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If MVC architecture is used for a Irrlicht based game, Irrlicht should be used as the graphic rendering engine. In other words, it is the View part. I'm wondering how the Model and Controller parts should be designed?
Since Irrlicht uses a scene manager to manage all scene nodes, is it redundant to track scene nodes in the Model part?
It's sometimes redundant, but in the general case you should create your own independent model and link from objects of your model to objects in the view. The controller will use parts of the Irrlicht event system, though, and thus might also interact bidirectional with the model.