Quadtree rendering is an alternative for the default BasicRenderEngine, which is the render engine we've used so far. We will not go into the algorithm used by this renderer. All we need to know about this rendering type is that most of the time it solves z-sorting issues. It's been mentioned earlier that quality often costs CPU power. That definitely counts for quadtree rendering as this is a real CPU killer. However, its use is very simple, so let's see how it works.
First we create a new project, based on the ViewportLayersExample class from the beginning of this chapter. Add the following import at the top of your document class:
import org.papervision3d.render.QuadrantRenderEngine;
Then, add the following to the init() method:
renderer = new QuadrantRenderEngine();
This code replaces the BasicRenderEngine, which was instantiated automatically by the BasicView class, with a QuadrantRenderEngine instance. That's all you have to do in order to render with the quadtree...
