4 ms·
How X-Plane Works
- krackers 2y agoThe developer's blog is really cool, has lots of neat practical opengl insights and stuff https://hacksoflife.blogspot.com/ https://hacksoflife.blogspot.com/
- smusamashah 2y agoJust watched the trailer, are those in-game graphics or is that a specially rendered trailer? It looks very realistic. Edit: in game graphics are pretty amazing https://youtu.be/Y35JsotTCNQ https://youtu.be/Y35JsotTCNQ
- delta_p_delta_x 2y agoThose are in-game. If you feel that was realistic, you should see what Microsoft Flight Simulator 2024 looks like[1]. [1]: https://www.youtube.com/watch?v=A4zEesJbKqE https://www.youtube.com/watch?v=A4zEesJbKqE
- amai 2y agoBut the MS Flight Simulator is not available for Mac. X-Plane on the other side is available also for Mac, Linux, iOS and Android.
- wkat4242 2y agoHmm several of those scenes look better in fs2020. Also many comparisons were made in totally different lighting conditions and aren't comparable. Like some taken at dusk in one version and daytime in the other. One thing that is noticeable to me is that they finally fixed the runways. In fs2020 they all look like they were built this morning, all pristine and saturated black. Anyone who flies for real knows that's very unrealistic :) Runways get very little maintenance and cleaning because they want to keep them open for traffic. The fs2024 look much more realistic.
- aitchnyu 2y agoIs FS 2024 low-poly or does flatter colors and bright lighting make it so?
- tomaskafka 2y agoIt’s fresh and buggy, the LOD system seems to make some areas have much less detail than necessary, and fix is being worked on (it’s among a top 3 issues in issue tracker)
- wkat4242 2y agoYeah there seem to be lots and lots of bugs involving VR too and they're very slow to fix them. Some of the fixes have been delayed to the second sim update So I hardly tried it yet myself. I'll just wait until it works properly. And I don't do flightsims without VR.
- tomaskafka 2y agoYep, I take it as having purchased a Flight Simulator 2026 with a bonus of early access to the betas. It will be a great game when it's finished :).
- wkat4242 2y agoYeah and at least we have 2020 which is pretty good by now. It was worse when 2020 first came out with so much stuff broken or missing (eg VR support). The only alternative I had then was X-Plane. Which is not bad but decidedly previous-gen in terms of visuals. Ps I really wish FS2024 would implement X-Plane's ergonomic yoke option for VR. I really miss that one.
- deleted 2y ago[deleted]
- t0mas88 2y agoFor the hackers around here: There is a plug-in by NASA called "XPlaneConnect", that allows you to control aircraft in X-Plane from code See here: https://github.com/nasa/XPlaneConnect https://github.com/nasa/XPlaneConnect I've used it to write some Python code that mimics upset recovery procedures that we teach human pilots. It's quite fun putting an aircraft in a tricky position and then seeing your code recover it nicely to straight and level flight. (Or seeing your code roll it over and fly it into the ground if you got the math wrong :-))
- disposedtrolley 2y agoI wrote a rudimentary autopilot in Go that used a Kalman filter to maintain straight and level flight. It was a fun exercise!
- auspiv 2y agoAnd I wrote one in Python to climb/turn as well! And to navigate to any of the built-in X-Plane navaids - https://austinsnerdythings.com/2024/04/06/adding-track-following-direct-to-with-cross-track-error-to-the-python-x-plane-autopilot/ https://austinsnerdythings.com/2024/04/06/adding-track-follo... and the first post in the series - https://austinsnerdythings.com/2021/10/15/creating-an-autopilot-in-x-plane-using-python-part-1/ https://austinsnerdythings.com/2021/10/15/creating-an-autopi...
- MPSimmons 2y agoI did a similar thing in Kerbal Space Program using krpc (though less for human training and more for fun) - https://github.com/standaloneSA/krpc_state_machine/tree/master https://github.com/standaloneSA/krpc_state_machine/tree/mast...
- cashsterling 2y agoAt a startup I worked at, we had our adaptive control pilot software flying our drone designs in XPlane for testing and demo purposes.
- davedx 2y agoWhat happens if you put a Boeing 737 MAX airframe into this simulator?
- snvzz 2y agoIt nosedives randomly? (if accurate)
- delta_p_delta_x 2y agoStrictly speaking the airframe of the 737 MAX is airworthy and stable, and it should remain straight and level given the physics simulations of the airframe. Whether or not it nosedives would depend on how accurately the problematic MCAS systems (which then actuate the flight surfaces) are simulated.
- arghwhat 2y agoWithout MCAS, the 737 MAX has a significant pitch up tendency. You can actively trim your way out of this, but it might be a quite notable effort. It is airworthy, but that does not mean it is automatically flying straight and level. With working MCAS, it should fly roughly like the pre-MAX version, with automatic trim adjustments to hide the significant pitch up tendency that the pre-MAX version with its much smaller engines did not have. With a buggy MCAS with the failure conditions met, you might have sporadic significant pitch-down. (... And with a blown load reduction device in the left engine, e.g. from a large bird strike, you'll have the cockpit filled with smoke at fatal toxicity within 39 seconds, but despite being completely avoidable by flicking one switch, and despite also affecting other aircraft with similar devices, the FAA doesn't find it worth any immediate action.)
- tzs 2y agoAll documentation I've seen says that MCAS only activates when the plane has a dangerously high angle of attack, flaps are retracted, and the autopilot is not engaged. Almost all flights other than by test pilots or air show pilots will never have MCAS do anything unless it receives faulty sensor data, as was the case in the two crashes.
- lars_francke 2y agoSorry for the slightly off-topic question: As a "kid" I loved Flight Simulator (this was 25+ years ago). If I wanted to get back into it today are there any recommendations what to use/get in terms of software and hardware today for a beginner? I did briefly (1h or so) try Flight Simulator 2020 but I was missing a kind of tutorial path starting with an absolute beginner. I might misremember this though! So: Any recommendations on software, hardware, tutorials? I'm not looking to become a pilot, just spend a few hours every week learning a bit and having fun.
- delta_p_delta_x 2y agoFor software, you're looking at, in no particular order: - X-Plane 12 - Microsoft Flight Simulator 2020/2024 - Prepar3d (fork of Flight Simulator X) - FlightGear (free, open-source) - Digital Combat Simulator World (aka DCS World, combat flight simulation; specialises in jet fighters) - Orbiter 2016 (space flight simulator; also free) Modern flight simulators today are generally quite intensive on hardware—especially the CPU—even at low rendering settings. The article is a great example; all of these calculations are fully CPU-bound. It is strongly recommended to get a high-frequency, high-core-count, large-cache CPU—this is probably any of the 3D V-cache Ryzens (5800X3D, 7800X3D, 9800X3D). A _decent_ GPU is recommended for graphics eye candy, but not strictly necessary for accurate flight simulation if you're happy to turn the graphics knobs down (although I've heard that FS2024 has offloaded some weather and physics calculations to the GPU; don't quote me). For simulation hardware, you can't go wrong with a Logitech Extreme 3D Pro joystick which is fairly inexpensive new (https://www.logitechg.com/en-gb/products/space/extreme-3d-pro-joystick.html https://www.logitechg.com/en-gb/products/space/extreme-3d-pr...), although you can actually still use mouse + keyboard if you're more interested in simulating the systems and procedures of jet airliners. Tutorials: I do believe the game simulators have built-in tutorials, though it's been a while since I've followed any of them. Searching for '<flight simulator> Cessna 172 VFR tutorial' is a decent place to start. For a more structured work-through, PilotEdge (a virtual ATC network) has some: https://www.pilotedge.net/workshops https://www.pilotedge.net/workshops Speaking of virtual ATC, at some point you'll get bored of being the only person simulating. All the game simulators have a multiplayer option, but if you want to get serious with the role-playing, VATSIM is a great place to start and has worldwide coverage, depending on when ATC providers log on. I've found that European ATC is generally online on weekday evenings UTC, and American ATC is generally online on Saturday mornings (UTC) and at the weekends. PilotEdge has more limited, but more round-the-clock coverage, and is a paid network, and takes the seriousness and realism to the next level.
- epaga 2y agoLooks like Austin found an editor to clean up his texts which otherwise end up super nerdy and way too long. This is excellent, readable, and punchy. Makes me consider getting X-Plane 12 even though I already have 11 (and MSFS 2020 and 2024).
- jhpankow 2y agoChatGPT
- rkagerer 2y agoHow's the simulation of planes in Kerbal Space Program or Juno New Origins work compared to this?
- sand500 2y agoI don't think vanilla KSP aerodynamics simulate airflow at all. You could have wings clipping and they would still pretend to be generating lift. The F.A.R. mods adds much more realistic aerodynamics.
- rkagerer 2y agoThanks. Does FAR use a similar strategy as this or something different?
- lutorm 2y agoSo, as I understand it, the wing is broken down in sections, each of which will use some tabulated lift and drag for that airfoil at the current velocity vector and dynamic pressure? That seems fine. But it doesn't talk about how it deals with the fuselage and how it calculates its lift/drag. Calculating pressure drag is complicated and depends on the details of the airflow around the fuselage, and there's intersection drag at the interfaces with the wings/empennage. A significant portion of the drag for piston airplanes is also the cooling drag of the air that's forced through the cowling and the engine baffles. Does anyone know to what extent this is taken into account?
- boricj 2y agoI'm not knowledgeable enough to tell if there are answers there, but some of these questions might be addressed in the deep dive of the F-4 Phantom modelization. https://developer.x-plane.com/2022/02/x-plane-12-flight-model-update-supersonic-transition-delta-wings-and-mass-properties/ https://developer.x-plane.com/2022/02/x-plane-12-flight-mode...
- SkyPuncher 2y agoThis is a good read
- martijn_himself 2y agoIn my experience this also uses tabulated data or simplified equations based on some geometric parameters (such as the exposed surface area). For the purposes of simulating flight, ball park figures are sufficient to get a reasonably accurate representation of an aircraft's behaviour and stability in various flight conditions. The additional accuracy you get from fluid dynamics simulations is computationally expensive and usually only needed in aircraft design.
- ramses0 2y agoThere was an ooooold DOS game called Flight Unlimited that correctly(-ish) modeled flaps, rudder, etc, and ran you through a flight school to teach barrel rolls, Immelmann turns, etc. I've been looking for an Xbox/Console game that lets you fly and crash a plane, shoot things in a game-like context, not slide around in some space invaders bubble with laser turrets painted to look like missiles. Flight Simulator misses the mark (I think) because it's not so game-y. All the fighter jet games I've tried miss the mark because their physics is way too arcadey. Any recommendations?
- tomaskafka 2y agoGreat article! However the kick into MSFS imo isn’t necessary, as it appears to use blade theory and CFD just as well: https://news.ycombinator.com/item?id=32073528 https://news.ycombinator.com/item?id=32073528
- Stevvo 2y agoThe article doesn't mention MSFS. However, MSFS does not use blade element theory, but a unique system of "normalization". https://docs.flightsimulator.com/msfs2024/html/7_Samples_Tutorials/Tutorials/Tuning_The_Flight_Model/Basic_Aerodynamics.htm https://docs.flightsimulator.com/msfs2024/html/7_Samples_Tut... CFD is only used in a couple of the dozens of aircraft in MSFS. It still uses the "normalization" process that feels a lot like stability derivatives. It can give good results, but overall the system in MSFS is too complex with too many parameters to tweak, leading to nearly all aircraft modeled having quite innacurate flight characteristics anywhere outside the normal flight envelope.
- sho_hn 2y ago> The article doesn't mention MSFS. It does, in the last paragraph.
- deleted 2y ago[deleted]
- paulgerhardt 2y agoThanks to the massive GPU/APU wave we’re starting to see some very fun demos using realtime computational fluid dynamic simulations instead of blade element models [1]. This would let you accurately sim helicopter prop wash on landings, wake turbulence, and some of the more extreme flight characteristics of the Alaskan style STOL aircraft with bush wheels and snow mobile engines [2]. In particular Blade Element simming struggles when one is riding the stall envelope as seen in the later field of aviation. [1] https://youtu.be/RIxrN7yedyQ https://youtu.be/RIxrN7yedyQ [2] https://youtu.be/B-brmk1ua1g https://youtu.be/B-brmk1ua1g
- zombot 2y agoI so miss that past X-Plane version where you could build your own planes and even fly around (and spectacularly crash) in the thin Mars atmosphere. And planes were still completely controllable from the keyboard.