Python VTK script to Display 3D xyz data

This Plot3 python matplotlib script is useful. But there are times when all I have is a txt or csv file with the xyz data and I just want to see the 3d view. Firing up python IDE , loading the data and using the plot3 script becomes too many steps. And the output 3d plot’s handling leave much to be desired.

So building on VTK docs python examples, have developed this python script to display 3D xyz data from a file.

The simple command is python xyzviewer.py filename

That’s it and you get a VTK window with interactive display of the data. Of course needs VTK installed in python.

Here’s a short 9 sec demo of the 3D display.

And if you are still curious, you can look at the plot3 here.

Update: If the formatting fails you, download vtkpointsdisplay from here.

And here’s the updated code for anyone interested. Thanks Ralv and Samir.

''' 
Modified Python 3 VTK script to Display 3D xyz data
'''

import vtk
from numpy import random,genfromtxt,size
      
class VtkPointCloud:
    def __init__(self, zMin=-10.0, zMax=10.0, maxNumPoints=1e6):
        self.maxNumPoints = maxNumPoints
        self.vtkPolyData = vtk.vtkPolyData()
        self.clearPoints()
        mapper = vtk.vtkPolyDataMapper()
        mapper.SetInputData(self.vtkPolyData)
        mapper.SetColorModeToDefault()
        mapper.SetScalarRange(zMin, zMax)
        mapper.SetScalarVisibility(1)
        self.vtkActor = vtk.vtkActor()
        self.vtkActor.SetMapper(mapper)
 
    def addPoint(self, point):
        if (self.vtkPoints.GetNumberOfPoints() < self.maxNumPoints):
            pointId = self.vtkPoints.InsertNextPoint(point[:])
            self.vtkDepth.InsertNextValue(point[2])
            self.vtkCells.InsertNextCell(1)
            self.vtkCells.InsertCellPoint(pointId)
        else:
            r = random.randint(0, self.maxNumPoints)
            self.vtkPoints.SetPoint(r, point[:])
        self.vtkCells.Modified()
        self.vtkPoints.Modified()
        self.vtkDepth.Modified()
 
    def clearPoints(self):
        self.vtkPoints = vtk.vtkPoints()
        self.vtkCells = vtk.vtkCellArray()
        self.vtkDepth = vtk.vtkDoubleArray()
        self.vtkDepth.SetName('DepthArray')
        self.vtkPolyData.SetPoints(self.vtkPoints)
        self.vtkPolyData.SetVerts(self.vtkCells)
        self.vtkPolyData.GetPointData().SetScalars(self.vtkDepth)
        self.vtkPolyData.GetPointData().SetActiveScalars('DepthArray')
 
def load_data(filename,pointCloud):
    data = genfromtxt(filename,dtype=float,usecols=[0,1,2])
     
    for k in range(size(data,0)):
        point = data[k] #20*(random.rand(3)-0.5)
        pointCloud.addPoint(point)
         
    return pointCloud
 
 
if __name__ == '__main__':
    import sys
 
 
    if (len(sys.argv) < 2):
         print ('Usage: xyzviewer.py itemfile')
         sys.exit()
    pointCloud = VtkPointCloud()
    pointCloud=load_data(sys.argv[1],pointCloud)
 
 
# Renderer
    renderer = vtk.vtkRenderer()
    renderer.AddActor(pointCloud.vtkActor)
#renderer.SetBackground(.2, .3, .4)
    renderer.SetBackground(0.0, 0.0, 0.0)
    renderer.ResetCamera()
 
# Render Window
    renderWindow = vtk.vtkRenderWindow()
    renderWindow.AddRenderer(renderer)
 
# Interactor
    renderWindowInteractor = vtk.vtkRenderWindowInteractor()
    renderWindowInteractor.SetRenderWindow(renderWindow)
 
# Begin Interaction
    renderWindow.Render()
    renderWindow.SetWindowName("XYZ Data Viewer"+sys.argv[1])
    renderWindowInteractor.Start()

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