XPlane2Blender v4.1.0-beta.1

This is a beta so make backups of your work before using!

New features!

Custom Spill Lights

Custom Spill Lights are now implemented (#312)! To use, make a light datablock with the XPlane2Blender light type as Custom Spill. Relevant properties are:

Custom Spill lights can make dataref driven custom omni-directional billboards and directional spot lights.
As with Automatic Lights, the goal is What You See Is What You Get.

In this photo the green light is a Custom Spill, where sim/graphics/animation/lights/traffic_light changes the color between green, yellow, and red! The white lights have different widths, all made without doing any math by hand.

Cockpit Device

X-Plane has pre-made high quality GPS devices that are easily accessible to the artist. Thanks to (#481) using one is as simple as making a mesh, and giving it a material with a Cockpit Device set. Pick the device, at least 1 electrical bus (matching Plane Maker), the lighting channel, and if the screen’s brightness should auto-adjust. You’ll get a fully functional GPS device just like that! You can have multiple devices in the same OBJ, as well as use of the panel texture.

The Cessna’s cockpit provides 2 great examples of using cockpit devices.

Cockpit Features UI

Given the changes and additions to our Cockpit Features, the UI has been changed slightly. On the material Properties tab use the “Cockpit Features” to find “Cockpit Regions” and “Cockpit Device”. The updater should adjust the setting for you if you were using regions.

Minor features

(#426) Shadow Blend’s Blend Ratio can finally be set. Thanks @kbrandwijk!
(#548) Non-Exporting Lights are back in. They’re intended as “work lights” and will never ever show up in the OBJ! Simply set the X-Plane Light Type to “Non-Exporting” and use freely.

Important fixes

• Light Level can now be used multiple times in the same .obj without tricks or getting lucky!

Thanks to everyone who downloaded alpha.1! I’m glad that this series has been so successful and I can wait to see what you make with the new light features! As always make backups!

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Release notes here.

This youtube video has a thorough explanation of the new flight modeling stuff.

PLUS new stuff for “official” beta 1:

Stall is now TRIPPED and you really have to lower the nose to recover the non-separated flow, as per reality. This really drops a wing more in the stall!

Rotor bounce back in ground effect now modulated by forward speed. Which is cool and causes a little bit of settle as you start to get going before ETL.

Thermals for gliders are found per element now, so the glider raises a wing in the edge of a thermal.

New wind PROFILE from wind sock to ground. This is from data on wind above ground carefully compiled for wind turbines!!! Har!
So while the metar or real weather or other weather setting sets the wind at 10 meters (the wind sock height), the profile from that down to the ground (by definition 0 for the atoms touching the pavement, and a curve in between) follows the wind turbine wind profile model

Now we have EXHAUST THRUST as well for the turbines and recips!
Plane-Maker > Default menu > Engines screen> Engines 1 tab > Top sort of close to the right.
TURBINE AND RECIP EXHAUST HORSEPOWER TO POUNDS OF THRUST
Enter how many pounds of thrust the exhaust puts out per horsepower output of the engine. We find it to be about 0.10 for the PT-6 turbines, and is almost certainly very close to 0 for any reciprocating engine.

Wake turbulence, better to track other planes! Command-m to see wake turbulence from your plane and others when in flight. Fly into the wake if you like! 3-D per-plane wake turbulence following wind and settling profile! Some of this wake turbulence tech comes from Xavion, where I developed it to avoid (another) wake-turbulence hit in the real airplane.

Better propwash swirl based on 4 different tech reports! Now we have thew swirl angles at all radial distributions dialed in! The insight here was to NOT track propwash swirl in meters per second, but instead track it in degrees of swirl from straight aft! In reality, the SWIRL ANGLE does NOT change with propwash speed or longitudinal location along the propwash stream tube, so tracking this swirl ANGLE in X-Plane instead of swirl SPEED gives us the most accurate propwash swirl in all locations, no matter how far behind the prop.

Now, X-Plane uses the efficiency and drag of the prop to estimate the swirl angle using conservation of energy, and then applying that swirl angle at all prop radial locations according experimental data, and holding that swirl as you move aft in the prop stream tube as per experimental data. So this is a very nice start with analytical conservation of energy to DETERMINE the swirl, then using empirical data to apply that swirl at the right places in the prop stream tube. So X-Plane now tracks experimental data very very very well in propwash swirl! This is good for tail-dragger and other handling where swirl angles over the tail matter.

So now, we can finally say that we have good propwash speed AND SWIRL over the tails of those tail-draggers! (And all other planes with engines in the front blowing propwash on the tail!)

Also, propwash now spirals in FRONT of the prop when in reverse! Good find for the person that reported this bug!

Also, propwash now tuned a bit more to follow the orientation of the prop, as we have found to be the case both with tail-draggers doing take-offs and the BackFly e-VTOL, which runs its’ wing in propwash without stalling, as long as there is propwash over them, proving that the flow is aligned to the props as long as power is put into the flow. So this should align propwash with the wings and fuselage more, which should be more accurate in the cases that I am seeing.

Delayed propwash over the tail! It is well known that the wings cast downwash over the tail based on the coefficient of lift of the wings, with the various flaps and ailerons on them. But here is where it gets tricky: Did it ever occur to you that it takes TIME for that downwash to make it back from the wing to the horizontal stabilizer?

This DELAY helps STABILIZE real airplanes in pitch, because as the nose is raised for example, the horizontal stabilizer is initially pushing down into UNDISTURBED air: The increased downwash from the wings might take 0.05 to 0.10 seconds or so reach the tail and push it down farther, de-stabilizing the airplane!

The only way I could think of to simulate this in X-Plane was to keep track of the downwash at all points in space and move it backward from wing to tail over time…this is completely NON-feasible for memory and CPU reasons, so I have never simulated this delayed downwash effect before in X-Plane! As a result, the simulator has always had just a little less pitch-damping than the real airplane, making it touchier in pitch than the real airplane.

Now, I have a solution, and here is what it is: Let’s say the angle of attack of a given airplane is increasing at 20 degrees per second as the nose is suddenly pulled up. And let’s say that that we know that each degree of angle of attack causes 0.5 degree of downwash. Then I am sure we can agree that the downwash is increasing at 10 degrees per second, right? It’s un-deniable!

So we KNOW that the downwash is increasing at a rate of 10 degrees per second, and let’s say that it takes exactly 0.1 seconds for the wash to make it from the wing to the tail (this is typical and easy to find: Simply the distance between the wing and the tail divided by speed of the airplane). So we know that the downwash is increasing at EXACTLY 10 degrees per second, and we know it takes EXACTLY 0.1 seconds for the wash to make it from the wing to the tail (at the speed and size of our imaginary airplane for this example). Then how much less wash will the tail have during this maneuver due to downwash delay? The answer is EXACTLY 0.1 seconds times 10 degrees per second equals one degree! COOL! This answer is exact, no approximation! (NOTE that we assume a constant angle-of-attack change-rate for our math to be perfect, so this is still an approximation since the angle-of-attack rate changes over time in the real airplane, but this is pretty darn close to perfect propwash tracking, at a cost of NO memory and basically NO CPU, since the downwash delay is found with some VERY simple algebra, instead of a ridiculously-complex and memory-hogging operation of trying to track an entire flow-field over time.

So, now, we have more accurate pitch-damping due to delayed downwash with simple algebra… and no CPU or RAM cost to get it! Cool!
This makes the airplanes in X-Plane less squirrely in pitch than they were before, and probably closer to reality!

Varied propwash across the prop disc!

For helicopters or VTOLs with running the prop discs edge-wise into the wind, the propwash through the prop is now less at the leading edge of the disc, and more at the trailing edge of the disc, to simulate the propwash building over time and distance as air flows aft over the advancing prop disc. This results in more rotor-flapping and rotor or rigid-disc pitch-up, with performance matching our eVTOL AVA, shown below. So we used the aircraft below as a test-vehicle to measure nose-up pitching moment to tune the rotor downwash model in X-Plane!

Control effectiveness improvement:
Looking now at chord ratio and deflection and a few different tech reports, we have the control effectiveness accuracy improved for ailerons, elevators, and rudders. Like most all of the stuff above, you need to have the experimental flight model ON to get this!

Better supersonic flight dynamics and transition TO supersonic:
If the experimental flight model is on, we now transition smoothly from subsonic to supersonic model on the wings, bodies, and downwash.

As well, in Plane-Maker, go to the fuselage (and any other body) screens where you set the coefficient of drag. You can now set area-rule factor for supersonic airplanes. This defaults to 1.0 (a multiplier of 1 means use standard compression shocks and expansion fans), and can normally be left there, but for planes like the T-38, which have very necked-in bodies in the middle to do an excellent job of area-ruling, which keeps a constant cross-section area along the length of the airplane by narrowing the body where the wings add equal area, you can change this number to a multiplier of something like 0.75 or so to reduce the supersonic drag that X-Plane computes, to account for the air moving around the wing to neatly fill the space in the necked-in body and inlets, as the T-38, for example, has.

Better wing/body separation:
Vert and horizontal stabs for T-tail no longer consider themselves to be one long wing for efficiency purposes, because the vert stab does not act as an endplate for the horizontal stab, because it is in the center, where there is no lateral flow. Vertical stabs and wings individually still connect into one effective wing just fine though.

Gliders:
The thermals are now a bit more tightly defined, to form stronger gradients for the thermals so you can feel a bit of pitch or wing-rock as part of your plane enters a thermal. Turn on thermals in weather as always and cycle through the visual flight model with control-m as always while in flight at altitude and below the tops of the thermals to see the vertical speed profile of the thermal pattern nearby… kind of cool. And the wings and tail will all grab the edges of thermals as well as you enter or traverse them, giving the tell-tale wing rock away from the thermals, nose rise when entering the thermals, etc.

Also for gliders, the tow-plane will stay on the centerline a bit better to get you going even if there is some crosswind.

Seaplanes:
Wave shape changed from sin wave to wave shape closer to what we actually see on the water as the wind picks up. This should help make seaplanes a little more accurate. Seaplane float dynamics also improved to be more accurate with better damping in the water.

Afterburner:
If you re-save in Plane-Maker, then the old: “Engage burner at 50% above this throttle setting” will become the new: “Engage burner at low level at this throttle setting, smoothly moving to max burner at full throttle” so the burner will smoothly increase as the throttle goes to maximum!

As well, if you re-save the aircraft in Plane-Maker, then: The throttle will run the N1 and N2 up to 100% by the time you reach the critical throttle entered in that slot in Plane-Maker. Then, ABOVE that throttle, since N1 and N2 will be at maximum dry thrust, the burner will add on top of that.

So, in summary, if you enter a throttle to engage the burner above: The N1 and N2 will come up to 100% as the throttle reaches that critical throttle position you entered in Plane-Maker, and THEN engage the burner smoothly above that throttle position as the throttle goes to maximum!

As well, jet engines with afterburners often do not show the afterburner fuel flow in the engine fuel flow indicator. So, we now have:

FLT_ARR_EXPR1("sim/flightmodel/engine/ENGN_FF_dry", sim_flightmodel_engine_ENGN_FF_dry, flt[p0].enpr[N].act_fm_FF_kgs__dry,flt[p0].enpr[N].act_fm_FF_kgs_dry,8)

FLT_ARR_EXPR1("sim/flightmodel/engine/ENGN_FF_", sim_flightmodel_engine_ENGN_FF_, flt[p0].enpr[N].act_fm_FF_kgs_tot,flt[p0].enpr[N].act_fm_FF_kgs_tot,8)

Where the dry datarefs are fuel flow without the afterburner, and the the regular fuel flow is the total of engine and burner together.

For Xavion:
Full next-gen ADS-B weather from X-Plane to Xavion (which you can get at the App Store) which makes for some pretty nice weather flying when setting convective weather in X-Plane! This includes icing, turbulence, and cloud-top, wind, temperature, freezing level, and airport METAR weather display in Xavion from X-Plane! A pretty cool weather setup!

Misc:
Airfoil Maker foil-load really does load the foil now when you load a foil from the menu, even if that same foil is already open.

Winds come down near the surface now, as per wind-profile chart created for wind-turbine designers, of all things!

Stowing the prop for motor-gliders now does a complete job of hiding the prop from the airstream.

Various panel brightness rheostats now saved for situations and replays.

Tail-rotor trim option now in Plane-Maker for any helos that might have that. (X-Plane used to use full-deflection with full tail rotor trim but now you control the amount of trim available.)

New individual flight control SURFACE failures for individual flight control surfaces on the wings. Used in engineering-level e-VTOL simulation now, but can be applied to any airplane!

Electric motors can spin BACKWARDS for reverse with fixed-pitch props! Just equip them with a reverse checkbox in the Engines screen in Plane-Maker like any other engine that goes into reverse, and go into reverse with a joystick button configured to toggle reverse, like for any other airplane!

New command line: —lock_fr=xxx, which limits the frame-rate to this speed, and also takes you to just 1 flight model per frame to maximize the per-frame speed and maximize your chances of hitting that target frame-rate.

See my latest work and other projects at
http://austinmeyer.com.

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XPlane2Blender v3.5.0-rc.1

XPlane2Blender is now X-Plane 11.30 ready! Not much has changed since beta.3, just some fixes to the particle stuff.

Bug Fixes

#373 – Test Script’s –filter flags now needs less escaping for its regexes
#377 – Show/Hide animations on empties is now being exported again
#384 – Particle follow non-colocated animations

Sound Emitter has been removed from the Empty Special types menu. One day it will be back in!

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Oxygen System

X-Plane has two separate oxygen systems, bottled/compressed O2 and chemical oxygen that can be used for both general aviation aircraft and airliners with separate crew and pax oxygen. How to set up the system for you airplane is explained here: https:/article/the-x-plane-oxygen-system/

Anti-Ice and De-Ice Systems

Airplanes can make use of electrical or bleed-air thermal anti-ice systems, inflatable boots de-ice or chemical TKS anti-ice systems, each with their own characteristics: https:/article/the-x-plane-anti-and-de-ice-systems/

Vacuum and gyro systems

Besides engine-driven vacuum pumps, X-Plane can now also simulate venturi-powered vacuum systems as found on vintage aircraft and electrical backup pumps that are sometimes found in slightly better equipped general aviation aircraft. The interaction of all the pumps, manifolds and instruments is explained here: https:/article/vacuum-systems/

The traditional vacuum-driven attitude indicator is now subject to the same limitations as in real life, and can be equipped with a caging or fast erect mechanism to help cope with them: https:/article/vacuum-gyro-limitations-and-caging/

Propeller Governors

Propeller-driven aircraft can have distinct behavior of the prop governors reaction to engine failure or loss of oil pressure. Depending whether your plane is a single or multi-engine, whether it is driven by piston engines or propeller turbines, and wether the turbines are of the free-rotating or single-spool design, the equipment might be drastically different. X-Plane now features negative torque sensing in addition or instead of auto-feather, overspeed governors and fuel topping governors, to make turboprop aircraft even more true-to-life: https:/article/propeller-feathering-systems/

Turboprop engines now have additional overspeed and fuel-topping governors for free turboprops, and fuel delivery control for fixed shaft turboprops. How to set up fuel delivery control is explained here: https:/article/setting-up-a-fixed-turboprop-engine-governor/

Autopilots

X-Plane now comes with a few pre-configured autopilots for airplane designers to chose from, and offers more flexibility in creating a custom one.

General Aviation Autopilots

X-Plane 11.30 adds support for single- and dual-axis rate-based autopilots, control over the trim servo, and a separate static system for an altitude pre-selector.

Airliner Autopilots

Airliner autopilots learn new auto-throttle modes, Control Wheel Steering, have two independent flight directors and up to three channels for auto land. They can optionally even have a directional servo for CAT 3 landing rollout guidance.

Learn more about the X-Plane autopilots here: https:/article/preconfigured-autopilots-and-other-autopilot-changes-in-11-30/

The documentation for tuning the autopilot constants has been clarified and expanded with new sections about the new autopilot functions in 11.30: https:/article/x-plane-autopilot-params/
Finally, have a look at the X-Plane airliner autopilot in action, performing an auto land in a gusting cross wind:

https://youtu.be/EAOKNaSPuo8

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Why and how we failed before

Before 11.10 the aircraft volume was based on the volume of, well, the aircraft. However, this includes things such as the aforementioned ground trucks, fuel trucks and what have you, that artificially blow up the volume calculation. The problem is, all these objects are technically part of the aircraft (eg. we move them around with the aircraft), but they are for the most part invisible and most people wouldn’t actually consider them to be part of the aircraft proper.

In 11.05 we added a change to also consider the physical volume which kind of has the right size for the plane but doesn’t include OBJs. It is based on the physical size of the plane only, which sounds like it’s the right thing. However, as it turns out, this volume breaks badly for things such as helicopters because the rotor of some third party helicopters are attached OBJs and won’t be considered part of the physical volume of the helicopter.

At this point I should probably also quickly note what happens if the shadow volume is too small: Everything that gets clipped by the shadow volume will cast a shadow into infinity and beyond due to the way the shadow mapping works. This is especially bad for the helicopters that now have very quickly rotating bits that are constantly clipped by the shadow volume resulting in shadows flickering all over the place.

In short: What we want is a shadow volume that is as tight as possible around the aircraft for shadow quality, but not too tight because that also leads to problems.

What’s new in 11.10

In 11.10 the algorithm to compute the shadow volume has been completely changed. Instead of trying to jiggle around with the physical volume and the volume of all OBJs together and then coming up with a sane value, X-Plane now looks at what is actually being rendered. We start out with the physical bounding volume as before, but then we look at what is actually rendered! For that, we go through every OBJ that is marked as casting shadows and run the OBJ engine as if we were to render the whole thing. So OBJ animations as well as kill datarefs etc are considered. This happens during the first frame, so everything is set up the way it would be during normal rendering. Everything that is visible will be marked as such and the shadow volume will be expanded to include this OBJ.

The result is a volume with a tight fit around what is actually visible and therefore considered “aircraft”. Everything else is not included in the shadow volume and therefore stops casting shadows altogether. Of course, this is only in aircraft only shadow mode and is not used when scenery shadows are on. In that case, everything is handled like it was before and everything that is supposed to cast shadows does cast shadows. So, if you see missing shadows in aircraft only shadow mode, this is probably due to this change.

To visualize the differences, here are 4 screenshots showing the quality difference as well as the new shadow volume:

One thing that should be noted though is that going forwards these kinds of extra OBJs should really be done via the new drawing API in the 3.0 SDK! This allows us to very accurately determine the size of the aircraft but it also means that culling will become more accurate. The old method will of course continue to work, but it’s not the best or most efficient way to approach ground vehicles and other ground clutter.

Aircraft icons

The calculated volume for the whole aircraft with attached OBJs was also used for the aircraft icon generation. This led to some weird cases where the camera was positioned in such way that the aircraft was incredibly tiny due to the fact that we tried to get “everything” in at once. So far the recommendation was for authors to create a version of their aircraft without all the extra OBJs attached, but now that we have an adequate measure of the aircraft volume this is fixed as well! Aircraft icons should be correctly generated now with the camera positioned to capture the plane at the right distance.

There is one more fix for aircraft icons: Some authors created aircraft that did some clever culling based on where the pilots head is and then using the kill dataref to prevent parts of the aircraft from being rendered. Reading the view dataref now correctly reports the camera as being an external camera so that those custom culling solutions work with the aircraft icon generator. If your aircraft still doesn’t generate proper icons after 11.10, please file a bug report and let us know!

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1. AI aircraft are often way more resource-intensive than they need to be. Users are fine paying a performance penalty to load, say, a super detailed 3-D cockpit model for their own aircraft, but for AI planes, where you’re never going to be in the cockpit, there’s no reason for that sort of thing. A significantly “dumbed down” version of the same aircraft would allow users to load more AI planes at once, with no visible downsides during normal use.
2. Many aircraft, for one reason or another, simply won’t function at all when used as AI planes. This is most commonly due to one of two issues:
   • reliance on third-party plugins (which only work for the user’s plane)
   • lack of support from X-Plane for flying aircraft like this (for instance, the X-Plane AI doesn’t know how to fly gliders, seaplanes, or rockets)

As a user, this is really frustrating, because it’s difficult or impossible to know in advance which aircraft will work as AI planes and which will either a) just sit on the runway, never able to take off, and/or b) tank your frame rate.

Coming in X-Plane 11.10: AI-Only and User-Only Aircraft

In the upcoming X-Plane 11.10 beta, we’ve added two new options to Plane Maker’s Author window: “supports user flight” and “supports AI flight.” By default, all aircraft support user flight, and do not support use as AI aircraft.

If a plane is configured for AI flight only, it will never be shown in the normal aircraft grid—only in the AI aircraft window.

If a plane is configured for user-flight only (or if it’s a pre–11.10 aircraft with no “supported flight type” info), it will be hidden in the AI aircraft window by default, but for the sake of backward compatibility with old planes, users will still be able to reveal them by checking a box labeled “Show aircraft without AI support.”

The upshot for aircraft authors

In the Glorious Future, we envision third parties shipping two versions of their aircraft:

• one marked user only, which include all the bells and whistles, plugin-enhancements, and as much detail as possible
• one marked AI only, which is stripped down for performance, only using plugin enhancements that have been tested in AI configurations.

The result will be a faster, more consistent, less error prone experience for users.

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Electric and remote gyro systems

Back in April, I flew a Mooney M20J with a KCS55A HSI in it, and realised that it was impossible to model in X-Plane correctly, so I got to work. See the manual for an explanation of this popular HSI/remote gyro system.

I’ve written a usage guide on the new datarefs and commands that I added, along with some more detailed explanation of all the different gyro systems X-Plane simulates, in this guide for aircraft developers. I also talked about the systems at length in a Youtube live stream earlier this year.

Separate GPSS autopilot mode

This is a feature that many add-on aircraft already simulate to some degree, but by means of more or less reliable plugin trickery. The X-Plane 11 default 737 and 747 are no exception. With X-Plane 11.10, a separate GPS steering mode for the autopilot becomes a standard feature.
The new datarefs and commands are explained in detail here.

Screen-only popup instrument windows

Several people who build home-cockpit setups have asked about removing the bezels from the popup displays, so they can have only the screen of a GNS430/530, FMS or G1000 instrument to put on an external monitor, with a hardware bezel around it. While this can already be achieved through some clever hacking in the Miscellaneous.prf file, we now offer a more straightforward way to do this: The popup and pop-out windows now get their bezel graphics from the library system, so you can override the bezel graphics. How to override the bezel with nothing, if your bezel is made of hardware? Simply supply a 1×1 pixel blank .png as a bezel graphic, and X-Plane will know that you really want no bezel at all. In the case of a bezel-less 430, you’d put a 1×1 pixel png as the “cockpit/radios/GPS FMS/Garmin_430_2d.png” resource of your plane.

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We are going to be releasing the XPlane2Blender 3.4 beta soon, and with it, a refresh of the UI and documentation. Thanks to a great e-mail about a lack of documentation, it was put as an important part of 3.4 release roadmap. It goes to show… we can’t fix it if we don’t know what’s wrong, even if its not a code problem. And we do want to fix it, I swear!

In addition, I want to remind everyone a core part of the Laminar Research philosophy, identity, and business plan is a thriving modding and third-party plugin ecosystem. Aside from build scripts and the like, Laminar Research employees use the same scenery development tools that are available to all. This is was a deliberate choice that elevates everyone to the same level – except when there is a gap of knowledge. This is never intentional, and never benefits anyone in the long run, especially third-party-devs. If your work is suffering because we forgot that not everyone knows what every little checkbox means, tell us! We’ll put it in the bug queue like everything else, and try to get back to you, personally, quickly.

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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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