"worldmatrix is only updated on demand.."
Yea, That also I have speculated...
"Try instead hooking up to matrix and parentmatrix plugs of the node
whose worldmatrix you want. They should get pushed to your node and
then you can just concatenate them in compute() to get the world
matrix."
My problem is little bit typical :). this is not about computing world
matrix...say like, my node is connected in this order: NodeA -> NodeB-
> NodeC->.......-> NodeD->MyNode. Now what I want to achieve, instaed
of using any callback system use DAG system, to evalute myNode's
compute block while any of the node in the hierarchy is changing
trasform matrix. Now if I plugin parentmatrix / matrix from nodeD, I
think if nodeD is affected then only it will evalute mynode....but not
for other nodes up in the hierarchy. So to find a clean way I have
tried to use worldMatrix of NodeD (as worldMatrix change is true for
change in any depth) as I not want to plug with all other node's
matrix in the hierarchy. But seems like I'm wrong :(...need to find a
better solution. Any way thanks man.
On Aug 13, 3:10 pm, Adam Mechtley <adam.mecht...@gmail.com> wrote:
> Iirc, worldmatrix is only updated on demand (eg, you getAttr on it or on a
> plug that depends on it). Try instead hooking up to matrix and parentmatrix
> plugs of the node whose worldmatrix you want. They should get pushed to your
> node and then you can just concatenate them in compute() to get the world
> matrix.
>
> Sent from my iPhone
>
> On Aug 13, 2010, at 6:44, susanta <susant...@gmail.com> wrote:
>
> > Hi Guys,
>
> > I'm trying to create a custom MPX node, which is doing some
> > calculation based on a bone's scale in a hierarchy. So far my compute
> > code is working properly. I want to run the compute block always if
> > the any bone in the hierarchy got new world matrix (either by pos, rot
> > or scale change). But what I'm getting here, worldmatrix attribute of
> > a node not getting changed always untill you querry from outside (eg.
> > through MEL). Below is my test code....I have a input matrix plug
> > which connected to worlMatrix of a tranformNode. I expect when I'm
> > scaling or moving position of the transform node...compute block of my
> > node should get called...but not getting desired result...am I missing
> > somthing?
>
> > Thanks
> > Susanta
>
> > class ChainLengthCalc(omx.MPxNode):
> > kPluginNodeTypeName = "ChainLengthCalc"
> > kPluginNodeTypeId = om.MTypeId(0xd1a9257)
> > def __init__(self):
> > omx.MPxNode.__init__(self)
>
> > def compute(self,plug,dataBlock):
> > if plug == self.currentChainLength:
> > print "hello"
> > return om.MStatus.kSuccess;
> > return m.MStatus.kUnknownParameter;
>
> > �...@classmethod
> > def creator(cls):
> > return omx.asMPxPtr( cls() )
>
> > �...@classmethod
> > def initialize(cls):
> > unitAttr = om.MFnUnitAttribute()
> > cls.currentChainLength = \
> > unitAttr.create("currentChainLength", "ccl",
> > om.MFnUnitAttribute.kDistance, 0)
> > unitAttr.setKeyable(False)
> > unitAttr.setWritable(False)
> > cls.addAttribute(cls.currentChainLength)
>
> > mAttr = om.MFnMatrixAttribute()
> > cls.drivingBoneMatrixAttr = mAttr.create( "drivingBoneMatrix",
> > "dbm")
> > mAttr.setStorable(True)
> > mAttr.setWritable(True)
> > cls.addAttribute(cls.drivingBoneMatrixAttr)
>
> > cls.attributeAffects(cls.drivingBoneMatrixAttr,
> > cls.currentChainLength)
>
> > --
> >http://groups.google.com/group/python_inside_maya
>
>
--
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