Editor displays a running history of executed commands
and the results of commands that Maya executes. You can copy most
commands from the history section of the Script Editor and
paste them in the input section to execute them.
To set up the Script Editor
> General Editors > Script Editor.
Editor window opens.
The lower half of the Script
Editor is the input section where you enter scripting
By default, Maya displays
basic feedback from executed commands. However, when Echo
All Commands is on, Maya shows all the history from a
command, including when a script calls another script or modifies
elements of the user interface. While learning MEL, the extra lines
of output produced when Echo All Commands is
on can be confusing because there is so much output. As you become
more experienced in MEL, the extra lines of history can be useful
for debugging a MEL script.
- In the Script Editor window,
ensure that there is not a check mark beside History
> Echo All Commands.
To observe script history
- In the Script Editor,
click the Clear History button.
You can more easily isolate
the command history created by the commands you perform when there
is no other history in the Script Editor.
- From the Shelf, select
the Surfaces tab in order to view
the tools located on that shelf.
- Click the NURBS Sphere button on the Surfaces
Command history is displayed
in the history section of the Script Editor:
sphere -p 0 0 0 -ax 0 1 0 -ssw 0 -esw 360 -r 1 -d 3 -ut 0 -tol 0.01 -s 8 -nsp 4 -ch 1;objectMoveCommand;
Several MEL commands
are executed when the Shelf button is pressed. The following happens
when the button is pressed:
- The NURBS Sphere button on the surfaces Shelf executes
a script called CreateNURBSSphere;.
- The CreateNURBSSphere script
calls the sphere MEL command
using flags to set the arguments of the command to the values currently
specified in the NURBS Sphere menu option window. The sphere MEL command is using flags in
- The objectMoveCommand is
executed every time a primitive is created. It moves the created
object to the origin.
Commands in MEL must
be separated with semicolons. Additional spaces and additional carriage
returns do not affect the execution of the scripts. Blank spaces
and returns make scripts easier to read. Flags cannot be separated
from the hyphen character by extra spaces or returns.
For more details
on these flags, see sphere
in the MEL
Command Reference gives a complete listing of the functionality
of all MEL commands and flags.
NoteYou can copy commands
from the Script Editor history section
and paste them in the input section to execute them.
- Delete the NURBS sphere by pressing the
delete key on your keyboard.
To type a MEL command in the Script
- Select a MEL tab in the Script
Editor tabs allow you to quickly switch between MEL and
Python script entry modes. You can create additional Script Editor
tabs to serve as a temporary holding area for scripts.
- Type the following command in the input
section of the Script Editor.
TipWhen asked to type
a command, you can copy it from these tutorials and paste it into
the Script Editor input section.
- Execute the command by pressing on the
numeric part of your keyboard.
You must always type on the
numeric keypad or + (the
regular Enter on your keyboard) to execute commands. Typing regular just
creates a new line in the Script Editor input.
A polygonal cube is created
at the origin.
The command is removed
from the input section of the Script Editor after execution.
The command and the result of the command is output to the history
section of the Script Editor:
Result: pCube1 polyCube1 //
NoteIn future lessons,
when a series of MEL or Python commands creates output, only the
output created by the commands will be referred to as output to
the Script Editor.
Comments in MEL begin
with // and anything which follows these characters on a line is
ignored by MEL. The same convention is used for displaying results
of commands and output in the Script Editor history section. Similarly,
results, comments and messages output by Python are prefaced with the
Python commenting character ( # ).
In the rest of this
lesson and the remaining MEL lessons, when asked to type a command,
execute the command after typing it with the Enter on the numeric
keypad on your keyboard. You can also execute commands with
TipIf you do not want
the command to be removed from the input section of the Script
Editor after execution, highlight the command before
execution by selecting it with the mouse.