[PySide Qt] :: Builder Window Story #1

Modular Rig Build

Building tools is always fun because of how much over-lap of tools are needed to support the main tool. I figured that it’s time to redesign my current builder with a new one hence this project is born.

When I design a complex window, I find that it’s always a good practice to break up the widgets into separate functions. In this case, my window only contains two widgets, ModuleForm and InformationForm, and PySide makes things easier in combining modules:

class MainWindow(QtWidgets.QMainWindow):
    HEIGHT = 400
    WIDTH = 400
    INFORMATION = {}

    module_form = None
    information_form = None
    # the main build blue-print to construct
    # every time a module is added to module form, this updates the blueprint dictionary

    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        # add the widgets to the layouts.
        self.main_widget = QtWidgets.QWidget(self)
        self.setSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
        self.main_layout = QtWidgets.QHBoxLayout(self)

        # add the two widgets to the main layout
        horizontal_split = QtWidgets.QSplitter(QtCore.Qt.Horizontal)
        self.main_layout.addWidget(horizontal_split)

        self.module_form = ModuleForm(parent=self)
        self.information_form = InformationForm(parent=self)

        horizontal_split.addWidget(self.module_form)
        horizontal_split.addWidget(self.information_form)

As you can guess the ModuleForm are where each rig module class is stored; and when that is selected, it triggers an InformationForm refresh, showing the necessary information for that module, and it works like so:

PySide Widgets' Relationship
PySide Relationships

This project is still in its infancy, I still need to add a blueprint file feature that saves and loads the module configuration as per rig specifications. My main purpose of this project is so that I can build creature rigs cleanly — including creature face work, I find that upkeep for creating faces is high, so having a modular based builder keeps file scenes nice and tidy.

I am not worried about the aesthetics of the tool for now, just its modular utility:

Modular Rig Build
Each module is responsible for each piece of rig.

As I can see, PySide offers much flexibility with UI tool design, for example, I found out that you can add separate widgets to a QListWidgetItem like so:

    @add_module_decorator
    def add_module(self, *args):
        """
        adds the module
        :param args:
        :return:
        """
        module_name = args[0]
        item = QtWidgets.QListWidgetItem()
        widget = ModuleWidget(module_name=module_name, list_widget=self.module_form.list, item=item, parent=self)
        item.setSizeHint(widget.sizeHint())

        # add a widget to the list
        self.module_form.list.addItem(item)
        self.module_form.list.setItemWidget(item, widget)
        return widget

And that QListWidgetItem contains a Widget with QLabel attached with a colored QtGui.QPixmap which can be changed just by re-assigning a different QtGui.QPixmap by using these two lines of code:

    def change_status(self, color="green"):
        """
        Change the status of the widget to "built"
        """
        self.q_pix = QtGui.QPixmap(buttons[color])
        self.icon.setPixmap(self.q_pix)

[Maya Rigging] :: Blend-Shape Based Face Rig.

Today I will explain how a blend-shape based face rig works for autodesk Maya. Understand that blendShapes is an additive mesh shape deformer, that one after another shape gets activated and can be driven by a single controller with values from 0.0 to 1.0 to drive shapes: shape0 + shape0_5 + shape1_0.

I had trouble finding a face mesh to work with, so I headed over to AnimSchool and downloaded their Malcom Rig and extracted the head mesh for me to work on:

https://www.animschool.com/DownloadOffer.aspx

While the set-up of the controllers are rather simple, each controller had to have a maximum value of 1. In addition to that, here is work needs to be done in creating the shapes themselves. For this reason, I chose to play with OpenMaya::MFnBlendShape class to add, and remove shape targets.

To initialize a blend-shape node without targets (important step):

def create_blendshape(mesh_objects, name=""):
    """
    creates a new blendShape from the array of mesh objects provided
    :param mesh_objects: <tuple> array of mesh shapes.
    :param name: <str> name of the blendshape.
    :return: <OpenMayaAnim.MFnBlendShapeDeformer>
    """
    blend_fn = OpenMayaAnim.MFnBlendShapeDeformer()

    if isinstance(mesh_objects, (str, unicode)):
        mesh_obj = object_utils.get_m_obj(mesh_objects)
        blend_fn.create(mesh_obj, origin, normal_chain)

    elif len(mesh_objects) > 1 and isinstance(mesh_objects, (tuple, list)):
        mesh_obj_array = object_utils.get_m_obj_array(mesh_objects)
        blend_fn.create(mesh_obj_array, origin, normal_chain)
    else:
        raise ValueError("Could not create blendshape.")

    if name:
        object_utils.rename_node(blend_fn.object(), name)
    return blend_fn

Each blend-shape index starts from 5000 and ends at 6000, so to get indices we need to use OpenMaya.MIntArray(), please understand that we need to use MIntArray and not a list of integers because otherwise Maya will not accept those integers:

def get_weight_indices(blend_name=""):
    """
    get the weight indices from the blendShape name provided.
    :param blend_name: <str> the name of the blendShape node.
    :return: <OpenMaya.MIntArray>
    """
    blend_fn = get_deformer_fn(blend_name)
    int_array = OpenMaya.MIntArray()
    blend_fn.weightIndexList(int_array)
    return int_array

Now we can add shape targets like by using the following code, the objects are accepted from targets_array and Maya’s specified index:

def add_target(targets_array, blend_name="", weight=1.0, index=0):
    """
    adds a new target with the weight to this blend shape.
    Maya has a fail-safe to get the inputTargetItem from 6000-5000
    :param targets_array: <tuple> array of mesh shapes designated as targets.
    :param blend_name: <str> the blendShape node to add targets to.
    :param weight: <float> append this weight value to the target.
    :param index: <int> specify the index in which to add a target to the blend node.
    :return:
    """
    blend_fn = get_deformer_fn(blend_name)
    base_obj = get_base_object(blend_name)[0]
    if isinstance(targets_array, (str, unicode)):
        targets_array = targets_array,
    targets_array = object_utils.get_m_shape_obj_array(targets_array)
    length = targets_array.length()
    if not index:
        index = get_weight_indices(blend_fn.name()).length() + 1
    # step = 1.0 / length - 1
    for i in xrange(0, length):
        # weight_idx = (i * step) * 1000/1000.0
        blend_fn.addTarget(base_obj, index, targets_array[i], weight)
    return True

One after another we an add all the shapes by code in whatever order of targets we want, adding in-betweens from 0.0 -> 1.0. I always choose to go in steps of “5”-ves. (0.0, 0.25, 0.5, 0.75, 1.0). This is because don’t really need to go any more complicated that that.

Over the course of constructing the blend-shape based rig, you need to have two base meshes: one for deformation and the other for duplicating mesh objects for sculpting. I used abSymMesh for mesh mirroring because the tool is already there and I did not need to re-invent another one. All in all I think I’ve done a good job with my face:

Face rig video of my repurposes Malcom face rig.

The complete module I used in this construction can be found at my GitHub page:

[OpenMaya] :: MPxLocator Python 2.0 Plugin

Okay following the previous vector posts, I decided to plunge ahead and create a plugin that capitalizes on that knowledge.

Previously, in OpenMaya 1.0, the MPxLocator has been defined by using the draw method by using Open Graphics Library (OpenGL) functions. Maya’s architecture has updated a new method, and I used the OpenMaya.MUIDrawManager class method to do the drawings, making things straight forward. Here, I draw a circle, rectangle and a line; I spent way too much time figuring out the nuances of this plugin.

At first, finding out which MPxLocator examples file work right out of the box has been an issue, except finally, I found this one: uiDrawManager/uiDrawManager.cpp

In addition to finding out how the 2.0 plugins work, I also wanted to learn a bit more on reflection math, and I put that to use in this plugin:

R = 2(N * L) * N – L

Which using Maya’s Python code looks like this:

# define normal vector at origin
normal = OpenMaya.MVector(0.0, 1.0, 0.0)

# get opposing vector through double cross product
opposing_vector = normal * (2 * (normal * input_point))
opposing_vector -= input_point

# now multiply it by the scalar value
opposing_vector *= scale
if as_vector:
   return opposing_vector
else:
   return opposing_vector.x, opposing_vector.y, opposing_vector.z

Maya viewport handles drawing by using the DrawManager, like this:

A circle:

        radius = 2.0
        is_filled = True
        position = OpenMaya.MPoint(0, 0, 0)
        normal = OpenMaya.MVector(0, 1, 0)
        drawManager.beginDrawable()
        drawManager.beginDrawInXray()
        drawManager.setLineWidth(line_width)
        drawManager.setLineStyle(drawManager.kSolid)
        drawManager.setColor(OpenMaya.MColor(plane_color))
        drawManager.circle(position, normal, radius, is_filled)
        drawManager.endDrawInXray()
        drawManager.endDrawable()

A rectangle:

        rect_scale_x = 1.0
        rect_scale_y = 1.0
        is_filled = False
        position = OpenMaya.MPoint(0, 0, 0)
        normal = OpenMaya.MVector(0, 0, 1)
        up = OpenMaya.MVector(0, 1, 0)
        drawManager.beginDrawable()
        drawManager.setLineWidth(line_width)
        drawManager.setLineStyle(drawManager.kSolid)
        drawManager.setColor(OpenMaya.MColor(plane_color))
        # For 3d rectangle, the up vector should not be parallel with the normal vector.
        drawManager.rect(position, normal, up, rect_scale_x, rect_scale_y, is_filled)
        drawManager.endDrawable()

A line:

        drawManager.beginDrawable()
        drawManager.setLineWidth(line_width)
        drawManager.setLineStyle(drawManager.kSolid)
        drawManager.setColor(OpenMaya.MColor(plane_color))
        drawManager.line(OpenMaya.MPoint(0, -1, 0), OpenMaya.MPoint(0, 1, 0))
        drawManager.endDrawable()

The reason why I dived into Maya’s Viewport drawing is because I was following Chad Vernon’s excellent C++ series, and his MPxLocator example no longer works in the current Maya 2020 version. The full working code can be found at my GitHub page:

[OpenMaya] :: MFnNurbsCurve.create

Alright, so this one is also lots of fun. We are going to create a NurbsCurve using OpenMaya, with a leading degree of 2 (Quadratic). Remember in the previous post about how I calculated the vectors between the two locator positions? Well this time, we are going to do the same, but creating nurbsCurve. This is because each CV needs a position vector array:.

def get_point_array(points_array, equal_distance=False):
    """
    calculate the positional array object.

    :param points_array:
    :param equal_distance: <bool> calculate the equal distance of CV's
    :return:
    """
    m_array = OpenMaya.MPointArray()
    if equal_distance:
        array_length = len(points_array)
        for idx, point in enumerate(points_array):
            if idx == 0:
                m_array.append(OpenMaya.MPoint(*point))
                m_array.append(OpenMaya.MPoint(*point))
            elif idx >= 1 and idx != array_length - 1:
                prev_p, cur_p, next_p = list_scanner(points_array, idx)
                cur_v = math_utils.Vector(*cur_p)
                prev_v = math_utils.Vector(*prev_p)
                new_vec = math_utils.Vector(cur_v - prev_v)
                new_vec = math_utils.Vector(new_vec * 0.5)
                new_vec = math_utils.Vector(prev_v + new_vec)
                m_array.append(OpenMaya.MPoint(*new_vec.position))
            elif idx == array_length - 1:
                prev_p, cur_p, next_p = list_scanner(points_array, idx)
                prev_v = math_utils.Vector(*prev_p)
                next_v = math_utils.Vector(*next_p)
                new_vec = math_utils.Vector(next_v - prev_v)
                new_vec = math_utils.Vector(new_vec * 0.5)
                new_vec = math_utils.Vector(prev_v + new_vec)
                # add two points in the same spot
                m_array.append(OpenMaya.MPoint(*new_vec.position))
                m_array.append(OpenMaya.MPoint(*point))
    else:
        for idx, point in enumerate(points_array):
            if idx == 1:
                prev_p, cur_p, next_p = list_scanner(points_array, idx)
                cur_v = math_utils.Vector(*cur_p)
                prev_v = math_utils.Vector(*prev_p)
                new_vec = math_utils.Vector(cur_v - prev_v)
                new_vec = math_utils.Vector(new_vec * 0.5)
                new_vec = math_utils.Vector(prev_v + new_vec)
                m_array.append(OpenMaya.MPoint(*new_vec.position))
            elif idx == len(points_array) - 1:
                prev_p, cur_p, next_p = list_scanner(points_array, idx)
                prev_v = math_utils.Vector(*prev_p)
                next_v = math_utils.Vector(*next_p)
                new_vec = math_utils.Vector(next_v - prev_v)
                new_vec = math_utils.Vector(new_vec * 0.5)
                new_vec = math_utils.Vector(prev_v + new_vec)
                m_array.append(OpenMaya.MPoint(*new_vec.position))
            m_array.append(OpenMaya.MPoint(*point))
    return m_array

So above is just a point array collector that recalculates positions from an existing array of positions: Like selected locators or joints. Preferably at world-space co-ordinates. We then take these recalculated positional array into the OpenMaya.MFnNurbsCurve.create function. I wrote this create_curve_from_points function below that uses this:

def create_curve_from_points(points_array, degree=2, curve_name="", equal_cv_positions=False):
    """
    create a nurbs curve from points.
    :param points_array: <tuple> positional points array.
    :param degree: <int> curve degree.
    :param curve_name: <str> the name of the curve to create.
    :param equal_cv_positions: <bool> if True create CV's at equal positions.
    :return: <str> maya curve name.
    """
    knot_length = len(points_array)
    knot_array = get_knot_sequence(knot_length, degree)
    m_point_array = get_point_array(points_array, equal_distance=equal_cv_positions)

    # curve_data = OpenMaya.MFnNurbsCurveData().create()
    curve_fn = OpenMaya.MFnNurbsCurve()
    curve_fn.create(m_point_array, knot_array, degree,
                    OpenMaya.MFnNurbsCurve.kOpen,
                    False, False)
    m_path = OpenMaya.MDagPath()
    curve_fn.getPath(m_path)

    if curve_name:
        parent_obj = object_utils.get_parent_obj(m_path.partialPathName())[0]
        object_utils.rename_node(parent_obj, curve_name)
        return curve_name
    return curve_fn.name()

In the function above, there is a boolean parameter: equal_cv_positions. The default is False. The result of this is creating CV’s at their locator’s positions, like so:

And if the equal_cv_positions is set to True, this is the result:

As you can see, this utility tool is going to become immediately useful. You could already guess at plans use this already!

[OpenMaya] :: MVector

I love math. Everything in life can change — your interests, your job, outside influences, but not math. Math never changes and I love about that very much.

Today, let’s go over why Maya’s MVector class object is so much fun: it’s a point in space (with a direction); we can add, subtract and multiply it against another MVector or a scalar value.

Right now, let’s deal with multiplying MVectors against scalar values.

Here we have two locators in space. Let’s have some fun with these two locators. First we will collect and manipulate information about these vectors using some Maya Python scripting. First, let’s show some code:

from maya.OpenMaya import MVector
from maya import cmds

class Vector(MVector):
    RESULT = ()

    def __init__(self, *args):
        super(Vector, self).__init__(*args)

    def do_division(self, amount=2.0):
        """
        divide the vector into sections.
        :param amount: <int> divide the vector by scalar amount.
        :return: <tuple> section vector.
        """
        self.RESULT = self.x / amount, self.y / amount, self.z / amount,
        return self.RESULT

    def do_multiply(self, amount=2.0):
        """
        multiply the vector by the amount.
        :param amount: <int> multiply the vector by scalar amount.
        :return: <tuple> section vector.
        """
        self.RESULT = self.x * amount, self.y * amount, self.z * amount,
        return self.RESULT

    def get_position(self):
        self.RESULT = self.x, self.y, self.z,
        return self.RESULT

    @property
    def result(self):
        return self.RESULT

    @property
    def position(self):
        return self.get_position()

def get_vector_position_2_points(position_1, position_2, divisions=2.0):
    """
    calculates the world space vector between the two positions.
    :param position_1: <tuple> list vector
    :param position_2: <tuple> list vector
    :param divisions: <int> calculate the vector by divisions.
    :return: <tuple> vector
    """
    positions = ()
    for i in xrange(1, divisions):
        vec_1 = Vector(*position_1)
        vec_2 = Vector(*position_2)
        new_vec = Vector(vec_1 - vec_2)
        div_vec = Vector(new_vec * (float(i) / float(divisions)))
        result_vec = Vector(*div_vec.position)
        positions += Vector(result_vec + vec_2).position,
    return positions

def get_vector_positon_2_objects(object_1, object_2, divisions=2):
    """
    calculates the world space vector between the two points.
    :return: <tuple> vector positions.
    """
    vector_1 = cmds.xform(object_1, ws=1, t=1)
    vector_2 = cmds.xform(object_2, ws=1, t=1) 
    return get_vector_position_2_points(vector_1, vector_2, divisions)

So this is a module I created for getting point positions between the two vectors. So let’s go through this step by step, in the get_vector_position_2_points function. Ignoring everything else but the math:

1.) we define the two vector positions.

2.) we subtract the first vector from the second to create a third vector at the origin.

3.) we loop through the number of divisions, dividing each number by the total number of divisions to give us the fraction that we can use to multiply with. (1/4, 2/4, 3/4, 4/4)

4.) we add the resultant origin vector by the second vector to place it relative to the second vector’s position.

5.) finally, we use this vector point to place our locators using the code below:

We are going to divide the space between the locators into 4 sections (divisions = 4). Let’s go into Maya and load up the script editor and paste this code there:

from maya_utils import math_utils
import maya.cmds as cmds
reload(math_utils)

positions = math_utils.get_vector_positon_2_objects('locator1', 'locator2', divisions=4)

for v_pos in positions:
    locator = cmds.createNode('locator')
    cmds.xform(object_utils.get_parent_name(locator), t=v_pos)

As we can see, between the locators, we have created four equal divisions, and have created the locators with the calculated positional vectors between the two original locators. This is useful in many of my rigging work, like creating springs, wires and folding wings.

It is important to be precise when creating any useful tool. So that we can eliminate any uncertainty in our work.

[OpenMaya] :: Iteration

As a tools developoer, it is in my best interest to make the code run fast, and if there is anything in Maya that makes things go fast, it’s OpenMaya:

Below is an example of how OpenMaya iterates a scene to find all the AnimCurve nodes connected to an object in Maya.:

# import maya modules
from maya import OpenMaya as om

def get_connected_nodes(object_name="", find_node_type=om.MFn.kAnimCurve): """ get connected nodes from node provided. :param object_name: <str> string object to use for searching from. :param find_node_type: <om.MFn> kObjectName type to find. """ node = get_m_obj(object_name) dag_iter = om.MItDependencyGraph( node, om.MItDependencyGraph.kUpstream, om.MItDependencyGraph.kPlugLevel) dag_iter.reset() found_nodes = [] while not dag_iter.isDone(): cur_item = dag_iter.currentItem() if cur_item.hasFn(find_node_type): found_nodes.append(cur_item) dag_iter.next() return found_nodes

Another way to go about doing this business is creating a generator object by introducing yield, in the same code, we just remove the return statement:

# import maya modules
from maya import OpenMaya as om

def get_connected_nodes_gen(object_name="", find_node_type=om.MFn.kAnimCurve): """ nodes generator. :param object_name: <str> string object to use for searching from. :param find_node_type: <om.MFn> kObjectName type to find. """ node = get_m_obj(object_name) dag_iter = om.MItDependencyGraph( node, om.MItDependencyGraph.kUpstream, om.MItDependencyGraph.kPlugLevel) dag_iter.reset() while not dag_iter.isDone(): cur_item = dag_iter.currentItem() if cur_item.hasFn(find_node_type): yield cur_item dag_iter.next()

We can test the speed of the code by utilizing the cProfile module:

# import maya modules
from maya import OpenMaya as om

# import local modules
import cProfile

# define variables
anim_key_nodes = object_utils.get_connected_nodes_gen('pCube1')

# run profiler
cProfile.run("for n in anim_key_nodes: print n")

<...>
<...>
<maya.OpenMaya.MObject; proxy of <Swig Object of type 'MObject *' at 0x000002776FB30B40> >
<maya.OpenMaya.MObject; proxy of <Swig Object of type 'MObject *' at 0x000002776FB306C0> >

213 function calls in 0.021 seconds

Ordered by: standard name

ncalls tottime percall cumtime percall filename:lineno(function)
1 0.020 0.020 0.021 0.021 <string>:1(<module>)
1 0.000 0.000 0.000 0.000 OpenMaya.py:1539(__init__)
1 0.000 0.000 0.000 0.000 OpenMaya.py:7370(__init__)
14 0.000 0.000 0.000 0.000 OpenMaya.py:84(_swig_repr)
1 0.000 0.000 0.000 0.000 OpenMaya.py:9666(__init__)
15 0.000 0.000 0.001 0.000 object_utils.py:60(get_connected_nodes_gen)
1 0.000 0.000 0.000 0.000 object_utils.py:80(get_m_obj)
42 0.000 0.000 0.000 0.000 {maya._OpenMaya.MItDependencyGraph_currentItem}
43 0.000 0.000 0.000 0.000 {maya._OpenMaya.MItDependencyGraph_isDone}
42 0.000 0.000 0.000 0.000 {maya._OpenMaya.MItDependencyGraph_next}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.MItDependencyGraph_reset}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.MItDependencyGraph_swiginit}
42 0.000 0.000 0.000 0.000 {maya._OpenMaya.MObject_hasFn}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.MObject_swiginit}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.MSelectionList_add}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.MSelectionList_getDependNode}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.MSelectionList_swiginit}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.new_MItDependencyGraph}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.new_MObject}
1 0.000 0.000 0.000 0.000 {maya._OpenMaya.new_MSelectionList}
1 0.000 0.000 0.000 0.000 {method 'disable' of '_lsprof.Profiler' objects}

And there we have it, we have covered OpenMaya iteration by traversing the node connections and finding the corresponding node (in this case the AnimCurve node), and a python generator to show the similarities between a loop and a generator. And yes, you can do the similar basic maya command, but it’s not as fun:

# import maya modules
from maya import cmds

def get_connected_anim(object_name=""):
    """
    get connected nodes from node provided.
    :param object_name: <str> string object to use for searching from.
    :param find_node_type: <om.MFn> kObjectName type to find.
    """
    anim_c = cmds.listConnections(object_name, s=1, d=0, type='animCurve')
    anim_b = cmds.listConnections(object_name, s=1, d=0, type='blendWeighted')
    anim_curves = []
    if not anim_c and anim_b:
        for blend_node in anim_b:
            anim_curves.extend(cmds.listConnections(blend_node, s=1, d=0, type='animCurve'))
        return anim_curves
    else:
        return anim_c

 ...
animCurveUL4
animCurveUL5
animCurveUL8
animCurveUL10
animCurveUL12

         2 function calls in 0.013 seconds
Ordered by: standard name
 ncalls  tottime  percall  cumtime  percall filename:lineno(function)
         1    0.013    0.013    0.013    0.013 :1()
         1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects} 

Yes this seems like regular maya commands are faster, but you’ve got to remember, this is just a couple of nodes. What if you had to loop through a large set of vertices on a piece of geometry? I’ve created two functions: One loops through vertices by using standard maya cmds, the other using OpenMaya MItMeshVertex:

def get_mesh_points(object_name):
    """
    Mesh points iterator.
    :param object_name: <str> object name.
    :return: <list> vertex positions
    """
    mesh_fn, mesh_ob, mesh_dag = get_mesh_fn(object_name)
    mesh_it = om.MItMeshVertex(mesh_ob)
    mesh_vertexes = []
    print("[Number of Vertices] :: {}".format(mesh_fn.numVertices()))
    while not mesh_it.isDone():
        mesh_vertexes.append(mesh_it.position())
        mesh_it.next()
    return mesh_vertexes


def get_mesh_points_cmds(object_name):
    """
    Mesh points iterator.
    :param object_name:  <str> object name. 
    :return: <list> vertex positions 
    """
    mesh_vertices = cmds.ls(object_name + '.vtx[*]', flatten=1)
    print("[Number of Vertices] :: {}".format(len(mesh_vertices)))
    nums = []
    for i in mesh_vertices:
        nums.append(i)
    return nums

Now let’s see how cProfiler works on them both by iterating through 429510 vertices mesh:

 # run cmdsiterator 
cProfile.run("object_utils.get_mesh_points_cmds('Emmanuel_Guevarra_Ian_McKellen_medres:Group2')")
 [Number of Vertices] :: 429510
          429516 function calls in 1.629 seconds
 Ordered by: standard name
 ncalls  tottime  percall  cumtime  percall filename:lineno(function)
         1    0.019    0.019    1.629    1.629 :1()
         1    0.038    0.038    1.609    1.609 object_utils.py:128(get_mesh_points_cmds)
         1    1.548    1.548    1.548    1.548 {built-in method ls}
         1    0.000    0.000    0.000    0.000 {len}
    429510    0.023    0.000    0.023    0.000 {method 'append' of 'list' objects}
         1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
         1    0.000    0.000    0.000    0.000 {method 'format' of 'str' objects}
# run OpenMaya iterator
cProfile.run("object_utils.get_mesh_points('Emmanuel_Guevarra_Ian_McKellen_medres:Group2')")
 [Number of Vertices] :: 429510
          1718065 function calls in 0.860 seconds
 Ordered by: standard name
 ncalls  tottime  percall  cumtime  percall filename:lineno(function)
         1    0.059    0.059    0.860    0.860 :1()
         1    0.000    0.000    0.000    0.000 OpenMaya.py:2790(init)
         1    0.000    0.000    0.000    0.000 OpenMaya.py:5304(init)
         1    0.000    0.000    0.000    0.000 OpenMaya.py:7701(init)
         1    0.000    0.000    0.000    0.000 OpenMaya.py:9666(init)
         1    0.313    0.313    0.801    0.801 object_utils.py:112(get_mesh_points)
         1    0.000    0.000    0.000    0.000 object_utils.py:142(get_mesh_fn)
         1    0.000    0.000    0.000    0.000 {isinstance}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MDagPath_extendToShapeDirectlyBelow}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MDagPath_node}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MDagPath_swiginit}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MFnMesh_numVertices}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MFnMesh_swiginit}
    429511    0.030    0.000    0.030    0.000 {maya._OpenMaya.MItMeshVertex_isDone}
    429510    0.035    0.000    0.035    0.000 {maya._OpenMaya.MItMeshVertex_next}
    429510    0.393    0.000    0.393    0.000 {maya._OpenMaya.MItMeshVertex_position}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MItMeshVertex_swiginit}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MObject_hasFn}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MSelectionList_add}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MSelectionList_getDagPath}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.MSelectionList_swiginit}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.new_MDagPath}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.new_MFnMesh}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.new_MItMeshVertex}
         1    0.000    0.000    0.000    0.000 {maya._OpenMaya.new_MSelectionList}
    429510    0.030    0.000    0.030    0.000 {method 'append' of 'list' objects}
         1    0.000    0.000    0.000    0.000 {method 'disable' of '_lsprof.Profiler' objects}
         1    0.000    0.000    0.000    0.000 {method 'format' of 'str' objects}

for cmds and OpenMaya, 1.629 seconds and 0.860 seconds respectively.