OGRE overview

High level overview

 
The class diagram shows the Root class of OGRE and all of the Manager classes that gives access to the different subsystems.

• The Root holds a reference to the current SceneManager and to an enumerator that allows other types of scene graphs to be loaded.  
• The RenderSystem is an abstract class that separates the Root from the specific implemention of the RenderSystem, OpenGL or Direct3D.  
• The ResourceManager is an abstract class that is subclassed by a number of managers that handles resources such as textures, materials and fonts.  
• All of the classes in the diagram except for RenderSystem, SceneManager and RenderWindow are using a singleton template to ensure that there is only one instance of each class.  

The render cycle

 

Inside the source I had figured out:

Resource Manager:

Render Source:

 

readMesh:

Movable Object: