[vtkusers] how to pick vtkActor2D?

[永强 谭]

Hi, all,

I have come across some problem picking a line, which is a vtkActor2D.

The following bellow is a simple code. Any suggestion is greatly 
appriciated. Thanks.

package require vtk
package require vtkinteraction

vtkRenderer ren
  [ren GetActiveCamera] ParallelProjectionOn

vtkRenderWindow win
  win AddRenderer ren
  win SetSize 512 512

vtkRenderWindowInteractor iren
  iren SetRenderWindow win
  iren AddObserver LeftButtonPressEvent { OnLButtonDown }

vtkLineSource lineSource
  lineSource SetPoint1 0 255.5 0
  lineSource SetPoint2 512 255.5 0
  lineSource SetResolution 100

vtkPolyDataMapper2D lineMapper
  lineMapper SetInput [lineSource GetOutput]

vtkActor2D lineActor
  lineActor SetMapper lineMapper
  [lineActor GetProperty] SetLineWidth 5.0

ren AddActor2D lineActor

vtkCellPicker cellPicker
cellPicker SetTolerance 0.01
cellPicker AddPickList  lineActor
cellPicker PickFromListOn

iren Initialize
iren Render

proc OnLButtonDown {} {
  set pos [iren GetEventPosition]
  set XPos [lindex $pos 0]
  set YPos [lindex $pos 1]
  
  cellPicker Pick $XPos $YPos 0 ren
  
  set path [cellPicker GetPath]
  
  if {$path != ""} {
    set property [lineActor GetProperty]
    $property SetColor 1.0 0.0 0.0
  }
}

wm withdraw .