llSetCameraAtOffset(vector offset)
Sets the camera at offset used in this object if an avatar sits on it. Use ZERO_VECTOR to cancel.
The same functionality can be found in llSetCameraParams and more.
The offset argument defines the point the camera is facing (relative to the position of the object containing the function call). For example, if <2,0,0.5> is given, the camera will look at a point two meters in front of and half a meter above the object. You’ll also have to define the camera position using llSetCameraEyeOffset.
offset must not be the same as the one specified in llSetCameraEyeOffset.
Remember, these offsets only take effect when an avatar sits on the object. You can’t call these functions to change the camera parameters once the avatar is sitting. To do this, the avatar would have to stand up and sit down again.
Example: See llSetCameraEyeOffset.