Category: Aircraft

Philipp Made The Cessna Trickier

Philipp made a change to the Cessna’s autopilot that makes it more realistic, but also slightly trickier to use.

As of 11.30, the Cessna’s autopilot uses HDG + GPSS for nav course selection. Philipp wrote a developer article explaining what all five of X-Plane’s nav course source modes do, but here are a few notes.

Among autopilots that aren’t totally hopeless (e.g. the Sperry, “none” for its course source) there are two major divisions:

  1. Autopilots that get the heading for a VOR or ILS from the autopilot heading bug.
  2. Autopilots that get the heading for a VOR or ILS from an (E)HSI, leaving you to use the heading bug to pick your own heading.

This first category is less high tech and less useful to the pilot, and it’s the bucket the Cessna is in. If you want to fly a localizer, you have to set your AP heading bug to the localizer’s course, or the autopilot is going to lose its mind.

What this means is: if ATC gives you a heading to intercept the localizer, you cannot just engage heading mode, arm localizer mode, and fly the course to intercept – when you intercept the localizer, you won’t track it properly. You will have to adjust your heading bug onto the localizer front course once you start intercepting it.

The GPS is a special case: It works like a VOR/LOC when you are in NAV mode (affected by the heading bug) and like you’d expect when you are in GPSS mode (not affected by the HDG bug). So if you want to fly a GPS flight plan with twists and turns fully automated, you must press the NAV button twice in order to turn the autopilot to GPSS.

Something that can trip people up is that you cannot use GPSS and APR/GS at the same time – if you want to fly a WAAS approach with vertical guidance, you have to step down from NAV GPSS to NAV APR, which means you’re dependent on the pesky heading bug again. Confusing? Yes. Annoying? Certainly. Realistic? Definitely! This is exactly as annoying as the real thing.

 

The second category gets the localizer heading from either magic (GPS/LOC) or the OBS knob “OBS”) and always gets the VOR radial from the OBS course (which make sense). These setups let you fly a “dual mode” approach – engage HDG, arm LOC, and fly the intercept heading – when the localizer comes alive, the AP can switch modes and know which way to turn to intercept without you having to mess with the HDG dial.

You’ll find GPS/LOC-based systems in our Kingair (which has an EHSI) and Baron (which has a HSI).

Posted in Aircraft, Cockpits by | Comments Off on Philipp Made The Cessna Trickier

New Manipulators and the Mouse Wheel

First, we are making progress toward X-Plane 10.50. I sent out a private beta a few days ago; how soon we get to public beta will depend on how buggy the private beta turns out to be. (I am assuming that it will have zero bugs, because I have decided to not write any more bugs in my code. So…there, I fixed it.)

Coming in 10.50: X-Plane supports new manipulators.

  1. In 10.50 you can add scroll wheel to any of the existing manipulators that takes one dataref. This is done via a second directive that sets the amount the dataref changes when the wheel moves.*
  2. There are six new manipulators (they form a set) to support knobs and three-way switches. Each one takes a pair of commands and provides a consistent UI experience.
  3. The no-op manipulator now takes a tool-tip, which lets you make tool tips for gauges and other unclickable geometry.

I want to make two things clear here:

  • This is support for these manipulators in the engine. This means that we can use them in our aircraft and third parties can use them in their aircraft. Adding these manipulators is a separate task, one we are working on, but which won’t be complete as of 10.50.
  • Third parties are welcome to use the new manipulators, and they are welcome to follow our internal usage guidelines. They are also welcome to keep doing what they are doing; none of this is binding, everything is opt-in.  Nothing about this breaks compatibility with any existing aircraft.

Why Did We Add These?

We’ve had a long term internal goal of making the 3-d cockpit as usable and user-friendly as possible. We’ve reached a point where 3-d cockpits are the norm, and all of our new aircraft development is 3-d only. But you can’t deny that 2-d cockpits are incredibly usable from a user interface standpoint. How do you make 3-d usable?

We already have view presets to let you get to a particular cockpit view easily. Once you have a good view of the surface you want to interact with, the next step is to have a mouse gesture that’s easy to use.

This is where the new manipulators come in. Rather than describing a mouse gesture (drag, click, etc.) they describe a type of physical hardware, one of a rotating knob, left-right multi-way switch or up-down multi-way switch.

Because the manipulators describe the physical hardware and not how the UI should work, we can change the interaction mode based on user preferences, available hardware, etc.

One of the big UI questions is: should you change a knob by clicking and holding or dragging? I built a test airplane with some of each and the company was split down the middle. By using knob manipulators (and not click or drag manipulators) we can change the way knobs work in the cockpit for all airplanes with one change of the code, rather than having our art team redo every single manipulator in every single airplane.

I don’t know whether we’ll use dragging or clicking-based knobs – or whether a user preference will be exposed. But by having a higher level manipulator type we make this a small programming problem and not an unmanageable authoring problem.

(The new knob manipulator automatically uses the scroll wheel – since we know it’s a knob, we can figure out how the wheel should work. The new command to add scroll wheel to legacy manipulators is necessary to provide the data the sim needs to make the user interaction good.)

The new higher level manipulators also give us flexibility for new input devices. For example, if we someday want to support multi-touch tablets and track-pads, we could map a pinch-rotate gesture to a knob – since we know the manipulator really is a round knob (and not just ‘something that you drag’) we can know that a rotating gesture makes sense.

How Do I Add Them?

The new manipulators are already supported in code in the Blender 2.7, Blender 2.49 and and AC3D. The manipulators are released in the newest Blender 2.7 exporter; I need to post newer 2.49 exporters. I do not know if/when there will be a public release of the AC3D exporter, but I can probably find the time at some point to do one more compile.

All aspects of the new manipulators are opt-in; if you don’t change your airplane, its functionality should not change.

What Aircraft Use Them

I’ve buried the lead a little bit here: X-Plane 10.50 will have a heavily upgraded Kingair C90 and Baron B58 that will use the new manipulators. We have not (yet) upgraded the rest of the fleet, and this upgrade will happen over a very long time-span. The goal of 10.50 is to lay the groundwork and make cleaner user interfaces possible by making the new manipulators available to our art team and third parties.

The guidelines I’ve been advocating for our artists are:

  • Large things that move a lot like throttles are dragged via an axis that tracks the actual 3-d motion.
  • Yokes track via a 2-d XY manipulator.
  • Anything that toggles or has only two states is a single click, particularly for small things.
  • Rotary knobs and rheostats use the new knob manipulators. The mouse wheel can turn them.
  • Linear switches with three or more positions use the new left-right and up-down switch manipulators. The mouse wheel can click them.

There’s no reason why third parties have to use these guidelines; I post them only to show how we are thinking about usability. A more “3-d” approach is possible, e.g. drag a banana switch up and down to toggle it; my view is that for Laminar’s default fleet, which are the first aircraft users are going to use, single clicks provide a more direct and less surprising user experience.

For power users, having single clicks for switches may also mean you can get more done in the cockpit faster. (In real life, a pilot can reach up and flip four metal banana switches on the overhead panel very, very quickly.) We’ll still use dragging for big 3-d motions.

 

*This feature targets one-wheel clicking Windows-style mice. 2/3 of our users are on Windows, and Apple has shipped a wide variety of strange input devices, so the one-axis clicking mouse wheel is the most consistent hardware target for us to aim at. And frankly, I think it’s the most useful since you get clear ‘detents’ as you scroll things – good for changing a radio by one notch.

Posted in Aircraft, Development by | 21 Comments

Blender 2.7 Exporter: New Version

Ondrej has posted a public thread about the new version of the Blender 2.7 exporter here.

The 3.3 release is the first release where we (Laminar Research) have worked closely with Ondrej to build what we hope will be one of the future cornerstones of modeling for X-Plane.

If you are currently using Blender 2.49 or AC3D, I expect that 2.73 will provide the best way forward for modeling in X-Plane.

New Stuff

The new release has a few major features, all aiming to create a new modern work-flow:

  • All animation bugs are fixed. (At least,we think – if you find one, please report it ASAP!) This means animation is WYSIWYG.  Armatures are supported for animation as well as animated data block containers.
  • The exporter understands all modern OBJ features, including ones scheduled for release in X-Plane 10.50.
  • Instancing is handled via a single option with exporter validation, so you don’t have to know how instancing works to get instancing.
  • The material rules are validated, and materials are found automatically; you can simply model as you want and Blender will do its best to export it or tell you if there is a problem.
  • Specular and Normal maps are ‘merged’ together from two separate sources.  This lets you set specularity and normal maps in separate material channels in Blender for a more WYSIWYG approach.  It also means no more messing with Photoshop to combine these layers.

The goal of many of these is to hide the idiosyncrasies of X-Plane’s modeling format and provide a cleaner, more artist-friendly view of modeling.

Regarding instancing: the model we have adopted is the one we used internally on the 2.49 exporter: you (the artist) tag an export as either “instanced” or not.

  • If instancing is on, the exporter writes only data to the OBJ that will be hardware-instanced by X-Plane.  If you do something that cannot be instanced, like animation, you get an export error telling you what you have to remove.
  • If instancing is off, the exporter writes the object normally.

The win here is that you don’t have to know the (complicated) instancing rules; set instancing for the scenery objects you need to make fast in bulk (e.g. a luggage cart, a house, something that will be used many times in a small area) and you’ll get optimal output.

Optimization – Coming Soon

The goal of the 3.3 release was to set up an environment where authors could work using the new work flow. We have not finished optimizing the OBJ output.

If you are using the existing 2.7 exporter for airplane work, the output should be similar in performance. If you are using the 2.49 exporter, the new output is (like the current 2.7 exporter) not as well optimized.

In a future update, we will tighten up the generated OBJ code; this should not affect anyone other than producing better OBJs.

Compatibility

The new exporter should be fully work-flow compatible with the previous Blender 2.7 exporter; if you find your existing project does not work, please file a bug!

Our plan is to create a migration tool for Blender 2.49 projects; this will forward-convert the datarefs on annotations, manipulators, and object properties from 2.49 to 2.73 format. This lets authors using 2.49 move forward to 2.73 and have a migration path for existing content. (This work is not started yet, but is planned – we have our own aircraft we need to keep working on.)

Posted in Aircraft, Aircraft & Modeling, Development, File Formats, Scenery, Tools by | 15 Comments

Don’t Ship Payware Using Beta Plane-Maker

In my previous post I mentioned that re-saving your aircraft in Plane-Maker from X-Plane 10.45 would opt you in to the new fixed torque model.

I’ve talked about this before, but it might bear repeating now:

Please do not ship an aircraft saved with a beta version of Plane-Maker.  Instead wait for X-plane to go final or use the previous non-beta version of X-Plane.

The problem is that file formats change during beta and if they do we do not provide compatibility; the file format is only “for real” when beta is over.

So if you need the torque bug fix, plan to ship your aircraft in a week or two when 10.45 beta is over.  If you need to ship now, use Plane-Maker 10.42.  Test against the beta, but don’t save using it.

Posted in Aircraft, Aircraft & Modeling by | 2 Comments

How to Apply the Torque Fix to Your Aircraft

X-Plane 10.45 beta 1 fixes a bug in X-Plane’s flight model where props applied too much torque to the aircraft. The effect is most noticeable on single engine aircraft where the prop torque is applied along the center of the fuselage.

Authors: in order to have the new correct torque applied to your aircraft, you must resave your aircraft in Plane-Maker 10.45. When X-Plane finds an aircraft authored with an old Plane-Maker, which includes all existing aircraft already shipped, we preserve the old torque behavior.

We put in this compatibility because some aircraft have plugins and other work-arounds that try to get correct flight dynamics assuming X-Plane will apply too much torque.  If we were to apply the fix to these planes, they’d then have too little torque (because we’d apply less torque and the work-around would already be in place). So this is an opt-in fix.

Authors: if you use Plane-Maker 10.45 to work on your aircraft, you will be opted in to the fix!  There is no way to work on a new aircraft and preserve the old torque. Our thinking is: the old torque calculating is physically wrong, so we’re not letting anyone preserve this mistake when working on a new aircraft.

So when you bring your aircraft in for its next feature update, note that you will be getting the torque fix and you should make sure the results are useful.

Posted in Aircraft, Aircraft & Modeling by | 6 Comments

SASL Crash Fixed – You’ll Need a New SASL

Since El Capitan came out, SASL has been crashing on quit when used in aircraft with customized sound. While I work on neither SASL nor El Capitan, both are (at least partly) open source, so I spent a few hours yesterday and located the bugs.

The good news is: this bug is fixed in SASL version 2.4. The bad news is: you’ll need to make sure the aircraft you are flying is using SASL 2.4 – and this applies to every aircraft that you have that uses SASL.

If you develop an aircraft using SASL, you can get the latest free version of SASL here. Note that this new version is apparently 64-bit only.

If you are using a freeware aircraft that is no longer supported, I think you could theoretically drop in the new SASL and see if it fixes things. If the aircraft is payware, the aircraft author might not be thrilled to have to support a “modified” aircraft and might prefer to do the upgrade in-house.

If you are a developer of SASL or you use OpenAL, you can read the gory technical details here.

Posted in Aircraft, Development, News by | 9 Comments

X-Plane 10.22: LuaJIT Memory for Windows and Linux

There are a number of changes to how X-Plane 10.22 beta 1 handles memory for LuaJIT plugins.

Windows and Linux 64-bit: X-Plane Manages Memory

Previously, 64-bit Windows and Linux LuaJIT plugins had to allocate their own memory, and often they did not succeed.  64-bit LuaJIT can only use certain special areas* of memory; if, by the time a LuaJIT-based plugin loads, some other code has used all of that memory, then the LuaJIT plugin cannot operate.

With 10.22 beta 1, X-Plane pre-allocates as much low memory as it can and then provides it to LuaJIT plugins on demand.

This change should fix problems where LuaJIT-based plugins run out of memory, fail to load, etc. on Windows with lots of scenery packs and rendering settings cranked up.

If you ship a plugin that uses LuaJIT, make sure your plugin can use the memory provided by X-Plane.  The process for doing this was defined during the X-Plane 10.20 beta and has not changed, so plugins that are coded correctly will just work.

OS X 64-bit: Crash Fix

Previously for OS X, when a LuaJIT used up all available low memory that X-Plane had reserved, X-Plane would crash.  This was a bug in our code; X-Plane now correctly simply tells the plugin “sorry, we’re out of memory for you.”

I have said this before in forum posts and I will say it again: your plugin should not exhaust Lua memory! There is typically over 1 GB of LuaJIT memory available; if your plugin exhausts it all, your plugin is doing something wrong.

So it’s good that this won’t crash, but if there were plugins that were causing this crash, those plugins probably need to be carefully examined – their memory use was way too high!

New Stats to Monitor Memory Use

There are two new “stats” in DataRefEditor (pick the “show stats” sub-menu option) for Lua memory use: lua/total_bytes_alloc and lua/total_bytes_alloc_maximum.  The first one tells you how many bytes of memory all Lua plugins are using, the second shows the highest memory allocation ever recorded.  A few notes:

  • This only measures memory use provided by X-Plane.  So 32-bit plugins will show “0” for both, because in 32-bit plugins, X-Plane does not provide memory to Lua.
  • Lua is garbage-collected, meaning it allocates memory for a while, then periodically throws out unused stuff.  So it is normal to see this value slowly rise over time, then periodically drop down by quite a bit.  It is not normal to see these values increase indefinitely without ever dropping down.
  • If your 64-bit Windows plugin uses LuaJIT but registers “0” for lua/total_bytes_alloc, your plugin is not getting memory from X-Plane and is not working correctly; fix your plugin ASAP!
  • This memory includes allocations by Lua scripts.  It does not include memory for textures, sounds, and other “native” resources provided by SASL or Gizmo.  So you should not see a 4 MB allocation just because you made a 1024 x 1024 texture, for example.

* The lowest 2 GB of virtual memory, to be specific.  Most other code running in X-Plane (the sim itself, the OpenGL driver, OpenAL, the operating system, other plugins) can use any memory, but they tend to consume some of this “LuaJIT-friendly” memory during normal operations.  Thus X-Plane’s strategy is to pre-allocate the LuaJIT-friendly memory and reserve it only for LuaJIT use.

Posted in Aircraft, Development by | 11 Comments

X-Plane 10.22 Beta 1: Memory for Lua and Landing Gear

X-Plane 10.22 Beta 1 is available now (release notes, bug reports).  To get this beta you’ll need to check “Get New Betas” in the X-Plane 10 Installer’s update screen.

This is a very small bug fix patch; there will not be an art asset update, and we’re only including three fixes that we think are critical enough to release ASAP, as well as support for the latest Xavion iPad app.

I will comment on Lua memory allocation in a separate post.

Landing Gear Problems

Plane-Maker 10.21 has a bug: when you save your airplane, the weight distribution coefficients for landing gear are calculated incorrectly, causing the plane to tilt or lean on the runway.  Astute users noticed that resaving the plane in Plane-Maker 10.20 fixed the problem.

This bug is fixed in Plane-Maker 10.22; if your plane has “the leans”, just re-save it in Plane-Maker 10.22 and the problem should resolve itself.

This bug was always a bug in Plane-Maker, not in X-Plane itself; airplanes whose data was not saved incorrectly would fly correctly in 10.21, which is why it took a while for the bug report to get to us.

Copy Protection

First: let’s agree to disagree re: copy protection.  No one likes copy protection, and we can all agree that copy protection is always imperfect.  (That is, it never avoids annoying users completely and it never stops piracy completely.)  Users who buy products and the companies that sell them often disagree about where to draw the line between deterrence and annoyance.

So please: no rants about how awful DVDs are in the comments section.  The goal of this part of the post is to explain what we fixed so that users who have seen a known bug can have better situational awareness.

X-Plane 10 “remembers” that you have inserted X-Plane DVD 1 recently, so that you do not need to have the DVD constantly in the drive to fly.  Right now X-Plane needs to see DVD 1 (for each product you purchased) every seven days or so.

Every now and then we get a bug report from a user where the process of saving the DVD information fails; due to a bug in X-Plane 10.21 and earlier, when this process fails, the DVD would not enable scenery loading at all and the user interface would tell a global scenery user that a regional DVD was found.  This was very confusing and also annoying (since it stops paying customers from using the product).

The bug in X-Plane is fixed in 10.22; furthermore if the preference-saving process fails we now put up a message for the user to contact tech support; previously it was a small item in Log.txt.  If this preference-saving process fails, we want to know about it and fix it.  (So far the only cases we’ve seen are Hackintoshes with hardware configuration issues and one case of a borked network preferences file.)

Water, Water Eveywhere

There is a separate bug in the copy protection system that I couldn’t fix for 10.22; we’ll revisit this issue for 10.30.  The issue is this:

  • When X-Plane needs to see your DVD to get out of demo mode, it tells you after you have started your flight.
  • By that time you are on a runway that is all water.
  • When you insert the DVD, does not reload scenery; you have to go to another airport and then come back to your original airport to “force” a scenery reload.

This behavior is confusing – X-Plane says “now you can fly anywhere in the world” but where’s your scenery?  We get a fair number of tech support calls about this.  The problem is that if we reload scenery when the DVD is inserted and your airplane is on the runway (in water-world) then once scenery is reloaded your aircraft is underground and your aircraft is destroyed.  So a fair number of things need to change (e.g. when we check for the DVD, what we do when we find it) to fix this use case.  That’s too much change for 10.22 and will have to wait for 10.30.

Posted in Aircraft, News by | 10 Comments

Aircraft Authors – View LuaJIT Memory Usage

If your add-on uses LuaJIT (e.g. via SASL, Gizmo, FlyLua, or directly) then this tool may help.  It’s a special build of X-Plane 10.21 for 64-bit Mac that can show total Lua memory use.  Use DataRefEditor and filter on “lua” to see the numbers.

Since Lua uses garbage collection, you’ll see the number rise up and then “fall” periodically as garbage gets cleaned up.  Non-Lua allocations by plugins are not counted.

If you use LuaJIT in your add-on (or a plugin that uses LuaJIT), please try to keep the amount of Lua memory used below 300 MB or so – more is available, but if you use it all, your plugin won’t inter-operate with other plugins.

Posted in Aircraft by | 3 Comments

Double Your Framerate: Pre-Fill

That got your attention, eh?  Sorry, this is not a tip on how to tune your X-Plane system; it’s a tip for aircraft authors to make sure their 3-d cockpits are running at maximum performance.

Prefill is when X-Plane blocks out the clouds that will be behind the airplane cockpit.  The biggest cause of GPU slow-down is cloud rendering, so reducing the area that the clouds have to fill is really important.

In the 2-d cockpit, X-Plane pre-fills automatically.  But in a 3-d cockpit, the airplane author has to specify which objects should be used to pre-fill.

Aircraft Authors: go watch this video or read this page to learn how to set up pre-fill in your aircraft!  If you aircraft has a 3-d cockpit this optimization is very important!

Posted in Aircraft, Cockpits, Modeling by | 9 Comments