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+# Chapter 11: Tesellation & Terrains 
+
+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 starter project
+
+You can more easily understand if you know the tessellation pipeline.
+
+![](./tessellation-pipeline.png)
+
+## Metal Performance Shaders
+
+There is the GPU hang issue on Xcode Version 13.3 (13E113). If you faced the GPU hang issue then add this before return a texture in heightToSlope(source:):
+
+```
+sleep(1)
+```
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  * [Chapter 8: Character Animation](https://github.com/daemyung/metal-by-tutorials/tree/main/08-character-animation)
  * [Chapter 9: The Scene Graph](https://github.com/daemyung/metal-by-tutorials/tree/main/09-scene-graph)
  * [Chapter 10: Fragment Post-Processing](https://github.com/daemyung/metal-by-tutorials/tree/main/10-trees-and-fog)
+ * [Chapter 11: Tessellation & Terrains](https://github.com/daemyung/metal-by-tutorials/tree/main/11-tesselation-and-terrains)
 
 ## Copyright