clouds & weather sat

The place to discuss creating, porting and modifying Celestia's source code.
Guest

clouds & weather sat

Post #1by Guest » 27.04.2002, 03:07

I was using celestia the other day and it occurred to me that it would be really cool if you could update the clouds from earth with an internet link. Thankyou guys.
David.

IlyaG
Posts: 15
Joined: 05.04.2002
With us: 22 years 5 months

Post #2by IlyaG » 29.04.2002, 23:03

I doubt that even a corporation like Microsoft, with a development budget in the millions, could successfully implement such a feature without serious bugs... not to mention the fact that this would mean that clouds would no longer be animated and you would not be able to go back and forth in time without erasing the entire cloud layer from the planet.

But, yes, it would be the coolest damn thing in the world. That I agree with. :P

Silh
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Joined: 18.03.2002
With us: 22 years 6 months
Location: Somewhere out there, Alberta, Canada

Post #3by Silh » 30.04.2002, 00:29

For a while, I had Xplanet running on my desktop background, with the cloud map updating every 6 hours (see http://xplanet.sourceforge.net/)

The Xplanet maintainer creates a 2000x1000 jpg cloud map every 3 hours from various satellite images, which is pretty nice, albeit funny looking at the poles (clones some data for that part, since the imagery isn't there I guess).

Overall, it worked pretty well, though on occasion the cloud data would be little funny and have little blocks in the middle where the clouds didn't line up properly.

If you're looking for something updated more frequently than 3 hours though... *shrug*

Guest

Post #4by Guest » 03.05.2002, 02:21

no, thats realistic.

I'll check it out.

David.

Guest

clouds and image

Post #5by Guest » 08.05.2002, 01:11

I loaded up xplanet, its excellent.

I tried to copy the clouds image into celestia textures without success, probably because the image size is wrong. Xplanet has a link at http://xplanet.sourceforge.net to a regularly updated satellite cloud map which is 2000 w 1000 high 300 horizontal and vert res, and celestia has
1024 x 512 at 75 res.

It would seem to me that if developers at celestia and xplanet were to decide on a common standard it would be of value to all.

Many thanks,

David.

Silh
Posts: 6
Joined: 18.03.2002
With us: 22 years 6 months
Location: Somewhere out there, Alberta, Canada

Post #6by Silh » 08.05.2002, 02:29

I suspect that particular texture size is fairly arbitrary, unless it's related somehow to the satellite data used in it. Xplanet doesn't really care too much about the texture size; compiling in GL support for it is optional. Otherwise, all the rendering is done software-side, so there's no concern about the dimensions of the texture, unlike Celestia which requires powers of 2 dimensions for the hardware accelleration part (iirc, correct me if I'm wrong).

It's easy enough to rescale the texture provided from Xplanet, though you'll create slight artifacts. Or email the author and request use of a different dimension (eg. 2048x1024)?

Guest

Post #7by Guest » 11.05.2002, 09:32

Hari Nair who wrote Xplanet very kindly solved my problem, if you want to have current weather on earth using celestia you can get it from his site, see previous posts, and convert it in linux, rename of course and paste into textures. It works.
Celestia is such a good simulation that it is as good as being there, this is a little extra icing on the cake, say you are outside ISS you can effectively be seeing Earth as they are.

Save $20 million!

Subject: Re: clouds image size and celestia
Date: Wed, 8 May 2002 07:59:11 -0700
Message body The body is in part(s) Message Source Hi David - it's pretty easy to resize an image.
ImageMagick is installed on most linux systems,
and you can do something like this:

convert -geometry 1024 x 512 clouds2000.jpg
clouds1024.jpg

Hari


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