qvtkrenderwidget.py

a very goog book

    def GetPicker(self):
        return self._Picker

    def Render(self):
        if (self._CurrentLight):
            light = self._CurrentLight
            light.SetPosition(self._CurrentCamera.GetPosition())
            light.SetFocalPoint(self._CurrentCamera.GetFocalPoint())

        self._RenderWindow.Render()

    def UpdateRenderer(self,x,y):
        """
        UpdateRenderer will identify the renderer under the mouse and set
        up _CurrentRenderer, _CurrentCamera, and _CurrentLight.
        """
        windowX = self.width()
        windowY = self.height()

        renderers = self._RenderWindow.GetRenderers()
        numRenderers = renderers.GetNumberOfItems()

        self._CurrentRenderer = None
        renderers.InitTraversal()
        for i in range(0,numRenderers):
            renderer = renderers.GetNextItem()
            vx,vy = (0,0)
            if (windowX > 1):
                vx = float(x)/(windowX-1)
            if (windowY > 1):
                vy = (windowY-float(y)-1)/(windowY-1)
            (vpxmin,vpymin,vpxmax,vpymax) = renderer.GetViewport()
            
            if (vx >= vpxmin and vx <= vpxmax and
                vy >= vpymin and vy <= vpymax):
                self._CurrentRenderer = renderer
                self._ViewportCenterX = float(windowX)*(vpxmax-vpxmin)/2.0\
                                        +vpxmin
                self._ViewportCenterY = float(windowY)*(vpymax-vpymin)/2.0\
                                        +vpymin
                self._CurrentCamera = self._CurrentRenderer.GetActiveCamera()
                lights = self._CurrentRenderer.GetLights()
                lights.InitTraversal()
                self._CurrentLight = lights.GetNextItem()
                break

        self._LastX = x
        self._LastY = y

    def GetCurrentRenderer(self):
        return self._CurrentRenderer
                
    def Rotate(self,x,y):
        if self._CurrentRenderer:
            
            self._CurrentCamera.Azimuth(self._LastX - x)
            self._CurrentCamera.Elevation(y - self._LastY)
            self._CurrentCamera.OrthogonalizeViewUp()
            
            self._LastX = x
            self._LastY = y
            
            self._CurrentRenderer.ResetCameraClippingRange()
            self.Render()

    def Pan(self,x,y):
        if self._CurrentRenderer:
            
            renderer = self._CurrentRenderer
            camera = self._CurrentCamera
            (pPoint0,pPoint1,pPoint2) = camera.GetPosition()
            (fPoint0,fPoint1,fPoint2) = camera.GetFocalPoint()

            if (camera.GetParallelProjection()):
                renderer.SetWorldPoint(fPoint0,fPoint1,fPoint2,1.0)
                renderer.WorldToDisplay()
                fx,fy,fz = renderer.GetDisplayPoint()
                renderer.SetDisplayPoint(fx-x+self._LastX,
                                         fy+y-self._LastY,
                                         fz)
                renderer.DisplayToWorld()
                fx,fy,fz,fw = renderer.GetWorldPoint()
                camera.SetFocalPoint(fx,fy,fz)

                renderer.SetWorldPoint(pPoint0,pPoint1,pPoint2,1.0)
                renderer.WorldToDisplay()
                fx,fy,fz = renderer.GetDisplayPoint()
                renderer.SetDisplayPoint(fx-x+self._LastX,
                                         fy+y-self._LastY,
                                         fz)
                renderer.DisplayToWorld()
                fx,fy,fz,fw = renderer.GetWorldPoint()
                camera.SetPosition(fx,fy,fz)
                
            else:
                (fPoint0,fPoint1,fPoint2) = camera.GetFocalPoint()
                # Specify a point location in world coordinates
                renderer.SetWorldPoint(fPoint0,fPoint1,fPoint2,1.0)
                renderer.WorldToDisplay()
                # Convert world point coordinates to display coordinates
                dPoint = renderer.GetDisplayPoint()
                focalDepth = dPoint[2]
                
                aPoint0 = self._ViewportCenterX + (x - self._LastX)
                aPoint1 = self._ViewportCenterY - (y - self._LastY)
                
                renderer.SetDisplayPoint(aPoint0,aPoint1,focalDepth)
                renderer.DisplayToWorld()
                
                (rPoint0,rPoint1,rPoint2,rPoint3) = renderer.GetWorldPoint()
                if (rPoint3 != 0.0):
                    rPoint0 = rPoint0/rPoint3
                    rPoint1 = rPoint1/rPoint3
                    rPoint2 = rPoint2/rPoint3

                camera.SetFocalPoint((fPoint0 - rPoint0) + fPoint0, 
                                     (fPoint1 - rPoint1) + fPoint1,
                                     (fPoint2 - rPoint2) + fPoint2) 
                
                camera.SetPosition((fPoint0 - rPoint0) + pPoint0, 
                                   (fPoint1 - rPoint1) + pPoint1,
                                   (fPoint2 - rPoint2) + pPoint2)

            self._LastX = x
            self._LastY = y

            self.Render()

    def Zoom(self,x,y):
        if self._CurrentRenderer:

            renderer = self._CurrentRenderer
            camera = self._CurrentCamera

            zoomFactor = math.pow(1.02,(0.5*(self._LastY - y)))
            self._CurrentZoom = self._CurrentZoom * zoomFactor

            if camera.GetParallelProjection():
                parallelScale = camera.GetParallelScale()/zoomFactor
                camera.SetParallelScale(parallelScale)
            else:
                camera.Dolly(zoomFactor)
                renderer.ResetCameraClippingRange()

            self._LastX = x
            self._LastY = y

            self.Render()

    def Reset(self,x,y):
        if self._CurrentRenderer:
            self._CurrentRenderer.ResetCamera()
            
        self.Render()

    def Wireframe(self):
        actors = self._CurrentRenderer.GetActors()
        numActors = actors.GetNumberOfItems()
        actors.InitTraversal()
        for i in range(0,numActors):
            actor = actors.GetNextItem()
            actor.GetProperty().SetRepresentationToWireframe()

        self.Render()
        
    def Surface(self):
        actors = self._CurrentRenderer.GetActors()
        numActors = actors.GetNumberOfItems()
        actors.InitTraversal()
        for i in range(0,numActors):
            actor = actors.GetNextItem()
            actor.GetProperty().SetRepresentationToSurface()

        self.Render()

    def PickActor(self,x,y):
        if self._CurrentRenderer:

            renderer = self._CurrentRenderer
            picker = self._Picker
            
            windowY = self.height()
            picker.Pick(x,(windowY - y - 1),0.0,renderer)
            actor = picker.GetActor()

            if (self._PickedActor != None and
                self._PrePickedProperty != None):
                self._PickedActor.SetProperty(self._PrePickedProperty)
                # release hold of the property
                self._PrePickedProperty.UnRegister(self._PrePickedProperty)
                self._PrePickedProperty = None

            if (actor != None):
                self._PickedActor = actor
                self._PrePickedProperty = self._PickedActor.GetProperty()
                # hold onto the property
                self._PrePickedProperty.Register(self._PrePickedProperty)
                self._PickedActor.SetProperty(self._PickedProperty)

            self.Render()

#----------------------------------------------------------------------------  
def QVTKRenderWidgetConeExample():
    """Like it says, just a simple example
    """
    # every QT app needs an app
    app = QApplication(['QVTKRenderWidget'])

    # create the widget
    widget = QVTKRenderWidget()

    ren = vtk.vtkRenderer()
    widget.GetRenderWindow().AddRenderer(ren)

    cone = vtk.vtkConeSource()
    cone.SetResolution(8)
    
    coneMapper = vtk.vtkPolyDataMapper()
    coneMapper.SetInput(cone.GetOutput())
    
    coneActor = vtk.vtkActor()
    coneActor.SetMapper(coneMapper)

    ren.AddActor(coneActor)

    # show the widget
    widget.show()
    # close the application when window is closed
    qApp.setMainWidget(widget)
    # start event processing
    app.exec_loop()
    
if __name__ == "__main__":
    QVTKRenderWidgetConeExample()