This is an interesting approach:
start = time.time()
cmds.select('nurbsSphereShape*')
size = len(cmds.ls(sl=True))
cmds.setAttr(".castsShadows", *(1 for _ in xrange(size)))
end = time.time()-start
print end
# 0.243406057358
... Though an extra slow down happens if you have to deselect.
On Aug 5, 2012, at 5:17 PM, Matt Estela wrote:
> (cc my reply to the group)
>
>
>
> On Mon, Aug 6, 2012 at 9:16 AM, Matt Estela <[email protected]> wrote:
> Yeah, again it was a contrived example, in production lighters will
> definitely be using whatever bizarro wildcards they can muster.
>
> As you say it appears to be a core limitation of wildcards, will have to
> rethink how we let lighters define object selections. In this case maybe we
> just can't let lighters use wildcards, instead they'll have to pre-define it
> using sets. Or possibly pre-filtering to specific object types, and running
> list comprehensions on that.
>
> Hmm, houdini's smart bundles would come in handy here... (dynamic sets based
> on wildcards, they run surprisingly fast)
>
> Thanks again for the help Justin, you saved me several days worth of
> research. :)
>
>
>
>
> On Mon, Aug 6, 2012 at 5:15 AM, Justin Israel <[email protected]> wrote:
> Ya, in some cases you can't beat the python commands module if you are only
> doing a single command. Most of the work is happening behind the scenes in
> C++. The wildcard searches just appear to be beasty no matter what.
>
> But considering you didn't need a wildcard pattern, and instead just want to
> say "Apply to all nurbsSurface objects under this root:
>
> #
> # cmds
> #
> start = time.time()
> sel =cmds.listRelatives('|set', ad=True, type="nurbsSurface")
> for each in sel:
> cmds.setAttr("{0}.castsShadows".format(each), 1)
> end = time.time()-start
> print ('cmds = %s' % end)
> # ** cmds = 0.290652990341 **
>
> #
> # api
> #
> start = time.time()
>
> sel = om.MSelectionList()
> dagFn = om.MFnDagNode()
> mObj = om.MObject()
> dagIt = om.MItDag()
>
> sel.add("|set")
> sel.getDependNode(0, mObj)
> dagIt.traverseUnderWorld(True)
> dagIt.reset(mObj, dagIt.kDepthFirst, om.MFn.kNurbsSurface)
>
> while not dagIt.isDone():
> curr = dagIt.currentItem()
> dagFn.setObject(curr)
> dagFn.findPlug("castsShadows").setBool(False)
> dagIt.next()
>
> end = time.time()-start
> print ('api = %s' % end)
> # ** api = 0.117326021194 **
>
>
>
>
> On Aug 5, 2012, at 7:01 AM, matt wrote:
>
>> Hmm... did some experimenting. Using your example as a base, I compared
>> modifying the castsShadows attr on 8000 spheres. I have them grouped in the
>> following way:
>>
>> `-- set
>> |-- a
>> | |-- nurbsSphere0001
>> | |-- ...
>> | `-- nurbsSphere4000
>> `-- b
>> |-- nurbsSphere4001
>> |-- ...
>> `-- nurbsSphere8000
>>
>> I get very similar results for both api and maya.cmds. Interestingly, I get
>> an incredible slowdown depending on how specific/general I am with the
>> search:
>>
>> search = set|*|*|nurbsSphereShape*
>> api = 27.6180000305
>> cmds = 27.018999815
>>
>> vs
>>
>>
>> search = nurbsSphereShape*
>> api = 0.956000089645
>> cmds = 0.403000116348
>>
>>
>> This is my first few hours playing with openmaya, already made some silly
>> mistakes (defining function-sets inside the loop is waaaay slower than
>> outside the loop), but wondering if there's something else I'm missing...
>> would appear wildcards should just be avoided at all costs. Here's my
>> contrived example:
>>
>>
>>
>> import maya.OpenMaya as om
>> import maya.cmds as cmds
>> import time
>>
>> #search = "set|*|*|nurbsSphereShape*"
>> search = "nurbsSphereShape*"
>>
>> print ("search = %s" % search )
>>
>> # API based
>> start = time.time()
>>
>> sel = om.MSelectionList()
>> sel.add( search )
>> iter = om.MItSelectionList(sel)
>> depFn = om.MFnDependencyNode()
>> mObj = om.MObject()
>>
>> while not iter.isDone():
>> iter.getDependNode( mObj )
>> depFn.setObject(mObj)
>> depFn.findPlug("castsShadows").setBool(True)
>> iter.next()
>> end = time.time()-start
>> print ('api = %s' % end)
>>
>> # maya.cmds based
>> start = time.time()
>> sel = cmds.ls( search )
>> for each in sel:
>> cmds.setAttr("{0}.castsShadows".format(each), 1)
>> end = time.time()-start
>> print ('cmds = %s' % end)
>>
>>
>>
>>
>> On Sunday, August 5, 2012 9:14:06 AM UTC+10, matt wrote:
>> Wow, definitely seems worth investigating. Thanks for the code snippet and
>> timing info!
>>
>> On Sunday, August 5, 2012, Justin Israel wrote:
>> As a random example...I created a nurbsSphere, and just simulated looping
>> over 5000 objects and setting and attrib.
>>
>> import maya.OpenMaya as om
>> import time
>> import maya.cmds as cmds
>>
>> sel = om.MSelectionList()
>> om.MGlobal.getActiveSelectionList(sel)
>> iter = om.MItSelectionList(sel)
>>
>> obj = om.MObject()
>> depFn = om.MFnDependencyNode()
>>
>> start = time.time()
>> for i in xrange(5000):
>> iter.getDependNode(obj)
>> depFn.setObject(obj)
>> depFn.findPlug("tx").setInt(4)
>> end = time.time()-start
>> print end
>> # 0.0979061126709 seconds
>>
>> start = time.time()
>> for i in xrange(5000):
>> name = "nurbsSphere1"
>> cmds.setAttr("{0}.tx".format(name), 4)
>> end = time.time()-start
>> print end
>> # 0.261173009872 seconds
>>
>>
>>
>>
>> On Aug 4, 2012, at 12:22 PM, Justin Israel wrote:
>>
>>> Some of the big speed increases are using the iterators and not having to
>>> do a bunch of string operations on dag paths. And the math speedups from
>>> using the OpenMaya objects with operators.
>>>
>>> Your best bet it to just profile some small tests. You can easily make use
>>> of the python `timeit` module to check the difference in speed of
>>> operations.
>>>
>>>
>>>
>>> On Aug 4, 2012, at 10:53 AM, matt wrote:
>>>
>>>> Apologies for the crosspost for anyone on maya_he3d, only remembered this
>>>> group existed seconds after I posted over there... Have tried to edit and
>>>> re-word for you smart people. :)
>>>>
>>>> Short version:
>>>> Would using the python OpenMaya module give big speed gains for selecting
>>>> thousands of objects and modifying their attributes?
>>>>
>>>> Long version:
>>>> We have a python based, text based render pass submission tool for
>>>> lighters at work. One of its core functions is grabbing whatever geometry
>>>> is defined by a lighter, and setting attributes. This sometimes means
>>>> adding attributes first (or connecting our custom attribute node), then
>>>> setting them.
>>>>
>>>> We're getting into the situation where we have _very_ heavy scenes, with
>>>> thousands of objects. Normally our system will process these scenes within
>>>> a minute or two per frame, if lighters use wildcards, eg 'set:tree*', that
>>>> can jump to maybe 6 mins per frame. Not too bad.
>>>>
>>>> Things get messy with our alembic style heirachical geo format. It can
>>>> contain many sub-objects, which our maya plugin doesn't allow us to list
>>>> or search for sub-objects names easily. Thus, if a lighter wildcards to
>>>> the sub-object level, eg "set:*|leaves*", the only safe way to do that is
>>>> to process every object, then every sub-object, unsetting atts those
>>>> objects which AREN'T leaves, and setting attrs on those objects which ARE
>>>> leaves. When this happens, processing jumps to 3 hours per frame. Yuck!
>>>>
>>>> In the short term we're getting lighters to be more careful with
>>>> wildcards, in the mid term getting assets collapsed down so they're not so
>>>> name and sub-object heavy, and in the long term getting our geo plugin
>>>> more inspectable. So that's good.
>>>>
>>>> I was curious though.... could this be helped in the short(ish) term by
>>>> re-writing that part of the code with the OpenMaya module? I recall
>>>> reading there's many things which are faster, a few which are slower, and
>>>> fewer still which have no OpenMaya equivalent and can only be done in
>>>> mel/python. I have a sneaking suspicion one of those slow things was
>>>> something fundamental like selection, but I'm hoping I'm wrong.
>>>>
>>>> Was curious if the basic idea of 'yeah, manipulating hundreds of objects
>>>> and their attributes is N times faster with OpenMaya' is worth pursuing.
>>>>
>>>> -matt
>>>>
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>>
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