in the CellPicking.py example, I rotate the actor. Now the picked cell is the original one, not the rotated. It seems the polydata of the vtkactor is un-rotated.
This is the result of the example, without rotating actor.
Here is the picking result after rotate actor
The python code to rotate the actor:
actor.RotateZ(30)
actor.RotateY(30)
What is wrong? Should I change picking or change the actor or mapper ?
source code of Cellpicking.py
#!/usr/bin/env python
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkCommonCore import vtkIdTypeArray
from vtkmodules.vtkCommonDataModel import (
vtkSelection,
vtkSelectionNode,
vtkUnstructuredGrid
)
from vtkmodules.vtkFiltersCore import vtkTriangleFilter
from vtkmodules.vtkFiltersExtraction import vtkExtractSelection
from vtkmodules.vtkFiltersSources import vtkPlaneSource
from vtkmodules.vtkInteractionStyle import vtkInteractorStyleTrackballCamera
from vtkmodules.vtkRenderingCore import (
vtkActor,
vtkCellPicker,vtkPicker, vtkPropPicker, vtkWorldPointPicker,
vtkDataSetMapper,
vtkPolyDataMapper,
vtkRenderWindow,
vtkRenderWindowInteractor,
vtkRenderer
)
# Catch mouse events
class MouseInteractorStyle(vtkInteractorStyleTrackballCamera):
def __init__(self, data):
self.AddObserver('LeftButtonPressEvent', self.left_button_press_event)
self.data = data
self.selected_mapper = vtkDataSetMapper()
self.selected_actor = vtkActor()
def left_button_press_event(self, obj, event):
colors = vtkNamedColors()
# Get the location of the click (in window coordinates)
pos = self.GetInteractor().GetEventPosition()
picker = vtkCellPicker()
# picker = vtkPropPicker()
# picker = vtkWorldPointPicker()
picker.SetTolerance(0.0005)
# Pick from this location.
picker.Pick(pos[0], pos[1], 0, self.GetDefaultRenderer())
world_position = picker.GetPickPosition()
print(f'Cell id is: {picker.GetCellId()}')
if picker.GetCellId() != -1:
print(f'Pick position is: ({world_position[0]:.6g}, {world_position[1]:.6g}, {world_position[2]:.6g})')
ids = vtkIdTypeArray()
ids.SetNumberOfComponents(1)
ids.InsertNextValue(picker.GetCellId())
selection_node = vtkSelectionNode()
selection_node.SetFieldType(vtkSelectionNode.CELL)
selection_node.SetContentType(vtkSelectionNode.INDICES)
selection_node.SetSelectionList(ids)
selection = vtkSelection()
selection.AddNode(selection_node)
extract_selection = vtkExtractSelection()
extract_selection.SetInputData(0, self.data)
extract_selection.SetInputData(1, selection)
extract_selection.Update()
# In selection
selected = vtkUnstructuredGrid()
selected.ShallowCopy(extract_selection.GetOutput())
print(f'Number of points in the selection: {selected.GetNumberOfPoints()}')
print(f'Number of cells in the selection : {selected.GetNumberOfCells()}')
self.selected_mapper.SetInputData(selected)
self.selected_actor.SetMapper(self.selected_mapper)
self.selected_actor.GetProperty().EdgeVisibilityOn()
self.selected_actor.GetProperty().SetColor(colors.GetColor3d('Tomato'))
print(self.selected_actor.GetPosition())
self.selected_actor.GetProperty().SetLineWidth(3)
self.GetInteractor().GetRenderWindow().GetRenderers().GetFirstRenderer().AddActor(self.selected_actor)
# Forward events
self.OnLeftButtonDown()
def main(argv):
colors = vtkNamedColors()
plane_source = vtkPlaneSource()
plane_source.Update()
triangle_filter = vtkTriangleFilter()
triangle_filter.SetInputConnection(plane_source.GetOutputPort())
triangle_filter.Update()
mapper = vtkPolyDataMapper()
mapper.SetInputConnection(triangle_filter.GetOutputPort())
mapper.StaticOff()
actor = vtkActor()
actor.GetProperty().SetColor(colors.GetColor3d('SeaGreen'))
actor.SetMapper(mapper)
# rotate actor
actor.RotateZ(30)
actor.RotateY(30)
print(actor.GetPosition())
renderer = vtkRenderer()
ren_win = vtkRenderWindow()
ren_win.AddRenderer(renderer)
ren_win.SetWindowName('CellPicking')
iren = vtkRenderWindowInteractor()
iren.SetRenderWindow(ren_win)
renderer.AddActor(actor)
# renderer.ResetCamera()
renderer.SetBackground(colors.GetColor3d('PaleTurquoise'))
# Add the custom style.
# style = MouseInteractorStyle(triangle_filter.GetOutput())
style = MouseInteractorStyle(actor.GetMapper().GetInput())
style.SetDefaultRenderer(renderer)
iren.SetInteractorStyle(style)
ren_win.Render()
iren.Initialize()
iren.Start()
if __name__ == '__main__':
import sys
main(sys.argv)