# TriangleStrip

VTKExamples/Python/GeometricObjects/TriangleStrip

### Description

The triangle strip is a composite two-dimensional cell consisting of one or more triangles. The points defining the triangle strip need not lie in a plane. The triangle strip is defined by an ordered list of n+2 points, where n is the number of triangles. The ordering of the points is such that each set of three points defines a triangle.

Info

See this wikipedia article for an explanation.

### Code

TriangleStrip.py

    #!/usr/bin/env python
    # -*- coding: utf-8 -*-

    import vtk

    def main():
        colors = vtk.vtkNamedColors()

        points = vtk.vtkPoints()
        points.InsertNextPoint(0, 0, 0)
        points.InsertNextPoint(0, 1, 0)
        points.InsertNextPoint(1, 0, 0)
        points.InsertNextPoint(1.5, 1, 0)

        triangleStrip = vtk.vtkTriangleStrip()
        triangleStrip.GetPointIds().SetNumberOfIds(4)
        triangleStrip.GetPointIds().SetId(0, 0)
        triangleStrip.GetPointIds().SetId(1, 1)
        triangleStrip.GetPointIds().SetId(2, 2)
        triangleStrip.GetPointIds().SetId(3, 3)

        cells = vtk.vtkCellArray()
        cells.InsertNextCell(triangleStrip)

        polydata = vtk.vtkPolyData()
        polydata.SetPoints(points)
        polydata.SetStrips(cells)

        # Create an actor and mapper
        mapper = vtk.vtkDataSetMapper()
        mapper.SetInputData(polydata)
        actor = vtk.vtkActor()
        actor.SetMapper(mapper)
        actor.GetProperty().SetColor(colors.GetColor3d("Cyan"))
        actor.GetProperty().SetRepresentationToWireframe()

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

        renderer.AddActor(actor)
        renderer.SetBackground(colors.GetColor3d("DarkGreen"))
        renderWindow.Render()
        renderWindowInteractor.Start()

    if __name__ == '__main__':
        main()