Autodesk Civil 3D

These images contain the hierarchy of all major objects. This is useful for determining which class instances are required to create an object of a particular type, or which objects can be accessed from an existing instance.

Legend

Graphic Meaning
An object with a classname of “AeccObject”.
An object with a classname of “AeccCollection”. This object is a list of other objects which can be enumerated. It also usually has a Count property and Add, Item, and Remove methods.
You can obtain object B from a property or method of object A.
From object X you can obtain a collection Y, which is a subset of a larger collection.