A. Rendering and interaction sub-systeml
The main function of rendering sub-system (RS) is to
render the 3D scene and model effectively at the client.
Actually, this paper developed a real-time rendering plug-in
which could be embedded in the browser based on source
open software, X3DToolkit [14]. In detail, the functions of
RS includes reading and converting X3D/VRML files, the
organization of X3D/VRML scene and model, converting
X3D/VRML scene and model into certain kind of scene
OpenGL supports. What’s more, several fast graphics
rendering algorithm, such as cutting Culling, LOD, and so
forth are employed in RS. The organization of scene graph
plays an important role in RS. The typical X3D scene graph
is showed in Figure 1.