Chapter 10: Fragnebt Post-Processing

📚 Official Books Metal by Tutorials
1

Hello Caroline, today I start to study the chapter 10, but I can not run the playground and I always receive this message: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value: file post_processing_Sources/Renderer.swift, line 271
So please tell me what can I do?

2

Do you receive this error when you run the supplied final playground?

What is your hardware? (Device and GPU).

Version of macOS and Xcode?

3

Hello Caroline, my version of macOS is Big Sur and my Xcode also newest version. I just want to try this final code with simulator

4

Apple changed the way to make libraries in playgrounds.

In Renderer.swift, change line 169-171 to:

//      guard let path = Bundle.main.path(forResource: "Shaders", ofType: "metal") else { return }
//      let source = try String(contentsOfFile: path, encoding: .utf8)
//      let library = try device.makeLibrary(source: source, options: nil)

let library = device.makeDefaultLibrary()!
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5

Issue still true for Big Sur 11.2.3 and Xcode Version 12.4 (12D4e). Updated the Renderer.swift lines 133-135. Works.

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