Can not run successfully

[funland]

The playground will stop before

self.view.addSubview(scnView)

in every playground

my iOS version is iOS12 and the playground is the latest
can you give me some advice ? thx

[ToshihiroGoto]

I do not have an IOS 12 version of the iPad,
but may be repaired with the following fixes.

Case 1:

let scene = SCNScene(named: "bg.scn")!

to

let scene = SCNScene()

Case 2:

scnView.translatesAutoresizingMaskIntoConstraints = false
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat:
    "V:|[scnView]|", options: NSLayoutFormatOptions(rawValue: 0),
                        metrics: nil, views: ["scnView": scnView]))
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat:
    "H:|[scnView]|", options: NSLayoutFormatOptions(rawValue: 0),
                        metrics: nil, views: ["scnView": scnView]))

to

scnView.translatesAutoresizingMaskIntoConstraints = false
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat:
    "V:|[scnView]|", options: NSLayoutConstraint.FormatOptions(rawValue: 0),
                        metrics: nil, views: ["scnView": scnView]))
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat:
    "H:|[scnView]|", options: NSLayoutConstraint.FormatOptions(rawValue: 0),
                        metrics: nil, views: ["scnView": scnView]))

In Case 1, resource acquisition failed.
In Case 2, change Swift's syntax.

[funland]

Thanks for you kindly reply , it looks the problem happens while the program will add the scnView to the mainview as a subview and it will be always crashed .
By the way , I 've tried the code above and it not works .

[funland]

When I run it on the mac , it noticed ：
error: 09_SceneGraph.playground:134:109: error: 'NSLayoutFormatOptions' has been renamed to 'NSLayoutConstraint.FormatOptions'
self.view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[scnView]|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: ["scnView": scnView]))
^~~~~~~~~~~~~~~~~~~~~
NSLayoutConstraint.FormatOptions

maybe I can give a try ，thank you！

[funland]

It warns me "Class NSLayoutConstraint haven't member FormatOptions" in iPad , but it can work on Xcode perfectly , wired .

[ToshihiroGoto]

Thank you for your reply.
When I tried it, the new Swift Playground on iOS 11 crashes in mainview.

Because it works with Xcode, it may be a bug in Swift Playground on iPad.
(official AR sample on the iPad works with SceneKit using the storyboard)

[funland]

OK , in some playground change NSLayoutFormatOptions can let the playground work correctly , but 09_SceneGraph is still has problem .
Thanks for your reply , you do an excellent job !

[funland]

update: I think some crash is caused by out of memory , when I remove some node , the program can run successfully , but sometimes it can not run even I just change the background color

[ToshihiroGoto]

If memory is a problem,
it may work with "PlaygroundPage.current.liveView = scnView" without using UIViewController.

Or set the size of the SCNView to remove the constraint