This class produces SceneGraphNodeEntities, based on the desired update behavior for the proxy.
TODO: comment this
creates SceneTreeNodes which are used to mirror the tree stucture of the scene graph.
THis class contains several tree nodes for the covered node.
class for generating proxy trees.
This class represents a tree version of a SceneGraphNode.
This class creates a proxy tree for the given sceneGraph from the root node and cares about adding and removing of objects.