Learning Notes - Python and Mel

MIT Leactures - Python Scripting
Book - Learning Python

I've played with Mel, (Maya embeded language), on and off over the years but, to be honest, I never dug deeply into it. I can't figure out why - would have made life so much easier. I'm thoroughly enjoying the process of learning Mel and python at the moment. It's so very addictive.... and helpful :)

Here is a few of the basics in mel...

Data types

Integers

          int $areWholeNumbers = `##`

Floats

          float $areFractions = `##`

Vectors

          vector $areX,Y,ZPositions = <<X,Y,Z>>

Array

          $##[starts at 0]

Conditional  Statements for mel

<: - less then, >: - greater then, == - equal to: != - not equal to, >= - greater or equal to: <= - less or equal to ?: -if else && -logical and || -logical or  +,- -plus,minus ^ -vector cross product / -divide * -multiply % -modulo ++, -- -increment,decrement by 1 ! -not

  Loops/Iterantion in Mel

While-Loops

    example;

          int $x =0;

          while ($x <10)

          {

                      $x =$x+1;
             print ($x + "\n");

          }

For-Loops   (loop start)   (loop end)   (increment)

    example;

          for ($t=0; $t<6; $t=$t+1)

          {

                       joint -name ("naths_" + "_jnt");

          }

For-In-Loops

    example

     select bob;

          string $bobsInHere[] =`ls -sl`;

          for ($allBobsAtributes in $bobsInHere)

          {

                    string $bobsAtributes[] = `listAttr -write $allBobsAtributes`;

                   for ($bobsWritable in $bobsAtributes)

                    {

                              print ($bobsWritable + " is a writable attribute of bobs" +"\n");

                    }

          }


Do-While Loop 
   int $t = 1;
        do 
{
    $t += 3;
print ($t + "\n");
}
 while ($t <= 10);

Special Characters of note

\ =escape,

\n = newline,

/t = tab,

 \r = carriage return

Procedures

An example is a global procedure. The procedure is called from memory with the bottom line and arguments are given for width, height, depth and name.

Example;

  global proc nathansCubeIT (float $width, float $height, float $depth, string $name)

     {

          polyCube -width $width -height $height -depth $depth -name $name;

     }

                                      nathansCubeIT 5 6 4 nathCube;