Maya - Python - Get a list of all UV shells in a selected object?

cromadbomber · Jan 2018

Looking for a function which returns a list of all UV shells from a selected object. Most of the stuff I found on the internet is a bit hacky and doesn't end up working well. I read through the official docs and I couldn't find anything like this so it makes me wonder does it even exist. Basically I would need a list of those UV shells and to be able to select faces/verts/edges inside of it.

MEL solution is fine aswel.

Using Maya 2018 by the way.

pasha_sevez · Jan 2018

Try this. Input the name of the mesh as argument.

import maya.OpenMaya as om
import maya.cmds as cmds

def getUvShelList(name):
    selList = om.MSelectionList()
    selList.add(name)
    selListIter = om.MItSelectionList(selList, om.MFn.kMesh)
    pathToShape = om.MDagPath()
    selListIter.getDagPath(pathToShape)
    meshNode = pathToShape.fullPathName()
    uvSets = cmds.polyUVSet(meshNode, query=True, allUVSets =True)
    allSets = []
    for uvset in uvSets:
        shapeFn = om.MFnMesh(pathToShape)
        shells = om.MScriptUtil()
        shells.createFromInt(0)
        # shellsPtr = shells.asUintPtr()
        nbUvShells = shells.asUintPtr()

        uArray = om.MFloatArray()   #array for U coords
        vArray = om.MFloatArray()   #array for V coords
        uvShellIds = om.MIntArray() #The container for the uv shell Ids

        shapeFn.getUVs(uArray, vArray)
        shapeFn.getUvShellsIds(uvShellIds, nbUvShells, uvset)

        # shellCount = shells.getUint(shellsPtr)
        shells = {}
        for i, n in enumerate(uvShellIds):
            if n in shells:
                shells[n].append([uArray[i],vArray[i]])
            else:
                shells[n] = [[uArray[i],vArray[i]]]
        allSets.append({uvset: shells})
    return allSets

cromadbomber · Jan 2018

@pasha_sevez Alright. That seemed to work. It pretty much returned this on a 4 point plane with UV shell spreading across entire 0,1 space.

[{u'map1': {0: [[0.0, 0.0], [1.0, 0.0], [0.0, 1.0], [1.0, 1.0]]}}]

0: - Representing first shell
[0.0, 0.0] -1st point
[1.0, 0.0] -2nd
[0.0, 1.0] -3rd
[1.0, 1.0] -4th
Now I managed to iterate through this and obtain each UV shell and its respective UVs.
Now the problem is using this data to obtain UV selection again. This needs to be put in a way that cmds.select() can understand.

pasha_sevez · Jan 2018

Ok, in your case it might be a good idea to modify a function a bit:

import maya.OpenMaya as om
import maya.cmds as cmds

def getUvShelList(name):
	selList = om.MSelectionList()
	selList.add(name)
	selListIter = om.MItSelectionList(selList, om.MFn.kMesh)
	pathToShape = om.MDagPath()
	selListIter.getDagPath(pathToShape)
	meshNode = pathToShape.fullPathName()
	uvSets = cmds.polyUVSet(meshNode, query=True, allUVSets =True)
	allSets = []
	for uvset in uvSets:
		shapeFn = om.MFnMesh(pathToShape)
		shells = om.MScriptUtil()
		shells.createFromInt(0)
		# shellsPtr = shells.asUintPtr()
		nbUvShells = shells.asUintPtr()

		uArray = om.MFloatArray()   #array for U coords
		vArray = om.MFloatArray()   #array for V coords
		uvShellIds = om.MIntArray() #The container for the uv shell Ids

		shapeFn.getUVs(uArray, vArray)
		shapeFn.getUvShellsIds(uvShellIds, nbUvShells, uvset)

		# shellCount = shells.getUint(shellsPtr)
		shells = {}
		for i, n in enumerate(uvShellIds):
			if n in shells:
				# shells[n].append([uArray[i],vArray[i]])
				shells[n].append( '%s.map[%i]' % ( name, i ) )
			else:
				# shells[n] = [[uArray[i],vArray[i]]]
				shells[n] = [ '%s.map[%i]' % ( name, i ) ]
		allSets.append({uvset: shells})
	return allSets

getUvShelList( 'pCone1' )

cromadbomber · Jan 2018

@pasha_sevez That works perfectly!

pasha_sevez · Jan 2018

cromadbomber said:

@pasha_sevez That works perfectly!

No sweat!

SoungHun · Mar 2018

@pasha_sevez

I want to get the mesh data of the FBX file object in view from MAYA. We also want to compare the mesh data before and after editing the object. Please

n4uj · Feb 2021

pasha_sevez said:

Ok, in your case it might be a good idea to modify a function a bit:

import maya.OpenMaya as om
import maya.cmds as cmds

def getUvShelList(name):
	selList = om.MSelectionList()
	selList.add(name)
	selListIter = om.MItSelectionList(selList, om.MFn.kMesh)
	pathToShape = om.MDagPath()
	selListIter.getDagPath(pathToShape)
	meshNode = pathToShape.fullPathName()
	uvSets = cmds.polyUVSet(meshNode, query=True, allUVSets =True)
	allSets = []
	for uvset in uvSets:
		shapeFn = om.MFnMesh(pathToShape)
		shells = om.MScriptUtil()
		shells.createFromInt(0)
		# shellsPtr = shells.asUintPtr()
		nbUvShells = shells.asUintPtr()

		uArray = om.MFloatArray()   #array for U coords
		vArray = om.MFloatArray()   #array for V coords
		uvShellIds = om.MIntArray() #The container for the uv shell Ids

		shapeFn.getUVs(uArray, vArray)
		shapeFn.getUvShellsIds(uvShellIds, nbUvShells, uvset)

		# shellCount = shells.getUint(shellsPtr)
		shells = {}
		for i, n in enumerate(uvShellIds):
			if n in shells:
				# shells[n].append([uArray[i],vArray[i]])
				shells[n].append( '%s.map[%i]' % ( name, i ) )
			else:
				# shells[n] = [[uArray[i],vArray[i]]]
				shells[n] = [ '%s.map[%i]' % ( name, i ) ]
		allSets.append({uvset: shells})
	return allSets

getUvShelList( 'pCone1' )

Cheers man for that

Maya - Python - Get a list of all UV shells in a selected object?

Replies