# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=130

[Latest](https://discourse.vtk.org/latest.md) · [Categories](https://discourse.vtk.org/categories.md) · [Tags](https://discourse.vtk.org/tags.md)

**Page:** 131

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## [Missing files or paths](https://discourse.vtk.org/t/missing-files-or-paths/3397)

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**Author:** [@Quinn\_B](https://discourse.vtk.org/u/Quinn_B)\
**Replies:** 2\
**Last updated:** [May 27, 2020, 4:49pm UTC](https://discourse.vtk.org/t/missing-files-or-paths/3397 "2020-05-27T16:49:12Z")

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Hello again while trying to configure the build and generate the files I ran into these errors and was wondering if I needed to install another package or modify some files

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## [Downgrade from OpenGL ES 4.6 Mesa 20.0.4 to OpenGL ES 3.0 Mesa 19.2.8 in ubuntu 20](https://discourse.vtk.org/t/downgrade-from-opengl-es-4-6-mesa-20-0-4-to-opengl-es-3-0-mesa-19-2-8-in-ubuntu-20/3395)

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**Author:** [@vacingforo](https://discourse.vtk.org/u/vacingforo)\
**Replies:** 0\
**Last updated:** [May 26, 2020, 8:38am UTC](https://discourse.vtk.org/t/downgrade-from-opengl-es-4-6-mesa-20-0-4-to-opengl-es-3-0-mesa-19-2-8-in-ubuntu-20/3395 "2020-05-26T08:38:52Z")

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I have an application based on VTK 8.1.0 which only runs with OpenGL ES 3.0 Mesa 19.2.8 (Ubuntu 18). I want to run it in ubuntu 20 but the problem is that the version of opengl library is OpenGL ES 4.6 Mesa 20.0.4. Is t…

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## [VTK8.2 from python 3.7 wheel, is it possible to force opengl 1.1?](https://discourse.vtk.org/t/vtk8-2-from-python-3-7-wheel-is-it-possible-to-force-opengl-1-1/3387)

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**Author:** [@eddy](https://discourse.vtk.org/u/eddy)\
**Replies:** 3\
**Last updated:** [May 25, 2020, 8:48pm UTC](https://discourse.vtk.org/t/vtk8-2-from-python-3-7-wheel-is-it-possible-to-force-opengl-1-1/3387 "2020-05-25T20:48:01Z")

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Hi all, I have to first disclaim that I’m very new to the graphics part, linux and cmake. I’ve been using paraview for some time, both the pvpython (very seldom) and the gui. However, we are now in the process of buildi…

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## [Problem with CMake and VTK](https://discourse.vtk.org/t/problem-with-cmake-and-vtk/3378)

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**Author:** [@Quinn\_B](https://discourse.vtk.org/u/Quinn_B)\
**Replies:** 11\
**Last updated:** [May 25, 2020, 4:48pm UTC](https://discourse.vtk.org/t/problem-with-cmake-and-vtk/3378 "2020-05-25T16:48:11Z")

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Hello! I’m trying to build VTK-8.2.0 using CMake and using Visual Studios 2019 as my configuration platform. Yet I keep getting an error about using either incorrect/unofficial files and it won’t even start the build. I’…

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## [A problem with vtkImageViewer2](https://discourse.vtk.org/t/a-problem-with-vtkimageviewer2/3391)

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**Author:** [@nik](https://discourse.vtk.org/u/nik)\
**Replies:** 0\
**Last updated:** [May 25, 2020, 3:11pm UTC](https://discourse.vtk.org/t/a-problem-with-vtkimageviewer2/3391 "2020-05-25T15:11:52Z")

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Hi! I am studying and I have problems with the example for reading and displaying, freezes and closes when scrolling slices. https://lorensen.github.io/VTKExamples/site/CSharp/IO/ReadDICOMSeries/

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## [undefined reference to \`PyErr\_Occurred'](https://discourse.vtk.org/t/undefined-reference-to-pyerr-occurred/3383)

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**Author:** [@jiapei100](https://discourse.vtk.org/u/jiapei100)\
**Replies:** 2\
**Last updated:** [May 24, 2020, 6:50pm UTC](https://discourse.vtk.org/t/undefined-reference-to-pyerr-occurred/3383 "2020-05-24T18:50:31Z")

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Hi, I’m trying to build VTK again, but it seems the settings are a little different from before. Anyway, RenderingGL2PSOpenGL2 seems to be set as DEFAULT, which seems to be YES. ... //Enable the VTK::RenderingGL2PSOpenG…

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## [QVTKInteractorAdapter Deprecation issues](https://discourse.vtk.org/t/qvtkinteractoradapter-deprecation-issues/3381)

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**Author:** [@ilandaniele](https://discourse.vtk.org/u/ilandaniele)\
**Replies:** 0\
**Last updated:** [May 23, 2020, 3:53am UTC](https://discourse.vtk.org/t/qvtkinteractoradapter-deprecation-issues/3381 "2020-05-23T03:53:05Z")

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As it says in the deprecated list: Member \[QVTKOpenGLWindow::GetInteractorAdapter\] in VTK 9.0 \[QVTKInteractorAdapter\] is an internal helper. My project was made in VTK 8.1 version.However, due to some issues, we needed…

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## [VTK 9 + PyQt + macOS = no rendering](https://discourse.vtk.org/t/vtk-9-pyqt-macos-no-rendering/3358)

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**Author:** [@panicbuttonvfx](https://discourse.vtk.org/u/panicbuttonvfx)\
**Replies:** 24\
**Last updated:** [May 23, 2020, 1:23am UTC](https://discourse.vtk.org/t/vtk-9-pyqt-macos-no-rendering/3358 "2020-05-23T01:23:59Z")

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Hi, Using the latest VTK 9 wheel (from a couple of days ago) for macOS (tested on 10.15.4), I’m experiencing rendering issues. The plotter viewport is transparent with PyQt 5.12.3 and black with PyQt 5.9.2, and nothing …

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## [building with gcc 10.1.0](https://discourse.vtk.org/t/building-with-gcc-10-1-0/3323)

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**Author:** [@hubutui](https://discourse.vtk.org/u/hubutui)\
**Replies:** 6\
**Last updated:** [May 22, 2020, 12:39pm UTC](https://discourse.vtk.org/t/building-with-gcc-10-1-0/3323 "2020-05-22T12:39:59Z")

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Hey, gcc 10.1.0 is released recently. Does anyone try to build vtk with gcc 10? I got something error like this: make\[2\]: Entering directory '/build/vtk-git/src/build-vtk-git' \[ 44%\] Building CXX object CMakeFiles/vtkIm…

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## [vtkTubeFilter - representation and intersections](https://discourse.vtk.org/t/vtktubefilter-representation-and-intersections/3371)

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**Author:** [@Andrea\_Gavana](https://discourse.vtk.org/u/Andrea_Gavana)\
**Replies:** 0\
**Last updated:** [May 22, 2020, 6:47am UTC](https://discourse.vtk.org/t/vtktubefilter-representation-and-intersections/3371 "2020-05-22T06:47:50Z")

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Dear VTK users/developers, I have a number of vtkPolyData in 3D, each of those representing some sort of trajectory. Every point of each polydata is a result of real-life measurements, and in this specific case the meas…

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## [Downsampling 3D image data in VTK without aliasing?](https://discourse.vtk.org/t/downsampling-3d-image-data-in-vtk-without-aliasing/3329)

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**Author:** [@msmerps](https://discourse.vtk.org/u/msmerps)\
**Replies:** 3\
**Last updated:** [May 21, 2020, 9:14pm UTC](https://discourse.vtk.org/t/downsampling-3d-image-data-in-vtk-without-aliasing/3329 "2020-05-21T21:14:44Z")

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Hi, I would like downsample some 3D image data by a factor of 2 without introducing aliasing artifact as described here: I am able to do the downsampling with vtkImageReslice.SetOutputSpacing. However, it doesn’t appe…

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## [GetMultiSamples() returns different value after doing Render()](https://discourse.vtk.org/t/getmultisamples-returns-different-value-after-doing-render/3364)

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**Author:** [@muryanto1](https://discourse.vtk.org/u/muryanto1)\
**Replies:** 0\
**Last updated:** [May 21, 2020, 6:12pm UTC](https://discourse.vtk.org/t/getmultisamples-returns-different-value-after-doing-render/3364 "2020-05-21T18:12:07Z")

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Running vtk-example.py (see script below) shows that in an environment with vtk 9.0.0.rc3 with mesalib, calling GetMultiSamples() after calling Render() returns 0, which is different from what GetMultiSamples() returns b…

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## [Changing opacity of volume rendering based on window width/window level in VTK](https://discourse.vtk.org/t/changing-opacity-of-volume-rendering-based-on-window-width-window-level-in-vtk/3363)

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**Author:** [@watson](https://discourse.vtk.org/u/watson)\
**Replies:** 1\
**Last updated:** [May 21, 2020, 5:33pm UTC](https://discourse.vtk.org/t/changing-opacity-of-volume-rendering-based-on-window-width-window-level-in-vtk/3363 "2020-05-21T17:33:13Z")

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I need to change the opacity transfer function of volume rendered image based in window width and window level .I need to know how to set the opacity transfer function with respect to WW/WL ie) OpacityTransferFunc…

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## [Compiling VTK without generating library symlinks](https://discourse.vtk.org/t/compiling-vtk-without-generating-library-symlinks/3359)

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**Author:** [@BotellaA](https://discourse.vtk.org/u/BotellaA)\
**Replies:** 4\
**Last updated:** [May 21, 2020, 12:37pm UTC](https://discourse.vtk.org/t/compiling-vtk-without-generating-library-symlinks/3359 "2020-05-21T12:37:28Z")

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VTK generates a lot of symlinks (at least on linux) while compiling. Like this one: libvtkWebCore-8.90.so -\> libvtkWebCore-8.90.so.1 libvtkWebCore-8.90.so.1 -\> libvtkWebCore-8.90.so.8.90.0 libvtkWebCore-8.90.so.8.90.0 M…

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## [Fitting vtkTextActor within a bounding box](https://discourse.vtk.org/t/fitting-vtktextactor-within-a-bounding-box/3362)

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**Author:** [@Nibba2018](https://discourse.vtk.org/u/Nibba2018)\
**Replies:** 0\
**Last updated:** [May 21, 2020, 11:21am UTC](https://discourse.vtk.org/t/fitting-vtktextactor-within-a-bounding-box/3362 "2020-05-21T11:21:45Z")

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Hello everyone, I was looking for a method to fit a vtkTextActor within a rectangular box having a particular width and height without providing the font size of the Text. In other words, I am looking for a solution in w…

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## [Acquire 3D Point data using LineWidtget2](https://discourse.vtk.org/t/acquire-3d-point-data-using-linewidtget2/3360)

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**Author:** [@Seram](https://discourse.vtk.org/u/Seram)\
**Replies:** 0\
**Last updated:** [May 21, 2020, 6:14am UTC](https://discourse.vtk.org/t/acquire-3d-point-data-using-linewidtget2/3360 "2020-05-21T06:14:08Z")

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Hello, I’m using VTK9 and VS2015 C++ and I loaded Ply Data and Line in 3D Space using LineWidget2. I want to get the coordinate (=X, Y) and height values (=Z) of 3D Point included in Line drawn with LineWidget2. Fin…

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## [Possible to specifiy "format" in vtp file?](https://discourse.vtk.org/t/possible-to-specifiy-format-in-vtp-file/3283)

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**Author:** [@Ahmed\_Salih](https://discourse.vtk.org/u/Ahmed_Salih)\
**Replies:** 5\
**Last updated:** [May 20, 2020, 8:22pm UTC](https://discourse.vtk.org/t/possible-to-specifiy-format-in-vtp-file/3283 "2020-05-20T20:22:45Z")

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Hello! Basically what I want is that when I open a file in Paraview, it automatically applies the necessary conditions to render it properly. Currently when I load my file, it displays nothing, and I have to manually se…

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## [Problem with transparency with VTK \>= 8.0 on Linux](https://discourse.vtk.org/t/problem-with-transparency-with-vtk-8-0-on-linux/3309)

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**Author:** [@tigarmo](https://discourse.vtk.org/u/tigarmo)\
**Replies:** 5\
**Last updated:** [May 20, 2020, 12:52pm UTC](https://discourse.vtk.org/t/problem-with-transparency-with-vtk-8-0-on-linux/3309 "2020-05-20T12:52:47Z")

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Hi, I have an issue with rendering transparent objects with any version of VTK from 8.0 onwards (tested up to 9.0.0). I’m running CentOS 7 inside VirtualBox, and glxinfo reports: OpenGL version string: 3.3 (Compatibilit…

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## [How to build python package from VTK source code?](https://discourse.vtk.org/t/how-to-build-python-package-from-vtk-source-code/3345)

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**Author:** [@caibf](https://discourse.vtk.org/u/caibf)\
**Replies:** 3\
**Last updated:** [May 20, 2020, 11:00am UTC](https://discourse.vtk.org/t/how-to-build-python-package-from-vtk-source-code/3345 "2020-05-20T11:00:42Z")

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In general, some one would like to use VTK with python through install vtk via pip. $ pip install vtk However, I built my VTK binaries from source code and expect to use python interface on it. How can I do that?

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## [Thickness analysis of a solid sheet metal](https://discourse.vtk.org/t/thickness-analysis-of-a-solid-sheet-metal/3341)

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**Author:** [@DFlyer](https://discourse.vtk.org/u/DFlyer)\
**Replies:** 1\
**Last updated:** [May 20, 2020, 12:26am UTC](https://discourse.vtk.org/t/thickness-analysis-of-a-solid-sheet-metal/3341 "2020-05-20T00:26:12Z")

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I have a CAD solid sheet metal part, I can mesh them to surface or volume elements. Is there a technique to extract the midsurface in VTK? Also is it possible to estimate thickness from the computed mid surface? The mai…

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## [installation of vtk 9.0 with python, java wrappers](https://discourse.vtk.org/t/installation-of-vtk-9-0-with-python-java-wrappers/3325)

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**Author:** [@Sohrab\_Azami](https://discourse.vtk.org/u/Sohrab_Azami)\
**Replies:** 10\
**Last updated:** [May 19, 2020, 5:27pm UTC](https://discourse.vtk.org/t/installation-of-vtk-9-0-with-python-java-wrappers/3325 "2020-05-19T17:27:06Z")

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hi all, I tried to install java and python wrappers in order to use them for calling VTK APIs, over last three days I have tried different approaches. first VTK\_BUILD?SHARED checked in CMake apparently that failed in in…

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## [Using VectorConfidenceConnected](https://discourse.vtk.org/t/using-vectorconfidenceconnected/3327)

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**Author:** [@flaviu2](https://discourse.vtk.org/u/flaviu2)\
**Replies:** 2\
**Last updated:** [May 19, 2020, 5:24pm UTC](https://discourse.vtk.org/t/using-vectorconfidenceconnected/3327 "2020-05-19T17:24:49Z")

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I have tried to use sitk::VectorConfidenceConnected with sitk::Image retrieved from a dicom images: sitk::Image imgTemp(img); .... .... img = sitk::VectorConfidenceConnected(sitk::Cast(imgTemp, sitk::PixelIDValueEnu…

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## [Unwanted top level OpenGL window & "Error freeing OpenGL context" exceptions](https://discourse.vtk.org/t/unwanted-top-level-opengl-window-error-freeing-opengl-context-exceptions/3337)

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**Author:** [@rruusu](https://discourse.vtk.org/u/rruusu)\
**Replies:** 0\
**Last updated:** [May 19, 2020, 12:39pm UTC](https://discourse.vtk.org/t/unwanted-top-level-opengl-window-error-freeing-opengl-context-exceptions/3337 "2020-05-19T12:39:33Z")

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Hi, We have an Eclipse-based application that uses VTK 8.2.0 for rendering 3D views in SWT widgets. In some situations an unsolicited window with a title of “Visualization Toolkit - Win32OpenGL #1” opens up and presents…

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## [Measurement of Draw Line and Point Height](https://discourse.vtk.org/t/measurement-of-draw-line-and-point-height/3334)

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**Author:** [@Seram](https://discourse.vtk.org/u/Seram)\
**Replies:** 0\
**Last updated:** [May 19, 2020, 8:18am UTC](https://discourse.vtk.org/t/measurement-of-draw-line-and-point-height/3334 "2020-05-19T08:18:12Z")

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Hello VTK 9.0 IDE : Visual Studio 2015 C++ I would like to draw a line by designating 2 points in space and graph X, Y, and Z data of the points in that line. I would appreciate it if you could send me the reference …

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## [How to convert vtkimagedata of vtk.js to opencv.js Mat](https://discourse.vtk.org/t/how-to-convert-vtkimagedata-of-vtk-js-to-opencv-js-mat/3330)

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**Author:** [@huatianyu](https://discourse.vtk.org/u/huatianyu)\
**Replies:** 0\
**Last updated:** [May 19, 2020, 2:44am UTC](https://discourse.vtk.org/t/how-to-convert-vtkimagedata-of-vtk-js-to-opencv-js-mat/3330 "2020-05-19T02:44:45Z")

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Like C++: // vtkImageData==\>Mat cv::Mat vtkImage2Mat(vtkImageData \*image) { int dim\[3\]; image-\>GetDimensions(dim); int imgType=CV\_8UC1; if(image-\>GetNumberOfScalarComponents()==1) imgType=CV\_8UC1; if(image-\>Get…

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## [Can I specify the value that vtkImageReslice pads output images with (instead of zero)?](https://discourse.vtk.org/t/can-i-specify-the-value-that-vtkimagereslice-pads-output-images-with-instead-of-zero/3324)

<div class="topic-metadata">

**Author:** [@MichelleKline](https://discourse.vtk.org/u/MichelleKline)\
**Replies:** 2\
**Last updated:** [May 18, 2020, 3:26pm UTC](https://discourse.vtk.org/t/can-i-specify-the-value-that-vtkimagereslice-pads-output-images-with-instead-of-zero/3324 "2020-05-18T15:26:28Z")

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Hello, When the vtkImageReslice attribute AutoCropOutput is set to “on”, the output images are either cropped or enlarged by padding. When the output image is padded, vtkImageReslice pads with zeros. Can I control the…

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## [Nifti to vtkImageData in memory](https://discourse.vtk.org/t/nifti-to-vtkimagedata-in-memory/3302)

<div class="topic-metadata">

**Author:** [@rijobro](https://discourse.vtk.org/u/rijobro)\
**Replies:** 18\
**Last updated:** [May 18, 2020, 2:33pm UTC](https://discourse.vtk.org/t/nifti-to-vtkimagedata-in-memory/3302 "2020-05-18T14:33:34Z")

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I have a 4D nifti\_image, representing a displacement field image. I would like to get the inverse using vtkGridTransform, which implies that I need to convert my nifti\_image to a vtkImageData. Is there the functionality…

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## [GL2PS Exporter and text justification](https://discourse.vtk.org/t/gl2ps-exporter-and-text-justification/3322)

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**Author:** [@Nicolas\_Lenoir](https://discourse.vtk.org/u/Nicolas_Lenoir)\
**Replies:** 0\
**Last updated:** [May 18, 2020, 7:51am UTC](https://discourse.vtk.org/t/gl2ps-exporter-and-text-justification/3322 "2020-05-18T07:51:03Z")

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Hello , I post this topic because I have a problem with the export of vtkCaptionActor2D with the vtkGL2PSExporter, when I center the text in the boxes, when i export the render window the text is not justify and go out o…

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## [where are the model files of vtk examples](https://discourse.vtk.org/t/where-are-the-model-files-of-vtk-examples/3321)

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**Author:** [@xuexl](https://discourse.vtk.org/u/xuexl)\
**Replies:** 2\
**Last updated:** [May 18, 2020, 6:42am UTC](https://discourse.vtk.org/t/where-are-the-model-files-of-vtk-examples/3321 "2020-05-18T06:42:00Z")

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Some vtk example need model files, e.g., StreamLines , it needs “xyzFile” and “qFile” , where are these files ? Can i download from any place? anybody know this ? Thank you.

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## [VTK CMake Usage](https://discourse.vtk.org/t/vtk-cmake-usage/3275)

<div class="topic-metadata">

**Author:** [@webbbn](https://discourse.vtk.org/u/webbbn)\
**Replies:** 8\
**Last updated:** [May 17, 2020, 9:58pm UTC](https://discourse.vtk.org/t/vtk-cmake-usage/3275 "2020-05-17T21:58:56Z")

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How does one find and use VTK in CMake with 9.0.0. I’m using find\_package(VTK REQUIRED …), and it’s seems happy, although the only output appears to be finding X11 and Xt. All the documentation that I can find is conflic…

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