How can we List all blendshape nodes of a object?

[5rivamsi]

I tried this

shapes = mc.listConnections(objectShape,s=1,type = 'blendShape')

however it gave only one (most recent one) output while the object has 3 shapes.

later i tried

with shapeEditorManger, it listed all blendshapes in scene, I wanted only particular object's.

[5rivamsi]

def getHistoryNodes(sel, type):
sortedList = []
for aNode in mc.listHistory(sel):
if mc.nodeType(aNode) == type:
sortedList.append(aNode)
return sortedList
selected = mc.ls(sl=1)[0]
print (getHistoryNodes(selected, 'blendShape'))

lost sourcelink

[mcw0 · Accepted solution]

You can also use "getChain" and filter non-blendShape nodes.

[zewt]

You definitely don't want to use listHistory.  That'll include blendShapes on other shape nodes that aren't actually deforming that shape, like blendShapes deforming upstream blendShape targets or morph targets.

[mcw0]

Unfortunately, getChain isn't as useful as it could be.  It doesn't return the list of deformers in order.  😞  So I have to use listHistory in conjunction with getChain to get what I want.  Uh Maya...hint, hint.

[zewt]

Try listHistory with -pruneDagObjects 1, which will make it stop if it reaches a different shape.  I'm not sure if there are any other gotchas, but that's what the input/output button in the toolbar uses.  With PyMEL:

import pymel.core as pm
for node in pm.ls(sl=True):
    print(node.listHistory(pruneDagObjects=True, type='blendShape'))

I wouldn't use getChain.  It looks like an ancient bit of MEL that nothing in Maya itself is actually using (usually a bad sign), and it looks like it hasn't been updated for 2022.  It still assumes groupParts nodes exist for deformers, which they usually no longer do, and at a quick look it seems to make bad assumptions about groupParts nodes (it seems to assume there will never be two groupParts nodes in a row, which happened all the time).  That's probably why it's not returning results in the correct order.

[mcw0]

Thank you very much!!!