Looks for the main camera used by the frame graph.
By default, this is the camera used by the main object renderer task.
If no such task, we try to find a camera in either a geometry renderer or a utility layer renderer tasks.
Parameters
frameGraph: FrameGraph
The frame graph to search in
Returns Nullable<Camera>
The main camera used by the frame graph, or null if not found
Looks for the main camera used by the frame graph. By default, this is the camera used by the main object renderer task. If no such task, we try to find a camera in either a geometry renderer or a utility layer renderer tasks.