How to show and hide objects based on mouse interaction?

ltphy · November 4, 2021, 10:23am

I have multiple point cloud data that are positioned based on pose graph’s vertices and I want to visualize it partly based on the camera position.

The updateZoomFromWheel function has already been written by default as an example.

github.com

Kitware/web-project-templates/blob/badc180432b7f9af8410276781a4f7df086f736a/vue-vtkjs-pvw-template/server/vtkpython/vtk_protocol.py#L58

    
      
          @exportRpc("vtk.cone.resolution.update")
          def updateResolution(self, resolution):
              self.cone.SetResolution(resolution)
              renderWindow = self.getView('-1')
              # renderWindow.Modified() # either modified or render
              renderWindow.Render()
              self.getApplication().InvokeEvent('UpdateEvent')
          
          

          
@exportRpc("viewport.mouse.zoom.wheel")
          def updateZoomFromWheel(self, event):
            if 'Start' in event["type"]:
              self.getApplication().InvokeEvent('StartInteractionEvent')
          
          
  renderWindow = self.getView(event['view'])
            if renderWindow and 'spinY' in event:
              zoomFactor = 1.0 - event['spinY'] / 10.0
          
          
    camera = renderWindow.GetRenderers().GetFirstRenderer().GetActiveCamera()
              fp = camera.GetFocalPoint()
              pos = camera.GetPosition()

First question
I want to write the mouse interaction function in the paraview’s backend which is similar to the following link. How can I achieve this?

github.com

Kitware/VTK/blob/5a3e0c25deba41d2087a1d60a9c7fd5d81d6e434/Web/Python/vtkmodules/web/protocols.py#L100

    
      
          
          
# =============================================================================
          #
          # Handle Mouse interaction on any type of view
          #
          # =============================================================================
          
          

          
class vtkWebMouseHandler(vtkWebProtocol):
              @exportRpc("viewport.mouse.interaction")
              def mouseInteraction(self, event):
                  """
                  RPC Callback for mouse interactions.
                  """
                  view = self.getView(event["view"])
          
          
        buttons = 0
                  if event["buttonLeft"]:
                      buttons |= vtkWebInteractionEvent.LEFT_BUTTON
                  if event["buttonMiddle"]:
                      buttons |= vtkWebInteractionEvent.MIDDLE_BUTTON

Second question
What is the efficient way to load and unload data, I have already found two ways:

Hide(point_cloud_ply, viewProxy)

and

Delete(point_cloud_ply)
del point_cloud_ply

Delete method seems to be more efficient than Hide.

jourdain · November 4, 2021, 3:07pm

Do you want/need to write it yourself? Or do you want to use the existing one since it is available?
Delete deletes and Hide hides. So only Delete truly free memory.

ltphy · November 5, 2021, 1:49am

Thanks. The answer to the second question is clear to me.
About the first question, I want to write it myself while using the existing one as reference.
Because I want to delete and show 3D objects based on camera position which is affected by the user’s mouse input.

ltphy · November 12, 2021, 4:49am

Hi. Any update for this question? Does Paraview support overriding mouse interaction function to add other functionality?