You can do it like this:
In your main view controller:
func showModal() {
let modalViewController = ModalViewController()
modalViewController.modalPresentationStyle = .overCurrentContext
presentViewController(modalViewController, animated: true, completion: nil)
}
In your modal view controller:
class ModalViewController: UIViewController {
override func viewDidLoad() {
view.backgroundColor = UIColor.clearColor()
view.opaque = false
}
}
If you are working with a storyboard:
Just add a Storyboard Segue with Kind set to Present Modally to your modal view controller and on this view controller set the following values:
As Crashalot pointed out in his comment: Make sure the segue only uses Default for both Presentation and Transition. Using Current Context for Presentation makes the modal turn black instead of remaining transparent.