OpenMaya.MDataBlock Class Reference

Class Description

Dependency node data block.

Inheritance diagram for OpenMaya.MDataBlock:

Public Member Functions
	__init__ ()
	context ()
	inputArrayValue ()
	inputValue ()
	isClean ()
	outputArrayValue ()
	outputValue ()
	setClean ()
	setContext ()

Constructor & Destructor Documentation

OpenMaya.MDataBlock.__init__

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x.__init__(...) initializes x; see help(type(x)) for signature

Member Function Documentation

OpenMaya.MDataBlock.context

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context() -> MDGContext

Returns a copy of the dependecy graph context for which this data block was created. The context is used to specify how a dependency node is going to be evaluated.

OpenMaya.MDataBlock.inputArrayValue

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inputArrayValue(plug) -> MArrayDataHandle
inputArrayValue(attribute) -> MArrayDataHandle

Gets an array handle to this data block for the given plug/attribute's data.  This is only valid if the given plug has array data.  The data represented by the handle will be valid.  If the data is from a dirty connection, then the connection will be evaluated.  If no connection is present, then the value that the plug has been set to will be returned.  If the plug has not been set to a particular value, then the default value will be returned.

* plug (MPlug) - the plug whose data you wish to access
 OR
* attribute (MObject) - the attribute whose data you wish to access

OpenMaya.MDataBlock.inputValue

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inputValue(plug) -> MDataHandle
inputValue(attribute) -> MDataHandle

Gets a handle to this data block for the given plug/attribute's data.  The data represented by the handle is guaranteed to be valid for reading.  If the data is from a dirty connection, then the connection will be evaluated.  If no connection is present, then the value that the plug has been set to will be returned. If the plug has not been set to a particular value, then the default value will be returned.

* plug (MPlug) - the plug whose data you wish to access
 OR
* attribute (MObject) - the attribute of the node that you want to access

OpenMaya.MDataBlock.isClean

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isClean(plug) -> bool
isClean(attribute) -> bool

Queries the dependency graph to see whether the given plug/attribute is clean.

* plug (MPlug) - the plug that is to be query
 OR
* attribute (MObject) - the attribute that is to be query.

OpenMaya.MDataBlock.outputArrayValue

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outputArrayValue(plug) -> MArrayDataHandle
outputArrayValue(attribute) -> MArrayDataHandle

Gets a handle to this data block for the given plug/attribute's data.  No dependency graph evaluations will be done, and therefore the data is not guaranteed to be valid (i.e. it may be dirty).  Typically, this method is used to get the handle during compute in order to write output data to it.

Another usage of this method is to access an input array attribute without evaluating any of its array elements. One can then use MArrayDataHandle.jumpToElement() to get to the particular element of interest, and evaluate its value using MArrayDataHandle.inputValue().

* plug (MPlug) - the plug whose data you wish to access
 OR
* attribute (MObject) - the attribute whose data you wish to access

OpenMaya.MDataBlock.outputValue

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outputValue(plug) -> MDataHandle
outputValue(attribute) -> MDataHandle

Gets a handle to this data block for the given plug/attribute's data.  The data is not guaranteed to be valid.  No dependency graph evaluations will be done. Therefore, this handle should be used only for writing.

* plug (MPlug) - the plug whose data you wish to access
 OR
* attribute (MObject) - the attribute of the node that you want to access

OpenMaya.MDataBlock.setClean

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setClean(plug) -> self
setClean(attribute) -> self

Tells the dependency graph that the given plug/attribute has been updated and is now clean.  This should be called after the data in the plug has been recalculated from the inputs of the node.

* plug (MPlug) - the plug that is to be marked clean
 OR
* attribute (MObject) - the attribute that is to be marked clean

OpenMaya.MDataBlock.setContext

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setContext(ctx) -> self

Set the dependency graph context for this data block. The context is used to specify how a dependency node is going to be evaluated, thus replacing the context for the given datablock. This does not modify the dirty state of the datablock so that they apply to the new context.

This function should not be used for timed evaluation.

* ctx (MDGContext) - the dependency graph context