In MEL, trying to create a group, if that group already exists delete it.

malcolm

I can't get this working, if I remove the break the script works, but it creates too many erroneous groups, with the break in there it creates a single group, but then when I run the script again it ignores the if statement? Any idea what I'm doing wrong?

string $transforms[] = `ls -tr`;

for ($t in $transforms)
{
    if ($t == "null1")
    {
        delete $t;
        print "Deleted group.";
    }
   
    else
    {
        CreateEmptyGroup;
        print "Created group.";
        break;
    }
}

sprunghunt

It's a bit hard to tell what's going wrong without seeing what the file your running this on looks like

To help with the debug you could make your print statement print the $t variable so you can see what it's doing when it creates the group. 

malcolm

Thanks for your reply, the file is an empty scene, we were able to figure out my problem. Here is the code that works, I needed to put a switch in there to test the if statement and set it to true or false, would be nice if you could use operators like ! on strings, but whatever this works now.

int $switch = 0;

string $transforms[] = `ls -tr`;

for ($t in $transforms)

{

    if($t == "null1")

    {

        delete $t;

        $switch = 1;

        print "Delete.";

        break;

    }

}

 

if($switch == 0)

{

    CreateEmptyGroup;

    print "Created.";

}

sprunghunt

you could try using gmatch, strcmp, or match instead of the == operator 

if you use one of the string comparison functions it can handle that a bit more robustly.

https://download.autodesk.com/global/docs/maya2014/en_us/Commands/gmatch.html
https://download.autodesk.com/global/docs/maya2014/en_us/Commands/strcmp.html
https://download.autodesk.com/global/docs/maya2014/en_us/Commands/match.html 

for example this is the same as using != :

if ((`strcmp $t "null1"`) == 1){<br><br>}

malcolm

Oh very cool, I didn't know there were ways to use the ==1 with a string.