Camera in BGE
Within the game engine, the camera may be used with its default characteristics (how it moves), or it may track an object using parent to the object, parent to a vertex of an object, or using a Camera actuator.
Any object may become a camera (see below), and when using camera tracking to an object, any object may be used (such as an empty).
To use the camera you must start the GE from the camera’s viewport (0 NumPad), and to avoid camera distortion, always zoom the view in until the camera object fills the entire viewport.
It is a view of the world with no camera movement.
Parent Camera to Object
The camera will follow the object. First select the camera and then select the object. Next CtrlP → Make Parent.
Note that if your object has any rotations then the camera will also have those rotations. To avoid this use “Parent to Vertex” (see below).
Parent to Vertex
The easiest way to accomplish this is to select your object and ⇆ Tab to Edit mode. Now select the vertex and ⇆ Tab back to Object mode.
Next, without any objects selected, select the camera and, holding the ⇧ Shift key, select the object. ⇆ Tab into Edit mode, and CtrlP and choose Make vertex parent.
Now the camera will follow the object and it will maintain its rotation, while the object rotates.
Object as a Camera
Any object may also become a camera with whatever properties are set for the object.
To make an object the camera, in Object mode select the object and press Ctrl0 NumPad on the numpad.
To reverse it, just select the camera and Ctrl0 NumPad again.