# The Scene Graph

You may need to read the article about transformation before this one.

A *scene graph* is a general data structure that arranges the logical representation of a graphical scene. It is a collection of nodes in a tree structure, with each node having one parent and a non-negative number of children. Only the top node has no parent.

Each node's transformation matrix is multiplied by all of its ancestors' to generate its *world matrix*, which represents its actual position in a scene relative to the origin. The transformation matrix represents its position relative to its parent.

The next article is about 3D.