Table of Contents
The placement of the camera update within the general update process is a delicate matter, because the camera depends on some components having been updated before it, whilst other components depend on the camera being updated before them.
Conceptually, there are four types of camera: fixed camera, FlexiCam, cursor camera, and free camera. The first three are client-controlled views, ranging from minimum user interaction to maximum user interaction. The last camera is completely user-controlled, but is not part of actual game play.
There are however just three camera classes:
FlexiCam, CursorCamera, and
FreeCamera. The fixed camera is implemented with a
FlexiCam object. They all derive from a common
BaseCamera class.
There is only ever one active camera at a time. The personality script usually handles camera management, since the camera is a global, but any script can also manipulate the camera, and the player script often does (although usually indirectly, through the personality script)
The base class and all the derived classes are fully accessible to Python. Any camera can be created and set to whatever position a script desires, including to the position of another camera. This is particularly useful when switching camera types to remove any unwanted 'jump-cuts'.
The cursor camera is a camera that follows the character in the game world. It always positions itself on a sphere centred on the character's head. It works primarily with the direction cursor so as to face the camera in the direction of the character's head. You may use any MatrixProvider in place of the direction cursor, and you may use any MatrixProvider in place of the player's head.
The direction cursor is an input handler that translates device input from the user into the manipulation of an imaginary cursor that travels on an invisible sphere. This cursor is described by its pitch and yaw. It produces a pointing vector extending from the head position of the player's avatar in world space, in the direction of the cursor's pitch and yaw. The direction cursor is a useful tool to allow a targeting method across different devices. Rather than have each device affect the camera and character mesh, each device talks to the direction cursor, affecting its look-at vector in the world. The cursor camera, target tracker, and action matcher then read the direction cursor for information on what needs to be done.
The cursor camera takes the position of the direction cursor on the sphere, extends the line back towards the character's head, and follows that line until it intersects with the sphere on the other side. This intersection point is the cursor camera's position. The direction of the camera is always that of the direction cursor.
The cursor camera is an instance of the abstract concept InputCursor. There can be only one active InputCursor at any time, and BigWorld automatically forwards keyboard, joystick, and mouse events to it. Upon startup, the cursor camera is the active InputCursor by default. You can change the active InputCursor at any time, using the method BigWorld.setCursor (for example to change the InputCursor to be a mouse pointer instead).
The Free Camera is a free roaming camera that is neither tied to a fixed point in space nor following the player's avatar. It is controlled by the mouse (for direction) and keyboard (for movement), and allows the user to fly about the world. The free camera has inertia in order to provide smooth, gradual transitions in movement. It is not a gameplay camera, but is useful for debugging, development, and demonstration of the game.
The FlexiCam is a flexible camera that follows the character in the game world. It always positions itself at a specified point, relative to the character orientation, and always looks at a specified orientation, relative to the character's feet direction.
It is called FlexiCam because it has a certain amount of elasticity to its movement, allowing the sensation of speed to be visualised. This makes it especially useful for chasing vehicles.