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Earthview - an orbital terrain rendering engine [v2.0]

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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby eekpo » Wed Mar 21, 2012 2:58 pm

Thorsten wrote in Wed Mar 21, 2012 8:16 am:Download link in first post. Needs a bit manual work to get full experience...

I've tried yesterday to take Vostok a bit higher up, and it works like a charm, basically all problems with rendering and atmosphere holes are gone now, and the view is quite spectacular.

Anyone who wants to contribute:

* improve the Earth model - it's just a textured sphere, any 3d modeller should be able to make the seams go away or texture it with higher resolution or even devise a smart texture management which loads with highres just the sheets you're flying over

* Vostok needs some love - sound files need to be converted to be audible again

* a few more spacecraft would be terrific


Hi, Thorsten

Great work.



When digging in the GRTux old database we had found ( ONLY 3D models )

Image

download link ( only the spacecraft and the launcher , not the launch pad Kennedy center )
https://sites.google.com/site/grtuxhang ... s1.tar.bz2

and this

Image
download link
https://sites.google.com/site/grtuxhang ... LV.tar.bz2

We don't know if it has been used yet.
It can be used by anyone

BTW: the downloading page is at
https://sites.google.com/site/grtuxhangar/home/download
look at the GPL_Models part ( bottom of the page )
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby longfly » Wed Mar 21, 2012 4:16 pm

Hi Thorsten,

great work! I just tested your packed and found a bug (i think):

First everything seems normal:
Image

Above 527000(km/ knotes ???) everything turns red ....
Image

and above 600000 (km/ knotes ???) everything turns black:
Image

I am using Ubuntu 12.04 Beta 1, ATI Radeon HD 5570 Driver: VESA: REDWOOD
No Log-output

Hope that helps
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby Thorsten » Wed Mar 21, 2012 5:28 pm

You didn't patch the atmosphere model as I described. That patch removes among other things the red and dark zone. I'm not sure if you have generic shaders on - if yes, the planet should light up in the dark zone as well. Also skydome shader on is a good idea.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby Thorsten » Thu Mar 22, 2012 8:39 am

When digging in the GRTux old database we had found ( ONLY 3D models )


Great! Jon has an almost complete FDM for the Jupiter Launcher, so it seems this combines to something which can be made to fly soon.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby Gijs » Thu Mar 22, 2012 1:00 pm

The Ares models are from http://www.nasa.gov/multimedia/3d_resources/models.html
We've also prepared the space shuttle model for FG, see viewtopic.php?f=19&t=9446&p=153795#p153795
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby longfly » Thu Mar 22, 2012 3:38 pm

thanks, I'll try it again with the patched FG.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby eekpo » Thu Mar 22, 2012 4:55 pm

[
David eekpo team.
Last edited by eekpo on Fri Mar 30, 2012 6:52 pm, edited 1 time in total.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby vitos » Fri Mar 23, 2012 10:01 pm

Whoa.

Perfect.

Image

Still it have some strange glitches, but I hade made Gagarins ~200/~300km orbit with real 10g on deorbit and so on.

I suppose it's time to unfreeze "Vostok" topic.

Until that, one more patch. Remove

Code: Select all
         <fcs_function name="calculations/aero/qbar-modified-psf">
         <function>
            <abs>
               <product>
                  <property>aero/qbar-psf</property>
                  <table>
                     <independentVar lookup="row">position/h-agl-ft</independentVar>
                     <tableData>
                        0.0      1.0
                        246062.0   1.0
                        328083.0   0.0001
                     </tableData>
                  </table>
               </product>
            </abs>
         </function>
            <output>aero/qbar-modified-psf</output>
         </fcs_function>


And change "aero/qbar-modified-psf" to "aero/qbar-psf" everywhere in "/Aircraft/Vostok/Vostok-1.xml" file, to make atmospheric reactions realistic. With that patch it will slow down in time on 100..150km orbit, so if You'll left it on 100km with some too long coffee break then You could return right to crash site.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby kyokoyama » Sat Mar 24, 2012 5:06 am

vitos wrote in Fri Mar 23, 2012 10:01 pm:I suppose it's time to unfreeze "Vostok" topic.


...Bring out Apollo and the Space Shuttle. :twisted:
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby Hooray » Sat Mar 24, 2012 6:30 am

Yes, welcome back vitos!
Glad to see that you started maintaining your vostok again!
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby vitos » Sat Mar 24, 2012 6:36 am

...Bring out Apollo and the Space Shuttle. :twisted:
(welcome back, Vitos!)


"Shuttle" is much possible, "Apollo" is not. There is no real Moon in FG, and I suppose to include it with celestial dynamcs, detailed enough landing sites, and illumination accounting, is too big work which would take long years. It's surely not task of Nasal level. You could not make it as addon, You need to get down to the core. That's why I was against Nasal based view project, because it not leads to far space flights directly. To get to completely different multibody core engine from additional "second language" based renderer, with great respect to authors of that incredible one, is not so closer way than to get to it from no renderer at all. So it would be very good if in 2019 someone will step on Moon in FG space, but it would be miracle if someone could do it faster. And that is surely not one man task, that fact is historically proven. We need command to do so...Three brave guys at least.

Ah, and mutiplayer is very jerky still, You simply could not dock manned thing to manned thing here. I do not know even if parralel pair flight is accesible now. Autopilot which could take You to same orbit is needed. On base of "Vostok" flights list, I do not think two FG pilots can make two close enough ones maually. I will think about making that autopilot in "Vostok", but right now have another tasks to do.

Plus, as I had mentione before, very strange glitches is making it all unfunny here still.

Glad to see that you started maintaining your vostok again!


Actually I did not started to do that yet, I am only talking about it so far.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby Hooray » Sat Mar 24, 2012 8:09 am

There is no real Moon in FG, and I suppose to include it with celestial dynamcs, detailed enough landing sites, and illumination accounting, is too big work which would take long years. It's surely not task of Nasal level. You could not make it as addon, You need to get down to the core.


I don't think it's a good idea to start this discussion again, like all of us know meanwhile (you and myself included), it has caused lots of frustration within the community.

As you can see, there's lots of stuff possible just from Nasal, without even touching the C++ code. Nasal is very good for prototyping purposes, like Thorsten has demonstrated once again.

And once you actually touch the C++ code (i.e. see Ron's atmosphere patch), things become even more convincing.

So I still wouldn't completely disregard Nasal here, it's always very easy to say "not possible in Nasal" and "requires C++ work" and "we need three guys" - but that's not necessarily true most of the time.

You could accomplish a LOT just by by disabling certain core features or making them slightly more configurable using a handful of properties. Exposing a control interface (via Nasal or the property tree) would be another option. Obviously, you are -once again- striving for a perfect solution - but that won't be available if you are not willing to compromise in the meantime.

Yes, obviously FlightGear doesn't currently have elevation data for celestial bodies like the moon or mars - on the other hand, once you get your hands on the data, you could could create coarse 3D models to dynamically add them to FG (using Nasal!). You might even be able to find a textured 3D model for moon or mars online.

Once you have 3D models for moon and mars you could -again- use Nasal to manage everything (i.e. placing models, transforming and animating the scene).

You could probably even use a slightly modified TerraGear toolchain to come up with native BTG terrain tiles, too. There are probably a number of hard coded assumptions, but apart from that it should be a matter of converting GIS data from several input formats to the FG output format and disabling tons of code (lakes, roads, airports, runways).


What I am trying to say is, you need to be able and willing to compromise, i.e. reuse what's there already and combine different things.

For example, doing a quick google search, brought up this free 3D model of the moon:
http://www.turbosquid.com/FullPreview/I ... /ID/553741
Image

Just searching for "moon 3d model download DEM" yields many other matches.

Thorsten's approach could certainly be generalized to add a bunch of other models and animate then properly.

So, if that's what you are interested in (i.e. flying to moon and mars), it would certainly be possible to come up with a workaround in Nasal space. Once you hit show stoppers, we can still look at switching off some core features or making them more configurable using a bunch of properties.

So it would be very good if in 2019 someone will step on Moon in FG space, but it would be miracle if someone could do it faster. And that is surely not one man task, that fact is historically proven.


I don't think the analogy is appropriate or even applicable: Just use a little imagination and ask yourself: what if Thorsten had used a textured 3D model of the Moon or Mars instead of Earth? And what if the tile loader were to be patched so that it could load tiles from a custom location on demand?

None of that is "rocket science" (pun intended) and it would only require very little C++ work on the C++ side.
I wouldn't even be surprised if you could come up with a workaround to trick the tile loader into loading custom scenery tiles ,without modifying the C++ code.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby vitos » Sat Mar 24, 2012 10:08 am

Hooray wrote in Sat Mar 24, 2012 8:09 am:I don't think it's a good idea to start this discussion again, like all of us know meanwhile (you and myself included), it has caused lots of frustration within the community.


Hooray wrote in Sat Mar 24, 2012 8:09 am:I wouldn't even be surprised if you could come up with a workaround to trick the tile loader into loading custom scenery tiles ,without modifying the C++ code.


Let me make it clear. Moon may be accounted as some addon to Earth, since it's in Earth gravity field deeply, but Mars surely not. It's other celestial body on itself, it's not attached to Earth anyhow. So You can get to Moon by accounting other ...some...body as addon, but can not get to Mars that way, both in real life and some simulation. Particularly, You gotta treat some other guy as equal to You, really. Not on words only, really. It's low level world view concepts conclusion. You can not change it by words, irrelatively to quality of speaking and writing. Me too. So high level Nasal is useless here, irrelatively to quality of it and Your belief in it.

I simply know that You can not get anywhere without changing Your mind accordingly, and words cant help with it. You know it too, simply was not realized it yet. I will not put my efforts in wrong way of useless attempts, right from beginning of it. I can send my sympathy to guys who make such attempts, as I send it to You, :D , but I will not put my efforts in it. So dont wait any quickfix patches from me. I told Ya it's core thing, and it's core thing.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby Thorsten » Sat Mar 24, 2012 10:12 am

Hooray, going to moon is *not* primarily a rendering question - it is a question of the numerical stability of the FDM. At distances of a million kilometers, even small rounding errors tend to become very large over time. Most people are likely not to sit 3 days in front of their computer but do the trip in fast-forward time. Yet the spacecraft is in vacuum, there is *no* damping force for any tumbling or other motion, so you have to ensure that the spacecraft motion is accurately computed across a really large distance in fast-forward time without you emerging in wildly spinning motion. At the same time, you have to solve a multi-body gravitational problem to some accuracy. Mars is worse by about two orders of magnitude.

I'm not convinced that JSBSim is up to that out of the box.

Compared to that, rendering stuff in space is really easy the Celestia way - we can add as many textured spheres as we like. Planetary positions are tabulated, we can simply use these tables to look where to put them at any given time. I suppose even using our default engine to define moon landing sites is not a substantial issue, I am fairly sure once we can get into a Moon orbit that people can be persuaded to allow to re-center the default terrain and to use Moon textured landclasses.

As far as I have been told, Mathias is working on a more sophisticated low orbit rendering engine. Let's focus on getting stuff into Earth orbits, see if we can't do any docking maneuvers there, get an ISS 'static' (?) carrier (?) model into orbit and iron out all the glitches, and then see how to go to Moon.
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Re: Earthview - an orbital terrain rendering engine [v0.1]

Postby vitos » Sat Mar 24, 2012 10:19 am

Thorsten wrote in Sat Mar 24, 2012 10:12 am:Let's focus on getting stuff into Earth orbits, see if we can't do any docking maneuvers there, get an ISS 'static' (?) carrier (?) model into orbit and iron out all the glitches, and then see how to go to Moon.


I suppose it's fine plan. But it's possible very that to time of real beginning of "Apollo" project FG will become too sophisticated, and it will become impossible to make it, not even mention Mars flight project.
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