Tuesday, February 9, 2010

MEL: Split A Joint / Bone Chain To A Specified Number Of Joints

Here's a procedure you can use in Maya to split a joint chain into multiple joints.

This proc requires jgArrToStr which you may recognize from yesterday's post. :)

Source them both first and then run it by typing:

jgSplitJointChain joint1 joint2 4 ;

(joint1 being the parent of the two.)
(4 being an example of how many joints you want to add.)

One note, currently it assumes y-up as your secondary axis orient. Maya doesn't let you query SAO so there's no way I know of to dynamically check what to use. Change it in the proc if it's not y-up in you're setup.


// **********************************************************
// Adds A Specified Number Of Joints Into A Chain
global proc jgSplitJointChain (string $parent, string $child, int $numJnts) {

// Adjustment For Math Purposes
$numJnts++ ;

// Checks
select -cl ;
if(!`joint -ex $parent`) error ($parent+" doesn't exist in scene or is not a joint.") ; // Does Parent Exist
if(!`joint -ex $child`) error ($child+" doesn't exist in scene or is not a joint.") ; // Does Child Exist
if(jgArrToStr(`listRelatives -p $child`, 0) != $parent) error ($parent+" is not the parent of "+$child+".") ; // Check Parent/Child Relationship

// Joint Positions
float $pPos[] = `joint -q -p $parent` ;
float $cPos[] = `joint -q -p $child` ;

// Parent Orientation
string $ro = `joint -q -roo $parent` ;
string $sao = "yup" ;

// Unparent Child
parent -w $child ;

// Vector
float $jointVector[] ;
$jointVector[0] = ($cPos[0]-$pPos[0])/$numJnts;
$jointVector[1] = ($cPos[1]-$pPos[1])/$numJnts;
$jointVector[2] = ($cPos[2]-$pPos[2])/$numJnts;

// Deselect All
select -cl ;

// Loop And Setup Joints
string $lastJntCreated = $parent ;
string $newJnts[] ;
for($i = 1; $i < $numJnts; $i++) {

// Create Joint
string $jnt = `joint -p ($pPos[0]+($i*$jointVector[0])) ($pPos[1]+($i*$jointVector[1])) ($pPos[2]+($i*$jointVector[2]))` ;

if($i == 1) parent $jnt $parent ;

// Set Last Created For Reference (Updates Until Last Iteration)
$lastJntCreated = $jnt ;

}

// Reparent End Joint
parent $child $lastJntCreated ;

// Orient Joints
joint -e -oj $ro -secondaryAxisOrient yup -ch -zso $parent ;

}

If you have any trouble using this or have questions/comments, send me a note!

5 comments:

  1. nice tool, I approached the split joint tool differently and used the insert joint tool to create new joints so that I could keep it as simple and fast as possible with out having to deal with all the vector math in mel.

    ReplyDelete
  2. Nice! I'm in the process of learning vector math so I was inclined to go this route as sort of practice. Seems to be working so far.

    ReplyDelete
  3. Cool, yeah always like to have a few ways to do something. I think I went the insert joint route because I the script I was fixing at the time was creating strange joint orient values once it added the new joints to the chain and I wanted the orient values to be left alone, and the insert joint method did that.
    Really nice blog Jay, good resource. thanks.

    ReplyDelete
  4. This comment has been removed by a blog administrator.

    ReplyDelete

Scripting Topics

MEL (41) Maya (39) Scripting (32) Scripts (21) programming (14) Free Mel Scripts (8) MaxScript (7) Coding (6) Rigging (5) tutorial (5) 3ds Max (4) Python (4) Tricks (4) faceware (4) image metrics (4) Learn (3) Namespace (3) Namespacing (3) animation (3) facial (3) webinar (3) Code (2) GDC (2) Game Developers Conference (2) Multiple Namespaces (2) Print Selected Objects (2) Recursive (2) Removing Namespace (2) Return (2) Set Driven Keys (2) TOkenize (2) Tips (2) Toggle Background Color with MEL (2) animation tools (2) animators resource (2) deformers (2) learning (2) maya tools (2) mesh (2) modeling (2) nodes (2) procedure (2) script swell (2) transforms (2) Animschool (1) Attribute (1) Background Color (1) Beer (1) Blur (1) Character Setup (1) Check if an object exists (1) Class (1) Command Line (1) Constraints (1) Create SDK (1) Create a directory with mel (1) Data (1) Export (1) FilterString (1) Fix (1) Floating Slider Time (1) Functions (1) Get Maya Version MEL (1) Get Parent (1) Google (1) Holiday (1) How To Write To A Text File (1) Import (1) Incremental Save (1) Index (1) Joint Chain (1) Make Set Driven Keys (1) Maya Version (1) Modules (1) Objects (1) Orient Constraint (1) PYMEL (1) Parent (1) Parent Constraint (1) Point Constraint (1) Position (1) Print (1) Print Current Selection (1) Print Random Quotes (1) Print Selection (1) Print Vertices (1) Progress Bar (1) Progress Window (1) PyQT (1) Removing Spaces From Names (1) Scene File Name (1) Select Connections (1) Select Outgoing Nodes (1) Split Bones (1) Split Joints (1) St. Patrick's Day (1) String Array (1) System (1) Transfer UVs (1) Viewport (1) White Space (1) Windows Username (1) Zero Out Attributes (1) animButtonState (1) arrays (1) articles (1) auto key (1) better (1) blendshapes (1) break (1) confirm dialog (1) continue (1) convention (1) e3 (1) efficiency (1) error (1) eval (1) executable (1) fclose (1) fopen (1) fprint (1) games (1) improving (1) infinite loop (1) joints (1) listHistory (1) listRelatives (1) logic (1) loops (1) milestone (1) nodeType (1) objExists (1) recursion (1) rotates (1) rotations (1) schools (1) sculpting (1) setAttr (1) shout outs (1) source (1) source a script with a variable (1) speed (1) tech-artists.org (1) translates (1) video (1) warning (1) world matrix (1) worldMatrix (1)
 
Script Swell - Blogged