Type of the Projection Surface resp. auxiliary Surface

There are three projection surfaces resp. auxiliary surfaces:

(Tangent-) Plane

The mapping (azimuthal projection) takes place directly onto a (tangent-) plane.

(Secant-, Tangent-) Rotation Cylinder

The mapping (cylindrical projection) takes place at first onto a (secant-, tangent-) rotation cylinder which then will be unwinded into the plane.

(Secant-, Tangent-) Rotation Cone

The mapping (conic projection) takes place at first onto a (secant-, tangent-) rotation cone which then will be unwinded into the plane.