Re: [Flightgear-devel] Re: Runway distance remainingsigns+placementscript "done".
You could simulate that too, if you have a strong force feedback joystick ;-) But this is a level of realism I can accept to live without. On Thursday 09 September 2004 16:15, Matthew Law wrote: > It's the same with forced landings. Making an approach into a field of > sheep is usually safe (my instructor has done it twice!). Making an > approach into cows probably isn't. They're not guaranteed to move out of > the way and in a small aircraft, hitting a cow would be bad :-) > > A while ago, a girl skydiving at my dropzone landed off the airfield in > a field of sheep. It was the middle of the lambing season and when she > stooped down to pick up here canopy she was butted in the chest and > ended up in intensive care with a badly broken sternum. > > All the best, > > Matthew. > > * Giles Robertson <[EMAIL PROTECTED]> [2004-09-09 14:00]: > > I'm aware that when ballooning, it is always preferable to land in > > sheep, rather than cows; cows are intensely curious, and so, although > > when the balloon lands, they scatter, after the envelope is deflated, > > they will approach and start trampling on it, and licking it with > > sandpaper-like tongues. The sheep just stay well away. :) > > > > -Original Message- > > From: Arnt Karlsen [mailto:[EMAIL PROTECTED] > > Sent: 09 September 2004 12:22 > > To: FlightGear developers discussions > > Subject: Re: [Flightgear-devel] Runway distance > > remainingsigns+placementscript "done". > > > > On Thu, 9 Sep 2004 06:40:53 -0400, David wrote in message > > > > <[EMAIL PROTECTED]>: > > > One thing we could add, at least for my part of the world, are > > > animated groundhogs all over the airport -- also flocks of birds near > > > the threshold. I also heard a story recently of cows eating the > > > fabric covering of a tube-and-rag airplane. > > > > ...that kinda realism might haven an impact on both the 3d model > > and the fdm's. ;-) > > > > -- > > ..med vennlig hilsen = with Kind Regards from Arnt... ;-) > > ...with a number of polar bear hunters in his ancestry... > > Scenarios always come in sets of three: > > best case, worst case, and just in case. > > > > > > > > ___ > > Flightgear-devel mailing list > > [EMAIL PROTECTED] > > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > > 2f585eeea02e2c79d7b1d8c4963bae2d > > > > ___ > > Flightgear-devel mailing list > > [EMAIL PROTECTED] > > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > > 2f585eeea02e2c79d7b1d8c4963bae2d > > ___ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > 2f585eeea02e2c79d7b1d8c4963bae2d -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
[Flightgear-devel] New type of ultralight aircraft
When will flightgear have a model of this?;-) http://www.yves-rossy.com/en/ (see the jet man link at the top right) -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: bo104 - patch
On Monday 09 August 2004 17:13, Melchior FRANZ wrote:
> * Gunnstein Lye -- Monday 09 August 2004 16:35:
> > Seriously though, it seems the problem here is that most, but not all,
> > find it logical to map the up/down behaviour of a collective to the
> > backward/forward motion of a joystick (or joystick throttle). There is no
> > right or wrong here, as there is no logical way to translate Y-axis
> > movement to the Z-axis.
>
> Yes, there is: pull -> raise, push -> sink. It doesn't matter how the
> joystick is mounted. This is the right and realistic way. The other may be
> consistent with fixed wing and newbie friendly, but fgfs' goal is realism.
> It's not a game, but a simulator after all. I'm tending more and more to
> revert today's patch.
Okay, for joystick throttles I agree with you. (Although personally I would go
for the "second joystick" option.)
For buttons, on the other hand, I think "up" should mean up.
> > Solution: make the default whatever most people agree on, but make it
> > easy to invert, as in X-Plane where you have an invert button next to
> > each joystick axis.
>
> That was my first solution, but the patch was rejected ("please not yet
> another property"). I inverted the collective axis in the YASim config
> then.
Too bad.
--
best regards,
Gunnstein Lye
Systems engineer
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Re: [Flightgear-devel] Newbee
On Monday 09 August 2004 03:35, Jim Wilson wrote: > > What O.S.? > > For this use any OS you want. A lot of folks using Linux, most any distro > will do. Mandrake is actually fine, gentoo might require a bit more > experience (or at least patience) to get started. For a linux beginner I would recommend suse (my favourite), mandrake or fedora/redhat. AFAIK, they have the best hardware support and the easiest installation. (Debian is great for gurus, not so great for beginners.) -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] bo105 + patch
On Monday 09 August 2004 17:12, Martin Spott wrote: > Gunnstein Lye wrote: > > How? If pulling the collective up makes the heli go up, then I would > > expect the keyboard to behave in the same way: press up/pageup to go up. > > (If he meant "mouse up", then I might agree) > > When you control the collective pitch of a heli flight sim you usually > don't look on what's written on the keys - at least _I_ don't ;-)) > To my sense the two keys substitute a little stick that has a flexible > mounting between them. When you pull the stick, the PgDown key gets > pressed down by the stick due to the flexible mounting. > Then you could adapt the action of "pulling the lever" from the real > heli, > > Martin. That is if the imaginary stick extends away from you (over the Pause/Break button on a normal keyboard). If it extends towards you the effect is the opposite. Anyway, for a user who has never seen the inside of a helicopter cockpit, this just means inverting the meaning of "up" and "down", which surely must be confusing. -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Re: bo104 - patch
On Monday 09 August 2004 15:22, Jim Wilson wrote: > Martin Spott said: > > Arnt Karlsen wrote: > > > On Sat, 7 Aug 2004 16:57:24 +0200, Melchior wrote in message > > > > > > <[EMAIL PROTECTED]>: > > > > Yes, that's widely known. But nobody would seriously assume that > > > > anywhere the collective lever is pushed down to raise, and pulled up > > > > to sink. > > > > > > ..heh, precicely this is done by many R/C heli pilots. ;-) > > > > R/C pilots use to have a long standing culture discussing how to to do > > it 'right' :-) > > > > To my knowledge there are mostly two parties: Those who know at least a > > little bit how things work on a real helicopter and thos who don't. You > > even can convince some of the second group to try a change by letting > > them sit im a real heli > > Mostly, but how about a third party that knows what a collective lever > looks like, realizes that the joystick looks nothing remotely like one and > thinks that binding the keyboard one way and the joystick the other way is > not a good idea. > My preference would probably be Alex's original patch. Buy a second joystick, and mount it horizontally next to your chair. It should make a decent collective, and would double as a hand brake for rally sims =) Seriously though, it seems the problem here is that most, but not all, find it logical to map the up/down behaviour of a collective to the backward/forward motion of a joystick (or joystick throttle). There is no right or wrong here, as there is no logical way to translate Y-axis movement to the Z-axis. Solution: make the default whatever most people agree on, but make it easy to invert, as in X-Plane where you have an invert button next to each joystick axis. -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] bo105 + patch
On Monday 09 August 2004 14:37, Martin Spott wrote: > Alex Romosan wrote: > > [...] i use the keyboard mappings and > > a mouse to "fly" and i noticed that the collective is mapped backwards > > (up goes down and down goes up). > > which very much resembles the controls of a real heli ! How? If pulling the collective up makes the heli go up, then I would expect the keyboard to behave in the same way: press up/pageup to go up. (If he meant "mouse up", then I might agree) > A helicopter has sort of a parking brake handle to control the > collective: Pulling the handle increases the collective angle of > attack. > I after updating from CVS I realized that the collective controls via > the keyboard interface have changed and I must admit that I'm pretty > much disappointed, > > Martin. -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] Anyone read polish?
On Friday 11 June 2004 16:39, Jon S Berndt wrote: > On Fri, 11 Jun 2004 16:22:30 +0200 > > Erik Hofman <[EMAIL PROTECTED]> wrote: > >Curtis L. Olson wrote: > >>Does anyone read enough polish to double check that everything these > >>guys are doing is within the spirit of the GPL? > >> > >>http://www.allegro.pl/show_item.php?item=26723501 > > > >As far as I can decipher it (based on a number of words I do somehow > >recognize) it's just another magazine article that is quite positive > >about FlightGear. It seems to mention it is Freeware and talks a bit > >about the amount of scenery available. > > > >I wouldn't worry too much. > > I found a Polish translator online. I think it's worth looking into. > It appears to be a FlightGear CD for sale. The GPL does not prohibit selling, and does not say anything about how much they can charge, as long as any changes they have made are made available for free (or the cost of the medium and postage). I could sell flightgear CDs for $1.000.000 if I wanted to. Doubt I would sell much, though. =) -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] FlightGear news letter
On Saturday 08 May 2004 00:28, Curtis L. Olson wrote: > For an upcoming newsletter article I am [hopefully] writing an > introduction to modeling aircraft flight dynamics in YASim. I can't help you here, I just want to say thanks for doing this. I'd like to create/modify a model, but lack an overview of how things work in FG. -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] FlightGear news letter
Air Time(s) Air Mail Ad NOTAM FlightMail -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] MinGW/cross-compiler writeup
On Friday 30 April 2004 02:57, Andy Ross wrote: > OK, I think I've got the kinks worked out of the MinGW work, and > have written up a little README (attached) describing how the > process works. Thanks to Norman and Frederic for the pointer to > the pthread library. Thanks for the info. Do you really have to build separate binaries of gcc for each target? I thought I could use the same binary for linux (native) and windows (crosscompiling). -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] OpenAL - http://www.openal.org
On Thursday 22 April 2004 22:03, Tracy Martin wrote: > Engine fails, lever fully down, adopt autorotation speed (depends on type > flown and where the field is) keep nose into wind with pedal*, adjust rrpm > ( depending on weight ) ...wait for the ground to get nearer, around 30 - > 40' stick gently back, gentle flare to reduce forward speed, level ship, > let her settle onto ground. > Switches: off, get cup of tea. Sounds easy.. =) How low can the engine fail, and you still be able to do a safe autorotation landing? (provided there is a field within reach) (I'm talking about the upper end, of course, I assume you could survive an engine loss at one feet (foot?)) -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] FGFS 0.9.4 - Aircraft Data - P51d
On Friday 02 April 2004 13:33, Jon Berndt wrote: [...] > drag coefficient of the aircraft. The P-51 was also the first aircraft to > utilize the NACA laminar-flow airfoil sections, discussed earlier. Although > it is doubtful that any significant laminar flow was achieved on production > versions of the Mustang, the low-drag airfoils did provide improved > characteristics at high subsonic Mach numbers." How is the situation in this area today? Do for instance modern jet fighters have laminar flow over the whole wing? (I guess the whole picture changes a lot when you go supersonic.) -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] FGFS 0.9.4 - Aircraft Data - P51d
On Friday 02 April 2004 09:41, Vivian Meazza wrote: > The Spitfire also had a drag-reducing radiator. I think the key _was_ the > wing section. The Spitfire was eventually fitted with a Mustang-like > laminar flow wing, which enabled the aircraft to reach 450+ mph. Pardon my lack of aero-engineering experience, but aren't all wings built for laminar flow? Or does the term mean "more laminar"? -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Trademark violations could be a problem
On Friday 26 March 2004 00:33, Arnt Karlsen wrote: > On Thu, 25 Mar 2004 17:28:23 -0500, Ethan wrote in message > > <[EMAIL PROTECTED]>: > > What I've found is that as long as you make someone's product look > > good(or at least not bad) then they are happy. So as long as we make > > Boeings look and act like Boeings, and Cessnas look and act liike > > Cessnas, we shouldn't have a problem. And besides, if no one has a > > problem with us modeling thier stuff, why should we be worrying about > > it? > > ..they don't even have to look or act like the real things, having > them act like kangaroos in a mine field will qualify as fair use in > _all_ civilized countries. I worry more about the US, [...] 3.. 2.. 1.. Flamewar!!! ;-) -- best regards, Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Paraglider model
On Monday 01 March 2004 18:19, Andy Ross wrote:
> There shouldn't be anything really weird about a paraglider. The big
> differences from airplane behavior are due to funny mass distribution:
> the engine acts near the c.g., but the lift and drag are rather high
> above it. My guess this is the source of the original complaint. In
> a YASim model, you could try playing with ballast tags to move the
> default weight distribution around.
I will have a look at it, thanks. Do you think YASim is better for this
purpose? I would think so, since as far as I understand it uses the shape of
the wing to calculate lift and drag.
> This holds so long as the parachute stays inflated. Handling the
> non-rigid behavior of a flopping chute is going to be hard, but that's
> more of a failure mode than a flight simulation issue. :)
Not necessarily. Controlled deflation is used as a way of controling the
glider. Wingtip collapses ("big ears") reduce the glide ratio, which can be
useful for landings, and B-stall allows you to descend vertically in a
controlled manner.
If I have full programming control of the wing shape, then "big ears" can be
at least partially simulated. The drag effect of the collapsed wing tips
would be difficult, of course.
best regards,
--
Gunnstein Lye
Systems engineer
[EMAIL PROTECTED] | eZ systems | ez.no
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Re: [Flightgear-devel] Paraglider model
On Monday 01 March 2004 13:28, Jon Berndt wrote: > > I'm a bit concerned about the physics model of flightgear. Are there > > certain > > physical limitations built into the sim, that makes paraglider physics > > impossible to model? I'm thinking particularly about the pendulum effect. > > Of course, everything is possible when you have access to the source > > code, but you know what I mean... > > > > Or is this simply a matter of improving David's paraglider model? > > There are several physics models for FlightGear. The main ones, JSBSim and > YASim are, I believe, both capable of handling a paraglider. However, it is > also possible that two of the other FDMs, LaRCSim and UIUC-Larcsim could be > useful. > > Andy Ross (author of YASim) would be able to tell you about modeling a > paraglider with YASim (which uses aircraft geometry and performance figures > to model flight physics, to give a very broad description of that > approach). The JSBSim model, to my knowledge, has not been used much, and > is a rough, first-cut, model. I have a hunch that some tweaking will give > you a better match for what you expect, and the first thing I'd change is > the location of the CG and the aero reference point. > > If neither of the two (YASim and JSBSim) are appropriate for your > expectations, you can code a special flight model in C within LaRCSim or > perhaps set up a special model in UIUC-LaRCSim, although I am not very > familiar with that. > > The point is, (and I say this from the point of view of someone who works > with flight simulators every day) with the total set of four FDMs (flight > dynamics model) you will have the ability to model a paraglider. But it > will require some work and study on your part. Thanks, I'll begin reading. I didn't expect this to be easy... =) But you've at least convinced me it's possible. Is this list the right forum for further discussion of the project, or should I go to the flightmodel or users list? best regards, -- Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Paraglider model
On Saturday 28 February 2004 22:00, Gunnstein Lye wrote: > On Saturday 28 February 2004 21:49, Gunnstein Lye wrote: > > On Saturday 28 February 2004 00:16, David Culp wrote: > > > --aircraft=paraglider-jsbsim > > > > > > Just remember to change the paths of course. > > > I have no experience in paragliders, so this model was just a guess. > > > > There is no paraglider included with flightgear as far as I can tell, but > > thanks for the other tips in your script. > > Correction: There is no paraglider in my version of flightgear. I just > found a reference to your model on the flightmodel mailing list, I'll get > flightgear 0.9.3 and try it out. I have tested paraglider-jsbsim now, and unfortunately I must say it flies like a plane, not like a paraglider. No offence, and I understand it's not easy to model when you don't have first-hand experience. When I push the stick to the right, it rolls like a plane, turning only slightly. I should have turned (yawed), first with a slight opposite roll, then with the correct roll, due to the pendulum effect. When I push the stick forwards, it will dive straight down like a plane. That's not possible in a paraglider, because of the distance between the center of gravity (the pilot) and the center of drag (the wing). The only way to dive is in a spiral dive. As soon as you stop spiraling, the dive stops (quite violently if you're rushing it, a spiral dive that's ended too quickly can end with a loop). I'm a bit concerned about the physics model of flightgear. Are there certain physical limitations built into the sim, that makes paraglider physics impossible to model? I'm thinking particularly about the pendulum effect. Of course, everything is possible when you have access to the source code, but you know what I mean... Or is this simply a matter of improving David's paraglider model? I'd like to know more about this before I spend any time coding... best regards, -- Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Paraglider model
On Saturday 28 February 2004 21:49, Gunnstein Lye wrote: > On Saturday 28 February 2004 00:16, David Culp wrote: > > > Which FDM should I use? I'm thinking YASim but I'm not sure. > > > > Try running FlightGear with this script: > > > > #!/bin/bash > > > > cmdline=" > > --fg-root=/home/dave/FlightGear/data > > --aircraft=paraglider-jsbsim > > --airport-id=KSFO > > --in-air > > --notrim > > --altitude=1000 > > --heading=280 > > --uBody=10 > > --wBody=8 > > --geometry=1024x768 > > --visibility-miles=10.0 > > --disable-sound > > --disable-clouds > > --disable-hud > > --start-date-gmt=2003:01:20:16:00:00 > > " > > > > /home/dave/bin/fgfs $cmdline > > exit 0 > > > > > > Just remember to change the paths of course. > > I have no experience in paragliders, so this model was just a guess. > > There is no paraglider included with flightgear as far as I can tell, but > thanks for the other tips in your script. Correction: There is no paraglider in my version of flightgear. I just found a reference to your model on the flightmodel mailing list, I'll get flightgear 0.9.3 and try it out. best regards, -- Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] Paraglider model
On Saturday 28 February 2004 00:16, David Culp wrote: > > Which FDM should I use? I'm thinking YASim but I'm not sure. > > Try running FlightGear with this script: > > #!/bin/bash > > cmdline=" > --fg-root=/home/dave/FlightGear/data > --aircraft=paraglider-jsbsim > --airport-id=KSFO > --in-air > --notrim > --altitude=1000 > --heading=280 > --uBody=10 > --wBody=8 > --geometry=1024x768 > --visibility-miles=10.0 > --disable-sound > --disable-clouds > --disable-hud > --start-date-gmt=2003:01:20:16:00:00 > " > > /home/dave/bin/fgfs $cmdline > exit 0 > > > Just remember to change the paths of course. > I have no experience in paragliders, so this model was just a guess. There is no paraglider included with flightgear as far as I can tell, but thanks for the other tips in your script. (My question was not "How to fly a paraglider in flightgear", but rather "Would it be possible to model a paraglider in flightgear, and if so then how". best regards, -- Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] Paraglider model
Hi all, (I'm new to this list, my apologies if this is the wrong forum for my questions.) I am a paraglider pilot who have been toying with the idea of modelling a paraglider in a flight simulator. I made a model in X-Plane first, but had to give up because X-Plane was too limited to be able to model the controls of a paraglider. (And because my model preferred spinning wildly out of control to actual flying...) I hope that the project can be done in FlightGear. At least it seams so, based on what I've read in the FAQs and docs. I have decent C++ programming experience, but only rudimentary 3D graphics knowledge. Just so that we are all clear on the subject: A lot of people confuse paragliders, parachutes and hanggliders. This is a paraglider (large image): http://mail.egroup.no/HLSK/Galleriet.nsf/0/E13D5199716A1920C1256BD6004D5F15/$FILE/EPSN0072.jpg In text, a paraglider is a ram-air inflated, flexible fabric wing, differing from a hangglider in that it has no spars, and from a square parachute in its higher aspect ratio and better glide angle. The pilot hangs suspended below the wing. It can be a glider or powered by a light engine. Do you think it can be done? Some challenges / more information: Take off and landing is usually done by foot, but a trike can be used (must be used for the simulation). Pendulum effect: The pilot, who weighs 10-18 times as much as the wing, is situated 8 meters below the wing. This means that the center of gravity is about 7 meters below the center of lift. Result: Extreme stability. You can let go of the controls in almost any situation, and the wing will soon fly straight. However, the pendulum effect can be used for various acrobatic manouvers: wing-overs, spiral dive, flat spin, SAT, etc., even loops. (The wing can never dive in a straight line, though.) If flightgear has a "real" physics engine, then this should be possible to simulate. Making a turn is radically different from a normal plane: A turn to the left is done by pulling down the trailing edge on the left side of the wing. This increases the lift on the left side, which first causes a roll to the right. However, the increased lift gives more drag, which causes a yaw force to the left, and as the wing turns the pendulum effect then causes a roll to the left. Weight shift is also used for turning. This counteracts the "wrong" roll at the beginning of a turn. The wing can be steered by weight shift alone, but the turn rate is less. Speed controll: To brake, pull down both sides of the wing equal amounts, thus increasing AOA. To speed up, there is a pulley system that pitches the wing profile down, decreasing AOA. Glide ratio control: To get a steeper glide, the wing tips can be folded backwards, which reduces wing area and aspect ratio. (This should be possible with flightgear too, I guess, by a little programming.) Other controlled wing deformations are also possible. Collapses: A paraglider will collapse if negative AOA occurs. This will be the most difficult property to model, I think. Collapses can be symmetric or assymetric, and of various sizes. A good simulation of collapse and recovery will be next to impossible, but it should be possible to do some crude approximations. Extreme terrain detail: To give a reasonably good flight experince the terrain detail must be a lot higher than in normal flight sims. Paragliders fly low and slow. Terrain resolution down to 1 meter, with textures down to maybe 10 pixels/meter, would be great. Also, trees would improve the feel a lot. This would of course require that only the closest terrain is modeled at this accuracy, and the areas that are further away use progressively less detail. Thermals and rigde lift for soaring would be great, is this supported? Some standard glider specs, for whom it may concern: Weight: 6 kg (wing) 10-15 kg (harness) 70-130 kg (with pilot) Speed: 20-50 (60) km/h Min. sink rate: 1 m/s (continous, can be 0 when flaring) Max. sink rate (in spiral dive): 20 m/s Best glide ratio: 7-9 Flat area: 25-35 sqm Flat wingspan: 11-13 m Flat aspect ratio: 4.5-6.5 Projected wingspan: 9-10 m Some other questions: Which FDM should I use? I'm thinking YASim but I'm not sure. Is the 3D-model mini-howto from 2002 still up to date? http://www.flightgear.org/Docs/fgfs-model-howto.html best regards, -- Gunnstein Lye Systems engineer [EMAIL PROTECTED] | eZ systems | ez.no ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
