This post has been on my todo list for a while – long enough that X-Plane 11.40 came out before I had time to write up a post saying “X-Plane 11.40” is coming. But just to put 11.40 into context, here’s what our patch roadmap looks like for X-Plane 11 this year.

All Physics All the Time

X-Plane 11.40 is a physics release. Almost all of the changes in X-Plane 11.40 come from Austin’s work on the physics engine over the last six months. This is a new approach for us. In the past, when we’ve updated the physics or systems, it would be in a giant “omnibus” release, where everybody’s latest code went out at once (e.g. X-Plane 11.10).

The problem with the omnibus releases is that they would take forever to get debugged. With so many people changing so many things, we never knew what had gone wrong when a bug report came in. And with all of the code changed, we had to investigate every single bug report carefully (no matter how unlikely or vague the report) because anything could have been broken.

So far, at risk of jinxing the beta, it appears that the physics-only approach is working a lot better. It has been quicker to find bugs when they are reported, and the overall level of crazy is a lot lower than in past releases.

NaNNaNNaNNaNNaNaNNaN Batman!

There aren’t many open bugs left in the 11.40 beta, but one particular bug has caused the beta count to run up: we were seeing crashes due to NaNs in the flight model.

NaN stands for Not A Number, and it’s what you get when you have divide-by-zeros run amok in the physics. To catch them, we’ve turned on a lot of auditing code and we’ve been collecting automatic crash reports. At risk of jinxing it, I think Austin has fixed one of the two root causes in beta 8. We are going to keep chasing them until the other one is fixed, then turn down the checks once we’re done. So we may make it to beta nine or ten and we may have another week with two betas; the high tempo is just to get more checks in fast.

Experimental Physics

There have been a number of questions in the comments on the state of the experimental flight model, so I want to clarify how it works and what is happening in 11.40.

Normally, new X-Plane features get beta tested during the beta of an X-Plane patch. This means we have somewhere between two and eight weeks to debug the feature and get it ready to ship. Once it ships, if we change the feature, we have to consider how this would affect authors using the feature and whether it would screw up their add-ons.

That’s not a lot of time to debug! In particular, it’s really not enough time for the flight model, where people need months just to develop the aircraft and measure the performance to get us feedback.

The experimental flight model is basically a giant year-long open beta of a future revision of the flight model that hasn’t shipped yet. By checking the “experimental FM” box, you’re getting to beta test the flight model of the future, now. By keeping the experimental flight model as an experiment for so long, this frees Austin up to simply fix bugs and improve it, as opposed to worrying how the X-Plane 11.40 experimental FM changes will affect X-Plane 11.30 users.

To be clear: there is no attempt at backward compatibility between the experimental flight model from one sim version to another! The goal is to have the experimental flight model not interfere with the “normal” flight model at all.

Physics changes in 11.40 fall into two broad categories:

  • Simulation changes that can change how an aircraft flies, improving the accuracy of X-Plane’s predictions about the airframe. An example of this is the delay in wash propagation from the prop to the tail of the aircraft. This makes the aircraft more stable, but may change how it flies; an author might have added artificial stability or reduced control surface efficacy to work around the lack of this feature in the past, and these work-arounds would be inappropriate with the new, more accurate physics.
  • Simulations that change how the aircraft flies in unusual circumstances that you can’t tune your aircraft to. Examples of this include stalls and wake turbulence. There isn’t going to be a book value for the effect, so all we can do is try to produce the most sane results given an aircraft that simulates properly in regular flight.

Features in the first category require the experimental flight model to be enabled, while the second category of features is always on.

At some point in the future, the experimental flight model will become the flight model for X-Plane, but we are not there yet, and we are not planning to do this as part of making X-Plane 11.40 final.

Third Party Aircraft

If you develop a third party aircraft, you need to test it now against both the experimental and non-experimental flight mode. If the non-experimental flight model doesn’t fly the same as 11.36, please file a bug, and please provide flight testing details. For the experimental flight model, you may see book numbers change a little bit; the real question is whether the overall physics response is better or worse.

Vulkan and Metal

X-Plane 11.50 will be the next major patch once X-Plane 11.40 is out of beta, and it will feature Vulkan and Metal support.

The marketing guys showed the Vulkan build of X-Plane live at Cosford last week; that build did not have any support for texture paging. Since then, Sidney has a basic texture paging implementation running, so hopefully we’re in good shape to get this into developer’s hands after 11.40.

Our expectation for add-on compatibility is:

  • Add-ons doing supported things, like 2-d panel drawing and UI should just work in Vulkan and Metal – we’ll take bug reports to fix compatibility issues.
  • Add-ons doing unsupported things won’t work in Vulkan and Metal at all. Your 3-d drawing callback won’t be called, or your attempt to grab internal GL resources will just fail (because none of our resources are GL).
  • X-Plane running under OpenGL should “just work” for pretty much every add-on, including ones doing sketchy things, and should be faster than 11.40 but not as fast as Vulkan or Metal.

I expect the Vulkan beta to be a relatively long one. We want it to start this year, but it probably won’t end this year, and my guess is that initially Vulkan will be fantastic for some users and will crash for others. During the beta we’ll gain useful information about how well Vulkan works “in the field” for different cards and drivers.

One reason I am looking forward to the Vulkan beta: we now have tremendous visibility into what the rendering engine and driver are doing. With OpenGL, the driver was often a black box. We still get reports of “the 3-d mouse in VR make my machine really slow” and frankly, we may never know why this happens to just some users and not others with the same hardware, drivers, and version of X-Plane.

With Vulkan and Metal it is going to be different. A lot more of the graphics work happens inside X-Plane, and the work that happens inside the driver is much more predictable, bounded, and can be viewed via modern profiling tools.

So while we will have a lot of debugging to do based on user feedback, it should be straightforward to get the information we need to really make the Vulkan renderer scream.

After Vulkan

It’s a little too soon to discuss what comes after Vulkan, but I can say this: for almost two years now, Sidney and I have been rewriting the rendering engine with a rather strange goal: performance and predictability, but with the same visual output. So anything that looked ugly on the screen is supposed to keep looking ugly. Vulkan was a change of the how but not the what of our rendering engine.

Once Vulkan is out the door, that all changes. We have a number of fundamental changes we want to make to how we deal with light, with the atmosphere, with color, and with organizing our frame. Once we have Vulkan, we get to use it as our foundation for what comes next.

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.

121 comments on “X-Plane 11.40 Beta 8 and a Roadmap Update

    1. maybe up the res of shadows a bit? or at lest give us slider for it have tested in the data refs up to 16k for the shadow cam the frame rate is less then using reflections

      changing from cube map to screen space reflections would be nice too faster and wouldnt update at 2 fps

    2. The shadow flickering and AA is REALLY awefull and immersion breaking. The visuals get so smooth and breathtakingly beautiful, then the shadows flicker and these huge jagged lines just scream for attention :-(.

  1. This sounds fantastically interesting and exciting. More of this please to keep me away from MSFS2020! Congrats and Cheers.

  2. A big thank you to the X-Plane crew for all the hard work and thanks for sharing the details.

    1. We do have a revamp of the Plane-Maker UI on our road map – it’s something we had in mind when we hired Stefan. But things like the global mobile release are higher priority right now.

      1. Speaking of the mobile release, what’s the time frame for that? I can’t wait to fly everywhere on my phone!

  3. Congratulations for the Team!

    I really like that you published X-plane roadmap for near future. It would be very nice if you would do this after each stable release.

    One question:
    – When do you plan to switch “experimental flight model switch” to be standard one and introduce “use old flight model”? I think it is important to do so to someday force 3rd party devs to switch to new one (or in worst case left it old, but we will still have possibilities to use it).

    Thanks, have a great weekend!

    1. I feel it would be nice to have the newer flight model to be the default, while the ‘previous’ default should be packaged as Legacy Flight Model. The usual check box can be used to enable X-Plane 11 revert to LFM.

      Note since I purchased X-Plane 11 early this year, I mostly use the Future Flight Model.

      Keep up the good work. Hope the see this implemented in 11.40 beta 9 😉
      Have a blessed weekend.

      1. It really should be a per acf planemaker option, half of the addons require it nowadays, half get broken by it and it’s a pain to keep track of.

        1. If a payware add-on _requires_ experimental FM, that is an error on the part of the acf author. Because they are going to have to constantly adapt their acf with every beta.

          1. I get that that was the original idea, unfortunately it doesn’t really work in practice, many addons require it nowadays, for taildraggers it is even quite understandable.

          2. I would prefer an option in ACF to select flight model version, where the ACF devs can choose for which one the ACF is optimized .. like the flatten in APT .. first it was global only, then you added it to APT file

          3. Some of the recent improvements make it desirable to use the experimental FM, but I would imagine it’s more stuff like the fuel system changes and datarefs that ‘break’ add-ons. FM changes should ‘just’ make planes fly a bit differently, rather than be broken. Right?

          4. If a systems change breaks an existing add-on, that is potentially a bug on our side. We always aim to conserve behavior for existing, “sane” airplanes. So unless the aircraft is intentionally ‘lying’ to X-Plane to achieve a certain behavior relying on bugs, it should survive an upgrade like the 11.30 and 11.35 systems upgrade without problems. New autopilots require Plane-Maker opt-in and new systems like bleed air require the usage of datarefs that didn’t exist before, so they don’t become active unless the author asked for them.

  4. Really appreciate you all working so hard as well as your dedication to X-Plane in general. Sounds like a heckuva hill y’all are climbing, just keep your positive attitudes flying high to success!
    Thanks for this update too!

  5. Hi Ben, I have a few questions.

    1) most of the article says Vulkan beta, when will Metal for Mac be in testing?

    2) Personally, I am not interested in physics or 11.40, so 11.50 + is more my speed. Do you have plans to add in more landmarks, new aircraft(it’s been a long time;F-14?) Enhance the weather and ATC? ie visuals.

    3) Is there anyway to make airports come alive by default, like a “game”. No add ons needed. Like your pushback truck, but make ground services, jetway bridge control, more traffic, etc. These may be “arcade like” to some but, MFS has had things like this for years and it would be nice to have an immersive environment out of the box.

      1. Gotcha cool. it would also be helpful if the crash reports for Mac automatically sent to you guys. I think that broke a long time ago. Happy to give metal feedback.

  6. Hi Ben,

    Thank you very much for all the clear explanations and the precious informations!

    Always good and instructive to test XP betas… You guys and the Professor Austin are so involved to make our flight sim experience better and realistic as much as possible, that it inspires admiration and respect!

    Always a pleasure to fly with Xplane as never and to maintain some flying skills especially for a grounded pilot like me until I get back in my cockpit, hopefully soon, meanwhile I enjoy XP a lot!

    My special wish is to avoid danger and severe weather conditions which is (almost) always the case when we are clear for take off, I’d like to feel the sky more alive (it’s getting so much better with the new physics of xp, the way of thermals are defined etc plus one of the reliable engine weather addon on top of that however it’s still missing some important stuff about it, (technically more than eyes candy visualization) …
    By the way, I’ve heard that it’s also some kind of features that Austin the magician would like to bring it out in a future as he said in a video on Youtube…
    Sounds exciting!

    I just say Yes You Can, keep going pilots!

    Happy Flyings honorable Captains!

    Lknfly, LFPL

  7. I want to personally thank you guys for all the hard work you and your team are putting into X-Plane. Absolutely love it. Keep up the Awesome work!!

  8. Will you support 2 Yokes and 2 rudderpedals for Home cockpit builders?
    I know its possible in P3d and I really miss that feature in Xplane having my two Seat cockpit.

    Maybe there already is a Way to get around it? The next best solution would be a switch that could decide if the captain side or first officer side is active.

    Best regards,

    1. Maybe someday – it’s a cool feature but it is _not_ obvious to me how we would do it.

      – For an aircraft like the A320, there is an obvious non-mechanical way to handle this, e.g. the computer defines the control deflection to be the sum of the two side-sticks.
      – For most aircraft the controls are physically linked, so you can’t have them out of sync; it’s not obvious how to handle that given discrete hardware.

      1. Right yoke at +30, left yoke at +50, sim control deflection = +50. Whichever is the greater deflection. Simulating more force.

        1. Sorry to object: If the trainee uses too much bank and the trainer tries to reduce it, that wouldn’t be possible (just for example).

        2. The problem with this method is around the zero point, where there would be constant swapping – probably fine if all the sticks are hall-effect, but if you have one noisy mechanical pot (eg most yokes, cheap sticks, most if not all throttles) it’ll throw off the good one.

      2. Software switch option? Set pilot or copilot to be the priority override…so the input of a single yoke works either side but if two inputs, the priority yoke always takes precedence.

      3. I’ve always thought something like detecting a significant deflection on an axis could make that controller take over that axis. May need a bit a bit of noise filtering/averaging but that would really help my use case of swapping between yoke and joystick, hotas throttle and saitek quadrant.

  9. I think you guys are great. Plane users are like a family with you.guys leading. It’s nice to see with so many users finding the time to communicate with its users.

  10. To me the important part: ‘We have a number of fundamental changes we want to make to how we deal with light, with the atmosphere, with color, and with organizing our frame.’ I’m very happy to see that you have recognized the incoming threat, and will be fighting back to FS 2020. I’m happy for the flight model improvements, but in my opinion your priorities should lay with graphical presentation at this point, in order to hold on to that high number of users you’ve managed to capture with X-plane 11 (which again, was the result of ‘populist reforms’, not flight model improvements). Flight model is important, but you are already market leaders in that category. Tweaking the colors and making the image less gloomy (probably less fog, X-plane is the ‘foggiest’ flight simulator I’ve ever seen, and it makes it look absolutely unappealing, no wonder you’ve introduced the ‘fog_be_gone’ dataref), plus adding some contrast to those colors would be nice to see, and these improvements can be done cheaply and easily. Having more variety in ground textures (since you won’t be streaming orthophotos, a higher variety of ground textures could make the ground feel more alive), and possibly develop (or more likely purchase the technology for) 3D clouds, possibly for X-plane 12. This way you could greatly lessen the impact of FS 2020 in my opinion. And proper ATC would be nice (at least on the level of MSFS 9), but I cannot ask for everything from a team of 10 people, you are already doing great, considering the circumstances :). I’m rooting for you guys!

    1. Lighting changes have been on our roadmap for _at least_ a year before this writing, if not longer – it’s something we considered almost immediately after shipping v11. So while they may become more important due to changes in the competitive landscape, they’re changes that we absolutely WOULD make even if we did NOT expect to have direct desktop competition. That’s true for a lot of our planned updates.

      1. I do recall Ben talking about getting X-Plane to be more photometric for a long while now. Amongst this, also improving lighting conditions inside the cockpit (I believe this may also be in reference to sunlight leaking from the back of the cockpit space). I’m sure there are plenty of other artistic directions the team wish to take too, so excited to see what Vulkan opens up!

  11. A sim that is on the lead in VR will be utterly important in the near future. That include support for handtracking. Hope X-Plane really emphasis this.

    1. Agreed. With MSFS2020 stating no VR (at least for now) you have a ton of people with no plans to leave XP. The Touch controller implementation is so close to perfect. A few polishes and tweaks would go a long way.

      Automatic functionality with 3rd party aircraft for the yoke is a big one.
      Also, still waiting on the fix for the yoke not automatically returning to center after letting go. I filed a report a year and a half ago (XPD-8952) but nothing fixed yet. Really destroys the need for trim without the yoke returning to center.

      1. So do you want it to return to neutral position, or don’t you want that it returns to neutral? IMHO returning to neutral is essential due to the basic instructions to trainees: If you are in panic let loose all controls, so the plane will level itself (more or less).

        1. Right. Its supposed to return to neutral like in an aircraft. Right now if you pull completely back on the yoke and then let go, it stays in the last place you let go.

    2. VR datarefs really need to be expanded to allow 3rd party devs to work some new visual magic. Left / Right controller location and orientation and position along with the position of the end effector origin (the point of the pointer or origin of the laser. (And 2 separate wands for Vive – left/right – please. 😉 )

  12. Awesome work guys! Keep it up.

    Please do volumetric clouds! Yes, they are expensive to render, but so are the 2D clouds in the current version, so getting rid of the 2D clouds gives you a lot of frame-time to work with.

    Would also be great to see an integrated store for 3rd party aircraft; you have proven the business model with of an in-game store on mobile, and the current vendors of 3rd party aircraft are making more money from desktop X-Plane than you are. i.e. Sell addons within the sim, adding a lucrative revenue stream, then you can double the the number of developers working on X-Plane!

    1. We are definitely NOT bringing back the gamma control – ever!

      The gamma control adjusted what color space the input textures were treated as coming from. People used it as sort of a fake brightness control and this has a ton of problems.
      1. It ONLY affects textures, not the ENTIRE lighting model, so the lighting ends up massively out of sync. In some cases you can’t get more brightness, you can just make the textures look like crap.
      2. Since it applies to compressed textures, the results make texture compression look worse.
      3. It screws up the hues of the textures.

      I think the underlying feature request is a _brightness_ or _contrast_ control, and interestingly we are looking at technology that would make both of these things possible over the whole image in a much cleaner way, while being HDR-display ready. I’ll post more about this in a week or so.

      1. Well, for me the gamma control did indeed stand in for a brightness/contrast control and worked very well. If you have something better up your sleeve that’s great, but please, sooner rather than later.

    1. I’d say you moonlight in marketing. 🙂 Also, no engineer would have put True Earth on the Vulkan build that didn’t have texture paging. 😉

  13. Ben, your work in X-Plane has been fantastic… Is it too far fetched to consider licensing Googles Earth API to replace OSM streets and utilize their Photo-geometry 3D rendering of trees buildings etc.? Gotta have something for the masses leaving to MS2020.

    1. I really don’t know how they will be able to compete against their stream tech and the unfair advantage MS has by owning the Bing Maps data-set (plus a ton of related stuff) as well as using the Azure infrastructure to augment it. That’s gonna be difficult if not impossible for everyone else and would probably feels cheap by comparison.

      A good example is FlyInside FS, they too stream Bing Maps with their last 0.6 release (they are not allowed to cache the data for offline mode I think), it is nice but the result is not as good as MSFS 2020, by far (it’s an understatement). Infinite Flight too stream a 15 m “satellite world” for their mobile sim… So it is possible but by comparison, the default scenery of X-Plane still is much better overall. The satellite maps and elevation alone are not enough. Except if you do it the MSFS 2020 “augmented” way…

      X-Plane has it’s own strengths like the flight model, Vulkan/Metal, VR (even if don’t care about that one), loved by the community, decades long commitment, etc. That doesn’t mean they should not try something against MSFS 2020.

      What? I don’t know. Supnik is probably going to roll is eyes but one idea, far-fetched for the current state and architecture of X-Plane (I guess) and time and money consuming as well, would be for them to have their own data-set to stream to users.

      I wonder if it would be possible to generate high quality DSF tiles based on a, let’s say, 15 meter satellite imagery. You would still have to find a global 15 m data-set to begin with, then use that and everything else (elevation data, OSM, autogen, etc) to build a “high-res” version. Probably using some AI and procedural wizardry to create details were there are not…

      To put it more clearly I’m thinking about something like what has done but for the whole world (pole to pole) and generated based on satellite imagery (instead of some landclass?) for the ground “texture look”. It would still be “generic” DSF tiles like the UHD meshes but even higher in quality (with a kind of “satellite look”) and it would be Laminar own way of doing things, without being a “lower quality” version of MSFS 2020 stream tech like what others are doing now (with due respect to devs of course, it is still a ton load of work and commitment).

      That is what we would stream from Laminar servers. You would be able to cache it depending on your storage capacity. And there would be no difference between an online and offline mode in terms of visual quality like you are going to have with MSFS 2020. All that of course require time and money…

      On top of that, let’s dream, you could stream data (but I don’t know if it’s possible or allowed) from a site like Flightradar24 to inject real time ATC trafic into X-Plane. Imagine the immersion! Now, don’t ask me how it would merge with X-Plane ATC engine… That is Ben problem 😉

      Oh well, all that is probably stupid ideas from a dev point of view anyways… I’m just rambling. But MSFS 2020 is going to be a tough competition if it is to be as good as it seems to pan out. Maybe it is just hype we shall see…

      Regards to the team !

    2. No, no, no: No Google APIs, please: Google changes their APIs way too often in incompatible ways. I have a commercial app that once could display Google maps, then only satellite views, and finally nothing at all. Google dropped the previous APIs.

  14. Seems like more was changed in the airliner AI than just landing characteristics and climb speed… gremlins found?

    1. For the airliner AI – a bunch of bugs and issues got fixed, at least hopefully. The aiming point and glide slope were fixed, as well as flare distances. There were a few funny interactions. For example, _if_ the aircraft landed long, such that the ATC’s prediction of when the aircraft could turn onto a taxiway (which is based on conservative braking) was _past the end of the runway_, ATC would just give the AI the _first_ turn it could find (which is a terrible choice for a long, fast landing) and the AI would try to hair pin it and end up on the grass. So there were dual bugs – the long landings exposed the poor instructions, which the AI then blindly followed.

      Another long-time bug fixed: the ATC wasn’t communicating initial clearance altitude to the AI – it was in the text and audio but not the channel to the AI (which gets instructions as function calls). So every AI flying a short hop would get an “altitude spanking” clogging up radio coms. Finally fixed.

      1. Others sims maybe trick the problem with (Tower speaking) “Make next turn off”, leaving the choice which turn to take to the pilot. Then when the runway is clear, the plane is handed off to Ground, which gives taxi instructions based on the current position of the plane.

    1. Why? Because X-Plane 11 is finished? Because version numbers are so expensive? Because X-Plane 11 does not attract new customers any more?
      Actually I doubt whether you can make more money by announcing new major versions frequently. X-Plane 10 should have had better ATC already, so X-Plane 11 should have very good ATC _and_ realistic AI pilots (and ground traffic) already. Otherwise it would just be “unfinished” IMHO.

      1. Thats how devs can make money and last version of X-Plane 10 was 10.51.

        By the sound of their plans, it really sounds like they want to release a new version of xplane (xp 12) with new visuals. I don’t think they would implement new visuals in xplane 11. It will be a long journey.

  15. Nom, Information good!
    I would think the whole Xplane community is rooting for Vulkan release and for it to be a successful implementation so you can quickly build upon it.
    Thank you for letting us know your plans for some of your intentions.

    There are still bugs outstanding from long ago though such as XPD-9512 which have never been fixed.
    Given this bug pretty much renders (pun not intended) reflections useless because nobody wants to use them because a) the horrible bouncing bug and b) the insane cost to performance (especially if you are CPU limited) and has not been fixed I’m wondering if this persists in you internal Vulkan build and if reflections and ground shadow rendering remain as costly as now?

    I’m hoping vulkan allows for the further beautification of Xplane with later releases once you have good data. Micro who?

  16. X Plane Priorities:

    1. Vulkan, multi-core and loading fixes.
    2. 3d clouds, maybe with Truesky?
    3. Much longer view distance, and end the sudden weather transitions. Further autogen draw distance.
    4. More detailed autogen. Make more types of default autogen and a tool for community to easily build out regions.
    5. Weather shader effects, snow/water buildup etc.

    1. Most of your list are really requests to intel to ship a 10ghz processor.

      2, 3 and part of 4 are well within LRs power to do today, but it’d melt your computer.

    2. No offense, but this isn’t really a request forum, and alot of these have already been stated by Laminar as goals already.

      All great achievements come with time…

    3. I hope for added attention to support more cloud layers….
      the weather engine needs extra love and attention as well to keep up with competition…

  17. Thanks for all the hard work!

    I recently picked up Aerofly FS 2 – it does a few things better than x-plane. Mostly the sky/hdri tone map (but not the lighting, which is basically static except the sun) and can drive a 5K display at ridiculous FPS.

    But, it doesn’t feel like flying at all. I took an F-15 to Mach 2.4 at 500 feet. I flew a 737 inverted with my hands off the controls. While the mix between objects and satellite imagery is pretty good in city centers, everywhere else it’s like playing Falcon 3.0.

    So. While I am excited for x-plane to get a little more cinematic (and for clouds to not be transparent at night??) and for ATC to stop vectoring me into mountains, I really really really appreciate the existing and especially experimental flight model. Holy crap.

    Everything else still feels like flying on rails compared to x-plane.

    So while I used to complain about FPS for silly reasons, now I am excited for metal so that we can get through the render loop faster for more flight model passes (yes yes I know about the slider)

    Thanks! Find a way for me to send you guys some more money.

  18. First I want to say that i absolutely love XP and I am really looking forward to see the wonders you can make with this sim. One thing I have been disturbed obout since I first bought XP is the ugliest thunderstorm lightning I have ever seen. It actually looks like a 3 y.o made it. Could you please fix something more exciting? A little bit more dynamic?
    Keep up the good work.

  19. Loving the new experimental flight model. Helicopters feel a lot more stable and controlled while hovering.

  20. Hi Ben,

    Great info and very much appreciated – thank you for all your hard work!

    Question…For users running current middle of the road graphic cards, will the move to Vulkan/Metal, allow them to experience greater frame-rates than that offered by the current OpenGL method?

    Thanks again!


  21. My short list for 11.50 is:
    – Major increase of FPS performance by multi-core and GPU optimisation
    – Fully functioning and reliable VFR and IFR ATC
    – Fully functioning and believable weather system (like Active Sky XP) combined with visually credible weather and atmospheric system
    – Overall graphics enhancement from dull colourless world to more lifelike colours, lightning and shadows (implement true HDR)
    – Better management of add-ons

  22. Do you have considered something like scenery and plugin organizer with

    – scenery check to reduce errors during flight and maybe detect errors in order or duplicates
    – scenery “pre-compile” to speed up scenery loading during startup and during cruise, because the checks are done
    – plugin (de)activation for plugins in plugin and scenery plugin folder

    I can’t count the posts in forums/on facebook regarding scenery order, plugin problems, …… which i see every day

    And i would like to see postponed scenery reload (or in background with much lower priority) and weather update during approach, maybe f.e. when height <200 above ground

    This are the things that annoy me most, especially when i crash the landing because scenery reload kills the fps to 1 digit numbers

    1. I’m surprised: When landing (final approach) all the scenery tiles should be loaded already, so I wonder what’s going on.
      I don’t know who X-Plane loads scenery, but obviously “near scenery” should have absolute priority over “distant scenery”, meaning if frame rate drops, drop loading distant scenery tiles.
      I also think X-Plane always loads full resolution scenery tiles. AFAIR Flight Unlimited II had some patented scenery encoding that had increasing layers of details, loaded as you got closer. At that time CPU cycles and RAM had to be saved. Today you can watch the satellite maps in Google maps loading more details incrementally. Maybe that could help X-Plane to get some faster rendering, but I don’t know.

  23. Nice; I’ve been flying with the experimental flight model and the 11.40 betas and so far liking it.

    One nice thing with the experimental flight model would be to make it a per plane preference instead of a global one. Mostly I fly with the experimental flight model but there may be a few planes for which this simply does not ideal.

    What’s the timeline for experimental flight model changes to stop being experimental? Is that with the next major release or still within the 11.x series?

  24. Hi Ben, I’m curious if Vulkan/Metal will improve the following issue:

    I noticed during flight on my Windows based machine the frame rate tanks significantly for several seconds when the hard drive is initially accessed to start loading the next set of scenery tiles. Once the load is in progress, the frame rate/smoothness starts to improve somewhat. When the load is completed, performance returns to normal.


    1. I would say if you _still_ see this in the 11.50 edition we may want to look at it. While an SSD will do you a world of help, there shouldn’t be any synchronous disk IO on the main thread in the Vulkan edition…if there is, we should fix it.

      1. I could make a video clip that shows the simulator’s performance drop with the task manager opened to the performance tab, which will show the activity of the CPU, GPU, and drives.

        1. That video would _not_ be useful for us. If you still have the perf drop in 11.50, file a bug, and someone will send you instructions for how to use a performance capture tool like ETW to capture a trace we can analyze.

    2. The other scenario that will cause extremely bad frame rate, along with subsequent stutters, is ortho-scenery, eg TrueEarth on machines with not enough ram. The problem there is the OS will swap RAM out to disk.

      I’m just testing my own ram upgrade from 16GB (not quite enough) to 64GB (overkill) by flying 500kts from south coast UK northwards, using 16x ground-speed, with Orbx TrueEarth GB. On windows, using Win+G, you can monitor the memory usage – worst case it got to 33%, about 21GB, but typical case was around 16GB (so you WILL get swapping in all cases).
      With the new RAM, I no longer got huge second-long pauses. But the frame rate was mostly at 19fps instead of 40+, until you set ground-speed to 1x, and let the scenery loader catch-up.

      Ben, do you think X-Plane’s frame-rate display should show when you’re running out of RAM?

      1. We don’t know when you’re running out of system memory, but there are lots of OS tools to show paging. IF you’re paging system memory to disk, get more RAM or turn things down. X-Plane is absolutely not designed to provide sane performance under paging.

        We will be able to show VRAM pressure in Vulkan for the first time. We may be able to show it in Metal under Catalina – we’re not sure about those APIs yet, but we do know how much we used.

        1. the issue is the sim isnt cleaning up after it self in windows ie. after it loads new textures its not UNLOADING the old ones you can OOM your self just swaping liverys if they are high enough res and you load enough of them
          so when people use lots of orthos and detailed scenery it just all keeps piling up in ram and the sim never clears out the unused textures

          1. I use Win 10 and 64 GByte RAM and orthos.
            After a while there is no more free memory, all 64Gbyte are used.
            Not really. About 40GByte are working as a file cache, holding unused but still valid data.
            But for memory demands this mem wil acct like free mem, it is ready for use, no write back, no write to the pagefile.

  25. How does Vulcan and metal affect networking,? If at all.? Any progress on the networking code? In the synchronization of the flight models over the wide area network i.e. Internet? Could you please add a topic for network in the “category section” it’s all about multiplayer now, and multi crew. But more importantly, multiplayer. But you know that already. Thanks, Ben.

  26. Xplane is by far the best flight model of all of them. I’m a former Fsx and P3d flyer. I fly VR only. Love it. Never going back to my 3x screens / Trackir.
    I purchased Flyinside and FS2. Great VR experience but “on the rails” flight model.

    Flyinside and MSFS both use scenery as you go cloud / bing. Flyinside is fairly rudimentary vs the MSFS implementation. I think that this is the future of flightsimming.

    Ben would you care to comment on this new technology? Is it something Laminar should be considering?


    1. We are not seriously considering using bing maps as an imagery source, although we _did_ consider writing a request to see how long it would take the bing team to figure out we were a competitor to another MS product. 🙂

  27. Currently, many plugins are using custom hacks to grab 2d panel texture and use it while drawing custom 2D ui. I guess this would not work with Vulkan. Could you please introduce some support for such drawing which would work Vulkan/Metal? Maybe add get2dPanelTextureID() to SDK? I think that would be essential for many addons. Many thanks!

    1. Depending on how it is done, this will probably just work, and is not considered to be a hack. In particular:
      – glCopyTexSubImage2D _will_ work from a panel drawing callback, even in Vulkan and metal.
      – glReadPixels will work, but *don’t ever do that* – use glCopyTexSubImage2D to avoid the fps hit.

      You should _not_ be reading the panel image back to the CPU in Vulkan or OpenGL – it will work in both, but the cost of bringing those pixels back to the CPU will be almost an entire frame lost. Hopefully everyone is keeping the panel entirely on the GPU. (The FPS hit of glReadPixels will be the same under Vulkan and GL.)

  28. Do we expect multi-monitor support to be much better with Vulkan? I currently run 3 1080p displays on a Nvidia 1070 (I know, not the greatest setup, I’ll upgrade soon). When I use Nvidia span, I always get much better performance today than if I setup 3 different displays in X-Plane, and I haven’t understood why that is.

    1. We do expect to increase the CPU side performance with Vulkan, but I don’t think we’ll be able to beat Nvidia Span. The unfortunate truth is that Nvidia Span is faster because it does less work, and we can’t emulate that behaviour from within X-Plane.

      The way it works if you let X-Plane run all three monitors, is that X-Plane will create three windows for each monitor and three virtual cameras for each window. To render a frame, X-Plane has to separately render each of the three cameras which means it’ll have to do rendering command generation (this will be faster, but not by 3x) as well as re-do culling decisions to figure out what’s visible on the screen. None of this is very fast, and it needs to be done three times.

      With Nvidia Span on the other hand, X-Plane is only a single window with a single virtual camera. Nvidia does the work of spanning that single window across all screens, which is only possible by the driver itself. So instead of 3x rendering command generation and culling, X-Plane will only have to do it once.

      Even if by some miracle you have a config where rendering a single window is 3x faster, so running Vulkan allows you to drive all 3 displays at the same FPS as using Nvidia Span right now with OpenGL… Well, you’d get a huge FPS booth by using Vulkan and Nvidia Span together, because it requires X-Plane to do even less work.

      1. Great answer. Makes perfect sense. Nvidia span isn’t nearly as nice as configuring 3 different displays due to the distortion, so I’m sticking with 3 independent displays.

  29. Hi, congrats to Vulkan.

    Do i read right: All not vulkan supported 3rd party (Scenery/Aircraft’s) will not work at or after 11.50 ?

    So all my add-on’s OpenGL base will then not work anymore ?

    How do we get all the OpenGL things converted ?


    1. 1. You did NOT read right. Many OpenGL add-ons will just work. And non-_code_ “just works”, e.g. a scenery pack of OBJs, DSFs, etc. just works.
      2. It whether your add-on’s OpenGL will work or not work depends on what it is doing.
      3. There are no Vulkan ways to do in Vulkan the things you cannot do in OpenGL (under Vulkan). So if you rely on these paths, your add-on is GL-hosted only.

  30. That sounds good Ben I ask because of I spend a lot of time in get XP11 that looking I like. And it will be worse for me as end consumer if all my aircraft’s and scenery broke that I have purchased.

    XP 11 is now at an point we’re we have a good aircraft fleet coverage. And it’s some kind of frustrating if this may broke due to vulkan and we must wait another couple of years of 3rd party devs updates that the fleet is alive again.

    Last thing for me now is, you write above that manipulating the Gamma will affect stability or errors ? What is your advise pointing the actual beta about Gamma (NIVIDIA Tool / Plugin correction) ?

    Thanks in advance


    1. Right – depending on the add-ons you use, when 11.50 comes out you might have to keep using the OpenGL version of the sim to keep using your add-ons. This is why we are trying very hard to not break add-ons in the OpenGL version even as we restructure the rendering engine.

      Re: gamma, my advice is to leave gamma alone – X-plane is meant to run on a calibrated sRGB monitor.

  31. This is a GREAT concept and gets as close to the real thing as it can get.
    I hope a good part of the revision/update strategy will be in the VR mouse arena.

    Flying VR mode, WITHOUT a reliable VR mouse, (or SOME ability to adjust knobs, switches, etc.) is like: waiting to take your brand new MERCEDES for a spin–but the key for it DOESN’T work!!!

    Overall an excellent game (when things are going well), but I’m waiting for the final product!

    Hopefully, VR mouse problems, (and any other annoyances that I have yet to discover) will be a thing of the past!

  32. It seems that XP11.5X will be the last of the 11 version. And it is going to have 2 major changes: New flight model and New rendering.
    I know you plan to substitute both of them, but I would BEG you, to leave just for XPlane11.5X final version a option to start xplane in default OpenGL and leave the option to have the physics we have now and leave the experimental flight model also as it is.
    I am not changing my planes as what is A today, tomorrow is B, so when you finish your product, we, the third party developers won’t have so much time, and a lot of work will be needed to make our planes compatible with the “old” 11.5X, when soon there will be a 12.0 that will catch most of the people. So Maybe we won’t like to make some of our addons 12.0 compatible, and would need a lot of work for just a few users that would continue using 11.5X.
    Even I would say that there are developers that left XPlane and won’t modify their addons, but they are still to use for lot of users, and not be able to choose the old rendering method or the old flight model will make those addons loose for ever.

    Of course we think 12.0 has to be a new start with new rules, but please don’t put things difficult to us. Of course we will make things compatible with new rendering and flight model methods, but leave the user the option to continue using our products as always until 12.0 is out.


    1. Javier, I think we’re already planning to do this.
      – As we have said before, we are NOT dropping OpenGL support for the entire v11 run. (Although I also expect that your aircraft will just work in Vulkan – what crazy thing have you done that would stop this? 😉 Remember, custom panel drawing in GL _works_ in Vulkan.

      – The experimental FM is experimental, and even when it becomes the official one, if that happens during the v11 run, you’d have to resave your aircraft to opt into it, so legacy aircraft would be unchanged.

  33. Hi Ben Supnik.
    With Vulcan coming, will it be possible to implement “heavier” graphic loads to the game?
    For helicopters with SAR it would be amazing to have “external camera” viewing downwards to the ground so the pilot could see what’s going on beneath the helo (on a monitor in cockpit mode).
    For now it’s not possible for the devs to make this, and flying a helo in 3rd person view isn’t optimal.
    I have been working a lot at making missions for helicopters, only to find out that a monitor option like this isn’t possible yet.
    Thanks in advance for any answers! 🙂

    1. You can do this already in X-Plane. Choose, “Build Weapons” from the expert menu in Plane Maker, then and a weapon with guidance set to “TV guide”, and add the “TV guide” instrument to your panel.

  34. Hi again,

    finally i switched now back to the latest stable version 11.36r2.
    For me there was no stable beta above. 2-3 hours flight and then random crashes in all variants. Hard crashes without logs and then some crashes with log and started 2nd XPlane.exe instance in taskmanager. No joystick profiles was saved. Cumulus bug again displayed in weather briefing FL350-450. Cirrus ? Then i get in the latest beta in experimental and none experimental flightmodel random prop overspeeds in turboprop. Also with limiter/govenor enabled. Some tricky in departure.

    Big test was 10thOctober from Seatle to Atlanta ferry flight, DO228, FL250. Eastbound. Trip planned under the bizzard for good groundspeed. But there after 3hours it kicked me out CTD.

    The last step was to start vanilla without plugins. 2-3 hours also crash. I noticed that for me it was every time weather related. If i am heading bad weather. I turned weather to custom and no crash for 6hours.

    Maybe the 11.36r2 is the maximum performance for XP11 stable at all ?

    11.36r2 more stutters but stable.


    1. this is related to the sim again not cleaning up after it self properly and doing garbage collection im HOPING that with Vulkan since they have manage there own stuff this gets fixed but it could just make it worse

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