vtk管線入門3

RequestUpdateExtent

測試1

import vtk
from vtk.util.vtkAlgorithm import VTKPythonAlgorithmBase
from vtk.util import keys
# 元數據
requestKey = keys.MakeKey(keys.IntegerRequestKey, "a request", "my module")

class MySource(VTKPythonAlgorithmBase):
    def __init__(self):
        VTKPythonAlgorithmBase.__init__(self,
            nInputPorts=0,
            nOutputPorts=1, outputType='vtkPolyData')
 
    def RequestInformation(self, request, inInfo, outInfo):
        print ("MySource RequestInformation:")
        return 1
 
    def RequestUpdateExtent(self, request, inInfo, outInfo):
        print ("MySource RequestUpdateExtent:")
        print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestData(self, request, inInfo, outInfo):
        print ("MySource RequestData:")
        return 1
 
class MyFilter(VTKPythonAlgorithmBase):
    def __init__(self):
        VTKPythonAlgorithmBase.__init__(self,
            nInputPorts=1, inputType='vtkPolyData',
            nOutputPorts=1, outputType='vtkPolyData')
 
    def RequestInformation(self, request, inInfo, outInfo):
        print ("MyFilter RequestInformation:")
        return 1
 
    def RequestUpdateExtent(self, request, inInfo, outInfo):
        print ("MyFilter RequestUpdateExtent:")
        print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestData(self, request, inInfo, outInfo):
        print ("MyFilter RequestData:")
#        print (outInfo.GetInformationObject(0))
        return 1


s = MySource()
 
f = MyFilter()
f.SetInputConnection(s.GetOutputPort())
 
# f.Update()

f.UpdateInformation()
outInfo = f.GetOutputInformation(0)
outInfo.Set(requestKey, 0)
f.PropagateUpdateExtent()

發送請求：

f.UpdateInformation()
outInfo = f.GetOutputInformation(0)
outInfo.Set(requestKey, 0)
f.PropagateUpdateExtent()

輸出：
MySource和MyFilter中原數據a request: 0

MySource RequestInformation:
MyFilter RequestInformation:

MyFilter RequestUpdateExtent:
vtkInformation (0000018D6DE58F50)
  Debug: Off
  Modified Time: 230
  Reference Count: 2
  Registered Events: (none)
  PRODUCER: vtkCompositeDataPipeline(0000018D6D5A0710) port 0
  DATA_OBJECT: vtkPolyData(0000018D6DE58440)
  UPDATE_PIECE_NUMBER: 0
  UPDATE_NUMBER_OF_PIECES: 1
  UPDATE_NUMBER_OF_GHOST_LEVELS: 0
  a request: 0


MySource RequestUpdateExtent:
vtkInformation (0000018D6DE59D50)
  Debug: Off
  Modified Time: 242
  Reference Count: 3
  Registered Events: (none)
  PRODUCER: vtkCompositeDataPipeline(0000018D6D5A2720) port 0
  DATA_OBJECT: vtkPolyData(0000018D6B33D280)
  CONSUMERS: vtkCompositeDataPipeline(0000018D6D5A0710) port 0
  UPDATE_PIECE_NUMBER: 0
  UPDATE_NUMBER_OF_PIECES: 1
  UPDATE_NUMBER_OF_GHOST_LEVELS: 0
  a request: 0

測試2

import vtk
from vtk.util.vtkAlgorithm import VTKPythonAlgorithmBase
from vtk.util import keys

metaDataKey = keys.MakeKey(keys.DataObjectMetaDataKey, \
  "a meta-data", "my module")
requestKey = keys.MakeKey(keys.IntegerRequestKey, "a request", "my module")

class MySource(VTKPythonAlgorithmBase):
    def __init__(self):
        VTKPythonAlgorithmBase.__init__(self,
            nInputPorts=0,
            nOutputPorts=1, outputType='vtkPolyData')
 
    def RequestInformation(self, request, inInfo, outInfo):
        print ("MySource RequestInformation:")
        # outInfo.GetInformationObject(0).Set(metaDataKey, vtk.vtkPolyData())
        # print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestUpdateExtent(self, request, inInfo, outInfo):
        print ("MySource RequestUpdateExtent:")
        print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestData(self, request, inInfo, outInfo):
        print ("MySource RequestData:")
#        print (outInfo.GetInformationObject(0))
        return 1
 
class MyFilter(VTKPythonAlgorithmBase):
    def __init__(self):
        VTKPythonAlgorithmBase.__init__(self,
            nInputPorts=1, inputType='vtkPolyData',
            nOutputPorts=1, outputType='vtkPolyData')
 
    def RequestInformation(self, request, inInfo, outInfo):
        print ("MyFilter RequestInformation:")
       # print (outInfo.GetInformationObject(0))
        # metaData = inInfo[0].GetInformationObject(0).Get(
        #     metaDataKey)
        # newMetaData = metaData.NewInstance()
        # newMetaData.ShallowCopy(metaData)
        # someArray = vtk.vtkCharArray()
        # someArray.SetName("someArray")
        # newMetaData.GetFieldData().AddArray(someArray)
        # outInfo.GetInformationObject(0).Set(metaDataKey, newMetaData)
        # print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestUpdateExtent(self, request, inInfo, outInfo):
        print ("MyFilter RequestUpdateExtent:")
        print (outInfo.GetInformationObject(0))
        areq = outInfo.GetInformationObject(0).Get(requestKey)
        inInfo[0].GetInformationObject(0).Set(requestKey, areq + 1)
        return 1
 
    def RequestData(self, request, inInfo, outInfo):
        print ("MyFilter RequestData:")
#        print (outInfo.GetInformationObject(0))
        return 1


s = MySource()
 
f = MyFilter()
f.SetInputConnection(s.GetOutputPort())
 
# f.Update()

f.UpdateInformation()
outInfo = f.GetOutputInformation(0)
outInfo.Set(requestKey, 0)
f.PropagateUpdateExtent()

輸出：

MySource RequestInformation:
MyFilter RequestInformation:
MyFilter RequestUpdateExtent:
vtkInformation (0000019826985EE0)
  Debug: Off
  Modified Time: 230
  Reference Count: 2
  Registered Events: (none)
  PRODUCER: vtkCompositeDataPipeline(00000198268DA7B0) port 0
  DATA_OBJECT: vtkPolyData(0000019823F0D670)
  UPDATE_PIECE_NUMBER: 0
  UPDATE_NUMBER_OF_PIECES: 1
  UPDATE_NUMBER_OF_GHOST_LEVELS: 0
  a request: 0


MySource RequestUpdateExtent:
vtkInformation (00000198269855E0)
  Debug: Off
  Modified Time: 243
  Reference Count: 3
  Registered Events: (none)
  PRODUCER: vtkCompositeDataPipeline(00000198268D9BD0) port 0
  CONSUMERS: vtkCompositeDataPipeline(00000198268DA7B0) port 0
  DATA_OBJECT: vtkPolyData(0000019826983120)
  UPDATE_PIECE_NUMBER: 0
  UPDATE_NUMBER_OF_PIECES: 1
  UPDATE_NUMBER_OF_GHOST_LEVELS: 0
  a request: 1

執行過程：
outInfo.Set(requestKey, 0)->MyFilter.RequestUpdateExtent()->MySource.RequestUpdateExtent()

1. 在RequestInformation中，源（source）生成的元數據（meta-data），默認向下遊複製以及修改後的值向下傳遞。
2. 在 RequestUpdateExtent中, 下游會發送改變元數據的請求，改變的值傳遞給上游。

RequestData

RequestInformation和RequestUpdateExtent傳遞的是輕量級的元數據。RequestData和RequestInformation相似都是向下遊傳遞數據，不同的地方是它傳遞的是重量級的數據。

測試

import vtk
from vtk.util.vtkAlgorithm import VTKPythonAlgorithmBase
from vtk.util import keys

requestKey = keys.MakeKey(keys.IntegerRequestKey, "a request", "my module")

class MySource(VTKPythonAlgorithmBase):
    def __init__(self):
        VTKPythonAlgorithmBase.__init__(self,
            nInputPorts=0,
            nOutputPorts=1, outputType='vtkPolyData')
 
    def RequestInformation(self, request, inInfo, outInfo):
        print ("MySource RequestInformation:")
        # outInfo.GetInformationObject(0).Set(metaDataKey, vtk.vtkPolyData())
        # print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestUpdateExtent(self, request, inInfo, outInfo):
        print ("MySource RequestUpdateExtent:")
        print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestData(self, request, inInfo, outInfo):
        print ("MySource RequestData:")
        print (outInfo.GetInformationObject(0))
        outInfo0 = outInfo.GetInformationObject(0)
        areq = outInfo0.Get(requestKey)
        s = vtk.vtkSphereSource()
        s.SetRadius(areq)
        s.Update()
        output =  outInfo0.Get(vtk.vtkDataObject.DATA_OBJECT())
        output.ShallowCopy(s.GetOutput())
        print (output)
        return 1
 
class MyFilter(VTKPythonAlgorithmBase):
    def __init__(self):
        VTKPythonAlgorithmBase.__init__(self,
            nInputPorts=1, inputType='vtkPolyData',
            nOutputPorts=1, outputType='vtkPolyData')
 
    def RequestInformation(self, request, inInfo, outInfo):
        print ("MyFilter RequestInformation:")
       # print (outInfo.GetInformationObject(0))
        # metaData = inInfo[0].GetInformationObject(0).Get(
        #     metaDataKey)
        # newMetaData = metaData.NewInstance()
        # newMetaData.ShallowCopy(metaData)
        # someArray = vtk.vtkCharArray()
        # someArray.SetName("someArray")
        # newMetaData.GetFieldData().AddArray(someArray)
        # outInfo.GetInformationObject(0).Set(metaDataKey, newMetaData)
        # print (outInfo.GetInformationObject(0))
        return 1
 
    def RequestUpdateExtent(self, request, inInfo, outInfo):
        print ("MyFilter RequestUpdateExtent:")
        print (outInfo.GetInformationObject(0))
        areq = outInfo.GetInformationObject(0).Get(requestKey)
        inInfo[0].GetInformationObject(0).Set(requestKey, areq + 1)
        return 1
 
    def RequestData(self, request, inInfo, outInfo):
        print ("MyFilter RequestData:")
        inInfo0 = inInfo[0].GetInformationObject(0)
        outInfo0 = outInfo.GetInformationObject(0)
        input = inInfo0.Get(vtk.vtkDataObject.DATA_OBJECT())
        output = outInfo0.Get(vtk.vtkDataObject.DATA_OBJECT())
        sh = vtk.vtkShrinkPolyData()
        sh.SetInputData(input)
        sh.Update()
        output.ShallowCopy(sh.GetOutput())
        print (output)
        return 1


s = MySource()
 
f = MyFilter()
f.SetInputConnection(s.GetOutputPort())
f.UpdateInformation()
outInfo = f.GetOutputInformation(0)
outInfo.Set(requestKey, 0)
f.PropagateUpdateExtent()
f.Update()

Reference

A VTK pipeline primer (part 3)