[vtkusers] vtkCellPicker failing to pick vtkPolyLine (using Python and wx)
David Gobbi
david.gobbi at gmail.com
Tue Dec 11 14:35:54 EST 2012
Hi Craig,
The Pick() method takes the renderer (i.e. the viewport) as a
parameter, so it is up to whichever code is calling the picker to
determine what viewport the mouse is interacting with. Hence the
problem you are seeing cannot be related to the picker, it must be
related to the widget/representation/interactor.
- David
On Tue, Dec 11, 2012 at 12:12 PM, Craig Henderson
<craig.henderson at intelligentultrasound.com> wrote:
> Hi,
> Could this be related to the problem I asked about a few days ago? I haven't
> had any responses.
> http://www.vtk.org/pipermail/vtkusers/2012-December/126783.html
>
> Thanks
> Craig
>
> On 11 Dec 2012, at 18:27, David Gobbi <david.gobbi at gmail.com> wrote:
>
> Hi David,
>
> You can get the polyline picking to work by increasing the tolerance:
>
> self.cellPicker.SetTolerance(0.005)
>
> I'll continue looking through the code to see why the new code
> behaves differently from the old, though. I suspect there have
> been minor changes to the way that tolerances are applied.
>
> - David
>
>
> On Tue, Dec 11, 2012 at 10:51 AM, David vanEe <david.vanee at convergent.ca>
> wrote:
>
> Sure, this version will work with just python/vtk. Thanks for taking a
> look.
>
>
>
> import vtk
>
>
> class MyInteractorStyle(vtk.vtkInteractorStyleTrackballCamera):
>
> def __init__(self, actorData, actorList):
>
>
> self.actorData = actorData
>
> self.actorList = actorList
>
> self.cellPicker = vtk.vtkCellPicker()
>
>
> self.AddObserver("MouseMoveEvent", self.OnMotion)
>
>
> def OnMotion(self, obj, event):
>
>
> iren = obj.GetInteractor()
>
> renwin = iren.GetRenderWindow()
>
> ren = renwin.GetRenderers().GetFirstRenderer()
>
>
> x, y = iren.GetEventPosition()
>
>
> # invert Y value
>
> actualY = ren.GetSize()[1] - y
>
>
> # dim all actors
>
> for (index, actor) in enumerate(self.actorList):
>
> (zValue, cellType, dimColor, brightColor) = self.actorData[index]
>
> actor.GetProperty().SetDiffuseColor(*dimColor)
>
>
> self.cellPicker.Pick(x, actualY, 0, 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)
>
>
> renwin.Render()
>
>
> # simple point coords used by both actors
>
> coords = [(0.0, 0.0),
>
> (1.0, 0.0),
>
> (1.0, 1.0),
>
> (0.0, 1.0)]
>
>
> 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))]
>
>
> ren = vtk.vtkRenderer()
>
>
> renwin = vtk.vtkRenderWindow()
>
> renwin.AddRenderer(ren)
>
>
> actorList = []
>
> for data in 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)
>
>
> ren.AddActor(actor)
>
> actorList.append(actor)
>
>
> interactor = vtk.vtkRenderWindowInteractor()
>
> interactor.SetInteractorStyle(MyInteractorStyle(actorData, actorList))
>
> interactor.SetRenderWindow(renwin)
>
>
> interactor.Initialize()
>
> interactor.Start()
>
>
>
>
> -----Original Message-----
>
> From: David Gobbi [mailto:david.gobbi at gmail.com]
>
> Sent: Tuesday, December 11, 2012 9:08 AM
>
> To: David vanEe
>
> Cc: vtkusers at vtk.org
>
> Subject: Re: [vtkusers] vtkCellPicker failing to pick vtkPolyLine (using
> Python and wx)
>
>
> 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
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