Next Generation Scenery

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Revision as of 17:10, 28 June 2012 by Hooray (talk | contribs)
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Request for Comments:

These are some ideas for new scenery and new scenery engine for FlightGear.

Why?

We would like to show more detailed scenery that's visible farther away, for a better VFR experience all around. Specifically, more detail makes the near-ground experience more realistic, especially for helicopter or VFR flight; scenery that truly extends to the visible horizon would make high-altitude flight more interesting. In addition, it's fun to fly around a richly detailed world.

Disclaimer

  • Most of these items have been collected from various places without reasonable evaluation. Thus, they might simply represent peoples random ideas without any warranty about a) making sense in the given context nor b) aligning with the plans of those who are actually driving FlightGear's Scenery development. So, read this with a grain of salt ....

Ideas

  • ability to dynamically enable/disable certain scenery features ([1])
  • Provide the foundation to eventually facilitate runtime-based creation of airport features (i.e. runways and taxiways), so that changes to the underlying data files (apt.dat.gz) could be immediately honored at runtime without having to recompile scenery tiles
  • Ability to cut in polygon models of airports. [2]
  • Ability to page terrain / textures so continuous flights around the world are still possible.
  • Ability to populate the world with arbitrary additional 3d objects. Note that our current ability to populate the world with random objects would not work with the new scheme. We'd need to completely overhaul that functionality to work in a photo texture drapped, LOD terrain world.
  • Care should be taken with object vertical placement so the terrain LOD doesn't move the 3d objects up and down noticable. And also so it doesn't noticably bury objects or float objects when the terrain LOD changes.
  • I assume all the current 2d polygon data would go away since this would be better represented by the photo texture overlay anyway.
  • LOD algorithm/system (with adjustable radius for high and low end users) The current irregular grid mesh works but it's not very efficient and we could get much better framerates with a nice LOD system. Alternatively much higher elevation resolution with similar framerates.
  • Texture overlays - FG scenery engine does the chopping and texture co-ord generation. (I won't go into details but this would greatly simplify LOD algorithms)
  • The ability to drape the textures at differing resolutions at different locations in the scenery. (ie. higher res data immediately adjacent to airports where the pilot is generally closer to the ground and to give good definition on final approach).
  • Some sort of fix or workaround for the stretched-textures-on-cliff faces problem that draped textures suffer from in mountainous regions - possibly the ability to cut in textured polygons on steep faces.


Data sources

Here is a list of possible data sources for better scenery.

Elevation data

  • SRTM Data - 30m resolution for North America, 90m for most other world. Data goes up to about 60 degrees north and 56 degrees south. Commercial/GPL use is restricted.
  • ASTER GDEM Aster data, 30m resolution for the whole world, from 83 degrees north to 83 degrees south. License is limited, might be able to get the data and use, but redistribute with non-GPL license.
  • Mountain data Personal work of Jonathan for filling&fixing SRTM data for mountain areas. There can even data be found for regions not covered by SRTM or ASTER, like Antarctica. Mostly 90m resolution, but some areas are 30m. Also has some data for north eurasia not available in SRTM. Data should be free to use, but not sure about the GPL compatibility, this might depend on the original data sources.

Shapefile data

Some sources for shapefiles, some of these are already available, the ones with links might not be yet.

  • GSHHS
  • VMAP0 & 1
  • OSM
  • TIGER
  • Corine landcover use data for Europe, the ones I have seen are 25m resolution. License is free, but might not be GPL compatible.

Photo data

To be defined, we might soon get a photo scenery support, so this section is reserved for acquiring free high resolution images for it. See also the article on Brest photorealistic scenery.

Related mailing list discussions

Related Projects/Efforts