Qt 中的 VTK Widget 未按预期更新

Question

我想在我的 Qt5-Gui 中显示 3D 动画。一切都按预期工作，但不幸的是，当我不与 vtkWidget 交互时，场景没有得到更新。换句话说：当我想看动画时，我需要用鼠标连续点击小部件。如果有任何帮助，我将不胜感激。

import sys
import vtk
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5 import Qt
import numpy as np

from vtk.qt.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor

class mainWindow(Qt.QMainWindow):
def __init__(self, parent = None):
    Qt.QMainWindow.__init__(self, parent)

    self.frame = Qt.QFrame()
    self.vl = Qt.QVBoxLayout()
    self.button = QtWidgets.QPushButton("TestButton")
    self.label = QtWidgets.QLabel("This is a label")
    self.vtkWidget = QVTKRenderWindowInteractor(self.frame)

    #Create Source
    self.source = vtk.vtkCylinderSource()
    self.source.SetCenter(0, 0, 0)
    self.source.SetRadius(5.0)
    #Create Mapper
    self.mapper = vtk.vtkPolyDataMapper()
    self.mapper.SetInputConnection(self.source.GetOutputPort())
    #Create Actor
    self.actor = vtk.vtkActor()
    self.actor.SetMapper(self.mapper)

    #Create poke matrix for cylinder
    self.pMatrix = vtk.vtkMatrix4x4()

    self.vl.addWidget(self.vtkWidget)
    self.vl.addWidget(self.button)
    self.vl.addWidget(self.label)

    self.ren = vtk.vtkRenderer()
    self.ren.AddActor(self.actor)
    self.renWin = self.vtkWidget.GetRenderWindow()
    self.renWin.AddRenderer(self.ren)
    self.iren = self.vtkWidget.GetRenderWindow().GetInteractor()

    #Settings
    self.ren.SetBackground(0.2, 0.2, 0.2)
    self.timeStep = 20 #ms
    self.total_t = 0

    #Inititalize Window, Interactor, Renderer, Layout
    self.frame.setLayout(self.vl)
    self.setCentralWidget(self.frame)
    self.ren.ResetCamera()
    self.show()
    self.iren.Initialize()

    # Create Timer
    self.timer = QtCore.QTimer()
    self.timer.timeout.connect(self.timerCallback)
    self.timer.start(self.timeStep)

def timerCallback(self, *args):
    self.total_t += self.timeStep / 1000
    #Rotate Cylinder
    angle = 2 * np.pi * self.total_t
    rotMatrix = np.array([[np.cos(angle), -np.sin(angle), 0],
                          [np.sin(angle), np.cos(angle), 0],
                          [0, 0, 1]])
    for i in range(3):
        for j in range(3):
            self.pMatrix.SetElement(i, j, rotMatrix[i, j])

    self.actor.PokeMatrix(self.pMatrix)
    self.ren.Render()


if __name__ == "__main__":
    app = Qt.QApplication(sys.argv)
    window = mainWindow()
    sys.exit(app.exec_())

Answer 1

在阅读 this file 的 paintEvent() 方法后，我设法发现，需要调用 Interactor 对象的 Render() 方法。因此，需要调用 self.iren.Render() 而不是 self.ren.Render()。然后一切正常。完整示例代码：

import sys
import vtk
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5 import Qt
import numpy as np

from vtk.qt.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor

class mainWindow(Qt.QMainWindow):
    def __init__(self, parent = None):
        Qt.QMainWindow.__init__(self, parent)

        self.frame = Qt.QFrame()
        self.vl = Qt.QVBoxLayout()
        self.button = QtWidgets.QPushButton("TestButton")
        self.label = QtWidgets.QLabel("This is a label")
        self.vtkWidget = QVTKRenderWindowInteractor(self.frame)

        #Create Source
        self.source = vtk.vtkCylinderSource()
        self.source.SetCenter(0, 0, 0)
        self.source.SetRadius(5.0)
        #Create Mapper
        self.mapper = vtk.vtkPolyDataMapper()
        self.mapper.SetInputConnection(self.source.GetOutputPort())
        #Create Actor
        self.actor = vtk.vtkActor()
        self.actor.SetMapper(self.mapper)

        #Create poke matrix for cylinder
        self.pMatrix = vtk.vtkMatrix4x4()

        self.vl.addWidget(self.vtkWidget)
        self.vl.addWidget(self.button)
        self.vl.addWidget(self.label)

        self.ren = vtk.vtkRenderer()
        self.ren.AddActor(self.actor)
        self.renWin = self.vtkWidget.GetRenderWindow()
        self.renWin.AddRenderer(self.ren)
        self.iren = self.vtkWidget.GetRenderWindow().GetInteractor()

        #Settings
        self.ren.SetBackground(0.2, 0.2, 0.2)
        self.timeStep = 20 #ms
        self.total_t = 0

        #Inititalize Window, Interactor, Renderer, Layout
        self.frame.setLayout(self.vl)
        self.setCentralWidget(self.frame)
        self.ren.ResetCamera()
        self.show()
        self.iren.Initialize()

        # Create Timer
        self.timer = QtCore.QTimer()
        self.timer.timeout.connect(self.timerCallback)
        self.timer.start(self.timeStep)

    def timerCallback(self, *args):
        self.total_t += self.timeStep / 1000
        #Rotate Cylinder
        angle = 2 * np.pi * self.total_t
        rotMatrix = np.array([[np.cos(angle), -np.sin(angle), 0],
                              [np.sin(angle), np.cos(angle), 0],
                                  [0, 0, 1]])
        for i in range(3):
            for j in range(3):
                self.pMatrix.SetElement(i, j, rotMatrix[i, j])

        self.actor.PokeMatrix(self.pMatrix)
        self.iren.Render() #NOT: self.ren.Render()


if __name__ == "__main__":
    app = Qt.QApplication(sys.argv)
    window = mainWindow()
    sys.exit(app.exec_())

Answer 2

谢谢@cakelover，我遇到了同样的问题，但在 C++ 中，你的解决方案帮助我解决了它：

//PCLVisualizer pointer
pcl::visualization::PCLVisualizer::Ptr viewer_3D;

//Renderer method to update the visualizer
viewer_3D->getRenderWindow()->GetInteractor()->Render();

Qt 中的 VTK Widget 未按预期更新

VTKWidget in Qt is not updated as expeced

qt5

pyqt5

python-3.6

vtk

qvtkwidget