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107
Chapter 10
10. Scene Graph Engines
There are classes that work with scene graphs, but are not nodes; they cannot be part of
the scene graph, but they serve the vital function of enabling animation. csEngine is such
a class.
This chapter describes csEngine and the multiple subclasses derived from it.
These are the sections in this chapter:
•“Engines on page 107.
•“Engines that Interpolate Values on page 110.
•“Engines That Change Shapes on page 117.
Engines
A csEngine performs a specied function on input data and outputs a result. These
results can be used, for example, to encapsulate scene graph behavior. If part of a scene
graph renders a car, you might, attach an engine to the transform node of each wheel to
animate its rotation. You might also tie the motion of the wheels to the motion of other
shapes in the scene so they appear to pass by when the car moves, or you might cycle the
car through a set of colors repeatedly.
csEngine is a derivative of csNode, but usually csEngines are not included as nodes in a
scene graph.