Disable or Catch VTK warnings in vtkOutputWindow w

问题:

I'd like to either disable the VTK warning window or, better yet, catch them to handle with my application's logging system. My application is using an embedded mayavi view, and I don't want error windows popping up that I have no control over. The following code demonstrates the warning window.

import numpy as np
from mayavi import mlab

x1 = np.array([1, 1, 2, 3])
y1 = np.array([1, 1, 4, 2])
z1 = np.array([1, 1, 5, 1])

mlab.plot3d(x1, y1, z1)

mlab.show()

Ok, I've done some research and discovered that vtk.vtkObject.GlobalWarningDisplayOff() will disable the window completely, which is nice. Better yet the followingcode will log the warnings to a file (found it here):

def redirect_vtk_messages ():
    """ Can be used to redirect VTK related error messages to a
    file."""
    import tempfile
    tempfile.template = 'vtk-err'
    f = tempfile.mktemp('.log')
    log = vtkpython.vtkFileOutputWindow()
    log.SetFlush(1)
    log.SetFileName(f)
    log.SetInstance(log)

So while this is nice, I'm still unable to pipe the warnings directly into a logging handler. I'd rather not have to have a vtk_log file next to my regular log files. Also I might want to handle the warnings in my GUI somehow, or give the user options on how to handle them and constantly watching a log file for changes seems like a poor way to do that.

Any suggestions on a robust pythonic way to handle vtk warnings in an application which embeds mayavi/vtk?

回答1:

I guess this partially answer your question, but you could implement an error observer in python as explained here http://public.kitware.com/pipermail/vtkusers/2012-June/074703.html and add it to the vtk class you are interested.

In c++ I find much simpler to redirect the output to stderr (this example is for windows):

vtkSmartPointer<vtkWin32OutputWindow> myOutputWindow = vtkSmartPointer<vtkWin32OutputWindow>::New(); 
myOutputWindow->SetSendToStdErr(true);
vtkOutputWindow::SetInstance(myOutputWindow);

In python I tried

ow = vtk.vtkOutputWindow()
ow.SendToStdErrOn()

it sends the error to console, but I still see the vtk window and it doesn't really seem catching the errors.

Another option could be to recompile vtk with VTK_USE_DISPLAY turned off ( http://osdir.com/ml/python-enthought-devel/2009-11/msg00164.html). I am not going to try this because I am using the vtk distribution already compiled in paraview

回答2:

You can create a subclass deriving from vtkOutputWindow and implement your message handling in the method void DisplayText(const char* someText). I did this is in a C++ project to redirect all output to cerr and even suppress specific warnings.

回答3:

I don't know whether this will work in the Mayavi environment, but this works for Python wrappings to VTK

# pipe vtk output errors to file
errOut = vtk.vtkFileOutputWindow()
errOut.SetFileName("VTK Error Out.txt")
vtkStdErrOut = vtk.vtkOutputWindow()
vtkStdErrOut.SetInstance(errOut)