If you have nothing connected the compute method is triggered by either a
UI ( think attribute editor or any other connectControl/attributeControl
element), when it is selected or visible: I rarely use setDependsDirty: my
node use basic relationship and attributeAffects is enough for me.
I have used pretty much all type of attribute as input and output in python
and C++( not the generic one that accept different type of data yet ).
What works for me is is to let maya control the dirty bit propagation
between connected attributes.
lets examine your node:
MyNode.aOutput = tAttr.create('output', 'output', om.MFnData.kDoubleArray)
this is a typeAttribute:
you can write and read from it several MFNData like MFnMatrixData,
MFnMeshData,MFnArrayAttrsData, MFnComponentListData, MFnDoubleArrayData(
etc more info on the documentation can be found).
Depending on your data type you must use the appropriate MFnfunction:
here MFnDoubleArrayData ()
outHandle = dataBlock.outputValue(MyNode.aOutput)
to write your data, you set an MObject created from this MFNDoubleArrayData:
#MObject create (const MDoubleArray &in, MStatus *ReturnStatus=NULL)
#<--- C++ notation
Lets say you have create a MDoubleArray: and fill it
OuputList = OpenMaya.MDoubleArray()
#here expand and fill your value
outputDataFn = OpenMaya.MFNDoubleArrayData()
outputDataObj = outputDataFn.create(OuputList)
outHandle.setMObject(outputDataObj)outHandle.setClean()
Let me know if it still refuse to works,
Le samedi 9 juin 2012 23:37:46 UTC+2, Judah Baron a écrit :
>
> You may benefit from at least testing out the setDependentsDirty call.
> Typed attributes are a bit more complex than standard base type attributes
> and Maya may handle them differently - I have no direct experience using
> them in compute. Unlike compute, setDependentsDirty is called every time an
> attribute value changes, allowing you to dirty the plugs required for your
> node to compute when needed. It's also good for dynamic multis and
> compounds, allowing you to pinpoint your computation in a manner not
> possible by using attributeAffects.
>
> -J
>
> On Saturday, June 9, 2012, WhileRomeBurns wrote:
>
>> In the real plugin, I do declare "Author Name", "Plug Version", etc. The
>> point of my example was to remove all that code (which Maya allows- it gets
>> initialized to default values) to make it clear to myself, and others, what
>> the problem is. Hence I cut out the normal try/except error stuff as well-
>> cleaner examples are nice.
>>
>>
>> *> then In your compute method there is no code to write some value on
>> your output and also no setClean call. *
>> Doesn't matter matter if I set it clean- compute never gets called in my
>> example, so adding in setClean() or any other function call isn't relevant
>> as far as I can tell- it never gets dirtied.
>>
>>
>> *> Your node must also be connected to another node.*
>> Does it always? There are nodes that update on attribute change without
>> being connected. My first example does this. Change 'input' int attribute
>> and compute() gets called, and 'output' updates. The dirty/clean stuff
>> works a charm- I told Maya that attributeAffects(MyNode.aInput, MyNode.
>> aOutput) and boom- input did indeed affect output as advertised! So
>> saying it must be connected is untrue for this case of kInt or KFloat, both
>> of which I've tested.
>>
>> Now if I do attributeAffects(MyNode.aInput, MyNode.aOutput) with aOutput
>> being an MFnTypedAttribute, compute() never gets called. attributeAffects()
>> does not work as described in the API docs (for this simple one node case)
>> and I want to know why. I assume there is a logical, maybe even
>> obvious, explanation; maybe it's an optimization on Maya's part because I
>> haven't actually created an array of data for the aOutput attr yet?
>>
>>
>> *> Do you have any prior experience with the API?*
>> Mostly writing translators, compiling others' c++ nodes to work with my
>> version of maya/environment. Just got into python api stuff though.
>>
>>
>> *> Have you a basic understanding of the concept of hierarchy ,
>> connections , attributes and plug ?( DAG versus dependency nodes )*
>> I would say that I definitely have at least basic understanding, but I
>> came here for the people with the advanced understanding. :)
>>
>>
>> Thanks again for your patience. I really want to resolve this simple
>> example before I start porting my code to Maya nodes.
>> -shawn
>>
>>
>>
>>
>>
>>
>>
>> On Friday, June 8, 2012 4:29:55 PM UTC-4, cedric bazillou wrote:
>>>
>>> first In your plugin declaration with the kDoubleArray output I would
>>> rather correct those lines( things can be done in a lot of different ways,
>>> this is how i do it ):
>>> "
>>>
>>> def initializePlugin(mobject):
>>> fnPlugin = omMPx.MFnPlugin(mobject)
>>> fnPlugin.registerNode(nodeType**, nodeId, nodeCreator, nodeInitializer)
>>>
>>> "
>>> by
>>> "
>>> kPluginNodeName = "spaceSwitch" #<-- replace by your plugin name
>>>
>>> kPluginNodeId = OpenMaya.MTypeId(your_Custom_**ID_number here)
>>> def initializePlugin(mobject):
>>> mplugin = OpenMayaMPx.MFnPlugin(mobject, "AuthorName", "VersionNum",
>>> "Any")
>>>
>>> mplugin.registerNode( kPluginNodeName, kPluginNodeId, nodeCreator,
>>> nodeInitializer, OpenMayaMPx.MPxNode.**kDependNode)# <-- As you can see I
>>> use the type of the node here a dependency node
>>> "
>>>
>>>
>>> then In your compute method there is no code to write some value on your
>>> output and also no setClean call.
>>> Your node must also be connected to another node. just few question
>>> bellow,
>>> Are your example the complete code for your nodes?
>>> Do you have an ascii maya file that can be used as an example?
>>> Do you have any prior experience with the API?
>>> Have you a basic understanding of the concept of hierarchy , connections
>>> , attributes and plug ?( DAG versus dependency nodes )
>>>
>>> Le vendredi 8 juin 2012 19:51:19 UTC+2, WhileRomeBurns a écrit :
>>>>
>>>> Thanks for the quick replies! So he basically tricks Maya into dirtying
>>>> his plug in the draw method? Nice. So in my example, I would query the
>>>> value of a third dummy attribute- something lighter weight than an array
>>>> like a float or int and use that to force the eval? Can do!
>>>>
>>>>
>>>> * > how about writing a node to compute your pointList and plug it to
>>>> your locator that will only draw from *
>>>> Absolutely the way to go, but I thought I would save time and test the
>>>> idea in one node. But then nothing worked :)
>>>>
>>>>
>>>> Additionally, I'm now fighting python just to call compute with *
>>>> MFnTypedAttributes*. Two examples, slightly modified versions of
>>>> Farsheed's skeleton code. The first one has MFnNumericAttribute as the
>>>> output attribute and it calls the compute method as expected. The second
>>>> one is bunk though and I cannot figure out why. Hmm. Take a look:
>>>>
>>>> nodeNumeric.py:
>>>> http://pastebin.ubuntu.com/**1030758/<http://pastebin.ubuntu.com/1030758/>
>>>>
>>>> Works a charm, compute gets called.
>>>>
>>>> nodeTyped.py
>>>> http://pastebin.ubuntu.com/**1030764/<http://pastebin.ubuntu.com/1030764/>
>>>>
>>>> Compute never gets called. Silently fails? Only changed the attr type
>>>> to TypedAttr and kDoubleArray. Nada. Zilch. Zippo!
>>>>
>>>> Did I miss something obvious? Thanks.
>>>> -shawn
>>>>
>>>>
>>>> --
>> view archives: http://groups.google.com/group/python_inside_maya
>> change your subscription settings:
>> http://groups.google.com/group/python_inside_maya/subscribe
>>
>
--
view archives: http://groups.google.com/group/python_inside_maya
change your subscription settings:
http://groups.google.com/group/python_inside_maya/subscribe
