Do you see purple edges when you go over it with the mouse?
Edges are only drawn up to al certain distance, so with models this big you will only see them when you are very close up. This is to prevent all gray models because of far away edges bleeding together.
you can override this by increasing the 'edgesVisibilityFactor' option in the main.cfg file, but I don't recommend it (performance wise).
You probably better of by using a stand in version of the landscape using two alternating poly colors (like in the povray renderings)
Edges are only drawn up to al certain distance, so with models this big you will only see them when you are very close up. This is to prevent all gray models because of far away edges bleeding together.
you can override this by increasing the 'edgesVisibilityFactor' option in the main.cfg file, but I don't recommend it (performance wise).
You probably better of by using a stand in version of the landscape using two alternating poly colors (like in the povray renderings)