Flightsimcon Videos

We've gotten a number of requests for video of the conference. Chris just posted these on our Youtube channel:

And the accompanying slides:

This is the original of Chris's VR demo - he looks super dignified with the HMD on.

Finally, here's video of the panel discussion from Saturday afternoon.

This one wasn't recorded by us.  There was a "serious" video camera at that event, so if there's video with a direct feed from the mixer, I'll post it.

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Posted in News | 80 Comments

Flightsimcon 2017

I just got back from Flightsimcon (I live close enough to Hartford that it's a day trip for me), but the show is still going on, and as you might have heard, we have X-Plane set up with built-in VR at our booth -- you can try it! Austin, Philipp, Chris, Marty, Alex and Jim will all be there tomorrow, so stop by if you can.

If you're local, stop by tomorrow - seeing the MD-82 cockpit in real stereo 3-d is something else. I've been working on VR support (on the rendering side) for the last few weeks and it's really made me appreciate what our art team does.

I also wanted to say thanks to everyone there who has been supporting X-Plane, and also to the rest of the LR team who didn't attend but who did the hard work that made today's announcements possible.

There is video of our presentation - if there isn't a better recording, Chris taped the thing, so we'll get it posted probably some time this week.

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Posted in News | 46 Comments

WorldEditor 1.6 Release Candidate 1 Is Here

Posted a few minutes ago: WorldEditor 1.6 release candidate 1.  RC1 has a bunch of key bug fixes, is gateway-ready now, and can edit X-Plane 11 truck routes.

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Posted in News, Tools | 37 Comments

Blender Exporter Testers

Ted and I have been working on a new version of XPlane2Blender for Blender 2.5. The new version mostly focuses on bug fixes and optimizations to get perfect WYSIWYG output from Blender to X-Plane with optimal OBJ code.

If you use the version 3.3.x of this exporter and would like to try test builds, please email me. We have a suite of test cases that we run the exporter through to confirm that it is operating properly, but it's also useful to run it on real-world examples to see if there are cases we missed.


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Posted in Development, Tools | 12 Comments

Roll Over Beethoven (and Pilot’s Head)

Long overdue, coming in 11.02 beta 2:


That's a new dataref that (finally) lets plugin authors tilt the pilot's head.

Previously this had to be done by manipulating the multi-monitor view offsets. That method worked (barely) but doesn't work with multi-monitor in v11.  The new dataref is multi-monitor friendly.

(The new dataref is also FMOD-sound-friendly -- that is, when you roll your head over you'll hear sounds above you out your left ear, as expected.  Monitor offsets do not do that - only the pilot's true virtual head position affects sound.)

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Posted in Development | 17 Comments

RFC: Plugin-Drawn Map Layers in X-Plane 11

We’re working now on updating the map drawing SDK for compatibility with X-Plane 11.

This post is a request for comments from programmers who write plugins that used to draw to the map—it is not a place for general feature requests for the map, or for off topic comments. (And off topic comments will be deleted.)

Background: What broke the map drawing in the first place?

Long story short, the map has changed drastically since the X-Plane 10 version—it didn’t just get a fresh coat of paint.

The biggest obstacle to backward compatibility comes from the fact that we now use an honest-to-God cartographical map projection for map coordinates. Moreover, the map projection changes for different map types—the normal map UI uses a transverse Mercator projection, while the GPS units use a stereographic projection. For that reason alone, just “splatting” old drawing code on top of the new map would not give you the results you want… the old OpenGL local (x, y, z) coordinates do not have a straightforward mapping to the new projected latitude/longitude locations.

A second major change is the fact that the map can now rotate to match the heading of the user’s aircraft. Unless you like the possibility of your map labels being printed upside down, this requires awareness of the map’s rotation and the fact that north isn’t necessarily “up”.

The final big change comes from the draw order. The map is now very strongly divided into layers, and we draw in 3 stages:

  1. Backgrounds (e.g., terrain)
  2. Icons (e.g., airports, NAVAIDs, etc.)
  3. Labels

An individual layer can draw in any or all stages. (For instance, the airports layer draws both airport icons and labels for each icon.) We draw each stage from the bottom layer up, beginning with the terrain at the bottom, then the NAVAIDs & airports somewhere in the middle, and then finishing with the aircraft at the very top. This layering ensures that bigger or less important elements don’t cover up smaller or more important elements—your aircraft, for instance, will always be visible (and selectable), even if it’s in the exact same place as a fix or NAVAID. Likewise, the label for your element will always be visible even if the actual icon is obscured by something above it. (In practice, of course, readability is going to be poor if you have labels overlapping, but that’s not really solvable without much more powerful cartographical tools than we have now.)

While it’s not essential that plugin drawing code respect the layering draw order, it would certainly be nice—it would allow you to ensure that a) your plugin-drawn layer doesn’t cover more important info, and b) less important info doesn’t cover your layer.

Proposed API

With all that in mind, our proposed API for map drawing looks like this:

  • Plugin code would call the SDK to create a new map layer. To do so, you would provide:
    • An optional drawing callback for OpenGL drawing (which would be layered beneath all built-in icons & text, but above things like X-Plane’s terrain drawing).
      • OpenGL drawing here is more or less a “free for all,” with one exception: manipulating the Z buffer is not allowed, due to our reliance on the Z buffer as a means of preserving layer ordering.
    • An optional icon callback, where you would provide a set of PNG icons to be drawn, along with their heading, opacity, etc., and X-Plane would “splat” them onto the map above all built-in icon types except the aircraft
    • An optional label callback, where you would provide a set of strings for X-Plane to draw above all built-in labels except the aircraft label
    • An optional “prepare cache” callback, called whenever the map’s total bounds change (e.g., when the scenery loader loads new DSFs). This allows you to keep your drawing callbacks fast, since you can cache only the data you need for drawing in the current area.
    • A flag to indicate whether you’d like your new layer to be disablable from the UI (if so, we would add a checkbox to the right-hand sidebar like we have now for the flight path and compass rose)
  • Drawing, icon, & label callbacks would receive:
    • The currently visible bounds of the map
    • The current zoom level of the map
    • The map units per unit of UI coordinates (useful for drawing text at a fixed size regardless of map scale)
      • If your layer is drawing in the standard X-Plane map window, this is map units per boxel; if you’re drawing within the GPS unit, it’s map units per “virtual device pixel,” whose size in real screen pixels is of course fluid since the user can move the camera relative to the GPS in the panel.
    • The map’s current mode (currently one of either sectional, low enroute, and high enroute)
    • An opaque handle that provides access to the new projection APIs. The projection APIs would provide the following functions:
      • project a latitude & longitude into map coordinates for drawing
      • unproject an (x, y) pair of map coordinates into a latitude & longitude
      • get the scale, in map coordinates, of 1 meter at a given (x, y)
      • get the heading (in degrees clockwise from “up”) corresponding to north on the map for a given (x, y)—this is necessary since the X-Plane 11 map can be rotated to match your aircraft’s orientation
  • Relative ordering of plugin-created layers would not be guaranteed. So, if you had two plugins which drew the same icon in the same place, but one drew in red and the other in blue, we would make no guarantees about which color the user saw. (And, indeed, some users may see red and others may see blue.)

Questions we have

While the proposal above meets what we believe the needs of third-party developers to be, we almost certainly haven’t considered every use case for this API. (And it’s possible we’re missing important features even for the use cases we have considered!)

To that end, here are some question you, dear plugin developer, can answer for us:

  • What’s your use case for the map drawing API?
  • Does the proposal above sound workable for your use case? (If not, what’s missing, or what would you change?)
  • Do you like the idea of allowing plugin developers to specify whether their new layer is togglable from the standard map UI? (If not, why, and what policy would you like to see instead?)
  • Do you have a use case for click selection and click-and-drag functionality in your plugin-created map layers? (This isn’t on the table for the initial update to the map API, but it’s a possibility for future updates.)

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Posted in Uncategorized | 32 Comments

FMOD Video Tutorial

We have a new video tutorial on using FMOD to add custom sounds to X-Plane 11. This simple tutorial shows how to add a snapshot and an event in FMOD.

The video also has a permanent home on the video page of this site, and on the X-Plane YouTube channel.

As always, let us know your thoughts in the comments and if you have requests for other tutorials. I'm starting to get the hang of creating movies, and if you don't troll me too hard about the quality I might make more. 😉

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Posted in Aircraft, Screencasts | 12 Comments

Suddenly surrounded by heliports? How to configure airport criteria for aircraft

With X-Plane 11.02 the built-in GPS and FMS units for X-Plane 11 aircraft will also display heliports and seaplane bases. While this change is obviously needed badly for the helicopter flying community, improperly configured fixed-wing aircraft might suddenly feel themselves confronted with unsuitable options in the nearest airport selection pages and on the moving map.

Filter criteria

Every X-Plane aircraft has three parameters for airport and runway filtering that can be used to configure the moving map. These settings have existed for a long time, influenced which airports were displayed on the moving map, and kind of worked with the X-Plane 10 GPS as well. X-Plane 11 completely broke those settings for airplanes using the new X430/530 GPS, and not all aircraft authors go through the trouble of setting them up correctly.

X-Plane 11.02 correctly filters airports for GPS and FMS use as well as for the moving map based on these parameters. Because the GPS now also displays heliports and seaplane bases, it is important to set these filter parameters correctly in Plane Maker, to prevent unecessary clutter on the map.

The three settings are:

  1. Only Airports on Map - If not checked, the GPS and moving maps will show helipads and seaports. Check when you do not want those to show up in the nearest airport list on the GPS
  2. Only Paved Runways on Map - If not checked, the GPS and moving maps will show airports with no solid runways like grass, gravel and water surfaces
  3. Minimum Runway Length to Show on Map - This will filter out airports where the longest runway is shorter than this distance

Note that the these settings work on a per-airport basis. That means:

  • At an airport with both runways and helipads, the helipads will still be shown regardless of setting.
  • At an airport with both paved and grass or water runways, both runways will still be shown.
  • In other words, airports are filtered out if they ONLY have helipads, or ONLY soft runways
  • For seaplanes, leave the "Only Airports" box unchecked but enter a runway length number in order to supress the heliports.

If you already set these parameters in the past and they worked in X-Plane 10, there's nothing for you to do. If you never bothered to set them, and suddenly see places inappropriate for landing show up in your built-in GPS, that is why.

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Posted in Aircraft, Aircraft & Modeling | 9 Comments

X-Plane 11.02 Beta 1 Is Out

To get this beta you'll need to run the updater and click "Check for New Betas" - we won't ever prompt you to install a beta when you have a final release of X-Plane. Here's the Release Notes. Please file bugs using the Bug Reporter!

11.02 is a small maintenance patch. Our main focuses were:

  • Performance tuning we could do without too much technical risk. (We'll do the more adventurous stuff in 11.10.)
  • Fine tuning the various SDKs.
  • Bug Fixes.

As a small beta, I'm hoping the entire beta period will be less than two weeks.

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Posted in Development, News | 59 Comments

Three Performance Optimizations for X-Plane 11.02

X-Plane 11.02 should be out this week; we're down to one bug, whose fix I am verifying now. There have been a number of questions about performance, so to start, here is some info on three things we've done to make 11.02 faster than 11.01.

8-bit Water. The dynamic FFT-based ocean wave textures we stream in X-Plane 11 are floating point textures in 11.01 (F32 on the CPU, F16 on the GPU). This was an easy decision for getting the tech working, but as it turns out, transferring the textures to the GPU is slow, particularly on the NVidia drivers.*

For 11.02, Sidney has rewritten the shaders to cope with 8-bit waves. The results look almost the same, but the amount of data transferred is 4x smaller, and more importantly, 8-bit RGBA is the path most likely to be handled well by the driver, so this should be a win.

Sidney also wrote some code to transfer the textures asynchronously, but we're holding off until 11.10 for that, as it may require debugging or behave weirdly on some drivers.

Faster Car Bucketing. The cars have always cost more CPU than they should, and profiling indicated that 90% of the work was in moving the cars around in our scenery system as they drove. The code to "rebucket" them has been modified and is now significantly cheaper. We are not turning the car density up yet (it's not that fast), but at this point with the cars at the highest setting we ship, they now take 2-3 ms total to compute, which means they have no frame rate impact.  I'd like to bring the density up in the future if we can get further performance wins, which I think we can.

Better Core Scheduling. If you've been reading carefully, you should be shouting at the screen about now about how the hell something that takes 2-3 ms total is "free" - 3 ms means that if you were running at 60 fps you're down to 50. That's not free?

I am declaring the cars free because they now run in parallel to the flight model, and it's very likely that the total flight model work takes at least 2-3 ms, even without AI planes. The third optimization is a big cleanup of the multi-core scheduling that we do within a frame.

X-Plane uses multiple cores both to load background scenery as you fly and to speed up some calculations within a frame. As of now, the major "per frame" multi-core computations are:

  1. The flight model (if you have more than one aircraft - we can't multi-core a single plane).
  2. DSF scenery maintenance (not super expensive, but does get multi-core acceleration).
  3. Car computation (typically uses 1-2 cores at most).
  4. FFT water calculations for the next frame (uses up to four cores).

X-Plane 11.01 was not scheduling these particularly well - here's a picture.

What you're seeing is X-Plane kicking off the FFT water too early, and that work blocks X-plane from completing AI aircraft calculations.  The big red bar up top is the sim waiting (and FPS dying) because the AI planes weren't done in time.

(The bottom 'track' with nothing on it is an IO thread that's waiting in case we need to do UDP I/O. Since I had IO off, it is efficiently sleeping.  This profile is on a 4-core machine so we couldn't have stuck work down there.)

Here's 11.02:

We start the (newly optimized) cars as early as possible so they complete at about the same time as the flight model; we get all DSF work done immediately, and we don't start water until the very end. In the meantime, the main thread is free to go do the actual frame rendering.

This is just an incremental step for multi-core use; we have been steadily adding more multi-core work for the last few years, and we'll be adding more in future X-Plane 11 updates. For example, X-Plane 10.50 re-structured the renderer, separating the work of discovering what to draw ("culling") from the work of actually drawing. In X-Plane 11, we can do that culling on multiple cores, improving total framerate.

I don't have great numbers on what kind of performance change you'll see in 11.02; it's actually hard to measure the improvements here with the FPS test because the FPS test runs a replay (and not the actual flight model) and doesn't run long enough to generate car traffic. But we think it should be a good incremental improvement.


* It is not a bug that this case was slow for the NVidia driver; no OpenGL driver is contractually obligated to do anything in a particular time frame. It was slightly surprising in that NVidia seems to go farther than other GL vendors to optimize less common and less efficient code paths.

NVidia does normally allow for complete threading of CPU-side driver work, so it's possible they thought there was no need to optimize this case directly since it would be on a worker thread; by comparison, Apple does not use a general worker thread for their driver but does use a worker thread for all CPU-based texture transfers, at least as far as we can tell by profiling X-Plane.

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Posted in Development, News | 101 Comments