[vtkusers] Depth peeling and Qt

[Ignacio Fernández Galván]

On 12/01/18, at 14:48, Sankhesh Jhaveri wrote:
> 
> In general, depth peeling is known to work with VTK and Qt5.
> Are you using the QVTKOpenGLWidget 
> <https://www.vtk.org/doc/nightly/html/classQVTKOpenGLWidget.html>?
> Could you post your modifications somewhere for us to see?
> 

I'm not using QVTKOpenGLWidget directly, I'm just using 
QVTKRenderWindowInteractor, as in 
https://www.vtk.org/Wiki/VTK/Examples/Python/Widgets/EmbedPyQt

My modified EmbedPyQt.py:

#==============================================
#!/usr/bin/env python

import sys
import vtk
from PyQt5.QtWidgets import QApplication, QFrame, QPushButton, 
QVBoxLayout, QMainWindow, QFrame
from QVTKRenderWindowInteractor_5 import QVTKRenderWindowInteractor

class MainWindow(QMainWindow):

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

         self.frame = QFrame()

         self.vl = QVBoxLayout()
         self.vtkWidget = QVTKRenderWindowInteractor(self.frame)
         self.vl.addWidget(self.vtkWidget)

         self.ren = vtk.vtkRenderer()
         self.ren.UseDepthPeelingOn()
         self.ren.SetOcclusionRatio(0.01)
         self.ren.SetMaximumNumberOfPeels(20)
         self.vtkWidget.GetRenderWindow().AddRenderer(self.ren)
         self.iren = self.vtkWidget.GetRenderWindow().GetInteractor()

         # Create source
         source = vtk.vtkSphereSource()
         source.SetCenter(0, 0, 0)
         source.SetRadius(5.0)

         # Create a mapper
         mapper = vtk.vtkPolyDataMapper()
         mapper.SetInputConnection(source.GetOutputPort())

         # Create an actor
         actor = vtk.vtkActor()
         actor.SetMapper(mapper)
         actor.GetProperty().SetOpacity(0.5)

         self.ren.AddActor(actor)

         self.ren.ResetCamera()

         self.frame.setLayout(self.vl)
         self.setCentralWidget(self.frame)

         self.show()
         self.iren.Initialize()


if __name__ == "__main__":

     app = QApplication(sys.argv)

     window = MainWindow()

     print window.ren.GetLastRenderingUsedDepthPeeling()
     sys.exit(app.exec_())
#==============================================

and QVTKRenderWindowInteractor_5.py is the same as 
https://gitlab.kitware.com/vtk/vtk/blob/1cea85a8d40114374c329c8d26d92c4356df678a/Wrapping/Python/vtk/qt5/QVTKRenderWindowInteractor.py 
with just a couple of changes:

$ diff -c QVTKRenderWindowInteractor.py QVTKRenderWindowInteractor_5.py
*** QVTKRenderWindowInteractor.py       2018-01-12 14:59:18.194879513 +0100
--- QVTKRenderWindowInteractor_5.py     2018-01-12 15:32:09.765069627 +0100
***************
*** 164,169 ****
--- 164,171 ----
               self._RenderWindow = rw
           else:
               self._RenderWindow = vtk.vtkRenderWindow()
+             self._RenderWindow.SetMultiSamples(0)
+             self._RenderWindow.SetAlphaBitPlanes(1)

           WId = self.winId()

***************
*** 366,372 ****
           self._Iren.KeyReleaseEvent()

       def wheelEvent(self, ev):
!         if ev.delta() >= 0:
               self._Iren.MouseWheelForwardEvent()
           else:
               self._Iren.MouseWheelBackwardEvent()
--- 368,374 ----
           self._Iren.KeyReleaseEvent()

       def wheelEvent(self, ev):
!         if ev.angleDelta().y() >= 0:
               self._Iren.MouseWheelForwardEvent()
           else:
               self._Iren.MouseWheelBackwardEvent()