Skip to content

GraphToPolyData

vtk-examples/Python/Graphs/GraphToPolyData

Description

This example creates a simple graph and then converts it to a polydata for visualization using Paraview.

Other languages

See (Cxx)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

GraphToPolyData.py

#!/usr/bin/env python

# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkCommonCore import vtkPoints
from vtkmodules.vtkCommonDataModel import vtkMutableUndirectedGraph
from vtkmodules.vtkFiltersSources import vtkGraphToPolyData
from vtkmodules.vtkRenderingCore import (
    vtkActor,
    vtkPolyDataMapper,
    vtkRenderWindow,
    vtkRenderWindowInteractor,
    vtkRenderer
)


def main():
    colors = vtkNamedColors()
    # Create a graph
    g = vtkMutableUndirectedGraph()

    # Add 4 vertices to the graph
    v1 = g.AddVertex()
    v2 = g.AddVertex()
    v3 = g.AddVertex()
    v4 = g.AddVertex()

    # Add 3 edges to the graph
    g.AddEdge(v1, v2)
    g.AddEdge(v1, v3)
    g.AddEdge(v1, v4)

    # Create 4 points - one for each vertex
    points = vtkPoints()
    points.InsertNextPoint(0.0, 0.0, 0.0)
    points.InsertNextPoint(1.0, 0.0, 0.0)
    points.InsertNextPoint(0.0, 1.0, 0.0)
    points.InsertNextPoint(0.0, 0.0, 1.0)

    # Add the coordinates of the points to the graph
    g.SetPoints(points)

    # Convert the graph to a polydata
    graphToPolyData = vtkGraphToPolyData()
    graphToPolyData.SetInputData(g)
    graphToPolyData.Update()

    # Create a mapper and actor
    mapper = vtkPolyDataMapper()
    mapper.SetInputConnection(graphToPolyData.GetOutputPort())

    actor = vtkActor()
    actor.SetMapper(mapper)

    # Create a renderer, render window, and interactor
    renderer = vtkRenderer()
    renderWindow = vtkRenderWindow()
    renderWindow.AddRenderer(renderer)
    renderWindowInteractor = vtkRenderWindowInteractor()
    renderWindowInteractor.SetRenderWindow(renderWindow)

    # Add the actor to the scene
    renderer.AddActor(actor)
    renderer.SetBackground(colors.GetColor3d('Green'))

    # Render and interact
    renderWindow.SetWindowName('GraphToPolyData')
    renderWindow.Render()
    renderWindowInteractor.Start()


if __name__ == '__main__':
    main()