diff --git a/18-rendering-with-rays/starter/Clouds.playground/Pages/1. SDF.xcplaygroundpage/Sources/Renderer.swift b/18-rendering-with-rays/starter/Clouds.playground/Pages/1. SDF.xcplaygroundpage/Sources/Renderer.swift
index 1e6733b..763c10a 100644
--- a/18-rendering-with-rays/starter/Clouds.playground/Pages/1. SDF.xcplaygroundpage/Sources/Renderer.swift	
+++ b/18-rendering-with-rays/starter/Clouds.playground/Pages/1. SDF.xcplaygroundpage/Sources/Renderer.swift	
@@ -16,9 +16,7 @@ public class Renderer: NSObject, MTKViewDelegate {
     device = MTLCreateSystemDefaultDevice()
     queue = device!.makeCommandQueue()
     do {
-      guard let path = Bundle.main.path(forResource: "Shaders", ofType: "metal") else { fatalError() }
-      let input = try String(contentsOfFile: path, encoding: String.Encoding.utf8)
-      let library = try device.makeLibrary(source: input, options: nil)
+      let library = device.makeDefaultLibrary()!
       guard let kernel = library.makeFunction(name: "compute") else { fatalError() }
       pipelineState = try device.makeComputePipelineState(function: kernel)
     } catch {
diff --git a/18-rendering-with-rays/starter/Clouds.playground/Pages/2. Raymarching.xcplaygroundpage/Sources/Renderer.swift b/18-rendering-with-rays/starter/Clouds.playground/Pages/2. Raymarching.xcplaygroundpage/Sources/Renderer.swift
index c32b2a9..eaf3c19 100644
--- a/18-rendering-with-rays/starter/Clouds.playground/Pages/2. Raymarching.xcplaygroundpage/Sources/Renderer.swift	
+++ b/18-rendering-with-rays/starter/Clouds.playground/Pages/2. Raymarching.xcplaygroundpage/Sources/Renderer.swift	
@@ -17,9 +17,7 @@ public class Renderer: NSObject, MTKViewDelegate {
     device = MTLCreateSystemDefaultDevice()
     queue = device!.makeCommandQueue()
     do {
-      guard let path = Bundle.main.path(forResource: "Shaders", ofType: "metal") else { fatalError() }
-      let input = try String(contentsOfFile: path, encoding: String.Encoding.utf8)
-      let library = try device.makeLibrary(source: input, options: nil)
+      let library = device.makeDefaultLibrary()!
       guard let kernel = library.makeFunction(name: "compute") else { fatalError() }
       pipelineState = try device.makeComputePipelineState(function: kernel)
     } catch {
diff --git a/18-rendering-with-rays/starter/Clouds.playground/Pages/3. Random Noise.xcplaygroundpage/Sources/Renderer.swift b/18-rendering-with-rays/starter/Clouds.playground/Pages/3. Random Noise.xcplaygroundpage/Sources/Renderer.swift
index ed7b97c..e6539a8 100755
--- a/18-rendering-with-rays/starter/Clouds.playground/Pages/3. Random Noise.xcplaygroundpage/Sources/Renderer.swift	
+++ b/18-rendering-with-rays/starter/Clouds.playground/Pages/3. Random Noise.xcplaygroundpage/Sources/Renderer.swift	
@@ -17,10 +17,8 @@ public class Renderer: NSObject, MTKViewDelegate {
   func initializeMetal() {
     device = MTLCreateSystemDefaultDevice()
     queue = device!.makeCommandQueue()
-    let path = Bundle.main.path(forResource: "Shaders", ofType: "metal")
     do {
-      let input = try String(contentsOfFile: path!, encoding: String.Encoding.utf8)
-      let library = try device!.makeLibrary(source: input, options: nil)
+      let library = device.makeDefaultLibrary()!
       let kernel = library.makeFunction(name: "compute")!
       pipelineState = try device!.makeComputePipelineState(function: kernel)
     } catch {
diff --git a/18-rendering-with-rays/starter/Clouds.playground/Pages/4. Clouds.xcplaygroundpage/Sources/Renderer.swift b/18-rendering-with-rays/starter/Clouds.playground/Pages/4. Clouds.xcplaygroundpage/Sources/Renderer.swift
index c32b2a9..eaf3c19 100644
--- a/18-rendering-with-rays/starter/Clouds.playground/Pages/4. Clouds.xcplaygroundpage/Sources/Renderer.swift	
+++ b/18-rendering-with-rays/starter/Clouds.playground/Pages/4. Clouds.xcplaygroundpage/Sources/Renderer.swift	
@@ -17,9 +17,7 @@ public class Renderer: NSObject, MTKViewDelegate {
     device = MTLCreateSystemDefaultDevice()
     queue = device!.makeCommandQueue()
     do {
-      guard let path = Bundle.main.path(forResource: "Shaders", ofType: "metal") else { fatalError() }
-      let input = try String(contentsOfFile: path, encoding: String.Encoding.utf8)
-      let library = try device.makeLibrary(source: input, options: nil)
+      let library = device.makeDefaultLibrary()!
       guard let kernel = library.makeFunction(name: "compute") else { fatalError() }
       pipelineState = try device.makeComputePipelineState(function: kernel)
     } catch {