Better handling of missing tiles. Added a range selector so we can completely ignore tiles that are beyond our visibility range. Added a routine to prep the ssg nodes before rendering by updating the transform and range selector values.
terrain.
Preparations for unstable development version 0.7.0 Some reorganizational changes. Beginning to test the use of ssg (part of plib)
SimGear and TerraGear appear to have been split off at this time.