Hopefully this document should provide a fairly good resource to answer most questions that commonly arise from anyone first learning mel.

DG, DAG, History, and Undo

Script Editor Basics

10 lines of script to access the world

So we have our data stored, now it's time to start asking questions and repeating actions.

When developing mel scripts you will often want ways of simplifying the task at hand. Often you may use a procedure or seperate script files to improve the readability and to simplify the code. You may also want to run external programs or other scripts. This section deals with all of that....

The main reason to have a scripting language in Maya is so that we can control our scenes in a flexible way. This obviously means that we must be able to find out what objects are present in our scene, and be able to set and get attributes on those objects.

The best part about mel is the ease with which you can create User Interfaces. Generally speaking it's always nice to provide a graphical means of driving your mel scripts. Often this involves responding to a user input event by calling a pre-defined mel procedure.

Expressions within Maya allow you to create small scripts that can be attached to a specific attribute to control it's value. These are known as Expressions. You can either use the Expression Editor to create them, or you can use the expression mel command.

The syntax of an expression is not exactly the same as that of mel, so you should bear that in mind whenever working with expressions.

Being able to load and save files from within mel allows you many possibilities such as, data caching, data import export etc.

These sets of notes are designed to demonstrate methods to access specific data types within mel. They do very little other than showing you the basics of how to create the node types, and also how to access the data they contain.

I've directly cross-referenced the mel notes here with the sections from the Maya Exporter Factfile. Basically, all [API] links demostrate accessing the same data from the Maya API. (just thought it might be useful for someone).

During the course of developing a script you will always have a problem of persistant data storage. Often values are stored in global variables, however the problem is that the values stored will vanish when either the script is run again, or maya is re-started. Loosely speaking, persistant data falls into 2 catagories.