
Chapter
4
Scene Graphs
C
hapters 2 and 3 were about dr awing geometric pr imitives to a window. This
chapter is about organizing the primitives to efficiently feed the renderer and
covers the two competing schools of thought; namely, that the organization should
be spatial, where objects are grouped together based on their spatial proximity, or
state based, where objects are grouped together based on their common render state.
I will briefly discuss both concepts here, concluding that the data structure for object
organization—called a scene graph—should support both aspects of spatial proximity
and render-state coherency.
4.1 Scene Graph Design Issues
Most ...