One of the great features of Houdini is its ability to combine its native hscript with almost any other scripting language, enabling the user to create interactive interfaces that talk directly to the software. In this article, we will take a look at one such example, exploring the process of using Tcl/Tk to build a 'light lister': a custom panel that will enable us to control each individual light in a scene at the flick of a button.
Before starting scripting, it's always a good idea to sketch out the design for an interface, and what features it should contain. There isn't space to go into this in detail here, but the finished script contains a full description of the feature set, to which you can refer.
Over the course of the article, we will start with a very simple core script, then build upon it. The scripts corresponding to each stage of the process are included on the CD, so if you want, you can copy them to your Houdini scripts directory (as explained below) and run them from there. However, it is a good idea to type each one from scratch. You will learn much faster this way.