虚幻头文件分析工具（UHT） 是支持UObject系统的自定义解析和代码生成工具。代码编译分两个阶段进行：
调用UHT。它将解析C++头文件中引擎相关类元数据，并生成自定义代码，以实现诸多UObject相关的功能。
调用普通C++编译器，以便对结果进行编译。
编译时，两个工具皆有可能出现错误，必须仔细检查。
Welcome to the new Unreal Engine 4 Documentation site!
We're working on lots of new features including a feedback system so you can tell us how we are doing. It's not quite ready for use in the wild yet, so head over to the Documentation Feedback forum to tell us about this page or call out any issues you are encountering in the meantime.
We'll be sure to let you know when the new system is up and running.