Just in case you would ever like to incorporate matplotlib plots into your vtk application, vtk provides a really easy way to import them.
Here is a full example for now:
1 from vtk import *
2
3 import matplotlib
4 matplotlib.use('Agg')
5 from matplotlib.figure import Figure
6 from matplotlib.backends.backend_agg import FigureCanvasAgg
7 import pylab as p
8
9 # The vtkImageImporter will treat a python string as a void pointer
10 importer = vtkImageImport()
11 importer.SetDataScalarTypeToUnsignedChar()
12 importer.SetNumberOfScalarComponents(4)
13
14 # It's upside-down when loaded, so add a flip filter
15 imflip = vtkImageFlip()
16 imflip.SetInput(importer.GetOutput())
17 imflip.SetFilteredAxis(1)
18
19 # Map the plot as a texture on a cube
20 cube = vtkCubeSource()
21
22 cubeMapper = vtkPolyDataMapper()
23 cubeMapper.SetInput(cube.GetOutput())
24
25 cubeActor = vtkActor()
26 cubeActor.SetMapper(cubeMapper)
27
28 # Create a texture based off of the image
29 cubeTexture = vtkTexture()
30 cubeTexture.InterpolateOn()
31 cubeTexture.SetInput(imflip.GetOutput())
32 cubeActor.SetTexture(cubeTexture)
33
34 ren = vtkRenderer()
35 ren.AddActor(cubeActor)
36
37 renWin = vtkRenderWindow()
38 renWin.AddRenderer(ren)
39
40 iren = vtkRenderWindowInteractor()
41 iren.SetRenderWindow(renWin)
42
43 # Now create our plot
44 fig = Figure()
45 canvas = FigureCanvasAgg(fig)
46 ax = fig.add_subplot(111)
47 ax.grid(True)
48 ax.set_xlabel('Hello from VTK!', size=16)
49 ax.bar(xrange(10), p.rand(10))
50
51 # Powers of 2 image to be clean
52 w,h = 1024, 1024
53 dpi = canvas.figure.get_dpi()
54 fig.set_figsize_inches(w / dpi, h / dpi)
55 canvas.draw() # force a draw
56
57 # This is where we tell the image importer about the mpl image
58 extent = (0, w - 1, 0, h - 1, 0, 0)
59 importer.SetWholeExtent(extent)
60 importer.SetDataExtent(extent)
61 importer.SetImportVoidPointer(canvas.buffer_rgba(0,0), 1)
62 importer.Update()
63
64 iren.Initialize()
65 iren.Start()
To have the plot be a billboard:
Comments
From zunzun Fri Aug 19 07:06:44 -0500 2005
From: zunzun
Date: 2005年8月19日 07:06:44 -0500
Subject:
Message-ID: <20050819070644-0500@www.scipy.org>
from http://sourceforge.net/mailarchive/forum.php?thread_id=7884469&forum_id=33405
If pylab is imported before vtk, everything works fine:
import pylab, vtkpython
pylab.ylabel("Frequency\n", multialignment="center", rotation=90)
n, bins, patches = pylab.hist([1,1,1,2,2,3,4,5,5,5,8,8,8,8], 5)
pylab.show()
If however vtk is imported first:
import vtkpython, pylab
pylab.ylabel("Frequency\n", multialignment="center", rotation=90)
n, bins, patches = pylab.hist([1,1,1,2,2,3,4,5,5,5,8,8,8,8], 5)
pylab.show()
then the Y axis label is positioned incorrectly on the plots.From earthman Tue Oct 25 15:21:14 -0500 2005 From: earthman Date: 2005年10月25日 15:21:14 -0500 Subject: Message-ID: <20051025152114-0500@www.scipy.org> The reason for this is that vtk comes with it's own freetype library, and this is the one being used if vtk is loaded first. Worse symptoms could be errors about fonts not being found. This is typically solved by importing vtk after other packages which might use freetype (pylab, wxPython, etc).
From mroublic Tue Jan 10 11:26:45 -0600 2006 From: mroublic Date: 2006年1月10日 11:26:45 -0600 Subject: One more change I had to make Message-ID: <20060110112645-0600@www.scipy.org> In-reply-to: <20050819070644-0500@www.scipy.org> When I first tried this, I had the error: Traceback (most recent call last): File "MatplotlibToVTK.py", line 61, in ? importer.SetImportVoidPointer(canvas.buffer_rgba(), 1) TypeError: buffer_rgba() takes exactly 3 arguments (1 given) I had to add 0,0 to the import line: importer.SetImportVoidPointer(canvas.buffer_rgba(0,0), 1) I'm using VTK from CVS using the 5_0 Branch from around November 2005
The above code didn't run on my system. I had to change the following line: fig.set_figsize_inches(w / dpi, h / dpi) into: fig.set_figsize_inches(1.0*w / dpi, 1.0*h / dpi)