Hi Thorsten, AFAIK, the Celestia textures are pretty much directly derived from the Blue Marble textures available from NASA
http://earthobservatory.nasa.gov/Features/BlueMarble/ http://visibleearth.nasa.gov/view_cat.php?categoryID=1484 Clouds: http://visibleearth.nasa.gov/view.php?id=57747 I think deriving directly from them would be most appropriate; Terms of Use are: http://visibleearth.nasa.gov/useterms.php 1) The imagery is free of licensing fees 2) NASA requires that they be provided a credit as the owners of the imagery ... which is GPL compatible as I read it. Thank you very much for beginning to tackle this! Regards, Johannes On 16.03.2012 11:12, Renk Thorsten wrote: > > In the last two days, I've managed to implement a scheme for orbital terrain > rendering which I had cooked up a while ago. > > Compared with what vitos had in mind (a complete overhaul of the rendering > engine) this is really low-tech and lives within the limitations of the > current engine - just a textured sphere of 58 km diameter in the scene which > is constantly repositioned using simple ray-optics to give the right > impression and has a dedicated shader to never fog it and work around the > high altitude light problem (see below). The results using Celestia Level 3 > texturing are quite compelling, although there are a few quirks left: > > http://www.flightgear.org/forums/viewtopic.php?f=6&t=15754 > > It took me 7 hours to get it to this point, less than 100 lines of Nasal, > some cut-past with the shaders - most of the time I spent stitching and > converting textures. Right now it is really dumb - one can go to even higher > resolution texturing by investing some smartness and introducing texture > management (currently Earth is effectively covered by 4096x8192, the cloud > layer adds the same amount). At low altitudes, it transits automatically to > default (not very seamless at this point...). > > I would very much like to fly this with something other than the ufo - > unfortunately there are a few problems in the way: > > 1) The weird 'zones' at high altitude: > > - below 300.000 ft, rendering looks normal, default terrain is basically > gone, but Earthview shows something > - from 300.000 ft to 500.000 ft: grey zone - the sky above turns fog grey. > Lauri explained to me that this is because we leave the skydome behind, so > there is really nothing left to paint on > - from 500.000 ft to 800.000 ft: red zone - everything turns now red. No idea > what this is. > - above 800.000 ft: dark zone: the light largely disappears apart from a deep > red hue and the background finally becomes the deep black of space as it > should be (I re-defined the light in the planet shader not to pay attention > to this, but the ufo itself is of course affected) . The visible disk of the > sun turns red. > > Can these effects be tracked and fixed to give a consistent background black > and reasonable light? > > 2) The high altitude FDM problem: > > Our only spacecraft (Vostok) makes just 150 km altitude, apparently to > prevent it from running into a region where the FDM breaks down. This isn't > nearly high enough to see nice orbit scenes without pushing gigabytes of > textures at the problem. I have not really understood the reason in detail, > but can the JSBSim people comment on that? Is it possible to get JSBSim to > fly up to 3000 km, or to otherwise address this problem? > > 3) Other Spacecraft: > > We currently have the X-15 (reaches barely 100 km and is in fact better with > the default rendering engine), SpaceShip-1 (doesn't really fly, the rocket > engine lacks the power to get anywhere, is also just a modern X-15), the > Vostok (see above) and a Space Shuttle FDM. > > Given the Space Shuttle FDM and the discussion of Space Shuttle SRBs in the > JSBSim model, it may just a wild stab in the dark, but does Jon have a > complete flight-worthy Space Shuttle FDM somewhere? > > It's one of the things I would like to fly at some point. Now there is > something to see in orbit, so maybe that makes it more interesting for 3d > modellers and FDM developers to work on some more spacecraft? It's a bit of a > chicken and egg problem, modelling orbital rendering isn't really so exciting > without a way to fly there, modelling spacecraft isn't interesting without > rendering - but I think there is progress. Right now, with Earthview FG looks > better than Orbiter out of the box, although Orbiter has the support for > hires texturing. But when you descend, Flightgear has a whole planet modelled > in really high detail to offer :-) > > Well, I hope this is a more reasonable approach than what Vitos had in mind. > All things said, I would like to see Flightgear go into space a bit more. No > need to switch to Windows then :-) > > I have tried to contact the Celestia people about the licensing of the > textures - as soon as I know, I can make this available in some form to > anyone interested. > > Cheers, > > * Thorsten > ------------------------------------------------------------------------------ > This SF email is sponsosred by: > Try Windows Azure free for 90 days Click Here > http://p.sf.net/sfu/sfd2d-msazure > _______________________________________________ > Flightgear-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/flightgear-devel ------------------------------------------------------------------------------ This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure _______________________________________________ Flightgear-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-devel
