= Ossim Planet Primer =

== Concepts ==

=== The Camera ===
The camera, or eye, is a point above the planet surface that has a degree of vertical tilt.

==== Line of Sight ====
The position on the surface directly under the center of the screen. If the center of the screen does not cross the surface, this value is infinite, with lat/long of zero.
==== Nadir Point ====
The point on the surface of the planet that is between the camera and the planet center.

==== Eye Point ====
The Eye Point is a point provided by a NodeVisitor. This point is the position of the eye, relative to the node. This allows you to get the distance between the two by calling eyePoint.length().

=== The Land Model ===