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Vexir's avatar
Vexir
Honored Guest
11 years ago

High-Res Satellite and Sky Images

Hey all,

I'm working on a game where my primary goal is to create the same feeling of insane height and atmosphere that space scenes give you (the Space bit of SightLine is a really good example). My goal is to set you up in an environment similar to that which you'd find yourself while skydiving - a big open sky above and land. Most importantly, the land should look quite distant - enough to make you believe that you're that high.

Unfortunately most of the Skyboxes I've found just have blank color at the bottom half. Same goes for skydomes. I've found a couple that include land on the bottom, but even those don't specify a 6th bottom image.

My current plan is to try and grab a high-res satellite image of a countryside and map it to a big plane or somewhat deformed mesh or terrain object and use a skydome on the top. This probably won't look like it's extending to the horizon line, but I'll give it a shot.

Anyone have any suggestions for how to create this effect and where I can find high-res enough assets for it?

4 Replies

  • Google for landsat and NAIP, both with "image download." Both are freely available. Landsat imagery has 30m/pixel resolution and covers the entire globe. NAIP ("national argricultural imaging program") has 1m/pixel resolution and covers the continental US. If you have a hard time finding anything, limit your site to usgs.gov (US geological survey). They have a map-based download portal, but it's a bit clunky. If you're OK with only seeing imagery from California, go to http://www.atlas.ca.gov/download.html . They have a very nice Google Maps-based download interface.

    Prepare to download dozens of gigabytes of data.
  • Vexir's avatar
    Vexir
    Honored Guest
    Thanks! Looks like there's lots of data available, I'll just need to figure out how to extract it.

    One question when it comes to terrain though is that when you look down, generally, the satellite image is fairly appropriate in representing what you're looking at. Looking up at the horizon line however, is a different story. You'd expect the land to compress towards the horizon and detail to blur into itself, eventually ending where the skybox begins.

    Any ideas on how to recreate that with simply satellite images? I could obviously stick several of these onto a huge plane and let the 3D rendering and perspective do it, but that sounds really expensive and I'd need to make it really big with lots of textures. I'm thinking a better solution is to bake that effect into a texture and map it onto the plane. Perhaps even an upside down sky dome (land dome?). The player will never actually reach it, so it doesn't need to reflect land elevation changes.

    I have no idea how to bake that kind of thing into the texture though.
  • Vexir's avatar
    Vexir
    Honored Guest
    I'm not finished experimenting yet, but I ended up just downloading Google Earth Pro's trial, taking screencaps of the main view with all the gridlines disabled, and then stitching them together with Photoshop's batch stitching tool.

    The end result is lower res than I'd like it to be though.