Earth animated background project

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Frostex

2[H]4U
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So the Windows7 beta has a cool new feature for backgrounds (desktop wallpapers) where you can set a rotation of several pictures and it phases from one to another on a timescale you set.

So I had a cool idea that if I could get my hands on pictures of the earth rotating in even spaced sequences that I could generate a sort of slowly animated background that rotates over a long period of time, even maybe in sequence with the actual rotation (over 24 hours)

Anyway getting the pics proved impossible, the few sets I found were either too infrequent (like quaterly shots) and were too low resolution, I wanted it for my 30" monitor which runs at 2560x1600

So I decided to make my own, heres how I did it. It took some investigation and some hacks to get the quality up but it worked a treat.

1) Download Celestia, a fantastic free simulation app - http://www.shatters.net/celestia/
2) The earth skin in Celestia is really low res so goto visibleearth.nasa.gov and aquire a high res picture of earth that is laid out flat, I grabbed the 48.7Mb TIFF from here
3) Celestia needs images in .png format, so edit the image and save as 100% quality .png file, I used Paint.net which is free, the image ends up about 50mb.
4) Go to your Celestia install folder and in there find the /Celestia/textures/medres/ folder, replace the old earth.png with your new one, keep a backup of thje original if you want to undo the change.
5) While you're in the Celestia folder also go to /Celestia/data/ and rename "spacecraft.ssc" to "spacecraft.ssc.org". This file contains the data for several satalites orbiting earth, I couldnt find a way to distable them inside Celesitas menu so renaming this file just stops Celestia from loading the data, you can rename it back afterwards, it's only a white spot that rotates around but I wanted mine perfect :)
6) For best quality you want to force AA and AF, go into your control panel and if with Nvidia create a profile for Celestia, for ATI just force AA and AF for now, and revert back aftwards, I forced 16xAA and 16xAF
7) Down fraps for free here, install it then run it, go to the "screenshots" tab and set a record key (I used numpad + as it wasnt a shortcut key for Celestia also) then tick the "Repeat screen capture every x seconds" and set X to 1, this will make fraps take screenshot at regular intervals, for the best quality set the type to BMP, this is completely uncompressed (2560x1600 shots come out at 12mb each)
8) Run Celestia, configuire this to how you like it, theres a few things you'll want to do to get the best image pictures:
  • Set "Toggle full screen" mode from the "Render" menu, also pick your monitors native resolution from the "Select Display Mode" menu.
  • In the "Render" menu go to "View options" and untick anything you dont want displayed such as "markers" and set the information text to "none" to remove the HUD stuff, I also got rid of Athmospheres because thats another seperate layer for earth which spoils the particular image I used since it already had clouds etc
  • Use [ and ] keys to decrease/increase the distance stars are rendered at, I increased a fair bit to get a fairly dense stary background which looks nice
  • Turn of Anti-Aliasing in the "Render" menu, this will just cause problems with the AA you forced previously
  • Use mousewheel to set distance, use right click-drag to set angle, if you left drag and take the earth off centre then just press the C key to re-centre.
  • If when animating the camera is roating about the earth causing the stars to also rotate then just press the F key to enter follow mode, this fixes the stars and just rotates the earth.

Use spacebar to pause/unpause roation and use K and L keys to decrease and Increase the speed, I set mine fast at first to get an idea of what it would look like from all angles, tilted to get the best angle then set it slowly.

All thats left is to set the time speed using the [ and ] keys so its rotating slowly (approx 80 sec full rotate I made mine out to be) and make a mental note of when you start the image capture, I waited until a particular part of a continent was right at the edge of the globe. Hit the record key (numpad + in my case) and let it rotate, press again when finished.

You should find yourself with approx 80 images if you used the same rotate speed as me, or less if you used a faster one. I renmaed mine all to keep them in order as just 1.bmp. 2.bmp etc, copy them all to a seperate folder somewhere safe and then in windows 7 just go to the background properties and select that folder, tick all the images, make sure shuffle is unticked and set the cycle speed, I set 1 minute. And you're done!

Here's a jpg compressed at 100% qality in paint.net, I dont know if it's identical but either way I couldn't host a 12mb BMP :D It's 1Mb (down from 12mb) it's the first frame I did, it's in 2560x1600, you can see the AF and AA did a nice job of cleaning up the high res source image.

Enjoy :)

(additional, this is the 87 origional files in bmp format uncompressed, 67Mb http://uploading.com/files/WLBIVUQ8/Earth.rar.html)

74174584.jpg
 
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Hey, saw your post over in the super high resolutions thread... Any chance you'd be willing to share when your done? This is going to be sweet... especially if you get it synced with actual rotation of the earth... Great idea, I'll be watching your progress :D
 
It's finished it already, I generated all 81 screenshots.

I hadn't planned on releasing them all but since they compress to 100% quality jpgs about 900k each i might consider packing them all into a zip or something. Wheres a good place to host about 70-80mb for free?
 
Rapidshare, or Megaupload I think. But Rapid is limited to a few downloads if you dont have a premium account.
 
Very cool idea, and a really clever implementation! If I had Win7 or a 2560 monitor, I'd be wanting to try this out too. :D

Looking forward to playing with this if/when I start using Win7. I would immagine once the OS is released, a lot of sites will pop up with image sets to use with this feature.

Frostex, for the destributed version of your images, you should probably set the jpg compression to about 75% - since the majority of this is the black sky, and the rest has good sharp details (as opposed to a lot of subtle color-shifts), it will probably compress extremely well, and you shouldn't lose much quality. Will make it a lot easier to transfer and maybe a little easier on your system memory.
 
Thanks for the suggestions, well a 100% quality jpg compressed file came out average of 1mb, but just compressing all the original 12mb bmps came to 67mb total with winrar on "good" compression, so I'm just uploading that.

To be specific, this archive is 87 shots as posted above but uncompressed .bmp files in 2560x1600 resolution at 12mb each, total compressed archive size is 67,542KB

Enjoy

http://www.mediafire.com/?giwddlnn2jm
 
sadly, windows doesnt let you set it up to go along with the actual earth..... it would have to change every 18 minutes which is not one of the options :(... and to get it right i'd have to redo it all by myself... seems like alot of work :p
 
Well the time multiplier is several discreet values in so the next slowest rotation would be real time i think or close to it, so you'd have to leave it taking screenshots all day or find some other mechanism for automatically taking screenshots at set intervals, fraps only allows integers with min 1s

Im not that bothered with it being out of sync, it's not massively accurate anyway since it jumps in rotations of like 4-5 degrees then sits still for bit then jumps again, but yeah re-doing it wouldn't be hard with the above walkthrough, 30 mins tops.

*edit* In fact you could probably find the background cycle speed in the registry somewhere and tweak that :)
 
Couldn't say for OSX, if you mean actually running them apps, I believe they're windows only.

As long as it supports cycling through images it should be fine, you may need to convert them if it doesnt support bmps and resize them if they look naff when they're shrunk to smaller screen.
 
Frostex: Thanks for the pictures! :)

EDIT: Just put em on. I like it very much. I wanted the Earth to be a bit bigger, so instead of the stretch option, I chose center. Works for me since I'm on 1280x800. :D
 
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Yeah I wasn't sure on the distance, it could go in a lot further I suppose.

The TIFF of the earth skin I got from the nasa site was like 8000x4000 res or something of that order, so it looks quite detailed even up close, I may take a 2nd set about 2x closer in, I'll post the archive again if I do.
 
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