Board index FlightGear Development New features

New Flight Gear Terrain Engine

Discussion and requests for new features. Please note that FlightGear developers are volunteers and may or may not be able to consider these requests.

Re: New Flight Gear Terrain Engine

Postby vitos » Mon May 16, 2011 12:53 pm

Thorsten wrote in Mon May 16, 2011 11:37 am:I just called your statement 'honest', didn't I? :-) I don't remember calling you dishonest.


To be exact, You called it "more honest" than other my statement. If one is more honest then other is less. If something is not honest on 100% then it's unhonest. So yes, You had.

Thorsten wrote in Mon May 16, 2011 11:37 am:I'm chiefly not talking to you (I'd do that by PN if needed)


Heh, then why You talks it in reply on my messages?

Thorsten wrote in Mon May 16, 2011 11:37 am:I'm talking to the same people you'd like to address - gathering a picture of what actually needs to be done before starting to do something. I actually consider that useful. You don't own this tread, so you'll have to put up with my opinion for the time being.


I do not own that thread of course. But I want to solve that problem more than You. Because me, not You, had started it. If You want to solve it too then better to find proper way to common work with me instead of "talks".

Thorsten wrote in Mon May 16, 2011 11:37 am:Who are you to tell me what is useless and what not? It seems you don't understand the structure of project management at all, ... (I'm kidding you a bit).


Well, I am a man who knows what You can not go somewhere until You get out of home. And if You _principally_ can not go outside the walls it's useless to think what You could do outside. Remember, currently only me had orbital flight in Flight Gear, on craft what I had made. It's no big deal, but I am talking on base of some own practice instead of You. I suppose You wasn't fly on Your own spacecraft even in Orbiter, right?

And I am knowing not only project management but whole Open Source as social structure. You can not goodly command people to whom You are not pay somehow really, that's it. So I am not command You of course. Only tell what is useful and what is useless really because I have experience.

About that long ago conversation, I did not get to that time what it's useful to talk only with people who personally intended to do something. It's part of my experience what I do not use on talking with You only because You did not said yet will You personally do something or not.

Thorsten wrote in Mon May 16, 2011 11:37 am:I found it always useful to see and define the big picture first.


Ok, to prevent future arguing let me show to You what needed to be done in more or less exact sequence. It useless really, but if it's useful for You somehow then...

1) Current FG terrain engine not only makes Earth invisible on altitudes higher than 25km, it still loads something, slows all to 4 times with time, sometimes drops to one fps, and even can lead FG to crash. It's really hard to manually control flight what is unease on itself already, and until current FG engine can not to be switched off on high altitudes there would be space flight only for fanatics.
2) Earth view is really needed for manual orientation on high altitudes. And no normal people would like to fly if there is dark hole with stars in middle of the Earth instead of surface and clouds makes a square around rounded atmosphere . So new FG terrain engine is needed very.
3) There is no possibility to put something on tail in FG currently. So I simply had add some JSB systems to make it react normally for 90deg rotated flow. It's no good for future spacecraft developers and that problem gotta be solved. At least some matrix angles recounting needed to make orientation indicators work as if nose of carrier really was pointed up, it's not comfortable to control it. These values could be useful for other developers too.
4) On switch between stages point of view moves because cg moves. So pilot can see outside space for moment. It's no good, some "pause view/change everything/continue view" procedure gotta be implemented.
5) JSBSim at now can not provide exact gyros on base of angular accelerations instead of shifts. It's needed to be exact for "real" control and indication systems with disturbances implementation.
6) Surface heating by air flow and air/surface color/brightness glowing calculations gotta be added in JSBSim. I made it for model, but not correctly enough. It gotta to calculate it itself on base of some surface properties, btw it needed not only for spaceflight but for SR-71, MiG-25, and other >3Mach vehicles.
6) JSB atmosphere, mostly aero/qbar-psf property, gotta be rechecked. It _inverts_, become less than zero on some altitude near 50km on reentry. I had parry it, thats why it becomes zero on some altitude. But it's not normal I suppose.
7) JSB atmosphere on higher altitudes gotta be checked and tweaked for long duration flights promotion.
8) Sun activity atmosphere reactions may be added.
9) Some hard thinking on FG carrier derivatives needed to implement manned/unmanned crafts docking.
10) Some thinking on FG carrier derivatives needed to implement pad.
12) Another hard thinking is needed to enable multiplayer manned/manned docking.
13) Sun heating system gotta be implemented.
14) Completely new celestial engine with gravity and jet implementation gotta be added for space flight to other celestial body.
15) Other celestial bodies, Moon at first, gotta be added.

And here is a lot of other small problems. But, again, there is no other way to make open source, really free for everybody, spaceflight than develop FG that way. So join or not join.
Last edited by vitos on Mon May 16, 2011 2:26 pm, edited 7 times in total.
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

Re: New Flight Gear Terrain Engine

Postby vitos » Mon May 16, 2011 1:29 pm

jonsberndt wrote in Mon May 16, 2011 12:17 pm:"Jacchia-Lineberry Upper Atmosphere Density Model"
http://ntrs.nasa.gov/archive/nasa/casi. ... 012203.pdf

Also, take a look at this survey of atmosphere models:
http://www.spacewx.com/Docs/AIAA_G_003C_2010_9-10.pdf


It looks not so hard for implementation, formulas is given, base values is given.

Victor
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

Re: New Flight Gear Terrain Engine

Postby Thorsten » Mon May 16, 2011 2:26 pm

vitos, let's stop arguing, okay? I said a few things which annoyed you, you said a few things which annoyed me, but I think with regard to the basic issues, we don't have a fundamental disagreement any more, if we ever had. So, can we make peace?

If you had the impression that I was calling you dishonest, then I am sorry - that was not my intention. I have great respect for you - both as a person and as a modeller.

I'd like to find the time to test Vostok in orbit and have a look how certain issues are treated and then provide some feedback. I am not a rendering person, so although I think the Celestia engine is most promising, I can't really help you with that, but I'll hang around and see if there is anything in reach where I can help.
Thorsten
 
Posts: 9530
Joined: Mon Nov 02, 2009 8:33 am

Re: New Flight Gear Terrain Engine

Postby vitos » Mon May 16, 2011 2:32 pm

Thorsten wrote in Mon May 16, 2011 2:26 pm:vitos, let's stop arguing, okay? I said a few things which annoyed you, you said a few things which annoyed me, but I think with regard to the basic issues, we don't have a fundamental disagreement any more, if we ever had. So, can we make peace?

If you had the impression that I was calling you dishonest, then I am sorry - that was not my intention. I have great respect for you - both as a person and as a modeller.

I'd like to find the time to test Vostok in orbit and have a look how certain issues are treated and then provide some feedback. I am not a rendering person, so although I think the Celestia engine is most promising, I can't really help you with that, but I'll hang around and see if there is anything in reach where I can help.


Cool, thanks. Actually I have not and did not had something against You. Simply try to found path to any man, not useful for me only.
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

Re: New Flight Gear Terrain Engine

Postby jonsberndt » Tue May 17, 2011 12:26 am

vitos wrote in Mon May 16, 2011 11:24 am:I had tested drag on orbit of course. Yes, I suppose it will not ask much, only slight tweaks. Maybe there is no void layer in other better atmosphere engine. Could You tell, how to switch on it?
Victor


Victor,

Look at FGFDMExec.cpp. There is a function near the botton, UseAtmosphereMSIS(). Call that function from the interface (JSBSim.cxx, wherever FGFDMExec is instantiated). That's how it should work - in theory, anyhow. I have not used this in a long time. I will try it tonight and see what happens in JSBSim standalone.

Jon
Jon S. Berndt
Development Coordinator
JSBSim Project
http://www.JSBSim.org
http://www.facebook.com/jsbsim
User avatar
jonsberndt
 
Posts: 205
Joined: Tue Aug 07, 2007 1:44 am
Location: Westminster, Colorado

Re: New Flight Gear Terrain Engine

Postby jonsberndt » Tue May 17, 2011 3:29 am

jonsberndt wrote in Tue May 17, 2011 12:26 am:
vitos wrote in Mon May 16, 2011 11:24 am:I had tested drag on orbit of course. Yes, I suppose it will not ask much, only slight tweaks. Maybe there is no void layer in other better atmosphere engine. Could You tell, how to switch on it?
Victor


Victor,

Look at FGFDMExec.cpp. There is a function near the botton, UseAtmosphereMSIS(). Call that function from the interface (JSBSim.cxx, wherever FGFDMExec is instantiated). That's how it should work - in theory, anyhow. I have not used this in a long time. I will try it tonight and see what happens in JSBSim standalone.

Jon


Looks like it's not working at the moment.

Jon
Jon S. Berndt
Development Coordinator
JSBSim Project
http://www.JSBSim.org
http://www.facebook.com/jsbsim
User avatar
jonsberndt
 
Posts: 205
Joined: Tue Aug 07, 2007 1:44 am
Location: Westminster, Colorado

Re: New Flight Gear Terrain Engine

Postby vitos » Tue May 17, 2011 5:50 am

jonsberndt wrote in Tue May 17, 2011 3:29 am:Looks like it's not working at the moment.


Ok, will wait a bit for correction. As I said previously, something what used rarely is first candidate to be broken. That's why I think what better to implement space flight in Flight Gear than create new space flight simulator. Possibly space flight in FG would be used rarely, and will be broken, but code will stay in git anyway and someone could continue development of it. In case of other simulator possibility to lost whole forgotten source code is too big.

Victor
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

Re: New Flight Gear Terrain Engine

Postby Thorsten » Sun May 22, 2011 12:53 pm

Vitos, just a very quick shot - I'm travelling at the moment.

I don't think we need any new engine - from a Celestia perspective, Earth is just a textured sphere with a normalmap and a reflection shader - nothing we couldn't render and place into the scenery even from nasal. So I'd basically work on just loading a new, very large model, because that's all we need, and ask to deactivate all features in the skydome which assume you're close to surface - with the atmospheric scattering, I don't think there are any.

Celestia in addition has 'virtual textures' to display the truly hires textures - but again, you can chop a model of a sphere into bits and just load the ones you see from a simple Nasal script - so assuming you can use the hires Celestia Earth textures, it doesn't even require any modification to the core to get an Earth model in - all can be done from Nasal.

I haven't tried anything yet, but I'm fairly certain the problem is much simpler than we thought.
Thorsten
 
Posts: 9530
Joined: Mon Nov 02, 2009 8:33 am

Re: New Flight Gear Terrain Engine

Postby vitos » Sun May 22, 2011 7:16 pm

Thorsten wrote in Sun May 22, 2011 12:53 pm:Vitos, just a very quick shot - I'm travelling at the moment.

I don't think we need any new engine - from a Celestia perspective, Earth is just a textured sphere with a normalmap and a reflection shader - nothing we couldn't render and place into the scenery even from nasal. So I'd basically work on just loading a new, very large model, because that's all we need, and ask to deactivate all features in the skydome which assume you're close to surface - with the atmospheric scattering, I don't think there are any.

Celestia in addition has 'virtual textures' to display the truly hires textures - but again, you can chop a model of a sphere into bits and just load the ones you see from a simple Nasal script - so assuming you can use the hires Celestia Earth textures, it doesn't even require any modification to the core to get an Earth model in - all can be done from Nasal.

I haven't tried anything yet, but I'm fairly certain the problem is much simpler than we thought.


1) I am simply wasn't get into source code because I know what doing it can not lead to any real result in most of cases when there is no already competent developer help, and only You had reacted on my proposition while no reaction in devel list almost.
2) Any addition can meet strong resistance from current developers who have other plans. I already tested FG community on that means and can tell what I am for sure not guy who will overforce it. There is no reaction in devel list on my propositions what means there could be such resistance.
3) There is problems what current terrain engine matter of. You need to switch it off somehow completely to avoid lags on high altitudes anyway. I do not even know if it's possible, engine can be linked to other code in many different places what could need some reactions of it or so.
4) To put some textured sphere and change texture on some place of it to more exact texture in case if it's below craft is what I am talking about exactly. But in case of nasal realization it could be matter of only one craft. It's gotta be done on core level as general addition what actual in any craft but can be switched off completely by common menu to avoid any current user problems. Nasal is not much harder than C, I know both and tell for sure.
5) osgEarth doing that exactly, uses osg and can be included in FG as any GPL project. Somehow I suppose what include it could be easier than do exactly same work again.

I still have a lot of questions in "Vostok" to solve, but really want to get into FG core to understand how it works and how it could be changed to let people fly to Moon and Mars in near future. So if You'll get close to real core functions then please tell me about it to let me know it too. I think other developers could be interested in that too, so please write about any real movement in that topic.

BTW, if someone interested in how "Vostok" works to make Mercury or Gemini which could be started at now to arrive exact to brand new engine realization then fell free to ask me in "Vostok" topic. I really want space FG hangar to grow and will provide any possible help. Actually to make spacecraft is harder than to make plane, but not as much for some advanced FG crafts developer.
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

Re: New Flight Gear Terrain Engine

Postby Thorsten » Sun May 22, 2011 9:10 pm

3) There is problems what current terrain engine matter of. You need to switch it off somehow completely to avoid lags on high altitudes anyway. I do not even know if it's possible, engine can be linked to other code in many different places what could need some reactions of it or so.


I had a look with the ufo what it does, and basically there are no terrain tiles loaded when the visibility is smaller than 100 km and you are above 100 km (hence the 'black hole with clouds' in my orbital screenshot). So I believe that setting visibility to 30 km and using an Earth model which simply doesn't get any fog distance fading (i.e. uses a dedicated shader without fog effects) would accomplish what you want. I also didn't have any lags - just a slightly weird view.

4) To put some textured sphere and change texture on some place of it to more exact texture in case if it's below craft is what I am talking about exactly. But in case of nasal realization it could be matter of only one craft.


Nope - the whole of Local Weather is written in Nasal and not tied to any aircraft and behaves pretty much like what you describe. While there are aircraft-specific Nasal files, there are also general Nasal files placed in /Nasal/ which are loaded for every Flightgear session. You can write a bunch of routines which manage Earth models whenever a menu item is ticked, but do nothing otherwise.

5) osgEarth doing that exactly, uses osg and can be included in FG as any GPL project.


But Celestia looks so much nicer, and if these textures are GPL... And we can do it now - without any core modification.

I'm not a core developer, and I'm not sure about Moon or Mars - but I am fairly certain we have all we need to render a hires Earth model below a spacecraft in a low Earth orbit.
Thorsten
 
Posts: 9530
Joined: Mon Nov 02, 2009 8:33 am

Re: New Flight Gear Terrain Engine

Postby vitos » Sun May 22, 2011 9:50 pm

Thorsten wrote in Sun May 22, 2011 9:10 pm:I had a look with the ufo what it does, and basically there are no terrain tiles loaded when the visibility is smaller than 100 km and you are above 100 km (hence the 'black hole with clouds' in my orbital screenshot). So I believe that setting visibility to 30 km and using an Earth model which simply doesn't get any fog distance fading (i.e. uses a dedicated shader without fog effects) would accomplish what you want. I also didn't have any lags - just a slightly weird view.


I have a lot of lags and even drops but not in first moments of flight, after some time of going on orbit. So I am pretty sure what it's needed to be switched off.

Thorsten wrote in Sun May 22, 2011 9:10 pm:Nope - the whole of Local Weather is written in Nasal and not tied to any aircraft and behaves pretty much like what you describe. While there are aircraft-specific Nasal files, there are also general Nasal files placed in /Nasal/ which are loaded for every Flightgear session. You can write a bunch of routines which manage Earth models whenever a menu item is ticked, but do nothing otherwise.


Well, it's nice but still there i no possibility to add it without some core changes because of things what I mentioned one string earlier.

Thorsten wrote in Sun May 22, 2011 9:10 pm:But Celestia looks so much nicer, and if these textures are GPL... And we can do it now - without any core modification.


To take textures is not so big story if it's GPL, but You forget about engine what allows to have different texture resolution on different places. To write it is harder than to use it, and osgEarth engine can be used with textures from Celestia.

Thorsten wrote in Sun May 22, 2011 9:10 pm:I'm not a core developer, and I'm not sure about Moon or Mars - but I am fairly certain we have all we need to render a hires Earth model below a spacecraft in a low Earth orbit.


Yes, I suppose yes. Of course You may try that Nasal way. Anyway, if it can be done in Nasal then it can be rewritten in core on C later. But I really think what You'll come to solving of already solved problems that way, that's why I proposing use of already existed solutions instead of it.
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

Re: New Flight Gear Terrain Engine

Postby mike4lin » Mon May 30, 2011 11:50 am

Without reading all, I remembered seeing fgfred64 doing tests:

http://www.youtube.com/watch?v=vFsrtfOA53A

For general compatibilty with sceneries alike:
http://sirx.flightsimulatorcenter.com/default.aspx
such might be the right way to go.

Also it might help updating to the current x-plane airport format?
mike4lin
 
Posts: 123
Joined: Tue Jul 06, 2010 5:58 am

Re: New Flight Gear Terrain Engine

Postby vitos » Mon May 30, 2011 2:29 pm

mike4lin wrote in Mon May 30, 2011 11:50 am:Without reading all, I remembered seeing fgfred64 doing tests:

http://www.youtube.com/watch?v=vFsrtfOA53A


Looks great, but why it's not in FG? I had wrote to fgfred, waiting for answer...


mike4lin wrote in Mon May 30, 2011 11:50 am:For general compatibilty with sceneries alike:
http://sirx.flightsimulatorcenter.com/default.aspx
such might be the right way to go.

Also it might help updating to the current x-plane airport format?


Do not know about compatibility with X-Plane and MSFS. It's have proprietary formats I suppose, and anyway would take a lot of work to get information from it. Currently me personally interested mostly in normal Earth view on high altitudes.
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

Re: New Flight Gear Terrain Engine

Postby Sealbhach » Tue May 31, 2011 1:06 am

Hi Vitos, I just saw this today, you might find it interesting: http://www.gamingonlinux.com/index.php? ... e-sim.468/

.
Sealbhach
 
Posts: 942
Joined: Wed Jun 30, 2010 9:17 am

Re: New Flight Gear Terrain Engine

Postby vitos » Tue May 31, 2011 6:57 am

Sealbhach wrote in Tue May 31, 2011 1:06 am:Hi Vitos, I just saw this today, you might find it interesting: http://www.gamingonlinux.com/index.php? ... e-sim.468/

.


I think author of it have a bit different interests, as I can see he want to make something as oolite. I will write to him, but dunno if it will be possible to incorporate his work in FG or Vostok project in his Pioneer Sim.

Update: "Vostok-1" project is frozen due to absence of interest of other developers and users.

On current terrain engine it hangs too often and on flight altitude shows not Earth but blue fog. Will like to continue project but only after will get some help on means of terrain engine improvement. Please write to me if You'll decide to help.

Slavutinsky Victor, vitosnet@mail.ru

P.S. Photo of current space oddities:
Image
Waste of time: too unprofitable for work, too exhausting for hobby.
User avatar
vitos
 
Posts: 583
Joined: Sun Jan 25, 2009 8:10 pm
Location: Moscow, Russia
Callsign: vitos
IRC name: vitos
Version: 3.4
OS: Debian

PreviousNext

Return to New features

Who is online

Users browsing this forum: No registered users and 3 guests