scSaveWeights for export/importing skinCluster weights in Maya

I have written an useful Maya python API plugin which exports out weights from polygon mesh or vertices to text file(optionally binary),Which can be used later.
This process is mostly useful when User wish to change position of joints in a rig with skinCluster , or just want to update rig file with latest weights from other file.
I have in past used Michael comets famous Mel script cometSaveWeights, which works great but is very slow when importing weights on dense mesh.

It was my first attempt at writing something in Maya API. Attached in plugin which I have tested on Maya 2008 to 2011.

Mel Command to export weights
scSaveWeights -roundOff 5 -action “export” -file “d:/weights.txt”;

Mel Command to import weights
scSaveWeights -action “import” -file “d:/weights.txt;


Go to windows>Settings/prefrence > plug-in manager and browse to the
I would suggest to open the py file in IDE and read through comments in the beginning of  script.

Exporting weights on polygon mesh with vertex count 12432 skinned with 255 joints took 7.6378 seconds
whereas Importing took 66.3445147672 seconds and in quick mode it takes 19.937 seconds while exporting
and takes 7.5559 seconds while importing.

Importing weights with cometSaveWeights.mel took more than 7 minutes on same Mesh. 

edit: updated script to work with selected polygon object and in component mode, while importing weights.

cometSaveWeights.mel for maya2011

Well nothing to say much, if you’re into maya rigging you can’t possibly haven’t came across cometTools. I’m a big fan of Michael comet and his tools specially PSD and his mel script.I noticed cometSaveWeights.mel is not working exactly as it has to be on maya 2011, as Autodesk have done some changes to mel commands, I have attached edited version of script which works very well on 2011.

check for yourself Download here

Edit: Enable normalize weights before you save weights in maya 2011,
“;” was missing in some line, that is fixed now.

Auto rotation for carTyre, Wheel in maya

I recently worked on creating solution for wheel auto rotations inside maya. Well I searched a lot for finding adequate solution but some lacks a thing or two.
most commonly used solution are rotating the wheel based on translation X & Z with circumference of wheel , which is working fine but gives error when controller
is rotated in reverse direction( 180° or more). Another solution I found is to use Infinite animCurve and attach it with multiplier and manually animating it!

A guy named darvy has created a set of vehicle rigging scripts I found above method nicely implemented in there.

I find one tricky way to calculate auto rotations without worrying about rotations and direction where our rig is going. In brief I wrote expression which finds direction magnitude
where our wheel is going (forward or back). Also expression calculate the distance covered by wheel between last frame and current and calculate distance using circumference (2 π r)


float $radius =1;
int $dirVec;
// get Joint translation value for calculating direction vector.
float $pastValX = `getAttr -time (frame -1) basePos_jnt.tx`;

float $pastValZ = `getAttr -time (frame -1)`;

// Now compare the difference of tip joint with base joint and basejoint’s previous frame

float $currPosX = tipPos_jnt.translateX – basePos_jnt.translateX;
float $currPosZ = tipPos_jnt.translateZ – basePos_jnt.translateZ;

// with past

float $pastPosX = tipPos_jnt.translateX – $pastValX;
float $pastPosZ = tipPos_jnt.translateZ – $pastValZ;

// now calculate the magnitude

float $currMag = `mag << $currPosX,0,$currPosZ>>`;
float $pastMag = `mag << $pastPosX,0,$pastPosZ>>`;

if ($pastMag >= $currMag) $dirVec = 1;

else $dirVec = -1;

// get controls translation value for actual calculations.

float $pastCtrValX = `getAttr -time (frame -1) placement_ctr.tx`;
float $pastCtrValZ = `getAttr -time (frame -1)`;

float $currDistX = placement_ctr.translateX – $pastCtrValX;

float $currDistZ = placement_ctr.translateZ – $pastCtrValZ;

float $distance = ($currDistX*$currDistX) + ($currDistZ*$currDistZ);

$distance = sqrt($distance);

// finding distance by dividing into circumfrence

float $rotation = $distance /(2* 3.1428*$radius) *-360 * $dirVec;
$rotation += tyreRot.rotateX;

tyreRot.rotateX = $rotation %360;

sample sceneFile

Saving skinWeights for massive from maya (scMassiveSkin.mel)

Some time ago I wrote a MEL script for saving out skinWeights for massive from maya skinCluster. Script writes out weight is massive’s native format (.w file extension).
Massive is crowd simulation software and is used for giving artificial intelligence to crowds and make them believable. Its common practice to skin character inside maya and take out skeleton ,mesh (as obj) inside massive for doing crowd sim. But we have to either skin it again inside massive which is defiantly not very intuitive or import weights from maya. So this script makes this task easier by writing out weights in separate file from maya itself.


Discovering PyMEL

Yes, i was the one who used to love mel like anything. I think i still do for its simplicity inside maya,
but it was time to move on..

I haven’t looked much around in other 3d packages but everyone was saying python is way foward.
I used python inside maya and find it pretty boring cluttered repetitive compared to MEL
(apart from standard python librarypython inside maya has nothing to offer).

And then about year pass by i was member of Google group PYTHON_INSIDE_MAYA they were developing PyMEL
guy named Chad Dombrova actually cook this whole new concept of pythonic way to look inside maya.

I gave PyMEL shot about a month back i installed release 0.9.1 and i was completely hooked. Before i go further i must say
I think PyMel is way forward to do scripting and programming inside maya (the python way). I also think there are some tiny miny glitches
here and there inside PyMEL which may prevent you from migrating, but with so many talented people collaborating i don’t think there would be
much problem once the final build is released.

Maya commands the PyMEL way:

mel code :

getAttr “pPlane1.translateX”


>>> plane = polyPlane(n=’myPlane’)
>>> plane.translateX.get()


>>> plane.translateX.set(10.0)

Basically what PyMEL does is it attaches attributes directly to object (PyNode) and then we can play with those attributes and properties (Methods)
It is whole OOPS based system with classes and all those modern language terminologies put into practice. With objects inheriting properties from
parent classes like “joint” inheriting from “transform” and all

scMirrorBlend.mel how to mirror blendShape !

Its been a month since i updated in here, i been working on few automation process for my rig setup.
i did almost six month ago. Well we do have some excellent scripts written by brendan ross
(a real hard working guy!)named abSymMesh but math behind both the scripts is different.
This proc came out as idea thrown out in cgTalk community.
Do let me know if you face any problem! Just a note script will itself duplicate the mesh and mirror shape.
I tried to catch things and did a mel script. Its a trick based on wrap deformer to mirror the one sided blend to other side.
You really become rusty if you leave something for long. so just to groove in i am posting one of my script
do modify closest distance in script if you need some adjustment .



Removing blendShape targets from blendShape node

Its really irritating that maya doesn’t allow any simple way of removing blendshape target (the attribute itself and Information stored) from blendShape node that already has his targets removed. The remove blendShape option only allow to remove those blendshape target index that already has there targets. If you see through hyperGraph connections you will see there is connection from shape node of targetShape.worldMesh[0] to your blendShape node to inputTarget multi index that will something like blendShape1.inputTarget[0].inputTargetGroup[0].inputTargetItem[6000].inputGeomTarget (a multiElement) all further targets you add will have something called weight index which is equivalent to inputTargetGroup[#] number. you can also query index number using this mel command aliasAttr -rm blendShape1.targetNameAttr; it will remove the alias name out of blendShape attribute and give you weight index number.


in above example 0 is the weight index. I hope i am able to explain how maya is storing blendShape in multiElement. I have written a script to remove blendshape targets with blendshape and target name as input. download it