When you look at your 3D scene through the MotionBuilder Viewer window, you are using a camera view. The camera represents your vantage point, framing your view of the objects inside the MotionBuilder 3D world.
In fact, when many people describe a scene in the Viewer window, they often are describing what they see happening in the Viewer window’s camera view.
MotionBuilder lets you use many camera views, some of which you can alter and some that contain preset angles.