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Draken updated

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Draken updated

Postby jam007 » Sun Jan 13, 2013 7:39 pm

I have made some improvements to Saab J-35 Draken.
It's work in progress and my first FG aeroplane modeling but I present it here as it is now.
I have changed the name to SaabJ35F to avoid conflict with the existing.
You can download it here.

Work so far:
Improved FDM based on information I found (link)
Some model and texture changes in and around cockpit to make it more like the real.
Instruments modelled on J-35: Speed*, Altitude, Fuel**, Alpha
Some other important instruments more or less standard: Attitude indicator, Gyro-Compass, Clock
Animated Tailgear, Speedbrakes and improved gear-door animation and gear dimensions.
Droptanks as separate objects.
A Swedish livery

There is a lot to do still. Both big things and adjustments.

Known problem:
Some problem in instruments with transparent textures that I have not figured out how to correct. At the rim of the instrument light from outside shines through for simple plane type instruments (eg. AI). :?:

Thoughts and suggestions appreciated.

* Simplified since I don't know how to model the logarithmic(?) scales and are unsure of the needles. Are they "tape" type needles?
** Actually from J-37 Viggen slightly modified
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Re: Draken updated

Postby jam007 » Mon Jan 14, 2013 9:33 pm

The transparent texture problem seems to be due to my laptop's graphics card (HP internal).
Updated the zip-file with some changes to the cockpit
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Re: Draken updated

Postby jam007 » Sat Jan 26, 2013 7:07 pm

Did some more work on the J-35 Draken.

Most of the important instruments are now functioning: Altitude, Airspeed (now with correct scale and tape type needle), Attitude Indicator, Fuel, Compass, RPM, EGT*, G- and Alpha-gauges.
Indicators for Gear, Speedbrakes, Droptanks and the gear reminder light.

It is possible to jettison** the droptanks in flight (Ctrl-J) and attach or remove them on ground (Shift-L). The droptanks weights ca 100 kg (+ fuel) and creates a small drag when attached.
A simplified version of Draken's autostart function is simulated. (Shift-S)
Fuel starvation after prolonged negative G is simulated. But not in air engine restart :twisted: (yet).

Aircraft ZIP-file here

Image
Image
* The temperature seems a bit high compared to sources. More to do...
** They are not jettisoned bombable style just hidden from view and removed in the calculations for fuel and aerodynamics.
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Re: Draken updated

Postby Gijs » Sat Jan 26, 2013 7:39 pm

Lovely! Are the cockpit textures licensed under the GNU GPL? If yes, I'd like to commit your updates to the J35 in Git (instead of creating yet another aircraft, with the original rotting away ;-) ). Just let me know...

Cheers,
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Re: Draken updated

Postby jam007 » Sun Jan 27, 2013 7:49 am

Gijs wrote in Sat Jan 26, 2013 7:39 pm:Lovely! Are the cockpit textures licensed under the GNU GPL?

They will be. Right now the radar and AHK (to the right of the radar) are not my original work/photo but I will replace these with working instruments with my original textures. How do you licence something under GNU GPL by the way?
Gijs wrote in Sat Jan 26, 2013 7:39 pm:If yes, I'd like to commit your updates to the J35 in Git (instead of creating yet another aircraft, with the original rotting away ;-) ). Just let me know...

Fine with me. I post here when radar+AHK are included.
Some thoughts
The real J35Oe differs in some important ways from J35F. Its heavier and has a different instrumentation, more modern and "ordinary". But the Oe in Git is essentially a nice exterior model, a basic cockpit 3D and a FDM generated by Aeromatic. And Austrian livery. To keep the name close to the appearance Draken J-35F would be more correct.
A few weeks ago RedSpade wrote about creating liveries for Draken. I do not know how far that has progressed.
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Re: Draken updated

Postby jam007 » Sun Feb 03, 2013 6:44 pm

Have made some more work on the Draken.
* Added the beginnings of Canvas based Radar. Right now only a sweep. No functions implemented.
* Added AHK (to the right of the radar.
The real AHK (swe.Avstånd Höjd Kommando, eng. distance altitude command) was an instrument connected to the Swedish air combat control centers (The system is part of "STRIL60"). It gave tactical information to the pilot by 20 different commands, displayed as words at the top of the instrument, and also on the distance scale and with the arrow needle on the height scale.
I have reused three of the commands as instrument modes. (This is Experimental)
In all modes the "HÖJD" (altitude) scale shows pressure-altitude. Dot-needle from 0-2000 m and tape-needle from 0-20000 m.
0 (zero): Only altitude shown
HÖJDÄNDRING (altitude change): Arrow shows height reached in one minute at current vertical speed. Scale 0-20000 m. "AVST" tape shows distance over ground to change altitude 1000 m at current vertical speed. Speed over ground calculated from IAS using standard atmosphere.
LANDA (land): Arrow shows height reached in one minute at current vertical speed. Scale 0-2000 m.
"AVST" tape shows distance over ground until tuchdown at sealevel and current vertical speed. Speed over ground calculated from IAS using standard atmosphere.

* Added Turn and bank indicator and implemented stall warning (at 15 deg)
* Redone the main panel texture to be based on my original work and photos
* Reworked part of the aerodynamics - after further studies of documentation.
* Made experimental vortice effect during stall. (The real aeroplane could violently pitch between +20-+100 degrees and yaw 50 deg/s if in superstall. ) Push it too far and you might have to bail out, Witch you can't...

Draken J-35F zip-file here
Image
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Re: Draken updated

Postby jam007 » Sun Feb 17, 2013 9:23 pm

Further development of Draken

* Better aerodynamics based on more sources.
* Elevons and non-linear pitch control response
* Correct heading indicator and AI for the aircraft.
* More work on the radar.
Download here

Edit 18/2: Updated with some corrections to FDM
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Re: Draken updated

Postby jam007 » Sun Feb 24, 2013 3:13 pm

24/2
* Added the last instruments and indicators to the main panel:
Course selector
secondary AI
Altitude selector
Altitude indicator - used by Auotpilot when implemented
Main warning light - not yet implemented as it indicates system faults.

*Some corrections and bug fixes

* First version of aircraft specific flightrecorder
Link to zip-file
Image
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Re: Draken updated

Postby jam007 » Sun Mar 31, 2013 9:16 am

Some more updates.
The version above is since a month ago in GIT.

I have made some more improvements since then:
* Support for liveries
* Pilot in external view
* Animated canopy with locking
* Rolling wheels
* Autopilot based on the functions available in the real aircraft (Altitude, attitude and damper, shut off at transonic speeds)
* Autopilot model in cockpit
* Radar shows aircraft "blips" in multiplayer mode.
* Cautionpanel (not all cautions implemented)
* Model of Draken's odd Nav-radio and mode selector in cockpit. No functions implemented yet.
* Some limits and FDM work

You can download the latest version here or try my git-clone. (I get a 500 Server error when trying to open the Draken files on gitorious...)
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Re: Draken updated

Postby jam007 » Thu Apr 04, 2013 8:50 pm

Have added functions to the navigation radio and mode selector.

Draken does not have ordinary navigation instruments. It has a special system that was integrated in the combat command and navigation system of the Swedish airforce. A letter code was used to select navigation beacons and airbase landing system. There was two parts of the system: Anita - general navigation and Barbro - landing guidance.
To simulate this and still be compatible with FG there is a file beacons.txt in the aircraft's directory that associates letter codes with NDB, VOR or ILS beacons. The file should be edited to suit the user.

The nav. modes sets input to course needle (cn), radar and AHK
FRÅN: (Off)
FÖRV: (Preselected) No nav radio, Radar off, AHK HÖJDÄNDRING, cn manual
STRIL: (Combat command) Activates Route Manager, Radar scanning, AHK NYTT MÅL, cn direction to next waypoint.
STRID: (Combat) No nav info, Radar scanning, AHK HÖJDÄNDRING, cn manual
NAVRIKTN: (Navigation direction) Uses NDB/VOR set by the two letters NAV. Radar shows direction pointer, AHK HÖJDÄNDRING, cn direction to beacon.
NAV 400: (Navigation 400 km) Uses VOR/NDB set by the two letters NAV. Radar shows direction pointer, AHK AVST. 400 (shows 0 if NDB), cn direction to beacon.
NAV 40: (Navigation 40 km) Uses VOR/NDB set by the two letters NAV. Radar shows direction pointer, AHK AVSTÅND 40 (shows 0 if NDB), cn direction to beacon.
LANDN 40: (Landing 40 km) Uses NDB/VOR set by the two letters NAV. Radar shows direction pointer, AHK LANDA, cn direction to beacon.
BARBRO: (Barbro) Uses ILS set by the three letters NAV+LANDN. Radar shows glide slope pointers, AHK BARBRO, cn direction to ILS beacon.

Latest version here
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Re: Draken updated

Postby Gijs » Fri Apr 05, 2013 7:07 am

Hi,

Could you please create a new rebased merge request? We had to reject your previous request because it contained dozens of commits that could easily be merged into one. There are plenty tutorials on that, e.g. http://gitready.com/advanced/2009/02/10 ... ebase.html

http://gitorious.org/fg/fgdata/merge_requests/194

Cheers,
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Re: Draken updated

Postby jam007 » Fri Apr 05, 2013 7:52 am

Did try earlier but got cold feet after reading warnings about losing my work and the 500 error...

Tried again and it looked like it was ok comparing to the tutorial but nothing seems to have happend...

In what branch should I be when doing the rebase?

EDit: Now I have spent more than an hour in this "easy" merge and probably only managed to mess my git up. :(
I used this tutorial when I started with git
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Re: Draken updated

Postby jam007 » Sun Apr 07, 2013 3:06 pm

Some improvements in the cockpit.
Working 3D models for control stick, rudder pedals, throttle, parking brake handle (pickable), canopy handle (pickable), nose wheel steering knob, landing gear handle (pickable).
3D model of brake parachute handle, not animated as parachute not implemented yet.

zip-file here
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Re: Draken updated

Postby Thorsten » Mon Apr 08, 2013 6:27 pm

I've just had a short look at the file linked in the first post:

* paths for submodels are scrambled - for instance it doesn't look for the afterburner in /Aircraft/SaabJ35F/Models/ but rather in /Models (i.e. relative paths aren't followed correctly

After I fixed those manually by editing the xml structure:

* flies reasonably well, I had somne difficulties with the approach, but that may be me not knowing the proper approach speed
-> some info in the aircraft help would really be nice

If I appraoched fast, I got a warning on touchdown, if I tried a slower approach, the visibility on the runway was lousy - not sure if this is real or not - does it come with flaps? Somehow I didn't get to see any effect trying to use them.

All in all, it looks very promising, although I think it's not there yet - the cockpit could still need some love, systems are rather rudimentary,... I guess you know this.
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Re: Draken updated

Postby jam007 » Mon Apr 08, 2013 7:52 pm

Thorsten wrote in Mon Apr 08, 2013 6:27 pm:After I fixed those manually by editing the xml structure:

Could you name the ones besides afterburner that is problematic.

Thorsten wrote in Mon Apr 08, 2013 6:27 pm:some info in the aircraft help would really be nice
If I appraoched fast, I got a warning on touchdown, if I tried a slower approach, the visibility on the runway was lousy - not sure if this is real or not - does it come with flaps? Somehow I didn't get to see any effect trying to use them.

Adding some info in the aircraft help is a good idea
The visibility of the runway was as I understand it lousy in the real aircraft.
Draken has no flaps.


Thorsten wrote in Mon Apr 08, 2013 6:27 pm: the cockpit could still need some love, systems are rather rudimentary,... I guess you know this.

If you mean switches etc. for different systems like hydaulics, electric. Yes. I must say I find these things a bit boring...
For the communication radio I must find out more on how it looked and worked before I try to model it.

Thanks for testing it.
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