Celestia Forums

Nasa's World Viewer!

http://learn.arc.nasa.gov/worldwind/

This thing looks very impressive. The only problem is that its only for Windows and requires DirectX. It looks like it won't be possible to copy much of the functionality from this program into Celestia, but it would be very cool if we could find the protocol it uses to download the data and implement that into Celestia. with their permsision, of course.

If one does not impose the requirement that the images or databases be downloaded and displayed in realtime, then it's possible for the current version of Celestia to display much of the same imagry as is shown by WorldWind.

There's no need to incorporate the download functionality into Celestia itself, for example. That can be done by an external program that downloads the images or data and creates an appropriate VT and AltSurface SSC for it. Then the user can restart Celestia.

Someone has to write that program, of course, but it doesn't have to be one of Celestia's developers.

If a "reload" command can be incorporated into Celestia (which only loads new or changed cataloged objects), then updating the images could even be done almost in realtime.

I've spent some time trying out the WorldWind software. It caches all the data it downloads and, as it turns out, with a little scripting it is easy to convert WorldWind caches into Celestia VT's. So folks can use WorldWind as a high resolution texture map import engine and then convert the textures into Celestia VT's. While on the subject, I can think of no reason why Celestia couldn't "borrow" the relevant importing code from WorldWind, thus removing the intermediary stage. However, the NASA open source license may vary too much from Celestia’s.

Some notes:
WorldWind counts tiles with the origin at the lower left.
WorldWind switches x and y with respect to the Celestia nomenclature
World Wind uses different base tilings for level0.
-WW BlueMarble(1km) is 5x10
-WW JPL Landsat(15m) is 90x180
-WW USGS(1m) is 180x360
-Celstia is 2x1
Hence different scalings are required when batching the WorldWind .dds files into VT .dds files.

I have tested this and it works fine for me.

As a side note, if you modify the "\Configuration\WorldLayers.xml" so that the USGS Urban Area Ortho-Imagery has "NumberLevels" set to 10 rather than the default of 8, then you get 1 ft resolution for select US cities as opposed to the default resolution of 1 meter.

cheers,
Walton

The Worldwind folks are currently in the early stages of porting the program to Linux/Mac and are trying to decide how to go about this, since they used C# and DirectX to do the windows one. They tossed around a lot of ideas, and I suggested that, since Celestia and Worldwind have similar features sets (at least as regards one planet ) that they just implement the import protocol into Celestia instead of re-inventing the wheel twice. You can see my post on the worldwind forum. Maybe if some Celestians came over to say they thought this was a good idea, it would be the start of a beautiful relationship?

Joe

Joe,

The upper management of the Worldwind project are well aware of Celestia. They're the same people who were using it for several TIE educational projects last year, which were never quite completed

See http://learn.arc.nasa.gov/exp/index.html

Joe, Selden,
the links you're provided seems out of work

learn.arc.nasa.gov is down for emergency maintenance.For World Wind information and software, please visit opensource.arc.nasa.gov.

So, is it the reason I cant load HiRes textures when i'm zooming on Earth, clicking Landsat or USGS in the soft? Or I have do not really understood how to process to see great pictures?Jeam

I've been exploring the WorldLayers.xml file. The whole process can be made much simpler with a few modifications to the XML file, by setting the WW level0 tiling equivalent to the Celestia level6 tiling of 2.8125 degrees per tile. Then rename the tiles into the celestia naming convention. Works great. No more need for resizing tiles and splicing them together into celestia tiles.

The tag for setting the tiling is <LevelZeroTileSizeDegrees> and it should be set to 2.8125 for all 4 JPL and 3 USGS layers. <NumberLevels> should be left at 7 for the JPL layers and bumped up for the USGS layers to 9, 8 and 11 for the Digital, Raster and Urban layers, respectively. If there is sufficient interest I could upload my WorldLayers.xml file to CelestiaMotherlode. Aesthetically, the Urban Areas data may be better to start at level 7 or 8 due to the white background that gets uploaded for this layer; in which case just halve are quarter 2.8125 and lower the number of levels from 11 to 10 or 9, respectively.

I long ago forgot how to write dos batch files and I don't see any point in distributing cygwin scripts when anyone who is capable of running these can also put together their own script without any trouble. Hopefully someone will put together a dos batch file for the majority of users who will not be able to write their own scripts so that they can enjoy 15m resolution anywhere in the world, 1m resolution in the states and 1ft resolution in select cities.

enjoy,
Walton

Hi Walton,
I am only one guy, but I hope I count as having sufficient interest. I lost you pretty quickly through your explanation. Also, keep in mind that I have a mac so if you could provide a unix-like solution as well, htis would be great. Thanks!

Joe

Joe,

I highly doubt the two projects are going to merge into a single development pathways. Ideally, the celestia developers will add the texture download capabilities to Celestia.

Until the mac port happens there isn't really anything I can offer you, because you are unable to get the caches. On the bright side, it seems certain that some of the texture artists in the community will use a similar mechanism to the one I have outlined from now on due to the enormous increase in efficiency that comes from using worldwind as the downloader compared with the methods they previously had at their disposal. So look forward to a faster pace of uploads of new VT add-ons in the future.

Walton

Jeam,
I got the same problem, may be it is specific for France!
Salut
MB
(Other celestians, please give us if you got better success)
Thanks

MB wrote:Jeam,
I got the same problem, may be it is specific for France!
Salut
MB
(Other celestians, please give us if you got better success)
Thanks

I would like somebody answering your question, MB: seems to me that USGSImages and USGSTopos (on USA map, of course) works fines too. (this is very impressive)
But nowhere the Landsat zooms are dowloaded... And these are those pictures that are insteresting with Celestia!
Sorry for my english/dis-moi lorsque je fais des fautes impardonnables (en anglais ou en Celestia!), please
Jeam

Hello everybody,

Jeam, I have the hsame problem you and MB have for landsat. I got a "default problem conecting to ,landsat... try again in 2 minutes" message. Like you I am not sure I I have done things the way they have to ...

Another thing that intrigates (is it english ?) me is that I was not able to find a way to have a "real" night and day feature.

Gordon

PS : long time I have not been here, glad to see almost everybody there.

Gordon wrote:Hello everybody,Jeam, I have the hsame problem you and MB have for landsat. I got a "default problem conecting to ,landsat... try again in 2 minutes" message. Another thing that intrigates (is it english ?) me is that I was not able to find a way to have a "real" night and day feature.
PS : long time I have not been here, glad to see almost everybody there.

Salut Gordon, nice to see you again. I have the same pb with night/day.. Jeam
PS: If I Remenber Correctly, you have translated the 1.3.1 Celestia Guide in French, yes? (I saw there are no credit yet in the Motherlode, and this could be update)

Jeam Tag wrote:

Gordon wrote:PS: If I Remenber Correctly, you have translated the 1.3.1 Celestia Guide in French, yes? (I saw there are no credit yet in the Motherlode, and this could be update)

yes I was the one with the help of MB

Too bad for the NASA viewer ... Just for searching where the problem comes from my provider is FREE. Are you with them ?

G.

Jeam Tag wrote:PS: If I Remenber Correctly, you have translated the 1.3.1 Celestia Guide in French, yes? (I saw there are no credit yet in the Motherlode, and this could be update)

Better now?
Gordon, I don't know your full name, so it's just "Gordon" for the moment.

Harald

Hi Harald,


My real name is Jean Anglade. i am use to use Gordon since, few years ago, i was using netmeeting for fun and had to face hot boys thinking Jean was a girl !!

As I think it retavely safe here on that side i will now sign Jean !


Jean