There are a couple of interesting and extremely useful properties of a virtual 3D camera that are missing from the 'Camera' class in the JS API:
1. Horizontal + Vertical field of view (FOV) [There's a 'fov' member but it's unclear what it is exactly. A clearer API documentation would help as well].
2. Projection Matrix of the Camera.
3. Roll angle (in addition to the existing yaw/heading and pitch/tilt)