[osg-users] [vpb] Mixed resolution databases

[Tobias Bellmann]

Hi,

I am trying to generate a database with very different sets of data resolution:

1. low resolution data (BlueMarble) covering the whole earth.
2. very high resolution data (20cm per pixel) for an area of interest (~30x 30 km rocket launch site)

The plan is to start a flight at the high res area, and end up in orbit of the planet earth.

I tried several ways to achieve this result:

1. All data is used in the same database: Very high levels are necessary, the database gets incredibly big, the generation time skyrockets.

2. using the --levels switch for blue marble data (levels 0-8 ) and high res data (levels 8-18 ): Works in principle, leads to a nasty transistion period, where a complete part of the earth is white (I think where the textures of the low res files are not shown because of the levels statement)

3. using the --patch switch to integrate the high resolution into the low res database: it seems, that the number of levels of a databased can not be increased after the first generation.

So it seems, my only option is to generate insanely huge databases (in an example with 80cm resolutions it got 300 GB large, although only a small part of the earth was covered by high res data).

Maybe there is another way I missed? Is there a way to integrate high resolution databases in low resolution planetary databases without creating very large files?

Kind regards,
Tobias

------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=71530#71530