pymel.core.animation.skinCluster

static animation.skinCluster(*args, **kwargs)

The skinCluster command is used for smooth skinning in maya. It binds the selected geometry to the selected joints or skeleton by means of a skinCluster node. Each point of the bound geometry can be affected by any number of joints. The extent to which each joint affects the motion of each point is regulated by a corresponding weight factor. Weight factors can be modified using the skinPercent command. The command returns the name of the new skinCluster.The skinCluster binds only a single geometry at a time. Thus, to bind multiple geometries, multiple skinCluster commands must be issued.Upon creation of a new skinCluster, the command can be used to add and remove transforms (not necessarily joints) that influence the motion of the bound skin points. The skinCluster command can also be used to adjust parameters such as the dropoff, nurbs samples, polygon smoothness on a particular influence object. Note: Any custom weights on a skin point that the influence object affects will be lost after adjusting these parameters.

Modifications:

• returns a list of PyNode objects for flags: (query and (geometry or deformerTools or influence or weightedInfluence))

Flags:

Long name (short name)		Argument Types	Properties
addInfluence (ai)		unicode
	The specified transform or joint will be added to the list of transforms that influence the bound geometry. The maximum number of influences will be observed and only the weights of the cv’s that the specified transform effects will change. This flag is multi-use.
addToSelection (ats)		bool
	When used in conjunction with the selectInfluenceVerts flag, causes the vertices afftected by the influence to be added to the current selection, without first de-selecting other vertices.
after (af)		bool
	If the default behavior for insertion/appending into/onto the existing chain is not what you want then you can use this flag to force the command to stick the deformer node after the selected node in the chain even if a new geometry shape has to be created in order to do so. Works in create mode (and edit mode if the deformer has no geometry added yet).
afterReference (ar)		bool
baseShape (bsh)		unicode
	This flag can be used in conjunction with the -addInfluence flag to specify the shape that will be used as the base shape when an influence object with geometry is added to the skinCluster. If the flag is not used then the command will make a copy of the influence object’s shape and use that as a base shape.
before (bf)		bool
	If the default behavior for insertion/appending into/onto the existing chain is not what you want then you can use this flag to force the command to stick the deformer node before the selected node in the chain even if a new geometry shape has to be created in order to do so. Works in create mode (and edit mode if the deformer has no geometry added yet).
deformerTools (dt)		bool
	Returns the name of the deformer tool objects (if any) as string string ...
dropoffRate (dr)		float
	Sets the rate at which the influence of a transform drops as the distance from that transform increases. The valid range is between 0.1 and 10.0. In Create mode it sets the dropoff rate for all the bound joints. In Edit mode the flag is used together with the inf/influence flag to set the dropoff rate of a particular influence. Note: When the flag is used in Edit mode, any custom weights on the skin points the given transform influences will be lost.
exclusive (ex)		unicode
	Puts the deformation set in a deform partition.
forceNormalizeWeights (fnw)		bool
	If the normalization mode is none or post, it is possible (indeed likely) for the weights in the skin cluster to no longer add up to 1. This flag forces all weights to add back to 1 again.
frontOfChain (foc)		bool
	This command is used to specify that the new deformer node should be placed ahead (upstream) of existing deformer and skin nodes in the shape’s history (but not ahead of existing tweak nodes). The input to the deformer will be the upstream shape rather than the visible downstream shape, so the behavior of this flag is the most intuitive if the downstream deformers are in their reset (hasNoEffect) position when the new deformer is added. Works in create mode (and edit mode if the deformer has no geometry added yet).
geometry (g)		unicode
	The specified object will be added to the list of objects being deformed by this deformer object, unless the -rm flag is also specified. When queried, this flag returns string string string ...
geometryIndices (gi)		bool
ignoreBindPose (ibp)		bool
	This flag is deprecated and no longer used. It will be ignored if used.
ignoreHierarchy (ih)		bool
	Disregard the place of the joints in the skeleton hierarchy when computing the closest joints that influence a point of the geometry.
ignoreSelected (ignoreSelected)		bool
	Tells the command to not deform objects on the current selection list
influence (inf)		unicode
	This flag specifies the influence object that will be used for the current edit operation. In query mode, returns a string array of the influence objects (joints and transform). In query mode, this flag can accept a value.
lockWeights (lw)		bool
	Lock the weights of the specified influence object to their current value or to the value specified by the -weight flag.
maximumInfluences (mi)		int
	Sets the maximum number of transforms that can influence a point (have non-zero weight for the point) when the skinCluster is first created or a new influence is added. Note: When this flag is used in Edit mode any custom weights will be lost and new weights will be reassigned to the whole skin.
moveJointsMode (mjm)		bool
	If set to true, puts the skin into a mode where joints can be moved without modifying the skinning. If set to false, takes the skin out of move joints mode.
name (n)		unicode
	Used to specify the name of the node being created
normalizeWeights (nw)		int
	This flag set the normalization mode. 0 - none, 2 - interactive, 3 - post (default) Interactive normalization makes sure the weights on the influences add up to 1.0, always. Everytime a weight is changed, the weights are automatically normalized. This may make it difficult to perform weighting operations, as the normalization may interfere with the weights the user has set. Post normalization leaves the weights the user has set as is, and only normalizes the weights at the moment it is needed (by dividing by the sum of the weights). This makes it easier for users to weight their skins.
nurbsSamples (ns)		int
	Sets the number of sample points that will be used along an influence curve or in each direction on an influence NURBS surface to influence the bound skin. The more the sample points the more closely the skin follows the influence NURBS curve/surface.
obeyMaxInfluences (omi)		bool
	When true, the skinCluster will continue to enforce the maximum influences each time the user modifies the weight, so that any given point is only weighted by the number of influences in the skinCluster’s maximumInfluences attribute.
parallel (par)		bool
	Inserts the new deformer in a parallel chain to any existing deformers in the history of the object. A blendShape is inserted to blend the parallel results together. Works in create mode (and edit mode if the deformer has no geometry added yet).
polySmoothness (ps)		float
	This flag controls how accurately the skin control points follow a given polygon influence object. The higher the value of polySmoothnmess the more rounded the deformation resulting from a polygonal influence object will be.
prune (pr)		bool
	Removes any points not being deformed by the deformer in its current configuration from the deformer set.
remove (rm)		bool
	Specifies that objects listed after the -g flag should be removed from this deformer.
removeFromSelection (rfs)		bool
	When used in conjunction with the selectInfluenceVerts flag, causes the vertices afftected by the influence to be removed from the current selection.
removeInfluence (ri)		unicode
	Remove the specified transform or joint from the list of transforms that influence the bound geometry The weights for the affected points are renormalized. This flag is multi-use.
removeUnusedInfluence (rui)		bool
	If this flag is set to true then transform or joint whose weights are all zero (they have no effect) will not be bound to the geometry. Having this option set will help speed-up the playback of animation.
selectInfluenceVerts (siv)		unicode
	Given the name of a transform, this will select the verts or control points being influenced by this transform, so users may visualize which vertices are being influenced by the transform.
skinMethod (sm)		int
	This flag set the skinning method. 0 - classical linear skinning (default). 1 - dual quaternion (volume preserving), 2 - a weighted blend between the two.
smoothWeights (sw)		float
	This flag is used to detect sudden jumps in skin weight values, which often indicates bad weighting, and then smooth out those jaggies in skin weights. The argument is the error tolerance ranging from 0 to 1. A value of 1 means that the algorithm will smooth a vertex only if there is a 100% change in weight values from its neighbors. The recommended default to use is 0.5 (50% change in weight value from the neighbors).
smoothWeightsMaxIterations (swi)		int
	This flag is valid only with the smooth weights flag. It is possible that not all the vertices detected as needing smoothing can be smoothed in 1 iteration (because all of their neighbors also have bad weighting and need to be smoothed). With more iterations, more vertices can be smoothed. This flag controls the maximum number of iterations the algorithm will attempt to smooth weights. The default is 2 for this flag.
split (sp)		bool
	Branches off a new chain in the dependency graph instead of inserting/appending the deformer into/onto an existing chain. Works in create mode (and edit mode if the deformer has no geometry added yet).
toSelectedBones (tsb)		bool
	geometry will be bound to the selected bones only.
toSkeletonAndTransforms (tst)		bool
	geometry will be bound to the skeleton and any transforms in the hierarchy
unbind (ub)		bool
	Unbinds the geometry from the skinCluster and deletes the skinCluster node
unbindKeepHistory (ubk)		bool
	Unbinds the geometry from the skinCluster, but keeps the skinCluster node so that its weights can be used when the skin is rebound. To rebind, use the skinCluster command.
useGeometry (ug)		bool
	When adding an influence to a skinCluster, use the geometry parented under the influence transform to determine the weight dropoff of that influence.
volumeBind (vb)		float
	Creates a volume bind node and attaches it to the new skin cluster node. This node holds hull geometry parameters for a volume based weighting system. This system is used in interactive skinning. The value passed will determine the minimum weight value when initializing the volume. The volume in be increase to enclose all the vertices that are above this value.
volumeType (vt)		int
	Defines the initial shape of the binding volume (see volumeBind). 0 - Default (currently set to a capsule) 1 - Capsule, 2 - Cylinder. Flag can have multiple arguments, passed either as a tuple or a list.
weight (wt)		float
	This flag is only valid in conjunction with the -addInfluence flag. It sets the weight for the influence object that is being added.
weightedInfluence (wi)		bool
	This flag returns a string array of the influence objects (joints and transform) that have non-zero weighting.

Derived from mel command maya.cmds.skinCluster

Example:

import pymel.core as pm

# Create a joint chain and a polygonal plane.
pm.select(d=True)
pm.joint(p=(-3.0, 0.0,-12.0))
# Result: nt.Joint(u'joint1') #
pm.joint(p=(-3.0, 0.0, -5.0))
# Result: nt.Joint(u'joint2') #
pm.joint(p=(1.0, 0.0, 5.5))
# Result: nt.Joint(u'joint3') #
pm.joint(p=(6.0, 0.0, 10.0))
# Result: nt.Joint(u'joint4') #
pm.polyPlane(w=20.0,h=20.0,sx=25,sy=25)
# Result: [nt.Transform(u'pPlane1'), nt.PolyPlane(u'polyPlane1')] #

# Bind the joint chain that contains joint1 to pPlane1
# and assign a dropoff of 4.5 to all the joints
#
pm.skinCluster( 'joint1', 'pPlane1', dr=4.5)
# Result: [nt.SkinCluster(u'skinCluster1')] #

# Undo the previous command and bind only joint1 and joint3 to pPlane1
#
pm.undo();
pm.skinCluster('joint1', 'joint3', 'pPlane1',tsb=True)
# Result: [nt.SkinCluster(u'skinCluster1')] #

# Set the maximum number of transforms influencing each
# point to 3
pm.skinCluster('skinCluster1',e=True,mi=3)

# Add transform joint2 to the list of transforms
# that influence the bound skin
#
pm.select('pPlane1')
pm.skinCluster(edit=True,ai='joint2')

# Query the influences for the skinCluster
#
pm.skinCluster('skinCluster1',query=True,inf=True)
# Result: [u'joint1', u'joint3', u'joint2'] #

# Add a curve influence object
#
pm.curve(d=3,p=[(2.0, 0.0, -7.0),(5.0, 0.0, -4.0),(6.0, 0.0, 1.0),(6.0, 0.0, 4.0),(5.0, 0.0, 6.0)],k=[0,0,0,1,2,2,2])
# Result: nt.Transform(u'curve1') #

# Get the number of nurbsSamples taken along curve1
#
pm.skinCluster('skinCluster1',edit=True,ai='curve1')
pm.skinCluster('skinCluster1',inf='curve1',query=True,ns=True)
# Result: 0 #

# Set the dropoff for joint3 to 5.0
#
pm.skinCluster('skinCluster1',e=True,inf='joint3',dr=5.0)

# Query for the dropoff for joint3
#
pm.skinCluster('skinCluster1',inf='joint3',q=True,dr=True)
# Result: 5.0 #