Separating semantics from rendering: a scene graph based architecture for graphics applications

A large number of rendering and graphics applications developed in research and industry are based on scene graphs. Traditionally, scene graphs encapsulate the hierarchical structure of a complete 3D scene, and combine both semantic and rendering aspects. In this paper, we propose a clean separation of the semantic and rendering parts of the scene graph. This leads to a generally applicable architecture for graphics applications that is loosely based on the well-known Model-View-Controller (MVC) design pattern for separating the user interface and computation parts of an application. We explore the benefits of this new design for various rendering and modeling tasks, such as rendering dynamic scenes, out-of-core rendering of large scenes, generation of geometry for trees and vegetation, and multi-view rendering. Finally, we show some of the implementation details that have been solved in the process of using this software architecture in a large framework for rapid development of visualization and rendering applications.