The simplest thing you can find in MEL are the commands.
Maya is build up by tons of commands. Every time
you do something in Maya at least one commands is executed,
mostly several. To figure out which commands
Maya executes you should turn on "echo all commands"
in the script editor. ( Script --> Echo all commands
Your number one sources when it comes to MEL are the scriptEditor
and the helpfiles. These are awsome.
Try creating a polygon sphere while you pay attention to
the history in the script editor. What you will see when
it is created is:
polySphere -r 1 -sx 20 -sy 20 -ax 0 1 0
-tx 2 -ch 1;
It returned a bunch of code here, but the essence is "polySphere".
All the other things here are flags and values. You see
a command is built up like this:
command [flags] [name]
The -r flag is the radius with a value 1 here and -sx and
-sy are divisions in those axes with values of 20.
Notice that the command polySphere does not have a name.
If you look in the helpfiles for polySphere you
see that this command actually does not have a name. ( you
can use the flag "name" to name the sphere,
but when I say name here I mean the ID at the end [name]
)If you are insecure, check the helpfiles. They are
If we look at the window command the helpfiles show us
window [flags] [windowName]
There are also different modes for the flags. "Create"
( which is default ) , "Edit", "Query"
and "Multiple use of
flag". I'm going to go through some of them in the following
If we take a look at the command window we can
add many flags, I'll use -width and -height
as an example.
//We're going to create a window with a
width of 100 and a height of 200.
window -width 100 -height 200 myWindow;
Now, what we did was create a window with a width of 100
and a height of 200. We also gave the window a
name, "myWindow" . This will ID the window later
like when we want to open it ( "showWindow myWindow")
You see, the window command doesn't show us the window,
it just creates it in the background. To actually
be able to see it, we have to tell Maya that we want to
see it by using the command showWindow. So
showWindow is another command you can look up in the
If we look at the command window again and check out the
flags we see that there's a flag called
"-widthHeight". You can also see that inside the
parantheses the short form for -withHeight is -wh. This
means that we can choose to write the long form or the short
form. There are disagreements whether you should use short
or long. Personally I like to use short ones because the
code will be shorter. On the other
hand the long name will be more explanatory. When I edit
scripts I tend to jump back and forth between
Maya and the helpfiles anyway...
Let's take another look at the window command:
//I want to know the width and the height
of a window.
window -q -wh myWindow;
If you look at the history in the scriptEditor you get
"result: 100 200". Of course we knew that, but
you can use
this for any window. If we scaled the window the result
would have been different. When we want to gather
information from a layout or other UI elements we have to
put it in "query"- mode. Say we wanted to get
label of a button we'd write:
button -q -l myButton;
Now, let's try and edit the window size. If you're paying
attention you'll know that we have to put the layout/
element in edit - mode. The code would look like this:
window -e -wh 150 100 myWindow;
Now we edited the size to a new value. Keep the window
open and change the values. You can see the window-
size change realtime.