By default, a drag selection will select all components under the mouse. This can be a problem when viewing the scene in shaded mode since your selection may include components hidden from your view.
You can use Camera based selection to only select components with a clear line-of-sight to the camera. This ensures that you don’t accidentally select components you can’t see.
To turn on Camera based selection
Now, if you Drag select objects in your scene, Maya only selects the components unobstructed by other components from the camera’s point of view.
You can also turn on Camera based selection from the Preferences window (Window > Settings/Preferences > Preferences). The option can be found in the Selection section under Settings.
