Hmm... first off, your virtual node class needs to inherit from a 'real',
non-abstract, non-virtual class - in your example, it's inheriting from
pm.nt.MyNode (which I'm surprised even works - essentially, it's inheriting
from the node that is created from itself??)
Also, the create method needs to return the string name of the created node
(unless you also add a postCreate callback, in which case it can return
whatever the postCreate can handle), which should be noted in the latest
documentation for virtualClasses.register (and in the customClasses.py).
Lastly, in the create method itself, you should not use pymel code - stick
to maya.cmds stuff. Also, you cannot simply do createNode('MyNode'), as
these are 'virtual' classes that only pymel knows about. You would have to
do createNode('myRealBaseClass').
Here's an example which should work:
import maya.cmds as cmds
import pymel.core as pm
import pymel.internal.factories as factories
class MyNode(pm.nt.Locator):
@classmethod
def createVirtual(cls, **kwargs):
print 'CREATING MY NODE!'
return cmds.createNode('locator', **kwargs)
@classmethod
def _isVirtual( cls, obj, name ):
return True
def test(self):
print 'MY NODE!'
factories.virtualClasses.register(MyNode, create='createVirtual')
myNode = MyNode()
- Paul
On Tue, Nov 1, 2011 at 9:12 AM, Justin Rosen <[email protected]> wrote:
> Thanks Seth! Again, I'm using pymel that comes with 2011
> pymel.__version__ == 1.0.0'
>
> I was able to get a small working example that works with pm.createNode:
>
> class MyNode(pm.nt.MyNode):
> @classmethod
> def _isVirtual( cls, obj, name ):
> return True
>
> def test(self):
> print 'MY NODE!'
>
> pymel.internal.factories.registerVirtualClass(MyNode)
>
> myNode = pm.createNode('MyNode')
> myNode.test()
>
>
> Although, I'd like to be able to create my nodes via a call to
> MyNode(). To do this I added the classmethod createVirtual:
>
> class MyNode(pm.nt.MyNode):
> @classmethod
> def createVirtual(cls, **kwargs):
> print 'CREATING MY NODE!'
> return pm.createNode('MyNode', **kwargs)
>
> @classmethod
> def _isVirtual( cls, obj, name ):
> return True
>
> def test(self):
> print 'MY NODE!'
>
> myNode = MyNode()
> # Error: ValueError: unexpect result locator1 returned by spaceLocator #
>
> Am I missing something here?
>
> Thanks,
> Justin
>
> On Tue, Nov 1, 2011 at 12:24 AM, Justin <[email protected]> wrote:
> > Thanks! The first example seemed a bit overkill which is why I asked
> the question, but the second example is exactly what I need (Except I'm not
> on the trunk):
> >
> > # make sure Mayatomr plugin is loaded ore the Mib_amb_occlusion might
> not exist
> > loadPlugin('Mayatomr')
> > class Mib_amb_occlusion(Mib_amb_occlusion):
> > """This is an example of how to replace a node. Use this technique
> with care"""
> > def occlude(self):
> > print "occluding!"
> >
> > # the callback always returns True, so we always replace the default
> with our own.
> > Mib_amb_occlusion.registerVirtualSubClass( lambda *args: True,
> nameRequired=False )
> >
> > def testMib():
> > n = createNode('mib_amb_occlusion')
> > n.occlude()
> >
> > But, I get the following error:
> > # Error: AttributeError: file
> /Applications/Autodesk/maya2011/Maya.app/Contents/Frameworks/Python.framework/Versions/Current/lib/python2.6/site-packages/pymel/core/general.py
> line 53: type object 'Mib_amb_occlusion' has no attribute '_isVirtual' #
> >
> > I'm running the version of pcl that comes with 2011. I assume there
> have been a bunch of changes since then that has made this process easier,
> not requiring _isVirtual to be defined or in the trunks case a callback to
> be specified? Can I accomplish the same task of replacing the mental ray
> node with the version of pcl that comes with Maya2011?
> >
> > Thanks,
> > Justin
> >
> >
> > On Oct 31, 2011, at 11:53 PM, Justin Israel wrote:
> >
> >> This seems to be a really straight forward example located here:
> >> http://pymel.googlecode.com/svn/trunk/examples/customClasses.py
> >>
> >> It outlines how to subclass, and what class methods must be provided. I
> believe the use of the id attribute is for the validation test function, in
> order to determine if the incoming object type is the right kind. In this
> case they use the joint id attribute from the original Joint class to
> check. If its a joint then allow this subclass to be returned. Technically
> you could perform any test you see fit as long as you stick to the api to
> do it and not pymel calls.
> >>
> >>
> >>
> >>
> >> On Oct 31, 2011, at 7:51 PM, Justin <[email protected]> wrote:
> >>
> >>> Hey all, It's been a super long time since I've been on this list!
> >>>
> >>> I was wondering if I could get a quick example on how to accomplish a
> simple wrapping of a pymel node as described here:
> >>> http://code.google.com/p/pymel/issues/detail?id=62
> >>>
> >>> allow users to add their own methods to any node. users can now easily
> import pymel and then subclass nodes to do what they like, but perhaps
> there's a way to register these user subclass modules to be loaded by
> pymel, such that they are found within the pymel namespace.
> >>>
> >>>
> >>>
> >>> import pymel.core as pm
> >>>
> >>> # Load plugin
> >>> pm.loadPlugin('pointless')
> >>>
> >>> # Print Node Type
> >>> print pm.nt.PointlessViewer
> >>>
> >>> How would I subclass this and add my own methods?
> >>>
> >>> class PointlessViewerNode(pm.nt.PointlessViewer):
> >>> def myMethod(self):
> >>> # Do something with my node
> >>> pass
> >>>
> >>> Do I have to follow the example under pymel.examples.customClasses.py?
> Where an extra attribute is added, ie cls._PointlessClassID? I'm not sure
> I need this extra attribute, I just want to add additional methods to the
> existing pymel node returned when creating nodes.
> >>>
> >>> viewer = pm.createNode('pointlessViewer')
> >>> viewer.myMethod()
> >>>
> >>>
> >>> Thanks,
> >>> Justin
> >>>
> >>>
> >>>
> >>>
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