This class keeps track of all the models in the scene that need to be updated and decides for which models to increase the quality and for which models to reduce. The behaviour can be tweaked using the TriangleBudget and the Quality parameters.
The Quality parameter is really a trade-off between quality and performance, bringing it close to 0 will make the quality very high but will drastically increase the amount of triangles that need to be rendered. Making the quality parameter higher will increase the performance at the cost of the quality.
Make sure each scene has at least one XrgStreamController, and every model holds a reference to a valid stream controller.