osgearth_package的一些用法

New options include:

--bounds xmin ymin xmax ymax:
Specify the bounds to export (in map coordinates)

--overwrite
Tells the packager to overwrite tiles that already exist in the TMS repo

--out-earth <earthfile>
Writes out a .earth file in the root folder of the TMS repo that points to the repo's contents

Caveats:

1) --out-earth will always put the earth file in the root folder if you specify a relative path.
2) --out-earth will always output an earth file based on the *most recent* packaging, regardless of what layers may already exist in the repo folder.
3) The TMS repo's tms.xml file will always have at least 23 tileset levels in it.
4) There is no "--min-level" option at this time, but you can always say "min_level" in your earth file.

一些例子：
osgearth_package test.earth --tms --ext png --out /tms_output_directory  --bounds 7.3828125000 46.8603050992 7.5586175468 46.9802523552 --max-level 13

osgearth_package gdal_my.earth --tms --max-level 20 --out g:\oren\testAir\tms\

osgearth_package --tms test_gdal.earth --out . --out-earth test_tms.earth --max_level 5 --overwrite

 osgearth_package --tms 3857_projected.earth --out . --out-earth tms_package.earth