Earth project

Started by Oshyan, March 26, 2007, 12:31:05 am

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Oshyan

I've started on a short project to find the best Earth data available and determine the maximum resolution Terragen 2 will allow me to load and render. I'm also incorporating city luminosity that should vary depending on whether the area is in the shadow of the planet. This will depend on some manual setting adjustment unfortunately - it won't just work automatically as you adjust the light position. Initial results are below.

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Note that the clouds seem to cut off at the terminator - I'm not quite sure yet whether this is really what's happening or if it's just the lighting of the atmosphere continuing on above the lower clouds. You can also see the lights of California on the left in shadow. This is before I added the Power Fractal noise and adjusted some other settings. Here are some real Earth images for comparison: http://www.freeimages.co.uk/galleries/space/earth/index.htm Still a little ways to go.

Admittedly it's not a very complicated scene to set up. I have 2 surface layers: 1 for base color, displacement and luminosity, and 1 for water with a specularity mask. The luminosity is driven by an image map and is filtered through a Power Fractal to give it a some fine noise and a better sense of realism (it looks quite soft and artificial otherwise). I am also using a cloud map with 3d volumetric clouds (yes it does make a difference visually for realistic orbit views).

The value here will be in having high quality texture maps pre-selected as the maximum resolution Terragen 2 will currently load (on a system with ~2GB of RAM) and in the fine-tuning of displacement, luminosity, etc. for best results. This "Earth" will be easily reusable in other scenes and will immediately give you nice-looking, realistic results. I'll make these files available when I'm done.

- Oshyan

old_blaggard

Sounds like a project I've been working on for a while, except yours is a whole lot better ;).  Are the clouds from an image mask or from the shaders in TG2?  If the latter, I'll be very interested in seeing the result.  Just a little side note, I've been working with 2 223 megapixel image maps in mine on a 1GB machine; how large are yours?  Also, are you planning on making this a planetary scale file only or are you going to make it realistic all the way down to ground level?  Either way it looks pretty impressive right now, and I can't wait to see the files you end up sharing :).
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Oshyan

Yeah I figured others were working on this - in fact I've seen some of the results others have had, but some mentioned problems. So I figured I'd see if I could resolve some of those issues and provide the scene files for others to play with.

The clouds are an image mask downloaded from the 'net. I can't quite get TG2's clouds to achieve that effect, though I've created some decent planetary-scale clouds before with large scales and high warp values.

The images I'm working with vary in size, but the main planet texture is "only" 5400x2700 at this point and you can see it's a little soft in the render I posted (more so at the original 1600x1200 size). I'll be working with the "Blue Marble Next Generation" data to make something higher resolution and see just how big I can make it before TG2 chokes. I'm also experimenting to see whether different image formats - tiff and jpg for example - allow for different resolution images to be loaded. Theoretically they should be roughly the same because jpg will be uncompressed for use in rendering, but theory often proves incorrect. ;)

Making this work from space down to the ground would be really, really hard, at least for real Earth topography. You'd need to use all the available DEM data for the entire Earth - something like 5 terabytes worth. :P I could work on doing it with procedurals, but the results probably wouldn't be all that great. So for now it's focused on just being a from-space scene, as close as low Earth orbit I'd say (still in space but close to the atmosphere).

- Oshyan

king_tiger_666

Oshyan, A friend at university, has access to military resolution dem/ GIS data, "navy perks" now thats some resolution I think it was a couple Petabytes of data collected over 11 days of shuttle orbit... now that would make some high detailed renders if you had something to run it on ;D ;D
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Oshyan

Quote from: king_tiger_666 on March 26, 2007, 02:05:45 am
Oshyan, A friend at university, has access to military resolution dem/ GIS data, "navy perks" now thats some resolution I think it was a couple Petabytes of data collected over 11 days of shuttle orbit... now that would make some high detailed renders if you had something to run it on ;D ;D

Hehe, wow that sounds awesome. Can you ask him what resolution it actually is? I know there is limited availability of 3m DEM's for small parts of the US. That in itself is frankly amazing detail. I can't imagine much smaller than that - 1m maybe.

The interesting thing about such large data sets is that unless you're rendering at *extremely* high resolution you will seldom see more than a few maximum detail tiles at any given time. So with an efficient level of detail system and multi-resolution data tiles you could actually visualize the entire Earth efficiently on an average computer, provided there was enough storage capacity. Several petabytes is pushing it, but my earlier example of 5tb wouldn't be so bad. 1tb hard drives are about to come out on the market and should be about $500 each initially. So for $2500 plus the base cost of your machine you could have that data set on your system.

TG2 already has a Mars MOLA data loader which operates on tiles and can theoretically load the whole planet. That may be adaptable to loading of tiled DEM data as well, in which case this could become a reality at some point in the future. Obviously most people wouldn't be using the entire data set, but even working with a couple of gigabyte subset of a single state or continent would be pretty awesome. I actually have the entirety of New Zealand at 90 meter resolution kicking around here somewhere...

- Oshyan

king_tiger_666

I think it was 1 meter, the GIS lecturer wanted to know where he got it, since you can't buy anywhere near the resolution, was the entire world ...


how big are the New Zealand files?,
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Oshyan

New Zealand was something like 700MB at 90m, if I recall correctly.

- Oshyan

king_tiger_666

are they commercial?, or is there a source for free downloads?,,,
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Oshyan

They're free, non-commercial. The entire Earth is offered at 90m resolution by the USGS, along with the entire US down to 10m, and 3m in select locations. That's definitely one area where the US government's citizen services excels over many other countries. Other countries that offer free DEM's of their native lands - let alone foreign lands - are few and far between. You can get full access to all the data here: http://seamless.usgs.gov/ There are other methods of accessing it (FTP for example), but that's generally the best tool in my opinion.

- Oshyan

rcallicotte

I can't wait to have time to see what you're doing here. 
So this is Disney World.  Can we live here?

king_tiger_666

Oshyan, do you know of any  dem program that can stitch dems together?. say if I got say the North Island of NZ or a section to make 1 big dem file...
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Oshyan

Yes, 3DEM can do this to the limit of your memory and it also exports to .ter, unfortunately it only supports up to 4097x4097 size: http://www.visualizationsoftware.com/3dem.html But it is free so that's nice.

Global Mapper is "the" ultimate tool to use for working with DEM data in my opinion - it is extremely powerful, has very broad format support (both import and export), supports .ter up to 16,000x16,000 and is constantly being updated with new features. Unfortunately it's a bit pricey at $279, but it's well worth it if you want to work with DEM's a lot. http://www.globalmapper.com/

- Oshyan

RealUser

Oshyan, great stuff! I am certain the finished version will be a great success in the community.
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Will

cool, I'll be watching this project, very intresting stuff.

Regards,

Will
The world is round... so you have to use spherical projection.

bigben

Quote from: Oshyan on March 26, 2007, 01:46:30 pm
Global Mapper is "the" ultimate tool to use for working with DEM data in my opinion -
...
Unfortunately it's a bit pricey at $279, but it's well worth it if you want to work with DEM's a lot. http://www.globalmapper.com/


I wimped out at version 4 which is cheaper but only does up to 2049 x 2049 TERs. In theory, you can generate multiple TERs and then tile them in TG. We've only got 90m DEMs here (for free) so that still gives me a large tile.

I've contemplated an animation going from space down to ground level by carefully placing TERs of differing resolutions. I've gotten out to a view of SE Asia (Australia, New Guinea, NZ and parts of Indonesia. I haven't tried joining up TERs in the northern hemisphere yet. It will be interesting to try and combine this set of TERs with an image based earth like this.

Have you tried an image masked water surface yet for the ocean?