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tuvd

Making Planet Earth In To Terrain

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Well i am designing a Game using DX9 and VB.Net and was wondering what the best way would be for me to Make a 3d version of planet earth, is it possible to use a color map to create a terrain or would i have to make a heightmap, or is ther a better way anyone got any ideas.

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Unless you''re trying to accurately model some specific part of the world (like a section of the Rocky Mountains or something) then what you''re looking for is a terrain generation algorithm. Do a search here in the DX forum, the Graphics Programming, or the Game Programming forum and you''ll see a lot of discussions on how to do terrain generation.

neneboricua

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I know about terrain generation, but what i am saying is i want an acurate model of planet earth , is it possible , i want to be aboe to either use ac actual map from Nasa or something for a height map or texture, i have to make it as acurate as possible is this possible?

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It''s entirely possible although incredibly improbable. www.vterrain.org is a site dedicated to what you''re talking about (only to a more realistic scale). By using a heightmap in conjunction with a bitmap of topographical satelite photos you can, in fact, model real to geography (to a certain degree) terrain. You won''t find data on the entire earth and you probably couldn''t render a project that big in real time but you can do specific sections. A friend of mine has a heightmap of Ireland he runs in openGL and it looks pretty cool. It''s probably only accurate to a few miles, of course, but who''s gunna know.

Good luck!

When you find yourself in the company of a halfling and an ill-tempered Dragon, remember, you do not have to outrun the Dragon...

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i would like to first state that that is an incredibly unrealistic project. however, with some type of grid of areas on a small enough scale that are loaded dynamically, you may be able to accomplish something. you will have to use a system of some type, probably a quad or oct tree combined with an VLOD system, to help cull out sections of the terrain that are loaded but not visible, but it may be semi-doable. i would suggest a grid of patches where you load 9 into memory and then furthur subdivide each patch, eliminating those that are out of the frustum. hey, good luck with it, and you should be able to get some good ROAM or quad-tree VLOD going from what you can find in google.

Have fun.
madman_k

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The saving grace here is that the curvature of the earth, and the curvature of its terrain, are not on the same scale. If you are close enough to a mountain range that bumpmapping does not look realistic, you are also close enough that you can use standard flat-plane terrain methods and not worry about the earth being a sphere.


How appropriate. You fight like a cow.

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Actually, I am doing this professionaly at the moment. It is possible, but unless you are a company or very rich, highly improbable.

We are using satelite data, and height information from satelites, but

a) this is really expensive and I doubt you could afford it
and
b) there is way too much data to fit on your computer, we are streaming our images and heights from a server. (We have about 15Giga bytes of image data, and this covers roughly 10% of the all the image data we would like to have.)

So it is possible, however it is highly unlikley that you can just write such a program by yourself. I wish I could send you screenshots but we are too early in development.

If you want to see a comparable system, check out something called Earthview, by a company called Keyhole. They are doing what you want (there was a downloadable demo, but they may have removed it from their site.)

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I have done something similar to this. It really depends just how accurate you need it, how much detail, etc. In my case, I simply needed the ability to render any potion of the map at any given zoom level. I used DEM files obtained from the USGS site. By today''s standards they do not have the resoltion of newer data but are still quite high enough for my purposes. In fact, I actually wrote a program to reduce their resolution in order to get the files to a manageable size.

The other thing that saved me is that I didn''t need actual satellite images for my textures. I generated the textures dynamically by reading the elevation data and assigning colors based on elevation. I was surprised at how good it looked. But if you are going for a flight sim or something close to the ground that technique will likely give you a blotchy look.

I have some screenshots somewhere of how the maps looked. If it sounds reasonably close to what you''re trying to do e-mail me at larryj@tvn.net and I''ll dig them up.

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well it dosent have to be exactly acurate it just has to look it and it will be on a game scalei dont really wanna make it too big , it just has to look like earth with at lease most coutrys, dosent have to have small islands.

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