[vtkusers] vtkCellPicker failing to pick vtkPolyLine (using Python and wx)

[David Gobbi]

Hi David,

I was the one who made the changes to the vtkCellPicker code,
and I'd be glad to investigate to see why the behavior changed.

Can you send me an example that uses just python, i.e. no wx?

 - David

On Tue, Dec 11, 2012 at 9:26 AM, David vanEe <david.vanee at convergent.ca> wrote:
> Hi all,
>
>
>
> I’ve recently updated my VTK from 5.4 to 5.10.1, and some old vtkCellPicker
> code isn’t doing what I want anymore.  This ‘simple’ example works fine in
> 5.4 (both the blue and red actor highlight when you mouse-over them), but in
> 5.10.1 only the blue (quad) actor works.  The only difference between the
> two actors (aside from coordinates and colors) is the cellType of
> vtk.VTK_POLY_LINE vs vtk.VTK_QUAD.
>
>
>
> I’ve tried looking for changes in the pick routine, but vtkCellPicker.cxx
> has undergone substantial changes and I was unable to locate the cause.  Any
> suggestions for getting the picker to pick the polyline?
>
>
>
> Thanks in advance,
>
> Dave
>
>
>
>
>
> import wx
>
> import vtk
>
>
>
> from vtk.wx.wxVTKRenderWindowInteractor import wxVTKRenderWindowInteractor
>
>
>
> class myVTKInteractor(wxVTKRenderWindowInteractor):
>
>     def __init__(self, parent):
>
>         wxVTKRenderWindowInteractor.__init__(self, parent, -1)
>
>
>
>         self.Enable(1)
>
>         self.AddObserver("ExitEvent", lambda o,e,f=self: f.Close())
>
>
>
>         self.ren = vtk.vtkRenderer()
>
>         self.GetRenderWindow().AddRenderer(self.ren)
>
>
>
>         # simple point coords used by both actors
>
>         coords = [(0.0, 0.0),
>
>                   (1.0, 0.0),
>
>                   (1.0, 1.0),
>
>                   (0.0, 1.0)]
>
>
>
>         self.actorData = [(1.0, vtk.VTK_POLY_LINE, (0.5,0.0,0.0), (1.0, 0.0,
> 0.0)),
>
>                           (0.0, vtk.VTK_QUAD, (0.0, 0.0, 0.5), (0.0, 0.0,
> 1.0))]
>
>
>
>         self.actorList = []
>
>         for data in self.actorData:
>
>             (zValue, cellType, dimColor, brightColor) = data
>
>
>
>             points = vtk.vtkPoints()
>
>             for (pointIndex, coord) in enumerate(coords):
>
>                 points.InsertPoint(pointIndex, coord[0], coord[1], zValue)
>
>
>
>             idList = vtk.vtkIdList()
>
>             idList.SetNumberOfIds(len(coords))
>
>             for pointIndex in range(len(coords)):
>
>                 idList.SetId(pointIndex, pointIndex)
>
>             cells = vtk.vtkCellArray()
>
>             cells.InsertNextCell(idList)
>
>
>
>             grid = vtk.vtkUnstructuredGrid()
>
>             grid.SetPoints(points)
>
>             grid.SetCells(cellType, cells)
>
>
>
>             mapper = vtk.vtkDataSetMapper()
>
>             mapper.SetInput(grid)
>
>
>
>             actor = vtk.vtkActor()
>
>             actor.SetMapper(mapper)
>
>             actor.GetProperty().SetRepresentation(1)
>
>             actor.GetProperty().SetLineWidth(5.0)
>
>             actor.GetProperty().SetDiffuseColor(*dimColor)
>
>
>
>             self.ren.AddActor(actor)
>
>             self.actorList.append(actor)
>
>
>
>         self.cellPicker = vtk.vtkCellPicker()
>
>
>
>
>
>     def OnMotion(self, event):
>
>
>
>         # invert Y value
>
>         actualY = self.ren.GetSize()[1] - event.GetY()
>
>
>
>         # dim all actors
>
>         for (index, actor) in enumerate(self.actorList):
>
>             (zValue, cellType, dimColor, brightColor) =
> self.actorData[index]
>
>             actor.GetProperty().SetDiffuseColor(*dimColor)
>
>
>
>         self.cellPicker.Pick(event.GetX(), actualY, 0, self.ren)
>
>         dataSet = self.cellPicker.GetDataSet()
>
>
>
>         if dataSet is not None:
>
>             # highlight picked actor
>
>             for (index, actor) in enumerate(self.actorList):
>
>                 if actor.GetMapper().GetInput() == dataSet:
>
>                     (zOffset, cellType, dimColor, brightColor) =
> self.actorData[index]
>
>                     actor.GetProperty().SetDiffuseColor(*brightColor)
>
>
>
>         self.Render()
>
>
>
>
>
> def wxVTKRenderWindowInteractorExample():
>
>     app = wx.PySimpleApp()
>
>
>
>     frame = wx.Frame(None, -1, "wxVTKRenderWindowInteractor",
> size=(400,400))
>
>
>
>     widget = myVTKInteractor(frame)
>
>     sizer = wx.BoxSizer(wx.VERTICAL)
>
>     sizer.Add(widget, 1, wx.EXPAND)
>
>     frame.SetSizer(sizer)
>
>     frame.Layout()
>
>
>
>     frame.Show()
>
>
>
>     app.MainLoop()
>
>
>
> if __name__ == "__main__":
>
>     wxVTKRenderWindowInteractorExample()
>
>
>
>
>
>
>
> --
>
> David A. Van Ee, BASc, EIT
>
> Convergent Manufacturing Technologies Inc.
>
> 6190 Agronomy Rd, Suite 403
>
> Vancouver BC Canada V6T 1Z3
>
>
>
> Email: david.vanee at convergent.ca | Tel: 604-822-9682 x103
>
> WWW: http://www.convergent.ca | Fax: 604-822-9659