MEL

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MEL

• Scripting Overview

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MEL commands

• Maya help -gt MEL command reference
• MEL command line
• Script editor
• Icon
• Window-gtGeneral Editors-gtScript editor

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Script editor

• Type in commands
• Shelf button highlight, cmd-click, drag
• Script file File-gtsource script

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Attributes
sphere listAttr nurbsSphere1 getAttr
nurbsSphere1.tx setAttr nurbsSphere1.translateY
10 aliasAttr up nurbsSphere1.ty setAttr
nurbsSphere1.up
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Simple Example

• For (j0 jlt10j)
• sphere
• move r 0 j 0

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Example
// arrayOfSpheres.mel // shows simple nested
'for' loops to create objects for (i0 ilt10
i) for (j0 jlt10 j)
sphere move -r i j 0
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Example
// simpleKeyframes.mel // shows // setting
object attributes (x and y translation in this
case) // how to set the special currentTime
variable // setting keyframes // the animation
can then be played back sphere -name ball
currentTime 0 SetKey currentTime 50
setAttr ball.translateX 10 SetKey
currentTime 100 setAttr ball.translateY 10
SetKey currentTime 150 setAttr
ball.translateX 0 SetKey currentTime 200
setAttr ball.translateY 0 SetKey
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Example
// from www.robthebloke.org/mel/DATA_mesh.html
polyCube -name myObj mesh "myObj" float
vert int vertexCount polyEvaluate -v
myObj print ("number of vertices "
vertexCount0 "\n") for(i0iltvertexCoun
t0i) // get world space vertex
coords vert xform -ws -q -t
mesh.vti // mesh.vtxi ltlt
vert0, vert1, vert2 gtgt print(
vert0 " " vert1 " " vert2 "\n"
)
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Animation expressions

• expression -s "nurbsSphere1.tx sin(time)"

Manipulate time slider (or hit play) to move
object
Window-gtAnimation Editors-gtExpression Editor
Maya-gtHelp Search on MEL Differences between
expression and MEL syntax
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Animation expressions
// http//www.fundza.com/melquickref2/expression1
// NOTE spherè returns 2 strings. thats why
obj is an array // and why obj0 is used in
the expression string exp "" string
obj int i for (i0ilt3i) obj
sphere move (rand(-3,3)) (rand(-3,3))
(rand(-3,3)) exp "select -r " obj0
"\n" "move -moveY (rand(0,2))\n" exp
"select -clear\n" expression -s exp -ae
1 playbackOptions -min 1 -max 30 play