How to us Custom MPxData from cpp in python.

[Cameron Fulton]

Hi all,

So I have a custom data type that I create in cpp that I use for an attribute on a custom node. My custom data type is pretty straight forward:

class BlindData : public MPxData
{


 public:
    BlindData();
    virtual ~BlindData();


  /**
   * Copy the local data from a similar data object
   *
   * @param MPxData
   *   Data object to copy from.
   */
  virtual void copy(const MPxData&);


  MStatus
  readBinary(istream& in, unsigned int length);


  MStatus
  writeBinary(ostream& out);


  MTypeId typeId() const;


  MString name() const;

  static MString typeName;
  static MTypeId id;
  static void* creator();


  std::vector<char> m_data;
};

And then I just use that as a type for my attr on my node

  MFnTypedAttribute tAttr;
  MStatus stat;

    blindDataAttr = tAttr.create("blindData",
                                 "blind",
                                 BlindData::id,
                                 MObject::kNullObj,
                                 &stat);
   addAttribute(mPoseDataList);

So now I want to set that in Python, but I'm not sure how too. Anyone run into this before?

[Cameron Fulton]

Ok, so after asking I plugged away and figured out how to do it. Here is what I found for anyone else who is interested in doing this.

def getAttrPlug(nodeName, attrName):
    selectionList = OpenMaya.MSelectionList()
    try:
        selectionList.add(nodeName)
    except:
        return None
    dependNode = selectionList.getDependNode(0)
    dagNode = OpenMaya.MFnDagNode(selectionList.getDagPath(0))
    attrNode = dagNode.attribute(attrName)
    return OpenMaya.MPlug(dependNode,attrNode)


def createPluginData(typeId, dataList):
    pluginDataCreator = OpenMaya.MFnPluginData()
    bdtID = OpenMaya.MTypeId(typeId)
    pluginDataCreator.create(bdtID)
    values = bytearray(dataList)
    pluginDataCreator.data().readBinary(values, len(dataList))
    return pluginDataCreator.data()

blindNode = getAttrPlug("blind", "blindData")

blindData = createPluginData(0x00001948, [84,111,111,32,69,97,115,121])

dataHandle = blindNode.asMDataHandle()

dataHandle.setMPxData(blindData)