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

cromadbomber

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

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

@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

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

@pasha_sevez That works perfectly! 

pasha_sevez

cromadbomber said:

@pasha_sevez That works perfectly! 

No sweat!

SoungHun

@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

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