def setSkinWeights(skinCluster, vertJointWeightData):
'''
vertJointWeightData is a list of 2-tuples containing the vertex component name, and a list of 2-tuples
containing the joint name and weight. ie it looks like this:
[ ('someMesh.vtx[0]', [('joint1', 0.25), 'joint2', 0.75)]),
('someMesh.vtx[1]', [('joint1', 0.2), 'joint2', 0.7, 'joint3', 0.1)]),
... ]
'''
#convert the vertex component names into vertex indices
idxJointWeight = []
for vert, jointsAndWeights in vertJointWeightData:
idx = int(vert[vert.rindex('[') + 1:-1])
idxJointWeight.append((idx, jointsAndWeights))
#get an MObject for the skin cluster node
skinCluster = apiExtensions.asMObject(skinCluster)
skinFn = MFnSkinCluster(skinCluster)
#construct a dict mapping joint names to joint indices
jApiIndices = {}
_tmp = MDagPathArray()
skinFn.influenceObjects(_tmp)
for n in range(_tmp.length()):
jApiIndices[str(_tmp[n].node())] = skinFn.indexForInfluenceObject(
_tmp[n])
weightListP = skinFn.findPlug("weightList")
weightListObj = weightListP.attribute()
weightsP = skinFn.findPlug("weights")
tmpIntArray = MIntArray()
baseFmtStr = str(
skinCluster
) + '.weightList[%d]' #pre build this string: fewer string ops == faster-ness!
for vertIdx, jointsAndWeights in idxJointWeight:
#we need to use the api to query the physical indices used
weightsP.selectAncestorLogicalIndex(vertIdx, weightListObj)
weightsP.getExistingArrayAttributeIndices(tmpIntArray)
weightFmtStr = baseFmtStr % vertIdx + '.weights[%d]'
#clear out any existing skin data - and awesomely we cannot do this with the api - so we need to use a weird ass mel command
for n in range(tmpIntArray.length()):
removeMultiInstance(weightFmtStr % tmpIntArray[n])
#at this point using the api or mel to set the data is a moot point... we have the strings already so just use mel
for joint, weight in jointsAndWeights:
if weight:
try:
infIdx = jApiIndices[joint]
except KeyError:
try:
infIdx = jApiIndices[joint.split('|')[0]]
except KeyError:
continue
setAttr(weightFmtStr % infIdx, weight)
def jointVerts(joint, tolerance=1e-4, onlyVisibleMeshes=True):
'''
returns a dict containing data about the verts influences by the given joint - dict keys are mesh names the
joint affects. each dict value is a list of tuples containing (weight, idx) for the verts affected by the joint
'''
newObjs = []
meshVerts = {}
joint = apiExtensions.asMObject(joint)
jointMDag = joint.dagPath()
try:
skins = list(set(listConnections(joint, s=0, type='skinCluster')))
except TypeError:
return meshVerts
MObject = OpenMaya.MObject
MDagPath = OpenMaya.MDagPath
MDoubleArray = OpenMaya.MDoubleArray
MSelectionList = OpenMaya.MSelectionList
MIntArray = OpenMaya.MIntArray
MFnSingleIndexedComponent = OpenMaya.MFnSingleIndexedComponent
for skin in skins:
skin = apiExtensions.asMObject(skin)
mfnSkin = MFnSkinCluster(skin)
mSel = MSelectionList()
mWeights = MDoubleArray()
mfnSkin.getPointsAffectedByInfluence(jointMDag, mSel, mWeights)
for n in range(mSel.length()):
mesh = MDagPath()
component = MObject()
mSel.getDagPath(n, mesh, component)
#if we only want visible meshes - check to see that this mesh is visible
if onlyVisibleMeshes:
if not isNodeVisible(mesh):
continue
c = MFnSingleIndexedComponent(component)
idxs = MIntArray()
c.getElements(idxs)
meshVerts[mesh.partialPathName()] = [
(w, idx) for idx, w in zip(idxs, mWeights) if w > tolerance
]
return meshVerts
