Evergreen: Pass Python Variable to mel

[mputtkam]

Hi,

This is about passing python vars to mel using an externally sourced
python script in maya 2008:
Simplified example:

import maya.cmds as cmds
import maya.mel as mel

joints = []
for i in range(5):
joints.append(cmds.joint())

def test():
global tmp
for i in range(5):
tmp = joints[i] + '_sum_up_inputs_calc'
cmds.shadingNode('plusMinusAverage', asUtility = 1, name =
tmp)
mel.eval('string $tmp = python("tmp")')
mel.eval('AEnewNonNumericMultiAddNewItem($tmp, "input3D");')
test()

Paste it in Maya. It should work. At least it does for me. However, it
does not work for me, when I source it via the usual import/reload
procedure using an external .py. Maya will then read: "Tmp not
defined".

I do not get it. I go crazy over it, because it does not make sense.
Paste directly, works. Source externally, does not. I tried putting
global tmp all over the place, but that did not help either. If I
source the script twice, the previously errored utility will suddenly
have four(!) inputs, while the other new ones will not have any.
That's weird for sure. I do not know what else to try to get this
working...

Help is much appreciated.
Martin

Thanks,
Martin

[Chad Dombrova]

it must have to do with what scope the "python" mel command is run
in. the most straightforward solution is to format the eval'd mel
string with the variable value:

mel.eval('AEnewNonNumericMultiAddNewItem("%s", "input3D");' % tmp )


alternately, if you're using pymel, you can just pass the value as if
it were a python script:

pymel.mel.AEnewNonNumericMultiAddNewItem( tmp, 'input3D' )

pymel will save you a lot of formatting head-ache when you start
passing string arrays, vectors, etc.

-chad

[Martin Puttkammer]

Hi Chad,

Thanks indeed, this saved me long hours this night.

Have a nice day,
Martin


2009/5/8, Chad Dombrova <cha...@gmail.com>: