Houdini VEX和Python编程教程 Introduction to Houdini VEX and Python

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Houdini VEX+Python编程优势和区别 FXPHD – HOU217 – Introduction to Houdini VEX and Python. TAUGHT BY JERONIMO MAGGI. 讲解Houdini基础的VEX表达式和Python编程，着重研究他的优缺点，在特效场景中的应用。学习VEX和Python语言的基础知识，以及如何使用Houdini的Python API，学习在什么情况下如何优先选择VEX或Python，学习VEX与VEXpressions之间的差异以及如何在SOP和DOP中使用它来优化系统，将使用Python处理节点，读取Houdini中的大数据集，创建从太空夜间观察一个国家的城市灯光的渲染效果，还有角色模型消失变成粒子的灰飞烟灭的特效。

This course covers the basics of VEX, Houdini’s expression language, as well as how to use Houdini’s Python API. We will look at the strengths and weaknesses and when you should favour one or the other. VEX is an essential tool for any technical director, so we will cover all the basics starting from its syntax, the difference between VEX and VEXpressions and how it can be used in SOPs and DOPs to optimize your systems. Later on, we will take a look at some more advanced examples like point cloud lookups and matrix transformations for dealing with deforming characters and finally creating a dissolve effect purely using VEX. Basic knowledge of Python and understanding of object-oriented programming is recommended as the whole Python component is completely concentrated on how Python works in Houdini and understanding the Houdini Object Model. In this part, we will go over manipulating nodes, parameters and geometry using Python, as well as reading a big data set in Houdini to create a render of a country’s city lights seen during the night from space. In the final exercise, we will create a shelf tool that will gather every Geometry ROP in the scene, create Fetch ROP for each one of them, and finally merge them together to have a convenient way to cache all the geometry.