Error importing vtkTkRenderWindowInteractor in vtk 8.2.0

Julie · April 27, 2019, 1:12pm

Hi, everyone

I am writing a simple GUI with simple inputs and vtk rendering in Python. One article about this is combing tk and vtk, namely vtkTkRenderWindowInteractor, the error and code is as below:

(1) Error-------------------------------------------------------

TclError Traceback (most recent call last)
in
22 # Setup for rendering window interactor
23 renWinInteract = vtkTkRenderWindowInteractor(root,
—> 24 rw=renWindow, width=400, height=400)
25 renWinInteract.Initialize()
26 renWinInteract.pack(side=‘top’, fill=‘both’, expand=1)

~/anaconda2/envs/py3/lib/python3.6/site-packages/vtkmodules/tk/vtkTkRenderWindowInteractor.py in init(self, master, cnf, **kw)
53 “”"
54 # load the necessary extensions into tk
—> 55 vtkLoadPythonTkWidgets(master.tk)
56
57 try: # check to see if a render window was specified

~/anaconda2/envs/py3/lib/python3.6/site-packages/vtkmodules/tk/vtkLoadPythonTkWidgets.py in vtkLoadPythonTkWidgets(interp)
85
86 # re-generate the error
—> 87 interp.call(‘load’, filename, pkgname)

TclError Traceback (most recent call last)
in
22 # Setup for rendering window interactor
23 renWinInteract = vtkTkRenderWindowInteractor(root,
—> 24 rw=renWindow, width=400, height=400)
25 renWinInteract.Initialize()
26 renWinInteract.pack(side=‘top’, fill=‘both’, expand=1)

~/anaconda2/envs/py3/lib/python3.6/site-packages/vtkmodules/tk/vtkTkRenderWindowInteractor.py in init(self, master, cnf, **kw)
53 “”"
54 # load the necessary extensions into tk
—> 55 vtkLoadPythonTkWidgets(master.tk)
56
57 try: # check to see if a render window was specified

~/anaconda2/envs/py3/lib/python3.6/site-packages/vtkmodules/tk/vtkLoadPythonTkWidgets.py in vtkLoadPythonTkWidgets(interp)
85
86 # re-generate the error
—> 87 interp.call(‘load’, filename, pkgname)

TclError: dlopen(libvtkRenderingPythonTkWidgets-8.2.dylib, 6): image not found

(2) Code-------------------------------------------------------
import tkinter
import sys
import vtk

from vtk.tk.vtkTkRenderWindowInteractor import vtkTkRenderWindowInteractor

Setup for root window

root = tkinter.Tk()
root.title( “Tkinter Test” )
frame = tkinter.Frame( root )
frame.pack( fill=tkinter.BOTH, expand=1, side=tkinter.TOP )

Setup for renderer

render = vtk.vtkRenderer()
render.SetBackground( 0.329412, 0.34902, 0.427451 )
render.ResetCameraClippingRange()

Setup for rendering window

renWindow = vtk.vtkRenderWindow()
renWindow.AddRenderer(render)

Setup for rendering window interactor

renWinInteract = vtkTkRenderWindowInteractor(root,
rw=renWindow, width=400, height=400)
renWinInteract.Initialize()
renWinInteract.pack(side=‘top’, fill=‘both’, expand=1)
renWinInteract.Start()

Begin execution by updating the renderer and

starting the Tkinter loop

renWindow.Render()
root.mainloop()

(3) Other information-------------------------------------------------------
vtk: 8.2.0
python: 3.6
os: macOS

Any solution to this?

Many thanks.

dgobbi · April 27, 2019, 3:46pm

Hi Julie,

The libvtkRenderingPythonTkWidgets dylib is the Tk extension that allows VTK to be used with Tkinter. If it is missing, then it was probably not built. Where did you get your VTK package from? You should contact the maintainer and see if they can build VTK with VTK_USE_TK turned on.

I notice that the official pypi package for VTK 8.1.2 wasn’t built with Tk support, either.

Julie · April 27, 2019, 3:52pm

Hi, David

Thank you for your fast response.

I installed the vtk package directly from anaconda (conda install -n py3 vtk=8.2.0).
Do you mean I should compile vtk using CMAKE to turn on VTK_USE_TK?

Thanks.

dgobbi · April 27, 2019, 4:16pm

Yes, if you build VTK yourself then you can tell cmake to turn on VTK_USE_TK. I recommend building the release branch of VTK (https://gitlab.kitware.com/vtk/vtk/tree/release), which will become 8.2.1. It has many fixes that aren’t in the 8.2.0 release.

After building, make sure there is a libvtkRenderingPythonTkWidgets-8.2.dylib in the build tree.

Julie · April 27, 2019, 5:02pm

Hi, David

Thank you. I’ll try it.

Julie · April 29, 2019, 2:35pm

Hi, David

I tried your method, building the vtk 8.2.1. However, the VTK_USE_TK parameter does not exist. The new error I got running the script is ad below:

TclError: couldn’t load file “libvtkRenderingPythonTkWidgets-8.2.so”: libvtkRenderingPythonTkWidgets-8.2.so: cannot open shared object file: No such file or directory

It seems some file is still missing.

dgobbi · April 29, 2019, 2:40pm

That’s strange. If you set Module_vtkRenderingTk:BOOL=ON, does VTK_USE_TK appear?

Julie · April 29, 2019, 3:42pm

Neither did I find the Module_vtkRenderingTk, the only one related to TK is ‘VTK_Group_tk’, after I turned it on. The error is still the same.

Could that be related to the version of QT? I installed qt5.9.7, but the manual mentions that 5.2.1 is recommended. However, it is always stuck installing 5.2.1.

dgobbi · April 29, 2019, 3:48pm

The Qt settings are independent of the Tk settings.

From what you describe, it seems that VTK 8.2 has some config bugs related to Tk. You will probably have to add VTK_USE_TK:BOOL=ON directly to your CMakeLists.txt file (or run cmake with -DVTK_USE_TK:BOOL=ON). Let me know if that works.

dgobbi · April 29, 2019, 6:53pm

I just tested VTK 8.2 on my own mac (using the system Python and Tcl, though).
VTK_USE_TK didn’t appear at first, but it appeared after I enabled VTK_Group_Tk.
The detected TCL_LIBRARY and TK_LIBRARY were incorrect, so I had to set them manually.

After that, the build succeeded and the vtkTkRenderWindowInteractor tests worked.

Julie · April 29, 2019, 6:57pm

Thank you. I will try that tomorrow.

Julie · April 30, 2019, 8:08am

Hi, David,

It still does not work. the error message is same as last time. By the way, where is the TCL_LIBRARY and TK_LIBRARY?
I did not see them in the configuration.

Here are the screenshots of my current configuration.

dgobbi · April 30, 2019, 9:20am

The TCL_LIBRARY and TK_LIBRARY are advanced options, so you’ll see them if you toggle the advanced mode (or open CMakeCache.txt in a text editor).

If VTK is using /usr/bin/python (the system Python), then it will need to link to Apple’s Tcl/Tk 8.5 (e.g. /System/Library/Frameworks/Tcl.framework/Tcl and /System/Library/Frameworks/Tk.framework/Tk).

If VTK is using a different Python, then it will probably require Tcl/Tk 8.6.

dgobbi · April 30, 2019, 9:26am

You’ll also have to turn on VTK_WRAP_PYTHON.
The libvtkRenderingPythonTkWidgets-8.2.dylib will not be built unless VTK_WRAP_PYTHON and VTK_USE_TK are both ON.

Julie · April 30, 2019, 10:09am

Hi, David

Thank you so much for your help. After I turn on VTK_WRAP_PYTHON, I can see VTK_USE_TK in the list of parameters. And now I can find the libvtkRenderingPythonTkWidgets-8.2.so file under the VTK-build folder.

One more question, how could I let anaconda know now it should use the new built vtk, instead of the previous one build from conda?

Thanks.

dgobbi · April 30, 2019, 12:34pm

Well, I’m confused about why you’re calling it “libvtkRenderingPythonTkWidgets-8.2.so” instead of “libvtkRenderingPythonTkWidgets-8.2.dylib”. You are still working on OS X, aren’t you? Be sure to test vtkTkRenderWindowInteractor before going any further.

It might be possible to replace the VTK libraries etc. that conda installed with the ones that you built, by setting CMAKE_INSTALL_PREFIX appropriately and then doing make install. You’ll definitely want to have a backup ready, though.

Julie · May 4, 2019, 8:28am

Hi, David,

Thank you very much for your help all these days.
Previously, I was building vtk in ubuntu, and it succeeded importing “vtkTkRenderWindowInteractor”. And the new error message is about libvtkRenderingPythonTkWidgets-8.2.so, not libvtkRenderingPythonTkWidgets-8.2.dylib.

Now I am repeating the process on my Mac. The missing file in the error message is libvtkRenderingPythonTkWidgets-8.2.dylib. When I did make, it succeeded. And I can also find the libvtkRenderingPythonTkWidgets-8.2.dylib in the lib of my vtk install folder. But then, when I was doing make install, I got the following error.

error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/install_name_tool: no LC_RPATH load command with path: /Users/julievon/anaconda2/envs/vtk/lib found in: /Users/julievon/anaconda2/envs/vtk/bin/vtkpython (for architecture x86_64), required for specified option “-delete_rpath /Users/julievon/anaconda2/envs/vtk/lib”

error: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/install_name_tool: no LC_RPATH load command with path: /Users/julievon/anaconda2/lib found in: /Users/julievon/anaconda2/envs/vtk/bin/vtkpython (for architecture x86_64), required for specified option “-delete_rpath /Users/julievon/anaconda2/lib”

Is there any parameter I set wrong?

Following is the cmake configuration.

Thanks.

dgobbi · May 6, 2019, 2:12pm

Hi Julie,

Use “otool -l” to check to see how the paths are set in the vtkpython executable. When “make install” runs, the “-delete_rpath” is used to remove any paths that point to the build tree. So it’s strange to see “-delete_rpath /Users/julievon/anaconda2/lib”, since this path is in the install tree. I don’t see anything wrong with your cmake configuration. This could be a conflict of sorts between the VTK that you are installing, and the VTK installed by conda.

You could try restoring the anaconda vtk from backup, and then manually copy just “libvtkRenderingPythonTkWidgets-8.2.dylib” to the “site-packages” within the anaconda directory tree. Here, again, “otool -l” can be used to check to see what libraries it links to.

Julie · May 7, 2019, 12:42pm

Hi David,

Thank you so much for your help, always.

I still can not make it. It nearly drove me crazy. I tried many combinations by tuning the parameters. And to make the environment clean, I uninstalled all the vtk packages previously installed via conda or pip. It still failed. But I also have some progress.

It failed when I “import vtk”, it seems the files are not installed in the correct place. Then I tried to find the difference with the bin&include&lib files between conda-install and source-install, I found the later one put the vtkmodules folder and vtk.py under /lib/python2.7/site-packages, but not /lib/python3.6/site-packages. After I copy these files to /lib/python3.6/site-packages, “import vtk” succeeded. However when I try to run the code which includes vtkTkRenderWindowInteractor, the program crashed, shown as below.

Another interesting thing: if I directly use the stable vtk version 8.2, I can successfully “import vtk”, after building, it does not make any mistake of python version (2.7 vs 3.6). However, the same thing is: when I try to run the code which includes vtkTkRenderWindowInteractor, the program crashed.

Do you know what the possible root cause is?

Thank you very much.

Best,
Julie

dgobbi · May 7, 2019, 1:53pm

A crash like this often suggests that a library that was linked at compile time doesn’t match the library that gets linked at runtime. The stack trace suggests that the Tk library is the one causing the problem. Make sure that the “_tkinter.cpython-36m-darwin.so” mentioned is linking to the same libtk and libtcl as “libvtkRenderingPythonTkWidgets-8.2.dylib” (use “otool -l” to do the check). Also make sure that this matches the libtk and libtcl in your cmake config.

One suspicious thing about the stack trace is that it references both “Tcl” and “libtcl8.6.dylib” as tcl libraries. When it references “Tcl”, it means the framework Tcl (i.e. in /Library/Frameworks or /System/Library/Frameworks) but when it references “libtcl.8.6.dylib” it means a tcl installed somewhere else, e.g. a tcl that is part of anaconda.