Melscript Attr toggle help

[Anonymous]

Hello! Im a bit new to melscript. I'm trying to create a script that will toggle the IK/FK attribute on a controller. I have it working before the "else" command but I cant seem to figure out how to get it to toggle 1 to zero in the second half. 

select -r samus_RIG:C_IkSpinehipCtrl ;

if ( "samus_RIG:C_IkSpinehipCtrl.toFkSpine" == 0 );

{

setAttr "samus_RIG:C_IkSpinehipCtrl.toFkSpine" 1;

}

else

{

setAttr "samus_RIG:C_IkSpinehipCtrl.toFkSpine" 0;

}

select -cl ;

[lee.dunham · Accepted solution]

You'll want to look at the usage of ! in mel scripts.

setAttr "pCube1.visibility" (!`getAttr "pCube1.visibility"`);

[mcw0 · Accepted solution]

If it's a true toggle you want, you only need the following...

1 - `getAttr samus_RIG:C_IkSpinehipCtrl.toFkSpine`;

[lee.dunham]

Possible to clarify what you mean by a "true toggle"?

[mspeer · Accepted solution]

Hi!

@Anonymous in case you are confused by these 2 complete different examples, that's because you can set boolean values by numbers (0 or 1) or by using a state (false or true).

So all of this is valid (example for cube visibility):

setAttr pCube1.visibility 0;
setAttr pCube1.visibility 1;
setAttr pCube1.visibility false;
setAttr pCube1.visibility true;

The example from @lee.dunham works by negating the true or false state (NOT ...).

Try both:

print (! true);
print (! false);

The example from @mcw0 works by using a simple mathematical calculation (1 - ...).

Try both:

print (1 - 1);
print (1 - 0);

[lee.dunham]

Worth pointing out that using as the not operator returns an integer (0/1), it can be used for most numerical attributes (int, float etc).

setAttr "samus_RIG:C_IkSpinehipCtrl.toFkSpine" (!`getAttr "samus_RIG:C_IkSpinehipCtrl.toFkSpine"`); 

Due to its behaviour, its usually easier to read from context that it will be 0/1, on/off, true/false.

[mcw0]

Lee,

I didn't see your response when I typed mine.  I only saw the post.  And in the original post, it was doing a setAttr of a value.  By "true toggle", I meant like a switch.  If it's 1, then flip it to 0.  And vice versa.  The conditional does that but with more lines of code.

I was unfamiliar with your usage of "!" so I've learned something new.  Thank you.

[hannah.novotny]

Thank you guys so much! I'm sorry for the delayed response, I'm mostly on my work computer during the week, but I'll try to test these out soon! 

[Dautryl]

Hi!
First of all, sorry for the digging and thank you for that solution, I have been using it for a while now.

I am trying to transition from MEL to Python, I can't find a way to make that one work... Anyone knows how to do it?

My progression so far:

import maya.cmds as cmds

attrList = [
    "myObject.holdOut",
    "myOtherObject.holdOut"
    ]

for i in attrList:
    cmds.setAttr(attrList, cmds.getAttr(not attrList))

Which result in `error line 9: No object matches name: False`

So it really is getting the boolean toggle mixed with cmds syntax that puts me int.

[lee.dunham]

for attr in attrList:
    cmds.setAttr(attr, not cmds.getAttr(attr))

You needed to use the iterated attr and invert the getAttr result 😉

[Dautryl]

Awesome! Thanks!!! 😊

[triffski]

Lovely stuff! 🙂