8. The crashman says:

    This is great news. The the new changes are great. however, seaplane water ops are a disaster, and most payware aircraft cannot even touch water with out a blown tire issue. Will there be a change to the modeling behavior on water for seaplanes and mor important (to me)..lol...if there is a fix implemented , will it possibly fix the issue with the a khamsin albatross being allergic to water, it's as of there is to much friction Co ef..or something...any way .thanks. This is one hell of a simulator keep the the great work.

  9. Jens says:

    "Under other views, they may kill your GPU"
    They certainly do. Once there are eough of those fluffy things on screen. CPU: 0.01 GPU 0.06 FPS 17
    But they are sooo nice to look at! I refuse to fly on clear sky anymore.

  10. John G says:

    Fuel tanks still show empty on the Cessna 172. Have the saitek throttle that does not work at all. You have to set the throttle and mixture with in mouse in the cockpit. tried to reset the throttle and mixture in the setup would not even accept anything.

  11. Gene Davis says:

    After 14 I am having the issue that occurred with threaded optimization being turned on even though it's still off via my card settings. It ran fine the day before the update.

  12. Johnny72 says:

    I have frames problem too... in day time flight the frames are 8-13. In night time 25-30 or less. In pb 13 was perfect for me. But I agree that clouds are the best. So a balance must be found so all the users to be happy. I hope that the default jets aircrafts and their fms will be completely ready soon.

  13. Nico87 says:

    Ben, you also broke the way x-plane deals with its files.
    I've sent a bug report about this.
    It seems that X-plane locks all the files so a plugin is unable to update them.
    Is this going to be fixed in beta 15?

  14. Abe says:

    Quick question on the engine issues developers are seeing. For example , the flight factor products . The throttles go up and down. Is this something that is fixed in the latest build and the developers have to implement. XP11 is coming along . Great job !

    • Ben Supnik says:

      I have _no_ idea what's going on with the throttles. Given how heavily scripted and customized the planes are, we need a bug report from the developer to investigate. I am not aware of open engine issues in the core sim.

  15. Vistek says:

    Good to hear about the FMOD documentation coming soon! Does it support airplanes int/ext sound only or is it possible to attach the sound sources to other airport objects or outside scenery objects to revive the deaf world? Congratulations.

  16. SNowblind_7 says:

    It is a bit of topic but I don´t know where I can get this info. I am working on a Regionalisation Project using the library.txt EXPORT commands, changing some ".ter" files, I have read the documentation of the dev blog, but I didn´t find if is possible do one thing. I would like to know if is possible to reference the x-plane default textures inside on a .ter file accessing by a folder at the "Custom Scenery". Something similar "BASE_TEX ../textures10/campo_irece2.png" but referencing a internal x-plane texture... (example: "X-plane folder\Resources\default scenery\1000 world terrain\textures10\loveg")

    • Ben Supnik says:

      You cannot do this. The library system intentionally does not give you access to the internals of OTHER library packages - doing so would create dependencies between unrelated work and make the library system work even worse than it does now.

      • SNowblind_7 says:

        Thank you for the info. I am changing some "far" urban textures but I want maintain the near urban textures without duplicating the file, I will try to find other way or create new textures.

        • Ben Supnik says:

          Ah - right , this isn't something you can do with the library. For example, if we change the .ter to not use the compositing shader, your change would make no sense.

          Email me privately and we'll talk about what licensing options are available.

  17. Igor says:

    > FMOD support is feature complete in public beta 14.
    Hm, I've tried FMOD once again today (with b15), but I still cannot bind custom commands to sound events. (I've filed a bug report much earlier). Default X-Plane commands & datarefs are working fine.

    Default C172 also does not bind any custom commands.

    Any advise? Am I doing something wrong?

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