Coordinate system
Every layer that you add to ArcScene™ has a spatial coordinate system, either projected
or geographic. A scene also has a coordinate system,
which overrides the coordinate systems of the layers within it.
This means that when you add a layer
to a scene, its coordinate system is temporarily transformed to match the
scene’s coordinate system. This transformation is
called on-the-fly projection. It allows layers that
have different coordinate systems to come into spatial alignment.
A new scene does not yet
have a coordinate system. By default, it takes the
coordinate system of the first layer you add to it. You
can select a different coordinate system for the scene at any time, causing all
layers within the scene to be reprojected on the fly.