Latest revision as of 10:05, 20 October 2026

Maya Rigging Concepts

Introduction

[Grouping, Parenting, Combining]

[Maya – Introduction to Joints and Bind Skin]

Maya Rigging Tools

MEL scripts

Usage demo for CV Curve Duplication and Quick Parent Constraints.

[Demo on usage of scripts]

Primitive Maya CV Curves

Link to MEL script library to create useful primitive CV curves:

Primitive Maya CV Curves

Quick Curve Duplication For Joints

Control curve duplication and place at selected joints pivot center

Usage: Select all the joints you want to duplicate a curve and place at the joints center, then select the curve which you want to duplicate last. Then execute the script. I recommend placing this script as a shelf tool.

// Get selection in order
string $sel[] = `ls -sl`;
if (size($sel) < 2)
{
    warning "Select one or more joints, then a curve LAST.";
}
else
{
    // Last selected object is the curve
    string $curve = $sel[size($sel) - 1];
    // Validate curve transform
    if (`nodeType $curve` != "transform")
    {
        warning "Last selected object must be a curve transform.";
    }
    else
    {
        // Loop through selected joints
        for ($i = 0; $i < size($sel) - 1; $i++)
        {
            string $joint = $sel[$i];
            // Skip anything that isn't a joint
            if (`nodeType $joint` != "joint")
                continue;
            // Get joint pivot position (world space)
            float $pivot[3] = `xform -q -ws -rp $joint`;
            // Duplicate curve
            string $dup[] = `duplicate -rr $curve`;
            // Move duplicate to joint pivot
            xform -ws -t $pivot[0] $pivot[1] $pivot[2] $dup[0];
        }
    }
}

Quick Parent Constraints

Parent constraints applied to joints en masse.

Usage: Select a control curve which will be the driving constraint, then select the joint to be constrained. Repeat the selection in order, curve then joint, for as many joints are going to be constrained. Then execute the script.

// Get ordered selection
string $sel[] = `ls -sl -o`;
int $count = size($sel);
// Need at least one curve-joint pair
if ($count < 2 || ($count % 2) != 0)
{
    warning "Selection must be in pairs: curve, joint, curve, joint, etc.";
}
else
{
    // Step through selection two at a time
    for ($i = 0; $i < $count; $i += 2)
    {
        string $curve = $sel[$i];
        string $joint = $sel[$i + 1];
        // Validate types
        if (`nodeType $joint` != "joint")
        {
            warning ("Skipping pair: " + $curve + " → " + $joint + " (second object is not a joint)");
            continue;
        }
        // Apply parent constraint (curve drives joint)
        parentConstraint -mo $curve $joint;
    }
}

Alternative Quick Parent Constraint Using Distance

Similar to the above quick parent constraint, instead of using the ordered selection method, the script takes the distance between the joint and the curve into account and applies the constraint based on the closest pair.

// Get selection
string $sel[] = `ls -sl`;
string $curves[];
string $joints[];
// Separate curves and joints
for ($obj in $sel)
{
    string $type = `nodeType $obj`;
    if ($type == "joint")
    {
        $joints[size($joints)] = $obj;
    }
    else
    {
        // Accept transform nodes with curve shapes
        string $shapes[] = `listRelatives -s $obj`;
        if (size($shapes) > 0 && `nodeType $shapes[0]` == "nurbsCurve")
        {
            $curves[size($curves)] = $obj;
        }
    }
}
// Validation
if (size($curves) == 0 || size($joints) == 0)
{
    warning "Selection must contain at least one curve and one joint.";
}
else
{
    // Loop through curves
    for ($curve in $curves)
    {
        vector $curvePos = `xform -q -ws -t $curve`;
        float $minDist = 1e10;
        string $closestJoint = "";
        // Compare against all joints
        for ($joint in $joints)
        {
            vector $jointPos = `xform -q -ws -t $joint`;
            vector $diff = $curvePos - $jointPos;
            float $dist = mag($diff);
            if ($dist < $minDist)
            {
                $minDist = $dist;
                $closestJoint = $joint;
            }
        }
        // Apply constraint
        if ($closestJoint != "")
        {
            parentConstraint -mo $curve $closestJoint;
        }
    }
}

Quickly Create Cluster Deformers on a NURBS curve/Spline

Use this script to speed up creating Spline IK rigs. Once the Spline IK Curve is created, select the curve and run this script.

Select the curve you want to apply cluster deformers to, then run the script.


string $sel[] = `ls -sl -type transform`;

if (size($sel) != 1)
{
    error "Please select exactly one NURBS curve.";
}

string $curve = $sel[0];
string $shapes[] = `listRelatives -shapes -noIntermediate $curve`;

if (size($shapes) == 0 || `nodeType $shapes[0]` != "nurbsCurve")
{
    error "The selected object must be a NURBS curve.";
}

string $shape = $shapes[0];

// Number of CVs on the curve.
int $spans = `getAttr ($shape + ".spans")`;
int $degree = `getAttr ($shape + ".degree")`;
int $numCVs = $spans + $degree;

// Create a cluster for every CV.
for ($i = 0; $i < $numCVs; $i++)
{
    string $cv = ($curve + ".cv[" + $i + "]");

    // Get the CV's world-space position.
    float $pos[] = `xform -q -ws -t $cv`;

    // Create cluster affecting only this CV.
    string $cluster[] = `cluster -relative $cv`;

    if (size($cluster) >= 2)
    {
        // Maya returns the handle and cluster node.
        string $handle = $cluster[0];
        string $deformer = $cluster[1];

        // Rename them.
        $handle = `rename $handle ("cluster_" + $i + "_handle")`;
        $deformer = `rename $deformer ("cluster_" + $i)`;

        // Snap the handle to the CV.
        xform -ws -t $pos[0] $pos[1] $pos[2] $handle;
    }
}

select $curve;

print ("Created and positioned " + $numCVs +
       " clusters on " + $curve + ".\n");