- model loading deferred to primary thread
- tile removal deferred to paging thread
- other tweaks and rearrangments.
Airport signs
- first stab at some support for adding taxiway and runway signs. This
is non-optimal, but I'm under the gun for a demo.
from the pre-ssg / render everything ourselves days. Replaced with a
material library manager that is much better suited for working in the
context of ssg. This simplified and cleaned up a ton of old junk.