Maya：第七周

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OpenMaya 对比 cmds优势：
1.适合插件的开发，因为拥有cmds未公开的功能
2.由于是Maya C++ API的Python库，速度上也会比cmds来的更快
3.在组件级别的对象（点边面），处理的效率会大幅度超越cmds

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测试环境：
对场景中的10000 polyCube 做位置旋转随机，缩放统一设置 0.2，并改名字：

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import maya.cmds as cmds

for i in xrange(0, 10000):
    cmds.polyCube(ch=False)[0]

Mel:

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$sel = `ls -tr "pCube*" `;
$start_time =  `about -ct`;
for ($x=0; $x<size($sel); $x++)
{
    float $x_v=rand(-12.0,12.0);
    float $y_v=rand(-12.0,12.0);
    float $z_v=rand(-12.0,12.0);
//    string $new_name ="AAAA_" + ($x+1);
    setAttr ($sel[$x] + ".translate") -type "double3" $x_v $y_v $z_v;
    setAttr ($sel[$x] + ".rotate") -type "double3" $x_v $y_v $z_v;
    setAttr ($sel[$x] + ".scale") -type "double3" 0.2 0.2 0.2;
    rename($sel[$x], "AAAAA");
}
$end_time =  `about -ct`;

由于用的是about -ct 来看的系统时间，可以看到大约是1秒的间隔

Cmds：

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# coding=utf8
import time

time_start = time.time()
sel = cmds.ls('pCube*', tr=True)
for obj in sel:
    x_val = random.uniform(-12, 12)
    y_val = random.uniform(-12, 12)
    z_val = random.uniform(-12, 12)
    cmds.setAttr('{}.t'.format(obj), x_val, y_val, z_val)
    cmds.setAttr('{}.r'.format(obj), x_val, y_val, z_val)
    cmds.setAttr('{}.s'.format(obj), 0.2, 0.2, 0.2)
    cmds.rename(obj, 'bbbbb')
time_end = time.time()

print(u'time:', time_end - time_start)

耗时大约2.01秒

Python Api：

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# coding=utf8
import maya.OpenMaya as om

time_start = time.time()
original_sel = om.MSelectionList()
sel = cmds.ls('pCube*', tr=True)
for item in sel:
    original_sel.add(item)

mob = om.MObject()
mTransform = om.MFnTransform()

api_lit_iter = om.MItSelectionList(original_sel)
while not api_lit_iter.isDone():
    # random values
    x_val = random.uniform(-12, 12)
    y_val = random.uniform(-12, 12)
    z_val = random.uniform(-12, 12)
    api_lit_iter.getDependNode(mob)
    mTransform = om.MFnTransform(mob)
    for attr in ['translate', 'rotate', 'scale']:
        plug = mTransform.findPlug(attr)
        if attr == 'scale':
            x_val, y_val, z_val = [0.2, 0.2, 0.2]
        for index, val in enumerate([x_val, y_val, z_val]):
            child_plug = plug.child(index)
            t_attr_val = plug.asDouble()
            child_plug.setDouble(val)
    mTransform.setName('ccccc')
    api_lit_iter.next()
    
time_end = time.time()

print(u'time:', time_end - time_start)

大约是2.39秒

结论是看得出常规操作中PythonApi并没有什么优势，
PythonApi。。。未完待续。。。。。。