Summerize Chapter 9: The Scene Graph

09-scene-graph/README.md

@@ -0,0 +1,39 @@
+# Chapter 9: The Scene Graph
+
+As I read this book, I summarize what I think is wrong. If you think my comments are wrong then please let me know. We can dicuss more and update your opinion.
+
+## The scene graph
+
+* You can also remove the light when you cleanup your code. In `Scene.swift`, add this:
+
+```
+var lighting = Lighting()
+```
+
+In `Renderer.swift`, in `func draw(in view: MTKView)`, replace:
+
+```
+var lights = lighting.lights
+```
+
+With:
+
+```
+var lights = scene.lighting.lights
+```
+
+* If you remove a camera in 'Renderer', you need to update `override func scrollWheel(with event: NSEvent)` in `ViewControllerExtension.swift`, replace:
+
+```
+override func scrollWheel(with event: NSEvent) {
+  renderer?.camera.zoom(delta: Float(event.deltaY))
+}
+```
+
+With:
+
+```
+override func scrollWheel(with event: NSEvent) {
+  renderer?.scene?.camera.zoom(delta: Float(event.deltaY))
+}
+```

README.md

@@ -23,6 +23,7 @@ You can see color images in this book at [here](https://www.raywenderlich.com/bo
  * [Chapter 5: Lighting Fundamentals](https://github.com/daemyung/MetalByTutorials/tree/main/05-lighting-fundamentals)
  * [Chapter 6: Textures](https://github.com/daemyung/MetalByTutorials/tree/main/06-textures)
  * [Chapter 8: Character Animation](https://github.com/daemyung/MetalByTutorials/tree/main/08-character-animation)
+ * [Chapter 9: The Scene Graph](https://github.com/daemyung/MetalByTutorials/tree/main/09-scene-graph)
 
 ## Copyright