python_maya_meshdata.py

import maya.OpenMaya as OpenMaya

# Get the selection and create a selection list of all the nodes meshes
selection = OpenMaya.MSelectionList()
OpenMaya.MGlobal.getActiveSelectionList(selection);

# Create an MItSelectionList class to iterate over the selection
# Use the MFn class to as a filter to filter node types
iter = OpenMaya.MItSelectionList ( selection, OpenMaya.MFn.kGeometric );

# This uses built in functions of the MItSelectionList class to loop through the list of objects
# NB: isn't a basic array, you must use the built in functions
while not iter.isDone():        #iterate selection

    vertexList = []
    edgeList = []
    polytriVertsList = []
    polyList = []
    connectedPolyList = []
    
    #get dag path of current iterated selection
    dagPath = OpenMaya.MDagPath()
    iter.getDagPath( dagPath )
    
    # get the selection as an MObject
    mObj = OpenMaya.MObject()
    iter.getDependNode( mObj )
    
    # create iterator of current mesh polygons
    polygonsIterator = OpenMaya.MItMeshPolygon( mObj )
    
    # Iterate through polygons on current mesh
    while not polygonsIterator.isDone():
    
        # Get current polygons index
        polyList.append (polygonsIterator.index())	
        
        # Get current polygons vertices
        verts = OpenMaya.MIntArray()
        polygonsIterator.getVertices( verts )
        
        # Append the current polygons vertex indices
        for i in range( verts.length() ):
            vertexList.append (verts[i])
        
        # Get current polygons edges
        edges = OpenMaya.MIntArray()
        polygonsIterator.getEdges( edges )
        
        # Append the current polygons edge indices
        for i in range( edges.length() ):
            edgeList.append (edges[i])	
        
        # Get current polygons connected faces
        indexConnectedFaces = OpenMaya.MIntArray()
        polygonsIterator.getConnectedFaces( indexConnectedFaces )
        
        # Append the connected polygons indices
        for i in range( indexConnectedFaces.length() ):
            connectedPolyList.append (indexConnectedFaces[i])
        
        # Get current polygons triangles
        pointArray = OpenMaya.MPointArray()
        intArray = OpenMaya.MIntArray()
        space = OpenMaya.MSpace.kObject
        
        # Get the vertices and vertex positions of all the triangles in the current face's triangulation.
        polygonsIterator.getTriangles(pointArray, intArray, space)	
        
        # Append vertices that are part of the triangles
        for i in range( intArray.length() ):
            polytriVertsList.append (intArray[i])
        
        # next poligon
        polygonsIterator.next()
    
    # print data for current selection being iterated on
    print ("Object name: {}".format(dagPath.fullPathName())) 
    print ("Vertex list: {}".format(vertexList))
    print ("Edge list: {}".format(edgeList))
    print ("Poly Triangle Vertices: {}".format(polytriVertsList))
    print ("Polygon index list: (index buffer?) {}".format(polyList))
    print ("Connected Polygons list: (or index buffer?){}".format(connectedPolyList))
    
    # next selected
    iter.next()