python - VTK 交互器和 PyQt 并行运行

Question

我需要获取 vtkChartParallelCoordinates 和其他使用与 PyQt 应用程序并行运行的 vtkContextView 的图表。问题是它们都使用无限循环来进行用户鼠标交互，而我一次只能运行其中一个。当我通过 view.GetInteractor().Start() 启动 vtk 交互器时，PyQt 应用程序不会显示，直到我关闭 vtk 窗口。我想我有两种选择:

1. 在 PyQt 循环中手动处理 vtk 对象的用户交互
2. 在 PyQt 应用程序内渲染 vtk 图

关于第二个选项:我无法使用 QVTKRenderWindowInteractor，它似乎不适用于 vtkContextView 图形。我找到了Kitware的一份文档: http://www.na-mic.org/Wiki/images/1/18/NA-MIC-VTK-Charts-2011.pdf在第 22 页，他们使用 QVTKWidget，但我的 vtk 编译没有它。

我尝试对选项 1 进行一些操作，但没有成功，没有可用的相关示例。

在下面的代码中，当我注释掉“view.GetInteractor().Start()”时，PyQt 窗口会显示并且是交互式的。

我在 Linux 上使用 python 版本 2.7.11、vtk 版本 7.0.0。

我将不胜感激任何帮助!

from PyQt4 import QtCore, QtGui
import vtk
import math




class Ui_widgetParallel(object):
    def setupUi(self, widgetParallel):
        widgetParallel.setObjectName("widgetParallel")
        widgetParallel.resize(802, 651)
        #button
        self.button = QtGui.QPushButton(widgetParallel)
        self.button.setGeometry(QtCore.QRect(180, 100, 75, 23))
        self.button.setText("Click on me")

        QtCore.QMetaObject.connectSlotsByName(widgetParallel)
        self.button.clicked.connect(self.testClick)

    def testClick(self):
        print('I was clicked on')




def selectionCallback(caller, event):
    #executes when new data is selected by the user
    #prints row numbers of all selected data rows
        annSel = annotationLink.GetCurrentSelection()
        if annSel.GetNumberOfNodes() > 0:
            idxArr = annSel.GetNode(0).GetSelectionList()
            if idxArr.GetNumberOfTuples() > 0:
                for ii in range(idxArr.GetNumberOfTuples()):
                    print(idxArr.GetValue(ii))




if __name__ == "__main__":
    import sys


    ############################
    # CREATE A DATA TABLE
    ############################

    arrX = vtk.vtkFloatArray()
    arrX.SetName("XAxis")

    arrC = vtk.vtkFloatArray()
    arrC.SetName("Cosine")

    arrS = vtk.vtkFloatArray()
    arrS.SetName("Sine")

    arrS2 = vtk.vtkFloatArray()
    arrS2.SetName("Tan")

    numPoints = 20
    inc = 0.2 / (numPoints-1)

    for i in range(numPoints):
        arrX.InsertNextValue(i * inc)
        arrC.InsertNextValue(math.cos(i * inc) + 0.0)
        arrS.InsertNextValue(math.sin(i * inc) + 0.0)
        arrS2.InsertNextValue(math.tan(i * inc) + 0.5)

    table = vtk.vtkTable()
    table.AddColumn(arrX)
    table.AddColumn(arrC)
    table.AddColumn(arrS)
    table.AddColumn(arrS2)


    ############################
    # STARTS THE QtGui application
    ############################
    app = QtGui.QApplication(sys.argv)
    widgetParallel = QtGui.QWidget()
    ui = Ui_widgetParallel()
    ui.setupUi(widgetParallel)
    widgetParallel.show()


    ############################
    # PARALLEL COORDINATES VIEW AND ANNOTATION
    ############################
    #render contextView and parallel coordinates view
    view = vtk.vtkContextView()
    view.GetRenderer().SetBackground(1.0, 1.0, 1.0)
    view.GetRenderWindow().SetSize(600,300)
    chart = vtk.vtkChartParallelCoordinates()
    view.GetScene().AddItem(chart)
    # Create a annotation link to access selection in parallel coordinates view
    annotationLink = vtk.vtkAnnotationLink()
    annotationLink.GetCurrentSelection().GetNode(0).SetFieldType(1)     # Point
    annotationLink.GetCurrentSelection().GetNode(0).SetContentType(4)   # 1 = GlobalIds, 2 = PedigreeIds, 4 = Indices
    chart.SetAnnotationLink(annotationLink)
    annotationLink.AddObserver("AnnotationChangedEvent", selectionCallback)

    #link input data and refresh attributes view
    chart.GetPlot(0).SetInputData(table)
    chart.GetPlot(0).SetScalarVisibility(1)
    chart.GetPlot(0).SetScalarVisibility(1)
    chart.GetPlot(0).SetWidth(5)
    chart.GetPlot(0).SetOpacity(0)
    #render view
    view.ResetCamera()
    view.GetRenderWindow().SetMultiSamples(0)
    view.Render()
    view.GetInteractor().Start()

    ############################
    # EXITS THE APPLICATION WHEN GUI LOOP IS CLOSED
    ############################
    sys.exit(app.exec_())

Answer 1

我不确定我是否完全理解你的第一个问题。不过，我附加了一个 python 原型(prototype)，以使用 QVTKRenderWindowInteractor 类在 Qt 主窗口中显示 vtk 图形。至于第一个问题，我认为通过附加的方法，您可以轻松地将 pyQt 事件与 vtk 事件连接起来。

from PyQt4 import QtCore, QtGui
from vtk.qt4.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor
import vtk
import math
import sys


class test(QtGui.QMainWindow):

    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self._initUI()

    def _initUI(self):
        self.setWindowTitle(self.tr("PyQt4 widgetParallel"))
        self.workspace = QtGui.QWorkspace()
        self.setCentralWidget(self.workspace)
        self.frame1 = QtGui.QFrame(self.workspace)
        self.hbox1 = QtGui.QHBoxLayout()
        self.frame2 = QtGui.QFrame(self.workspace)

        self.frame1.resize(600, 600)
        self.frame2.resize(600, 600)
        self.frame2.move(QtCore.QPoint(600, 0))

        self.hbox2 = QtGui.QHBoxLayout()

        self.widgetParallel = Ui_widgetParallel(self.frame2)

        self.widget = QVTKRenderWindowInteractor(self.frame1)
        self.iren = self.widget.GetRenderWindow().GetInteractor()

        self.arrX = vtk.vtkFloatArray()
        self.arrX.SetName("XAxis")

        self.arrC = vtk.vtkFloatArray()
        self.arrC.SetName("Cosine")

        self.arrS = vtk.vtkFloatArray()
        self.arrS.SetName("Sine")

        self.arrS2 = vtk.vtkFloatArray()
        self.arrS2.SetName("Tan")

        numPoints = 20
        inc = 0.2 / (numPoints-1)

        for i in range(numPoints):
            self.arrX.InsertNextValue(i * inc)
            self.arrC.InsertNextValue(math.cos(i * inc) + 0.0)
            self.arrS.InsertNextValue(math.sin(i * inc) + 0.0)
            self.arrS2.InsertNextValue(math.tan(i * inc) + 0.5)

        self.table = vtk.vtkTable()
        self.table.AddColumn(self.arrX)
        self.table.AddColumn(self.arrC)
        self.table.AddColumn(self.arrS)
        self.table.AddColumn(self.arrS2)

        self.view = vtk.vtkContextView()
        self.view.SetInteractor(self.iren)
        self.widget.SetRenderWindow(self.view.GetRenderWindow())

        self.ren = self.view.GetRenderer()
        self.ren.SetBackground(1.0, 1.0, 1.0)
        self.renWin = self.widget.GetRenderWindow()

        self.iren.SetRenderWindow(self.widget.GetRenderWindow())

        self.chart = vtk.vtkChartParallelCoordinates()
        self.view.GetScene().AddItem(self.chart)
        # Create a annotation link to access selection in parallel coordinates
        # view
        self.annotationLink = vtk.vtkAnnotationLink()
        # Point
        self.annotationLink.GetCurrentSelection().GetNode(0).SetFieldType(1)
        # 1 = GlobalIds, 2 = PedigreeIds, 4 = Indices
        self.annotationLink.GetCurrentSelection().GetNode(0).SetContentType(4)
        self.chart.SetAnnotationLink(self.annotationLink)
        self.annotationLink.RemoveObservers("AnnotationChangedEvent")
        self.annotationLink.AddObserver("AnnotationChangedEvent",
                                        self.selectionCallback)

        # link input data and refresh attributes view
        self.chart.GetPlot(0).SetInputData(self.table)
        self.chart.GetPlot(0).SetScalarVisibility(1)
        self.chart.GetPlot(0).SetScalarVisibility(1)
        self.chart.GetPlot(0).SetWidth(5)
        self.chart.GetPlot(0).SetOpacity(0)

        self.renWin.AddRenderer(self.ren)
        self.renWin.SetMultiSamples(0)

        self.hbox1.addWidget(self.widget)
        self.hbox2.addWidget(self.widgetParallel)

        self.frame1.setLayout(self.hbox1)
        self.frame2.setLayout(self.hbox2)

        self.workspace.addWindow(self.frame1)
        self.workspace.addWindow(self.frame2)

        self.widget.show()
#        self.widgetParallel.show()
        self.iren.Initialize()

    def selectionCallback(self, caller, event):
        # executes when new data is selected by the user
        # prints row numbers of all selected data rows
        annSel = self.annotationLink.GetCurrentSelection()
        if annSel.GetNumberOfNodes() > 0:
            idxArr = annSel.GetNode(0).GetSelectionList()
            if idxArr.GetNumberOfTuples() > 0:
                for ii in range(idxArr.GetNumberOfTuples()):
                    print(idxArr.GetValue(ii))


class Ui_widgetParallel(QtGui.QWidget):

    def __init__(self, parent):
        super(Ui_widgetParallel, self).__init__(parent)
        self._setupUi()

    def _setupUi(self):
        self.setObjectName("widgetParallel")
        self.resize(802, 651)
        # button
        self.button = QtGui.QPushButton(self)
        self.button.setGeometry(QtCore.QRect(180, 100, 75, 23))
        self.button.setText("Click on me")

        layout = QtGui.QHBoxLayout()
        layout.addWidget(self.button)

        self.setLayout(layout)

#        QtCore.QMetaObject.connectSlotsByName(self)
        self.button.clicked.connect(self.testClick)

        self.show()

    def testClick(self):
        print('I was clicked on')


if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)
    mainwindow = test()
    mainwindow.show()
    sys.exit(app.exec_())

附:除了 QWidgets，您还可以使用 QDockWidgets。