Flight Gear 0.98 / Flight Gear Legacy version

[openflight]

Not sure how this will go down on this forum but here goes:

I have been studying the FLight Gear system and am trying to add some information and new aircraft to FG. Many of the aircraft, say about 56 out of 400 don't have the basic instruments and animations.

I want to create new aircraft, add instruments etc, but to which version? Some of the aircraft are not backward compatible.

My absence from this forum and from flying FG was mainly due to my search for a Linux OS that would allow me to run FG 2.6 on my Dell D600 P4 machine with 700 MB of RAM. I have installed and run:

Puppy Linux 5
Lubuntu 12
Centos
Slitaz (!)

and attempted Vector Linux and CrunchBang as well

I finally reverted to Ubuntu 10.04 LTS and I have installed Centos on my other partition. Broadband issues, software installation and installation of WINE were some of the reasons that led me from one to another, not to mention the Nvidia n96 Video hardware.

Looks like I am stuck with FG 1.9 or lower.

I am seriosuly thinking of contributing to the FG 0.98 version and creating aircraft, upgrading instruments and doing write - ups for that version only.
Maybe I will call it FG Legacy or something to that effect, of course it wil be GPL. Especially for low resource PCs and users with slow connections.

My reasons:

FG 0.98 W 32 can be run in WINE with minimal issues
File size is 70+ mb which is easy to downlaod on slow connections
FG 0.910 ( maybe 0.98 as well) have working aircraft shadows
The detail is not so bad
It starts within 1 minute
Good Frame rates and graphics
Good realism
Decent instruments

I hope to modify and reconfigure or re-engineer the aircraft to work with FG 0.98 by

Getting the 3D model to load
Re-doing animations
Adding instruments

At least I will have a working FG with fully compatible aircraft that will run on low end PCs (Both Win and Linux).

Just the other day I saw a You Tube Vid saying 'Try FG 0.910 - it's outdated but you wil like it'

No offense to all Rembrant, but for me this is the most efficient way I can think of.

Try Flightgear 0 9 10 It's Great!.wmv - YouTube
http://www.youtube.com/watch?v=NhHpnQWkDzAShare
Oct 6, 2011 – It may be an old version but Flightgear 0.9.10 ain't half bad! It's a lot lighter on resources if your computer struggles to run the latest versions.

[Thorsten]

Not sure how this will go down on this forum but here goes

You are certainly free and welcome to do that, but I don't think there will be too much interest in that either from user or devel side.

I'm pretty certain if you run 2.10 in legacy mode (i.e. disable all shaders, use lowres textures, disable AI system,...) it will actually turn out to be faster than 0.9.1 since there have been several optimization cycles since.

[Hooray]

I'm pretty certain if you run 2.10 in legacy mode (i.e. disable all shaders, use lowres textures, disable AI system,...) it will actually turn out to be faster than 0.9.1 since there have been several optimization cycles since.

Agreed with Thorsten, please see our wiki for instructions:
http://wiki.flightgear.org/Settings_for ... hics_cards
http://wiki.flightgear.org/Howto:Debugg ... ar_Crashes

I have done exactly that on notebooks as old as 5-7 years (including one Intel GMA laptop), and they could all be made to run fgfs after lots of manual customizations.

Also, people running Linux have additional optimization opportunities by building from source and by using a lightweight window manager/desktop environment.

[stuart]

FYI - the releases up to and including 1.0.0 were pre-OSG and used plib for graphics. It may be the case that without the overhead of OSG there will be a perf gain to be had.

I don't recall there being any reason to choose 0.9.8 rather than 1.0.0 though I do recall at the time that a number of people chose to stay on 0.9.8 rather than upgrade. Can't recall whether that was for stability or performance.

-Stuart

PS: a piece of FG trivia - the 1.0.0 release was only named as such because we decided that the next incremental release number after 0.9.10 was 0.9.11 and not desirable.

[Hooray]

the releases up to and including 1.0.0 were pre-OSG and used plib for graphics. It may be the case that without the overhead of OSG there will be a perf gain to be had

The main performance gain to be had is likely due to the hardware requirements for <= 1.0 and the fact that even average/outdated hardware these days will easily outperform systems that were considered to be powerful 6-7 years ago.

[Thorsten]

Stuart, this is a good point which I didn't consider. I stand corrected then...

[Hooray]

I gave it a try by also building FG 1.0 from source and running it my old laptop (NVIDIA 7600 GO) and an Intel GMA laptop (HD 3000):
Ignoring the regressions between pre-OSG(plib) and 2.10 (OSG), I'm getting better performance in the form of higher frame rates and less jitter here, obviously with many more features.

Obviously there are tons of regressions and new features that cannot be easily compared. For example, given that FG/plib has shadows and we only get shadows with Rembrandt(OSG), it's difficult to compare things without really downstripping the config to a reduced subset of features supported by both versions, same goes for weather and other features that cannot be directly compared.

Advanced Weather kills frame rate obviously on the old laptop, cloud instantiation looks like a slideshow

Seriously, the main issue is getting FG OSG to run on old/underpowered hardware "out of the box", while FG/plib does run fairly well even without tons of manual customizations on such hardware, because its requirements and default settings are not as demanding.

Basically, if we could get 2-3 core developers to also test and optimize FG for such hardware for a single release cycle, i.e. without focusing on recent GPUs - and maybe specifically with Intel GMA hardware in mind, FlightGear/OSG >= 2.10 should be pretty capable to run even on underpowered hardware.

It's a fairly common issue that software developers tend to have fairly modern and really powerful computers and that they write software that's tested and optimized for their own platforms obviously, rarely for different platforms/OS or even outdated hardware...

To be honest, I still wouldn't suggest to waste any time on non-OSG based FG versions - it will be LESS work to customize FG/OSG for use on older hardware, than backporting all the 2.10 resources we have to FG/PLIB.

Using the "minimum startup profile" detailed in the wiki, the performance in FG/OSG is still superior to FG/PLIB here.

[stuart]

Hi Hooray,

Thanks for doing research on this - one can't argue with actual performance data .

Just so I'm clear: you have found that a suitably configured 2.10 FG is running faster than a 1.0.0 FG on older hardware? That's really interesting and a pleasant surprise.

-Stuart

[Hooray]

I'm not sure if my comparison is really representative, I only had the chance to test this very briefly on two "old" laptops, using a very downstripped test-case, i.e. the "minimum startup profile" that basically disables most features to check frame rate and then frame spacing using a Nasal script. The performance monitor and the OSG stats are obviously not available in FG/plib. And I haven't done any real profiling.

To draw a clear conclusion, we would need to come up with a better test case and repeat everything on different hardware.

Like I mentioned, plib works "better" for people who want to see certain "eye candy" (shadows) on otherwise outdated hardware - simply because FG/OSG often doesn't even work without lots of "insider knowledge" on customizing the FG defaults such that FG would even start up. From that perspective, I can actually now relate to people using such old FG versions - simply because it's probably a real pain to manually configure FG/OSG.

Still, I stand by my earlier statement that customizing FG 2.10 should be more feasible than using PRE-OSG FG to backport existing features or even develop new ones, including aircraft.

It would probably only take 2-3 people who know how to build FG from source to provide patches to make FG start up on such old hardware without segfaulting, many problematic settings can already be overridden using config files and/or properties. Obviously, Rembrandt and other modern shader features are a nogo, but there are other things that seem to cause segfaults reliably - including certain scenery locations and aircraft combinations.

Finally, keep in mind that a laptop with nvidia 7600 GO hardware (512 MB) would be considered pretty powerful in the PRE-OSG era...and obviously, PRE-OSG FG would be very unlikely to use features supported by "POST-OSG hardware".

With all the work going on behind the scenes related to better and more explicit memory management, and more fine-grained subsystem instantiation, FG/OSG is probably going to become even more competitive in comparison to the PRE-OSG fgfs binary, just think about all the memory leaks that got fixed meanwhile and other fixes unrelated to the PLIB->OSG migration - for example, see: 63eec9934730532f92730fc4f81deed34b769d95 ("Pigeon : save about 110Mb when the UIUC FDM is not used" with a single patch for FG pre 1.0). And there are more of such examples to be found for the post FG 1.0 era.

So anybody who's seriously interested in contributing to (and not just USING!) FlightGear, is really well-advised to look at a recent release and customizing its startup settings accordingly. On the other hand, I do understand that end-users who are not into tailoring their FG setup, may find it much easier to still use FG PRE-OSG - and live with the fact that it's generally considered unsupported.

[openflight]

I must say I was not fully aware of the 'OSG' and 'PLIB' graphics systems : here is what I just read on Wikipedia:

PLIB is a suite of Open Source portable computer game libraries, originally written by Steve Baker in 1997 and licensed under the LGPL.

PLIB includes sound effects, music, a complete 3D engine, font rendering, a simple windowing library, a game scripting language, a GUI, networking, 3D math library and a collection of utility functions. All are 100% portable across nearly all modern computing platforms. Each library component is fairly independent of the others to encourage replacement with other libraries like SDL or FLTK.

PLIB has been used by many projects (not all games, and not all open source), but has not kept pace with technical developments that happened after its original conception (e.g., shader technology), so it is currently outdated and rarely used for new projects. While nowadays there are better portable and Open Source replacements for all of its components are available, a similar comprehensive suite of libraries is still missing.

OSG is current, supported, and has more features, right?

[openflight]

Point taken about configuring 2.4 to run on slower machines: I had done just that with 1.1.9 that I used before my last OS installation.

Two problems with a more recent version:

1) Slower start up times - I don't want to spend too much time waiting in the modify aircraft - test aircraft cycle. After 20 + times restart it does make a difference

2) Linux version instead of W 32 0.98 that I am running would need me to sudo nautilus etc to access and modify files each time

3) Lack of the sheer sense of achievement of running a nice flight sim with a 70 MB disk footprint and general compactness.

For now, I will be running 0.98 and doing a lot of aircraft conversions and learning about configurations, converting the aircraft file structure to the recommended one, documenting the process for creating new aircraft and so on.

Just converted the Cessna 150 to show up in 0.98a using the FDM of the PA 28. Some work for be done.

Once I have got that done, maybe I will look at doing the same for 1.9.1 and beyond.

My laptop dates to around 2004, Dell D600, but with Nvidia 32 MB N96 graphics

http://www.cnet.com/laptops/dell-latitu ... 57345.html

I really feel good about this.

[openflight]

So anybody who's seriously interested in contributing to (and not just USING!) FlightGear, is really well-advised to look at a recent release and customizing its startup settings accordingly. On the other hand, I do understand that end-users who are not into tailoring their FG setup, may find it much easier to still use FG PRE-OSG - and live with the fact that it's generally considered unsupported.

I understand your point.

If anyone is developing a "Flight Gear Lite" version, and there have been some requests over the years for this, not just from me, the following would be the most wanted features I think:

1) Smaller download : one or two aircraft, no AI objects. Ideally 200 MB

2) Faster start up times

full .deb or .rpm packages to download once and install many times would also be nice

Alternatively, you could set up FG to run in a browser remotely, while at the same time downloading client installation files to run locally offline.

For example after the first 10 hours of playing FG online you will have the full version on your PC use offline.

Just an idea

Using even an older version I realize how many features FG has, some of which I have not even used so far. Great stuff by any standards.

[Hooray]

download size has been repeatedly mentioned before, and is a real issue for many users obviously.
Start up times are generally pretty good, and roughly scale with the complexity of location (airport) and aircraft model.
To see for yourself, use the ufo in a less complex location and FG will be up and running within a few seconds, even on old hardware.
Actually, some recent 2.10 reviews by new FG users specifically emphasized FlightGear's fast startup times, especially when compared to FSX and XP. So, I'd argue that this is mostly a matter of improving the underlying 3D models/textures for some scenery locations/aircraft (i.e. the artwork side).

[openflight]

Maybe someone will look at download sizes then. That seems an easy target.

As for start up times, I have to agree wit you: installed a FS from another commercial software provider and it took ages to start. Coincidentally it ended with the numbers 98 as well.

[flywisher]

For what it's worth, I still run FG 1.0.0 on my Win2K IBM Thinkpad T30 with its 16MB VRAM (yes MEGA, not GIGA), and have had a lot of fun with it over the years. Got the laptop and FG years ago. Still use the laptop when traveling, as it still does what I want and carries a lot of software I've found and installed over the years.

My FG stutters a little with faster or more complex airplanes, but I get good results with the C172, J3 Cub and the F80C that I started with. Trying to land the P51, for example, can result in such a low frame rate as I approach the runway that it becomes unusable - sometimes. But with a little altitude even it flies OK.

Oh, and it flies the ... I forget... that "Bo1--" yellow rescue helicopter, and the Robinson R22 and the Chinook about as well as my desktop machine (HP Pavilion, 3 GHz P4, 3 GB RAM, GeForce FX5700LE-256) which is running 2.4 (or 2.6? Don't recall. Haven't found a version # in that thing).

I've stopped upgrading FG on my desktop machine because I cannot use FG's shaders at all, or I get frame rates of 2 fps. Unusable. So the recent improvements are simply not available to me. So I turn them off and still have fun with it. Whether version 1.0.0 or 2.4+, FG has 'way better 3D cockpits than the M$ or X-Plane sim's I've used. That's a lot of the fun for me.