Maya开发实践课（二） - Vanny Yuan's Blog

L15 走进 PyMEL 编程

什么是PyMel

了解PyNode

pynode转化

node = pm.PyNode('pSphere1')

# ! 查询方法
dir(node)

# ! 查询属性
dir(node.attr())

连接属性

import maya.cmds as cmds
import pymel.core as pm
ball = pm.PyNode('ball')
ball_tx = ball.attr('tx')

box = pm.PyNode('pCube1')
box_tx = box.attr('tx')

ball_tx >> box.tx

断开连接

ball_tx //  box_tx

使用API方法

ball = pm.PyNode('ball)
baii.__apiobject__()

练习

使用PyMEl实现原来融合节点的连接。


import pymel.core as pm

lam_A = pm.createNode('lambert')
lam_B = pm.createNode('lambert')
lam_C = pm.createNode('lambert')
bc = pm.createNode('blendColors')

lam_A.outColor >> bc.color1
lam_B.outColor >> bc.color2
bc.output.connect(lam_C.color)

L16 为 Maya 安装第三方 Python 包

拷贝安装
pip安装
编译安装

练习

给Maya安装yaml模块和numpy模块。

Numpy

官方文档

https://numpy.org/install/#python-numpy-install-guide

简介

https://www.runoob.com/numpy/numpy-tutorial.html

python安装

python -m pip install numpy

maya安装

下载wheel
https://pypi.tuna.tsinghua.edu.cn/simple/numpy/
安装
mayapy -m pip install C:\Users\Administrator\Desktop\numpy-1.14.0rc1-cp27-none-win_amd64.whl

yaml

python安装

python -m pip install pyyaml

maya安装

下载wheel
https://pypi.tuna.tsinghua.edu.cn/simple/pyyml/
安装
mayapy -m pip install C:\Users\Administrator\Desktop\pyyml-0.0.2-py2.py3-none-any.whl

L17 自定义 Maya 环境变量

为什么自定义软件环境

统一管理
快速部署
方便切换

环境变量的用户变量会覆盖系统变量。

cmd设置环境变量

set MAYA_DISABLE_CLIC_IPM=1

python设置环境变量

查询
```
os.environ
```

设置

_env = os.environ.copy()
_env['XXX_ENV'] = 'hello'
import subprocess
subprocess.Popen("C:/Program Files/Autodesk/Maya2017/bin/maya.exe",env=_env)

常用环境变量

练习

使用Yaml编写一个环境配置文件，读取里面内容使用subprocess启动软件。

写入yaml

import os
import yaml

yaml_str = """
name: yaml_env
date: 20200716
version: ['maya2018','maya2019']
"""

yaml_data = yaml.load(yaml_str, Loader=yaml.SafeLoader)

with open('D:/td_tech/yaml_test/yaml_write.yaml', 'w') as f:
        yaml.dump(yaml_data, f)

启动软件

import os
import yaml
import subprocess

with open('D:/td_tech/yaml_test/yaml_write.yaml', 'r+') as f:
        data = yaml.load(f, Loader=yaml.Loader)

_env = os.environ.copy()

for (key,value) in data.items():
        _env[key] = str(value)


subprocess.Popen("C:/Program Files/Autodesk/Maya2018/bin/maya.exe",env=_env)

L18 Maya API 基本类型介绍

Maya API基本结构

API语言支持

API编译的插件后缀：

Linux：.so

Windows: .mll

Mac OS X：.bundle

通用性插件：.py
API内置库：

OpenMaya 基本的操作工具类

OpenMayaUI 界面工具类

OpenMayaAnim 动画工具类

OpenMayaFX 特效工具类

OpenMayaRender 渲染工具类
API命名规则

M classes - 基本的数据类型

MFn - Function 函数工具类型

MIt - Iterator 迭代器类型

MPx - 代理类型，拓展Maya功能需要继承的类

DependencyNode、 DagNode

DependencyNode：Maya最基本的节点类型

DagNode：Maya带有层级的节点类型

DagNode由DependencyNode继承而来，DagNode有层级关系继承。

MObject

查询API帮助文档 API1.0

MObject() 相当于python的init()，可以用于实例化对象

静态方法static Mobject：在没有实例化节点之前就能使用

析构函数~Mobject()：变量在销毁的时候执行的操作

通过Pymel创建Mobject

import maya.OpenMaya as OpenMaya
import pymel.core as pm

ball_node = pm.PyNode('pSphere1')
ball_api_node = ball_node.__apimobject__()

# 通过pymel转化的MObject已经有了对象
print ball_api_node.isNull() # True
# 通过OpenMaya直接创建的MObject是空的
print OpenMaya.MObject().isNull() # False

# 查询api类型
print ball_api_node.apiType() # 110
print ball_api_node.apiTypeStr() # kTransform
ballshape_api_node = pm.PyNode('pSphereShape1').__apimobject__()
print ballshape_api_node.apiType() # 296
print ballshape_api_node.apiTypeStr() # kMesh

# 使用 == != 判断两个物体是否相等
print ball_api_node == ballshape_api_node # False
# 使用 = 直接赋值
ballshape_api_node = ball_api_node
print ballshape_api_node.apiTypeStr()

DagPath

# 创建一个空的MDagPath
ball_dag_path = OpenMaya.MDagPath()
# 建立DagPath联系
OpenMaya.MDagPath.getAPathTo(ball_api_node,ball_dag_path)
# 获取DagPath名字
print ball_dag_path.fullPathName() # |pSphere1
print ball_dag_path.partialPathName() # pSphere1
# 判断是否显示
print ball_dag_path.isVisible() # True
# 通过MDagPath获取API类型
print ball_dag_path.apiType() # 110
# 通过MDagPath返回MObject
print ball_dag_path.node() # <maya.OpenMaya.MObject; proxy of <Swig Object of type 'MObject *' at 0x0000014894705F90>

思考

既然Maya已经提供了cmds这个编程的接口，为什么还要提供OpenMaya的呢？

L19 Maya API的三种基本类型

MFn

MFnDependencyNode：处理任何节点的普通方法

MFnDagNode：处理大纲物体的常用方法
MFnMesh：处理多边形操作

普通MFn记录Maya内所有节点的类型，MObject中的apiType返回的就是MFn列表的索引值

其他的有MFnSet、MFnMesh等等。

MIt

MitDag：处理大纲层级所有物体

MitCurveCV：处理曲线的点

MitMeshEdge：多边形的线的循环

MitMeshFaceVertex：处理多边形面点

MitMeshPolygon：处理多边形面

MitMeshVertex：处理多边形点

MitSelectionList：处理列表中的任何物体

MitDependencyGraph：通过一个节点寻找上下游所有节点

MitDependencyNodes：过滤场景内的任何节点

MPx

用于编写maya没有的物体

MpxCommand：编写一个命令

MPxNode：编写一个节点

总结

L20 Maya API中基本容器的使用

MSelectionList

import maya.OpenMaya as OpenMaya
import pymel.core as pm

# 创建一个空的MSelectionList
# <maya.OpenMaya.MSelectionList; proxy of <Swig Object of type 'MSelectionList *' at 0x0000014894705780> > 
lst = OpenMaya.MSelectionList()
print lst.isEmpty() # True

# 添加物体
lst.add('pSphere1')
# 查询个数
lst.length() # 1
# 添加所有的球体
lst.add('pSphere*')
lst.length() # 2

# 合并两个列表
b_lst = OpenMaya.MSelectionList()
b_lst.add('pCube?')
lst.merge(b_lst)

print lst.length() # 3

MItSelectionList

import maya.OpenMaya as OpenMaya
import pymel.core as pm

sel_lst = OpenMaya.MSelectionList()
sel_lst.add('pSphere?')

# 返回列表每一个物体的长名
dag_path = OpenMaya.MDagPath()
lst_iter = OpenMaya.MItSelectionList(sel_lst)
while not lst_iter.isDone():
        lst_iter.getDagPath(dag_path)
        print dag_path.fullPathName()
        
        lst_iter.next()

练习

通配符

import maya.cmds as cmds
import maya.OpenMaya as OpenMaya
import pymel.core as pm
from datetime import datetime

# create 10,000 balls
for i in range(1, 10000):
        cmds.polySphere()

# cmds
start_time = datetime.now()
sel_lst = cmds.ls(sl=True)
for sel in sel_lst:
        pass
end_time = datetime.now()
# 36000
cmds_time = (end_time - start_time)

# OpenMaya
sel_lst = OpenMaya.MSelectionList()
for i in range(1, 10000):
        sel_lst.add('pSphere{}'.format(i))
iter_lst = OpenMaya.MItSelectionList(sel_lst)
dag_path = OpenMaya.MDagPath()

start_time = datetime.now()
while not iter_lst.isDone():
        iter_lst.getDagPath(dag_path)
        iter_lst.next()
end_time = datetime.now()
# 28000
OpenMaya_time = (end_time - start_time)

# Mel

L21 Maya API 的全局操作方法 - MGlobal

MGlobal

import maya.OpenMaya
from maya.OpenMaya import MGlobal

print MGlobal.mayaVersion()
# 2018
print MGlobal.apiVersion()
# 20180500

# 把选择的物体传入sel列表
sel = OpenMaya.MSelectionList()
OpenMaya.MGlobal.getActiveSelectionList(sel)
print sel.length()

# 选择sel列表的物体
OpenMaya.MGlobal.setActiveSelectionList(sel)

# 执行python或mel命令
MGlobal.executeCommand('ls -sl')
MGlobal.executeCommand('createNode "joint"')
# MGlobal.executePythonCommand('cmds.createNode("joint")')

MGlobal.isYAxisUp()
# True

MGlobal.displayInfo('info ..')
MGlobal.displayWarning('warning ..')
MGlobal.displayError('error ..')

# 设置当前帧
MGlobal.viewFrame(30)

MGlobal常用方法

练习

尝试使用MGlobal选择屏幕某一块区域的物体。

import maya.OpenMaya as OpenMaya
from maya.OpenMaya import MGlobal
import pymel.core as pm

MGlobal.selectFromScreen(0,0,1920,1080,MGlobal.kAddToList,MGlobal.kSurfaceSelectMethod)

L22 Maya API 的文件操作 MFileIO

import maya.OpenMaya
from maya.OpenMaya import MFileIO

print MFileIO.currentFile()
# D:/test/test/test.ma

MFileIO.setCurrentFile('D:/test/test_1.ma')
print MFileIO.currentFile()
# D:/test/test_1.ma

print MFileIO.fileType()
# u'mayaAscii'

lst = list()
MFileIO.getFileTypes(lst)
print lst
# [u'mayaAscii', u'mayaBinary', u'mel', u'OBJ', u'directory', u'plug-in', u'audio', u'move', u'EPS', u'Adobe(R) Illustrator(R)', u'image', u'fluidCache', u'editMA', u'editMB', u'Alembic', u'RIB']

# 新建场景
MFileIO.newFile(True)

# 保存场景
MFileIO.saveAs('D:/test/test/ball.ma', 'mayaAscii')
MFileIO.save()

MFileIO 常用方法

练习

列出场景内所有的材质shadingGroup节点，并使用API导出为文件。

import maya.OpenMaya as OpenMaya
import pymel.core as pm

sg_lst = pm.ls(type='shadingEngine')
lst = OpenMaya.MSelectionList()

# 列出所有sg节点
for sg in sg_lst:
        sg_mobj = sg.__apimobject__()
        lst.add(sg_mobj)

# 选择所有sg节点
OpenMaya.MGlobal.setActiveSelectionList(lst)

# 导出选择的节点
OpenMaya.MFileIO.exportSelected('D:/test/sg_test.ma')

L23 Maya API 中的节点迭代器和函数类

MFnDependencyNode

import maya.OpenMaya as OpenMaya
import pymel.core as pm

mfn = OpenMaya.MFnDependencyNode(pm.ls(sl=True)[0].__apimobject__())
print mfn.typeName()
# transform
print mfn.name()
# pCylinder1
mfn.setName('new_pCylinder')
print mfn.name()
# new_pCylinder
mfn.attributeCount()
# 249

iterator = OpenMaya.MItDependencyNodes(OpenMaya.MFn.kMesh)
while not iterator.isDone():
        print OpenMaya.MFnDependencyNode(iterator.thisNode()).name()
        print OpenMaya.MFnDependencyNode(iterator.item()).name()
        iterator.next()

练习

import maya.OpenMaya as OpenMaya
import pymel.core as pm

mit = OpenMaya.MItDependencyNodes(OpenMaya.MFn.kMesh)
sh_sg_connects = {}
while not mit.isDone():
        mfn = OpenMaya.MFnDependencyNode(mit.item())
        plug_array = OpenMaya.MPlugArray()
        mfn.getConnections(plug_array)
        for i in range(plug_array.length()):
                des_array = OpenMaya.MPlugArray()
                plug_array[i].destinations(des_array)
                if des_array.length():
                        if des_array[0].node().apiTypeStr() == 'kShadingEngine':
                                sh_sg_connects[mfn.name()] = des_array[0].name().split('.')[0]
        mit.next()

for (key,value) in sh_sg_connects.items():
        print '{} connected to {}'.format(key,value)

L24 Maya API 层级迭代器与物体函数类

MFnDagNode


import maya.OpenMaya as OpenMaya
import pymel.core as pm

mfn = OpenMaya.MFnDagNode(pm.PyNode('pSphere1').__apimobject__())
print mfn.partialPathName()
# pSphere1
print mfn.fullPathName()
# |pSphere1
print mfn.childCount()
# 1

iterator = OpenMaya.MItDag()
while not iterator.isDone():
        print iterator.partialPathName()

        iterator.next()

练习

import maya.OpenMaya as OpenMaya
import pymel.core as pm

# 选择所有mesh
mit = OpenMaya.MItDag(OpenMaya.MItDag.kDepthFirst,OpenMaya.MFn.kMesh)
sel_lst = OpenMaya.MSelectionList()
while not mit.isDone():
        m_dag = OpenMaya.MFnDagNode(mit.item())
        sel_lst.add(m_dag.fullPathName())
        mit.next()


OpenMaya.MGlobal.setActiveSelectionList(sel_lst)

L25 Maya API 中的多边形处理MFnMesh MItMesh

MFnMesh

import maya.OpenMaya as OpenMaya
import pymel.core as pm

mfn = OpenMaya.MFnMesh(pm.PyNode('pSphere1').__apiobject__())
print mfn.numPolygons()
# 400
print mfn.numVertices()
# 382

point = OpenMaya.MPoint()
mfn.getPoint(0, point)
print point.x,point.y,point.z
# 0.148778125644 -0.987688362598 -0.0483409427106
mfn.getPoint(381, point)
print point.x,point.y,point.z
# 0.0 1.0 0.0

# 设置点位置
point = OpenMaya.MPoint(0,2,0)
mfn.setPoint(381, point)

iterator = OpenMaya.MItMeshVertex(pm.PyNode('pSphereShape1').__apiobject__())
while not iterator.isDone():
        # 查询点位置
        point = iterator.position()
        print iterator.index(), point.x, point.y, point.z
        
        # 设置点位置
        point = OpenMaya.MPoint(0,0,0)
        iterator.setPosition(point)
        iterator.next()

练习

使用MFnMesh和MItMesh里的迭代器，寻找两个物体穿插的部分。

L26 Maya API 中的指针 - MScriptUtil

MScriptUtil

import maya.OpenMaya as OpenMaya
import pymel.core as pm

iterator = OpenMaya.MItMeshVertex(pm.PyNode('pSphereShape1').__apimobject__())
# 定义float2类型指针
s_util = OpenMaya.MScriptUtil()
uv_ptr = s_util.asFloat2Ptr()

while not iterator.isDone():
        # 打印出每个点的uv值
        print iterator.index(),
        iterator.getUV(uv_ptr)
        print s_util.getFloat2ArrayItem(uv_ptr, 0, 0),
        print s_util.getFloat2ArrayItem(uv_ptr, 0, 1)
        iterator.next()

练习

L27 Maya API 中的事件捕获 - MMessage

Message

import maya.OpenMaya as OpenMaya
import pymel.core as pm

def func(*args):
        print 1

# 添加时间触发事件    
callback_id = OpenMaya.MTimerMessage.addTimerCallback(2, func)

# 移除时间触发事件
OpenMaya.MTimerMessage.removeCallback(callback_id)

# 获取可以调用的事件种类
event_names = list()
OpenMaya.MEventMessage.getEventNames(event_names)
print event_names()

# 创建时间轴变化事件
callback_id = OpenMaya.MEventMessage.addEventCallback('timeChanged',func)
# 移除时间轴变化事件
OpenMaya.MTimerMessage.removeCallback()

Message使用方法

定义函数
addCallback
removeCallback

练习

使用MSceneMessage创建一个事件，当文件reference创建完成之后，修改它的namespace。

Maya Maya开发实践课

MAYA SCRIPT

本博客所有文章除特别声明外，均采用 CC BY-SA 4.0 协议，转载请注明出处！

UnrealPython基础学习上一篇

Maya开发实践课（一）下一篇