FlightGear: Thoughts, Tips & Tweaks (especially for AMD vid.)

[+VonS 1,424]

Recently I had an opportunity to re-install FlightGear (stable ver. 2020.3.19) on my 2013 Mac Pro and was pleasantly surprised - with no crashes, decent FPS for the most part, and various other improvements that were incorporated over the years. I had dabbled briefly in FlightGear a couple of times before (around 2013, and again around 2020) - but eventually removed the flight simulator from my hard drive on both of those occasions.

Since my particular setup(s) are with dual AMD video cards, I thought I would post some (illustrative) tips below, as well as representative pics of the sim when at best, or very good, settings. I will this time around keep FlightGear on my hard drive - makes for a good, free flight simulator.

For command line entries and tips that should be plugged into the "Additional Settings" option of FlightGear, see the info. immediately below. Make sure to remove the info. included in brackets if copying the commands into the relevant settings section.

-----

--prop:/sim/gui/current-style=0 (better GUI style for AMD cards)
--prop:input/mice/mouse/mode/button[2]/binding/value=2 (gets rid of horrible mouse-as-yoke feature that sometimes automatically turns on)
--prop:/sim/rendering/photoscenery/enabled=true (gives more photo-realistic scenery whenever possible; to be fully implemented in later FG versions)
--prop:/sim/rendering/hdr/envmap/update-continuously=false (disables continuous siphoning and updating of terrains, to enable seconds command below)
--prop:/sim/rendering/hdr/envmap/update-rate=5 (terrain refresh rate set in seconds; good values are 5 or 10, for minimal stuttering)
--prop:/sim/rendering/max-paged-lod=1300 (stock max paged LOD no. is "200"; recommended is not to exceed about "1900" on AMD)
--prop:/sim/rendering/plod-minimum-expiry-time-secs=60 (stock min expiry time is "180" secs.)
--prop:/sim/rendering/multithreading-mode=DrawThreadPerContext (should improve multithreading capacity, at least slightly, and add a few extra FPS)
--prop:/sim/rendering/database-pager/threads=12 (stock thread rendering no. is "4," with more threads improving ave. FPS; set as per your CPU threads no.)
--prop:/sim/rendering/vsync-enable=false (force disables vsync to improve FPS)
--prop:/sim/rendering/multi-sample-buffers=true (this is anti-aliasing; set to false to disable and remove entry immediately below it)
--prop:/sim/rendering/multi-samples=2 (anti-aliasing value; lowest is 2, also good is 4; avoid 3)
--compositor=Compositor/HDR/hdr (modern rendering pipeline for better graphics details and shaders; rarely breaks scenery; still mostly experimental on AMD vid. cards)
--units-meters
--disable-splash-screen
--disable-horizon-effect
--enable-distance-attenuation
--enable-specular-highlight
--enable-clouds3d
--fog-nicest ("nicest" improves look of fog with more subtleties while "fastest" makes fog appear and disappear more quickly; no real impact on AMD FPS)
--shading-flat ("smooth" apparently improves look or depth of shaders; preference is for "flat" since I have not noticed difference in quality on AMD)
--texture-filtering=2 (this is anisotropic value; lowest is 1; also good is 4 or 2; avoid 3)
--bpp=32 (can also use 24 but have not noticed an FPS improvement with 24; would say 32 is better for FPS overall)
--terrain-engine=pagedLOD
--lod-levels=3 2 5 3 1 (also good is 4 3 6 4 2 for best visual quality on AMD but still mostly FPS-friendly; recommended is 3 2 5 3 1 for balance between visual quality and solid FPS)
--lod-res=2 (default is 1; also good is 3; avoid any other values besides 2)
--lod-texturing=raster (better than "bluemarble" as far as I have been able to test, with smoother loading of textures)
--lod-range-mult=3 (default is 2; also good is 1; avoid all other values besides 3)
--enable-texture-cache

-----

On a broader note, it's important to tweak the rendering, shaders, and LOD range settings in FlightGear - to get the best experience on your AMD video rigs (be it a dual or single AMD setup).

The frequencies, by the way, on my dual FireProD700s have been OC-ed, via MSI Afterburner, from a clock/memory of 850/1370 to 1024/1380 MHz.

Be sensible with the rendering options - particularly with the maximum number of scenery and aircraft tiles - anything above a value of 1900 or so is both useless and an FPS hit. (The scenery/aircraft tiles no. may also be set via the relevant command line entry indicated above in this post.)

Take note as well of cloud density and visibility values. Anything beyond a visibility of 35 km or so is questionable since it does not widen further the cloud carpet but is, once again, an FPS hit.

Pic 1 - Sensible/Best Rendering Choices for AMD Video (in FlightGear)

Next we look at the shader options that also require careful thinking and tweaking. Take note that "landmass," "urban," also "water" - give different visuals if they are set to the maximum level (of five). I personally prefer how the landscape/terrains look with those three settings at a value of four - with crisper graphics - but tweak according to taste. Also worth noting is that I always run the LOD value on my rig(s) at "-1," via the excellent little program "ATISetLod" that is available under the top post of this thread.

Pic 2 - Sensible/Best Shader Options for AMD Video (for crisp and fairly realistic graphics)

Also important is to tweak the LOD range settings to get a good balance between visual quality and decent FPS, with no stuttering or crashes. Focus in particular on the maximum distances for the detailed, rough and bare scenery ranges - I decided eventually on cutoffs of 3, 17.5 and nearly 45 km. Other cutoffs worth considering are 2.5, 15, and 40 (or so) km, as well as 3.5, 20, and 50 km. Anything beyond the latter values will, again, most likely not make much of a difference with the visuals but will contribute a noticeable FPS hit. Take note also of the "high detail" and "AI/MP interior" values. I'm getting good results with values of 250 - 260 pixels for those options; also good are values of 300 (or so) pixels. Those two values may be tweaked to taste, for the most part - but, again, be sensible since they may impact on FPS.

Pic 3 - Sensible/Best LOD Range Values for AMD Video

Last, let's not forget to tweak our custom FlightGear profile (in our AMD settings panel) as best we can, to minimize stuttering, pausing, or crashes. Take note in particular how the shader cache is set to "On," not to "AMD Optimized," and how, even though I have enabled CrossFire mode, frame pacing is set to "Off" (which eradicates stutters on my rig in FlightGear - had tried with frame pacing "On" and was not pleased with the results). If you have only a single AMD video card, experiment with leaving the CrossFire option on (set to "AFR compatible"), or turning it off entirely. (NOTE: I have not noticed any FPS downgrade with anti-aliasing set to 4EQ and edge-detect, anisotropic value at 8, and tessellation at 16. Tweak to taste obviously.)

Pic 4 - Good AMD Settings for a Custom FlightGear Profile

Recommended also, if having any instability with FlightGear on AMD video, is to stick with the "Pro" variant DLLs (drivers) for AMD, instead of the consumer/Adrenalin ones. I particularly like the ver. 19.x.x Pro series of drivers, as well as the venerable ver. 17.x.x ones (the latter of which I have installed on the 2013 Mac Pro). To find links to the Pro 19.Q3 DLLs (the last version of the Pro DLLs to support CrossFire, by the way), see this page.

Below follow several representative pics with the settings illustrated above applied - FlightGear provides a nice selection of aircraft with usually very good monoplane FMs, especially for tricycle-gear (small) civilian aircraft such as Cessnas, also for airliners like the (classic) Boeing 707. For multi-wing contraptions on the other hand and more realistic/historical FMs for biplanes, triplanes, and the odd multiplane, the gold standard(s) remain heavily-modded First Eagles 2 and RoF, as well as recent iterations (UE edition onwards) of the excellent WoFF series.

Happy flying,

Von S 

Edited April 12 by VonS
Edited post.

[+mue 707]

Always nice to see FlightGear mentioned here on this site.
I'm a big fan of this open source flight simulator and I already tried to combine my love for the Thirdwire sims with my love for FlightGear: https://combatace.com/forums/topic/93840-strike-fighters-2-meets-flightgear/.
I'm still working on and off on a tool that in the end should be able to automatically convert SF2 (and FE2) aircraft into FlighGear aircraft (with a JSBSim flight model).

[+VonS 1,424]

FM tweaks available in relevant aircraft folders in E. Baranger's FlightGear Hangar.

(The WACO S-220 conversion is based on the SIAI-Marchetti S.205R that's available there, by the way. All Von S FM tweaks for FG fall under the GNU GPL.)

 

Brief, approximate performance specs. per type:

Bleriot XI 1909 Model - max 42 / cruise 39 kts

Egerton & Mann 140-HP SPAD 7 - max 103.6 / cruise 97.2 kts

Piper PA-28 B Model 150-HP - max 120 / cruise 110 kts

Early Grumman AA1 - max 125 / cruise 120 / never exceed 169.5 kts

AA1 150-HP Conversion - max 142 / cruise 137 / never exceed 169.5 kts

WACO S-220 - max 161 / cruise 152 / never exceed about 175-180 kts

 

Tips:

- use opposite-to-turn rudder on the Bleriot and SPAD if you are falling into a side-slip and/or spin; also good for tight turns

- watch speed on the Grummans owing to the early variant "hot wing" on them; unexpected sharp stalls pop up sometimes below about 85 knots, sometimes at higher speeds too for added excitement

- WACO, similar to the S.205R, lands best when close to stall speed a foot or two above a runway

- about 10% front-stick is required on the Grummans while on the ground, to control steering (transition smoothly to about 10% back-stick while accelerating to take-off; takes practice)

- about 10% back-stick during take-offs (to get the nose up) on the WACO; will "fly itself" once it passes about 80-85 knots

 

Representative clips:

- various flight tests available further below (simply click on a pic. to open the relevant clip hosted on DropBox; clips average 7 - 10 mins. in length approx.)

- airport where flight tests recorded is near Grazzanise, Italy (airport code: LIRM)

- all clips recorded via Game Bar (on Windows 10) and further compressed via VLC Player

- version of FlightGear used for flight and tests is the stable ver. 2020.3.19 (which is recommended for AMD video, particularly on Intel Macs; newer, nightly versions of FG may not be stable on AMD vid. and/or on Mac setups and "Wintosh" hybridizations for now; experiment as per taste)

- Bleriot model visible in the relevant clip is a mixed/hybrid combination of old and new files and model components, taken from the main aircraft launcher/hangar in FlightGear and also from E. Baranger's hangar, for personal testing; a newer model is available in E. Baranger's hangar

- Anzani and Hisso sounds for the Bleriot and SPAD are extractions from my FM/Realism package for First Eagles 2

- landing rate add-on visible upon landing in the flight test clips is a customization of the one available here; an earlier edition for older vers. of FlightGear may be found at this link

Cheers all & good flying in FG,

 

Edited March 30 by VonS
Edited info.

[+VonS 1,424]

One more friendly public service post  under this thread, regarding FlightGear. Many thanks first of all to Emmanuel Baranger for pointing me in the right direction for how to enable photo/ortho-scenery in this fine, open-source simulator.

Most of the important details regarding photo-scenery and proper installation of packages, programs, etc., in order to have everything function properly - are available under the "Julia Photoscenery Generator" tutorial. Thank you "abassign" for the original instructions, coding, and tutorial. Also many thanks to Manuel who has done a video run-through of the main components of that tutorial.

I wish, however, to draw attention to a few peculiarities that are likely relevant only to Intel-era Macs and/or to specific "Wintosh" combinations such as I am running, and perhaps others are running too. Tips and directions below are for the stable ver. 2020.3.19 of FlightGear, by the way.

 

Five important things to keep in mind:

a) when downloading necessary applications to enable photoscenery, as indicated in the tutorial, such as the "Photoscenary" files, the Julia compiler, and the ImageMagick application that converts images to the DDS format, make sure to download the *actual installer* for ImageMagick (indicated with an .exe extension) - it is fine to download the portable version of the Julia compiler, but do *not* download the portable version of ImageMagick; the full installer for the latter is necessary; furthermore, while installing ImageMagick, make sure to select the two options for "set system path to files/program installed," as well as for "legacy converters"; also important is to install the Visual C++ Redistributable Package that is linked to near the bottom of the main ImageMagick website - only with all of those details followed does ImageMagick work properly on an Intel Mac

b) once all of the necessary programs and files are installed, go into the "Photoscenary" folder, open the two text files titled "conn" and "args" - delete the contents of both - and paste in *either* of the following two sets of commands into *both* files (don't forget to save once the information is entered):

option one, for great photo-imagery quality and decent FPS, even if flying in multiplayer:

--connect
127.0.0.1:5000
-s
5
-r
30
--attemps
3
--over
1
--sdwn
2

option two, once again for fine photo-scenery quality and good FPS, even in multiplayer (but perhaps slightly better for lower-end rigs):

--connect
127.0.0.1:5000
-s
4
-r
40
--attemps
3
--over
1
--sdwn
1

c) while still inside the "Photoscenary" folder, right-click on the "photoscenary.jl" application and select the option to open it with Notepad; once the application is opened in Notepad, scroll to the following code:

julia -t 10 -p 2 photoscenary.jl

 

and change, for example, to:

 

julia -t 5 -p 2 photoscenary.jl

 

(the suggested change reduces noticeably the no. of threads that the "photoscenary" application uses to download satellite imagery for FlightGear; the general rule of thumb is to set the no. of threads to 50% or slightly less of your total no. of processor threads available; furthermore, the "-p 2" command references the no. of processor cores to dedicate to photo-imagery downloading; a sensible no. for the cores is no more than 50% of the total cores that you have -- anything higher than such percentages devoted to ortho/photo-siphoning is excessive and will not improve tile-download smoothness or overall FPS in FlightGear -- from my tests, I have noticed that I am getting very good results either with 6 threads and 3 cores, or 5 threads and 2 cores, devoted to the tile siphoning/download process; the total no. of threads on my system is 12, and the total no. of cores is 6, by the way)

d) make sure, before running the "photoscenary.jl" application (i.e., before double-clicking it so that it begins to fetch photo-scenery for FlightGear), to unselect any custom scenery that you might have installed in FlightGear and that is visible under the "Add-ons" menu; then run "photoscenary.jl" and it will proceed to set up a default "Orthophotos" folder at the following directory path - \FlightGear\Downloads\TerraSync\Orthophotos

e) last, it is vital directly to select the created "Orthophotos" folder as your custom scenery folder in FG's "Add-ons" menu; otherwise, photo-scenery will not be visible while flying in FlightGear; if you have other custom terrain folders, you may re-select them at this point, but make sure that the "Orthophotos" folder is always at the top of the hierarchy (see illustrative pic. below)

NOTE 1: "photoscenary.jl" will on its next run set up another "Orthophotos" folder within the one that we have already locked to FlightGear, but that is fine; allow the directory structure to exist as \TerraSync\Orthophotos\Orthophotos (and feel free to delete any other folders that may have been created in the meantime in the first "Orthophotos" folder of the directory path, right after "TerraSync")

NOTE 2: if running the application OSArmor (or the older variant "NoVirusThanks OSArmor"), make sure to *disable protection* before running "photoscenary.jl"; otherwise, blocked process warnings will pop up with every photo-scenery download and will likely disrupt operation of the whole photo-scenery fetching mechanism

 

Below follow several representative pics. of photo-scenery functioning properly in ver. 2020.3.19 of FlightGear on an Intel Mac. I have not noticed any drop in FPS with photo-scenery enabled; on the contrary, my overall FPS seems to have improved by a few frames when compared with flight over stock TerraSync terrains in FG.

While there are so many wonderful things about photo-scenery, one of the details worth mentioning is that the terrain now overlaps very closely with what is seen on the "mpmap" if you enjoy tracking your flight's progress that way too. Take note, for example, of the subtle depression in the grass where the Piper PA-28 B Model has been parked, and also of the location where it sits on the Google maps pic. (great stuff).

As well please find included, below the pics., a small attachment that includes a few ALS shader tweaks for FlightGear, to improve graphics crispness and/or to stabilize FPS further on AMD-vid rigs.

FlightGear_ALSshaderTweaks_VonS.zip

Good flying to you,

Edited April 10 by VonS
Added info. regarding threads, cores, and download smoothness of photo-scenery.

[+VonS 1,424]

Have recently tinkered with a Fokker E.II (mid-production batch) FM conversion for Emmanuel Baranger's excellent E.III for FlightGear - the FM changes are now offered as an option in E. Baranger's FG Hangar. While testing the FM, I also updated my WoFF series shaders profile (for ReShade ver. 4.9.1), so that it works well with FlightGear too and creates a "pseudo-HDR" effect, among other things. The shaders file is included in zipped format underneath the video link (to the Fokk. E.II tests) that follows.

You may have good luck with vers. 5.x.x or 6.x.x of ReShade too, but for convenience please find relevant download links to the venerable/stable ver. 4.9.1 under this thread. Take note, when installing ReShade for FlightGear, to choose "OpenGL" as the API option; then install the default shader package, as well as the Fubax and Astray packages. Necessary filters to activate, after installation of the shader packages, are: Vibrance, DPX, FXAA, LumaSharpen, Smart_Sharp, and Clarity. Also don't forget to select "performance mode" in the ReShade options.

The video below (click on pic. to open link) is with my FG shaders profile activated and with satellite photo-imagery being siphoned into FlightGear; see instructions in the previous post, above, for how to enable photo-imagery in your FG installs on AMD-vid rigs, etc.

(NOTE: Various rotary engine sounds in the video linked to below are © OBD Software, copied over for personal use from my WoFF UE/PE-era install, and are not supplied with the Fokk. E.II FM modification that's available via E. Baranger's FG Hangar.)

FGshadersVonS.zip

Happy flying,

Edited April 20 by VonS
Edited info.

[+VonS 1,424]

Quite pleased with how my (ReShade ver. 4.9.1) shaders profile for FG is functioning on my rig, I began thinking about how to improve the ave. FPS further in the sim, beyond the tips located in the top post of this thread, for AMD-vid rigs running the sim. Finally, I stumbled on an odd little tweak that works well enough and is worth sharing in this post.

The tweak requires that you download the OPENAL64.DLL file hosted over here on the DLL-Files.com website that has been around for at least a couple of decades. Once you download and unzip the DLL rename it to "OpenAL32.dll" (without the quotation marks). Then, navigate to your FlightGear "bin" directory (the actual sim folder located somewhere in your c_drive usually, not into the folder that hosts downloaded aircraft, custom aircraft, and whatnot). Once you are in the relevant "bin" directory (see illustrative pic. below), find the file called "OpenAL32.dll" and save a backup of that DLL somewhere - after that, replace/overwrite the DLL (that is ver. 1.x.x, a fairly old one) - with the one that you have downloaded and renamed identically.

On average, I am noticing an FPS improvement in FlightGear with the OPENAL64 driver masquerading as OpenAL32 - an improvement of anywhere from 5 to 20 FPS (or so), depending on cockpit views, angle of views, as well as weather details and photo-scenery loading rates. The driver replacement also cuts down satisfactorily on any possible stuttering when FPS occasionally do drop. Your mileage may vary - but from what I've seen on my AMD-vid rig the results of this little tweak are good enough to improve overall smoothness and quality of flying in FlightGear.

(NOTE: the driver-replacement tip mentioned in this post *may not* be as helpful on Linux, considering the possibility that you are already perhaps running newer OpenGL drivers in your Linux-variant FG installation. The tip will most likely be of greatest help on Windows systems and/or "Wintosh" hybridizations where Windows is installed on a Mac. Can't say anything regarding Mac OS X/macOS because I don't have FG installed on the Mac OS side of my computer.)

Some representative pics. of FlightGear ver. 2020.3.19 follow below, with photo-scenery, my "pseudo-HDR" shaders profile loaded (via ReShade), and the OpenAL driver replacement tip at work. The flight was around Naples, Italy, at about 10,000 feet alt. (with take-off from the LIRM airport).

The Morane-Saulnier Type N used in the pics is a re-skinned and FM-overhauled version of the non-GPL model originally done by Lester Boffo and located here. I am also thinking of re-skinning and FM-overhauling his Albatros D.I, perhaps to be done up in Ottoman livery so that I can do some photo-realistic flying above the Mesopotamian front (c. 1917). The Boffo model overhauls are only for my private use since they follow various types and sub-types of non-GPL licenses. Download those yourselves from the non-GPL FlightGear repositories and tweak to taste, if so inclined.

Good flying to all,

 

Edited April 17 by VonS
Edited post.