#programming 1

Global Procs.  - Can be seen anywhere.  - Can be stored on hard disk (script directory). Done simply by selecting the whole script and save it in the script folder / directory. This saves it to maya's scripts so now you don't ever have to create the script again. You'll just have to run it (do this by typing the name of the script into the mel bar at the bottom eg: rapidRename)

Rename exercise. (take snippet of)

SymbolButton.  - Allows us to use an image as a button (gifs / pngs).

GridLayout.  - Determines the number of columns and cellWidthHeight.

Global Procs:  - Can be seen anywhere  - Can be stored on your hard disk (in the script directory). This saves it to Maya's scripts so now you don't ever have to create the script again, all you have to do is run it - type the name of the script, eg: rapidRename into the Mel bar at the bottom. 

Symbol Button: Allows us to use an image as a button (gifs and pngs work well) :) 

Creating a script for listing lights.

Proc: Own custom command.

Eg: 

proc daysToHours (float $days) //argument

{

      print ($days*12) //hours in a day

}

daysToHours (1.0) //argument

So here, we create our proc and state an argument. Print is returning the argument value x 12.  Now we can print the proc with the number of values (1.0) and it will return the correct hours to the respected days input.

Maya Scribble:

M flag = can be used more than once in the command.

Environmental variables.  When we run programs from the exec cmd raw path finder - programs such as calculator are a default program and are placed in the environmental variable of the pc.  Eg: photoshot is not, paint and calculators are.

For programs like photoshop, you have to know the absolute path of the program (can be found in the program properties). Remember to swap all the backward slashes to forward slashes though.

Week 3 moodle notes:

if (`window -exists tmpWin`) deleteUI -window tmpWin;                    //If this is true it will delete the window.

If you run just this: `window -exists tmpWin`;  It will check if you've already run the code and if 'TmpWin' is already in the ram. If this is true is will return a 1. 

Command properties.  Allows us to run Mel Commands if in different modes.  - Create mode.  - Edit mode.  - Query mode. 

Go to the 'command documentation' to see the different modes. 

To see query mode:

textField -query -text myTxtFld;

To see create mode: (default)

textField -text myTxtFld;

To see edit mode (to edit the output).

textField -edit -text "Ted" myTxtFld;

To change geo: Linear: 

xform -translation 0 2 3.2

xform -scale 2 2 4 (xyz)

Proc = procedure = multiple commands. Eg: 

proc MakeMyBall()

{

sphere; xform -translation 0 2 3.3 xform -scale 2 2 4;

}

You'll notice that if we run this it doesn't create the ball or 'sphere' straight up. It's just creating the proc in the ram.  To make it appear, all we have to do is write: MakeMyBall;

LS Command. - Populates lists in various catagories based upon flags used.  A LS is a string[] (so a string array).

This is important because we can use the LS in conjunction with the selection flag to fetch a list of the currently selected items. 

Select Command.  Selects all items.  Eg: Select -cl

This is to deselect

What is an 'if' statement?

The If statement alternatively referred to as a conditional expression or a conditional statement is a statement that checks if a predetermined / defined condition is true or false. 

Some modern programming languages allow different data types to be stored in lists and arrays (sequences). These are broken down into two distinctive catagories:  1. Homogenous. 2. Heterogenous.  MEL can only support the homogenous approach which must contain the same type of data (eg: ALL string).  Heterogeneous: can include different types of data.

Operator Precedence. Operators are '+' '-' and '*' Note: You always have to wrap equations in normal brackets. [like normal maths, you have to use brackets to create a specific order of operations].

Creating 'if' statements.

Eg: if ( 8 == 8 ) { print "yes this is true" }

Double >> arrows will run everything in the complete script and will never remove it as it does so.  Single > arrows will delete your whole script if you have nothing selected. Be very careful, only use the single key if you want to run just a selection of code. 

'Else' statements are very much like 'if' statements. They both need the curly brackets.  Eg:  if ( 6 > 8 ) { print "yes this is true" }  else { print "no this is not true" }

You can also stack if statements - to create a really complex elimination sequence. 

Your basic syntax for an 'if and else' statement of code is this: if ( // condition ) {     // if true } else // condition {     // if false }

Loops.  A loop is a sequence of instructions that is continuously repeated until a certain condition is reached. 

'For loop example' is the most common, easily used method.

'While loop'  - Uses the same syntax as the 'if' statement.  Eg: while ( 6 < 10 ) { print "something" } -Now because 6 is always less than 10, it continuously tests Maya for this. This will crash Maya badly. D: 

$counter = counts the number of loops. 

"++" '$counter++' This means to '+1'. It adds to the existing value. They are both the same, '++' just uses less code. 

'For loop' example. For ($i = 0; $i < 10; $i ++) //initialise counter ; set max ; add 1. { print ("Hello World!" + $i + "/n"); // print Hello World! and add the current iteration value.  }

$ - the dollar sign assigns something as a variable within the text. 

You can also look up mel commands under the help files.  Linear = a float in world space. 

Making stairs example float $stairWidth = 10; float $stairHeight = 1; float $stairDepth = 1; int $stairAmount = 25;

Make sure you declare these before you keep going with the coding.  The spaces and clear labels allow for effective readability.

Now...  for ($i = 0; $i < $stairAmount; $i ++) { polyCube -w $stairWidth -h $stairHeight -d $stairDepth -n "step#"

xform -translation 0 ($stairHeight * $i) ($stairDepth * $i); }

window -tile "stair master"; columnLayout; floatfieldGrp -numberOfFields 1 -lable "stairWidth";