This function can be used to set the default camera to use a custom camera that you have previously created using one of the camera_create functions. When you create a room with no active view ports or view cameras, GameMaker Studio 2 still uses a camera to show the action in the game. This camera is called the default camera and can be set and manipulated (and even destroyed) just like any other camera.
Argument Description camera_id The unique camera ID value returned when you created the camera
var new_cam = camera_create_view(0, 0, 640, 480, 0, obj_Player, 5, 5, -1, -1); camera_set_default(new_cam);
The above code creates a new camera and then assigns it as the default camera to use.