MEL script help getting my toggle boolean statement to work in a global proc?

malcolm · Sep 2018

Hi, so I created this code which executes fine in the script edtior, it toggles the checker map on/off each time you run the script in the UV editor.

//This works fine
int $uvToggleChecker = !$uvToggleChecker;
if ($uvToggleChecker == 1)
{
print ("UV checker map turned on.");
}

else if ($uvToggleChecker == 0)
{
print ("UV checker map turned off.");
}

Buuuuut, when I run this exact same script in my MEL GUI it always returns true and won't toggle? What gives, I must be missing some secret formatting or something?

//This always returns true which is the exact same code in a window
global proc button20UVmapper ()
{
int $uvToggleChecker = !$uvToggleChecker;
if ($uvToggleChecker == 1)
{
print ("UV checker map turned on.");
}

else if ($uvToggleChecker == 0)
{
print ("UV checker map turned off.");
}
}

if (`window -exists TestWindow`)
{
deleteUI TestWindow;
};
window -title "" -toolbox true -sizeable true -resizeToFitChildren true TestWindow;
columnLayout -adjustableColumn true;
button -bgc 0.51 0.51 0.51 -width 60 -label "checker toggle" -command "button20UVmapper";

showWindow;

bitinn · Sep 2018

you need to understand the scope of a variable. in a proc the variable is local, thus you always initialized it with the same value. you need a global variable to remember the state.

also good to understand variable declaration, which answers your problem with previous thread, you were declaring it twice.

sprunghunt · Sep 2018

a better way to do this would be to check if the UV checker is turned on or off and toggle it based off that - and not use a boolean at all.

you can read the state of the checker map by querying the UI like this:

int $checkerState = ` textureWindow -q -displayCheckered polyTexturePlacementPanel1`;

then you can use the variable $checkerState to switch your if statements

https://help.autodesk.com/cloudhelp/2016/CHS/Maya-Tech-Docs/Commands/textureWindow.html

like this:

global proc button20UVmapper ()
{
    int $checkerState = ` textureWindow -q -displayCheckered polyTexturePlacementPanel1`;

    if ($checkerState == 1)
    {
        textureWindow -e -displayCheckered 0 polyTexturePlacementPanel1;
    }
    
    else if ($checkerState == 0)
    {
        textureWindow -e -displayCheckered 1 polyTexturePlacementPanel1;
    }
    
};

<br>

malcolm · Sep 2018

Thanks guys, I'm just learning MEL so I don't really understand the rules yet and I'm not a programmer this is my first programming language. Global variable was the problem, and I'll also check out if I can query the panels as suggested as that would be a bit cleaner, I'll post back if I can't get the panels working on my own.
Here is the code that works with the global variable in a generic sense.

global proc button20UVmapper ()

{

global int $uvToggleChecker;

$uvToggleChecker = !$uvToggleChecker;

if ($uvToggleChecker == 1)

{

print ("UV checker map turned on.");

}

else if ($uvToggleChecker == 0)

{

print ("UV checker map turned off.");

}

if (`window -exists TestWindow`)

{

deleteUI TestWindow;

};

window -title "" -toolbox true -sizeable true -resizeToFitChildren true TestWindow;

columnLayout -adjustableColumn true;

button -bgc 0.51 0.51 0.51 -width 60 -label "checker toggle" -command "button20UVmapper";

showWindow;

MEL script help getting my toggle boolean statement to work in a global proc?

Replies