MEL: Remove Namespaces From A String or Object Name

Dealing with namespaces is a pain in the ass. Period.

Veteran TD's and Maya guys will tell you how easy it is and that there are so many ways to deal with them and this and that. They are correct. However, they are still a giant, giant pain in the ass.

Thankfully there's a simple trick to remove namespaces from using the tokenize MEL command.

What tokenize does is split a string into multiple parts using a character(s) as the splitting point. For example, if an object is named this_Object if you were to tokenize it and split it using the character "_" than you would end up with two tokens: "this" and "Object".

We know that if an object has a namespace, or in some cases multiple namespaces that the object name will always be prefixed with the namespace and a colon. (:)

So, let's tokenize it out using a colon.

string $objectName = "Character:r_arm_CTRL" ; // Our Object Name
string $buffer[] ; // Create Empty Array To Hold Tokens
tokenize $objectName ":" $buffer ; // Split $objectName by ":"

// Now...
string $namespace = $buffer[0] ; // "Character"
string $object = $buffer[1] ; // "r_arm_CTRL"

With this example we've done a basic namespace removal. However, this is prone to errors for multiple reasons. What if you have multiple namespaces? By hardcoding which index you're getting from $buffer you will end up potentially grabbing the wrong data. A way around this is to use a programming trick to always grab the very last item in an array. As with namespaces, we always know the last item will be the object itself so we'll end up with the correct string.

string $objectName = "Character:r_arm_CTRL" ;
string $buffer[] ;
tokenize $objectName ":" $buffer ;

string $objectWithoutNamespace = $buffer[size($buffer)-1] ;

By getting the size of the array, and subtracting one, you'll end up with the last index of a zero-based array. If it were Maxscript, arrays are one-based (they start with one, not zero) so you wouldn't need to subtract one from the size.

(If you're curious, the equivalent of tokenize in Maxscript is filterString)

So there you are, a quick, easy, non-dirty way of getting rid of namespaces in an object's name.

MEL: Working With Multiple Level Namespaces

I learned a great trick today concerning Maya scenes with objects that have multiple levels of namespaces.

Namespaces in general are a bit difficult to work with as they tend to break scripts if you don't constantly check for them, so this trick is a simple and very useful way to check for them and prevent errors.

Let's say you have an object you want to select called, "r_hand_CTRL". You want to select it, but you need to test for namespaces because it might actually be named "Char:r_hand_CTRL" in your Maya scene. Or for more fun let's say it's named, "Post:Char:r_hand_CTRL".

Selecting r_hand_CTRL isn't going to work as it doesn't exist if it's prefixed with namespaces, so we have to search for what the namespaces are. Maya's namespace MEL commands are annoying and difficult to use. So here is a trick.

// Define Control
string $ctrl = "r_hand_CTRL" ;

// This int is used below to prevent an infinite loop
int $i = 0 ;

// Loop until it finds all the namespaces
// Stop at ten if it still can't find it
// Hopefully you don't have more than ten recursive namespaces
// May the Gods help you if you do.

// Check forever until the object exists, or $i = 10
while(!`objExists $ctrl` || $i == 10) {

  // Append *: until it can find the object
  $ctrl = ("*:"+$ctrl) ;

  // Increment $i so we don't do this infinitely
  $i++ ;

}

// Note:  You could also use a FOR loop.  But I didn't here.

// Now that we know $ctrl exists, we can do whatever we want with it
select -r $ctrl ;

I've already used this trick like forty times, it's awesome. Enjoy!

Edit: Since learning this, people have mentioned that you can just use the following command to find your object:

ls -recursive 1 "myObject" ;

Quite handy, and much more useful than what we worked on above! I wish I had the entire MEL docs memorized.... :)