# Latest

**URL:** https://discourse.vtk.org/latest.md?page=170

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

**Page:** 171

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## [Unsymmetric contour rendered by symmetric data](https://discourse.vtk.org/t/unsymmetric-contour-rendered-by-symmetric-data/5848)

<div class="topic-metadata">

**Author:** [@kamyar](https://discourse.vtk.org/u/kamyar)\
**Replies:** 1\
**Last updated:** [July 8, 2021, 5:13pm UTC](https://discourse.vtk.org/t/unsymmetric-contour-rendered-by-symmetric-data/5848 "2021-07-08T17:13:56Z")

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Hi, The problem of “Unsymmetric contour rendered by symmetric data” explained in Paraview support on the following links: https://discourse.paraview.org/t/unsymmetric-contour-rendered-by-symmetric-data/4118 https://di…

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## [Plane cut through tetrahedron grid preserving only whole original cells](https://discourse.vtk.org/t/plane-cut-through-tetrahedron-grid-preserving-only-whole-original-cells/6154)

<div class="topic-metadata">

**Author:** [@steffen-sch](https://discourse.vtk.org/u/steffen-sch)\
**Replies:** 0\
**Last updated:** [July 8, 2021, 3:58pm UTC](https://discourse.vtk.org/t/plane-cut-through-tetrahedron-grid-preserving-only-whole-original-cells/6154 "2021-07-08T15:58:15Z")

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I want to cut through an unstructured grid of tetrahedrons by a plane. The resulting grid should only contain original cells that are on one side of the plane. It should not contain new dissected cells. How can this be …

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## [Need help displaying processed NumPy array properly.](https://discourse.vtk.org/t/need-help-displaying-processed-numpy-array-properly/3499)

<div class="topic-metadata">

**Author:** [@rishyak](https://discourse.vtk.org/u/rishyak)\
**Replies:** 1\
**Last updated:** [July 8, 2021, 3:35pm UTC](https://discourse.vtk.org/t/need-help-displaying-processed-numpy-array-properly/3499 "2021-07-08T15:35:44Z")

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I have a model that uses NumPy arrays. The inputs and outputs are those arrays. I want to display this on a webpage and I’m struggling with that. I believe the problem I’m facing is that out model uses marching cubes w…

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## [VtkRenderer error](https://discourse.vtk.org/t/vtkrenderer-error/6143)

<div class="topic-metadata">

**Author:** [@Synfony](https://discourse.vtk.org/u/Synfony)\
**Replies:** 4\
**Last updated:** [July 8, 2021, 3:23pm UTC](https://discourse.vtk.org/t/vtkrenderer-error/6143 "2021-07-08T15:23:44Z")

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Hi, I am getting “Re-setting view-up since view plane normal is parallel” runtime error message arising from …\\Rendering\\Core\\vtkRenderer.cxx line 1175 This error message is showing when I move the outline box to view…

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## [about polygon](https://discourse.vtk.org/t/about-polygon/6149)

<div class="topic-metadata">

**Author:** [@Hurmean](https://discourse.vtk.org/u/Hurmean)\
**Replies:** 0\
**Last updated:** [July 8, 2021, 7:47am UTC](https://discourse.vtk.org/t/about-polygon/6149 "2021-07-08T07:47:45Z")

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code as follows: vtkSmartPointer pts = vtkSmartPointer::New(); vtkSmartPointer cs = vtkSmartPointer::New(); pts-\>SetNumberOfPoints(4); pts-\>InsertPoint(2, 100, 200, 0); pts-\>InsertPoint(3, 50, 50, 0); pts-\>InsertPoin…

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## [ProteinRibbonFilter](https://discourse.vtk.org/t/proteinribbonfilter/4545)

<div class="topic-metadata">

**Author:** [@Facundo\_Mercado](https://discourse.vtk.org/u/Facundo_Mercado)\
**Replies:** 1\
**Last updated:** [July 7, 2021, 5:55pm UTC](https://discourse.vtk.org/t/proteinribbonfilter/4545 "2021-07-07T17:55:31Z")

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Hello! I have been using the vtkProteinRibbonFilter to render .pdb files. I managed for the visualization to work. A short snippet of what im doing: self.\_molecule\_reader = vtk.vtkPDBReader() self.\_molecule\_read…

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## [Rigid registration between a surface and a set of points.](https://discourse.vtk.org/t/rigid-registration-between-a-surface-and-a-set-of-points/6135)

<div class="topic-metadata">

**Author:** [@Miguel\_Socorro](https://discourse.vtk.org/u/Miguel_Socorro)\
**Replies:** 2\
**Last updated:** [July 7, 2021, 5:52pm UTC](https://discourse.vtk.org/t/rigid-registration-between-a-surface-and-a-set-of-points/6135 "2021-07-07T17:52:23Z")

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I have a 3D surface as a polydata and a small set of points (30 or 40 points), I need to perform a rigid registration algorithm between these points and the surface. I need to know if it is possible to carry out this ty…

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## [Program crashes when removing actors](https://discourse.vtk.org/t/program-crashes-when-removing-actors/4470)

<div class="topic-metadata">

**Author:** [@Daniel](https://discourse.vtk.org/u/Daniel)\
**Replies:** 1\
**Last updated:** [July 7, 2021, 2:55pm UTC](https://discourse.vtk.org/t/program-crashes-when-removing-actors/4470 "2021-07-07T14:55:23Z")

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Hello everybody, I try to remove actors from the renderer, but my program always crashes. the following error message appears: vtkWin32OpenGLRenderWin:217 ERR| vtkWin32OpenGLRenderWindow (0000000027348C40): wglMake…

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## [Change Uniform var of Shaders on vtk 8.2](https://discourse.vtk.org/t/change-uniform-var-of-shaders-on-vtk-8-2/6144)

<div class="topic-metadata">

**Author:** [@WailmerPail](https://discourse.vtk.org/u/WailmerPail)\
**Replies:** 0\
**Last updated:** [July 7, 2021, 1:28am UTC](https://discourse.vtk.org/t/change-uniform-var-of-shaders-on-vtk-8-2/6144 "2021-07-07T01:28:59Z")

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Hi groups, I already know in vtk-9.1, we can easily get uniforms by vtkShaderProperty. But with vtkOpenglMapper, we only have addreplacement and reset function. Does it means we have to save the shader code in memory,…

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## [CI/CD infrastructure on gitlab](https://discourse.vtk.org/t/ci-cd-infrastructure-on-gitlab/6142)

<div class="topic-metadata">

**Author:** [@kayarre](https://discourse.vtk.org/u/kayarre)\
**Replies:** 6\
**Last updated:** [July 6, 2021, 9:49pm UTC](https://discourse.vtk.org/t/ci-cd-infrastructure-on-gitlab/6142 "2021-07-06T21:49:03Z")

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Hi, TL;DR: Can someone suggest a medium complex CI/CD example project that builds on Linux, OSX, and windows? I have been trying to follow the VTK implementation but it got dense fast for me. (maybe a paired down exampl…

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## [Unstable sorting of nodes in e.g. vtkColorTransferFunction](https://discourse.vtk.org/t/unstable-sorting-of-nodes-in-e-g-vtkcolortransferfunction/6141)

<div class="topic-metadata">

**Author:** [@Jesper](https://discourse.vtk.org/u/Jesper)\
**Replies:** 4\
**Last updated:** [July 6, 2021, 7:31pm UTC](https://discourse.vtk.org/t/unstable-sorting-of-nodes-in-e-g-vtkcolortransferfunction/6141 "2021-07-06T19:31:51Z")

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Hi I am working with a vtkColorTransferFunction with AllowDuplicateScalarsOn() and noticed after building it by repeated calls to AddRGBPoint() that the order comes out unexpected. This appears to result from the call t…

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## [Creating a mesh from .nrrd file using marching cube](https://discourse.vtk.org/t/creating-a-mesh-from-nrrd-file-using-marching-cube/6093)

<div class="topic-metadata">

**Author:** [@vsrivastava](https://discourse.vtk.org/u/vsrivastava)\
**Replies:** 4\
**Last updated:** [July 6, 2021, 12:40pm UTC](https://discourse.vtk.org/t/creating-a-mesh-from-nrrd-file-using-marching-cube/6093 "2021-07-06T12:40:07Z")

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Hello, I am trying to create a 3D mesh for my application. For this, I am reading the .nrrd files which contain the information about the segmentation and want to create a 3D model from these .nrrd files. I read about ma…

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## [about the using of ITKHelper](https://discourse.vtk.org/t/about-the-using-of-itkhelper/6131)

<div class="topic-metadata">

**Author:** [@zrxiaojie](https://discourse.vtk.org/u/zrxiaojie)\
**Replies:** 4\
**Last updated:** [July 6, 2021, 7:00am UTC](https://discourse.vtk.org/t/about-the-using-of-itkhelper/6131 "2021-07-06T07:00:22Z")

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Hi, when I used the ITKHelper, I found that the result is not the same as expected. readImageDICOMFileSeries(file).then(({image, webWorkerPool}) =\> { imageData = convertItkToVtkImage(image) // setInputData(imageData…

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## [Issue using Vtk with python 3.6](https://discourse.vtk.org/t/issue-using-vtk-with-python-3-6/6117)

<div class="topic-metadata">

**Author:** [@SAYOUD\_RAMI](https://discourse.vtk.org/u/SAYOUD_RAMI)\
**Replies:** 2\
**Last updated:** [July 2, 2021, 2:17pm UTC](https://discourse.vtk.org/t/issue-using-vtk-with-python-3-6/6117 "2021-07-02T14:17:12Z")

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Hi, I have an issue when trying to read some HDF5 files using vtk, When I try to import vtk (8.2) using python : import vtk, it gives me the following error: Traceback (most recent call last): File "/usr/local/lib/py…

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## [Smoothing of vtkUnstructuredGrids](https://discourse.vtk.org/t/smoothing-of-vtkunstructuredgrids/6103)

<div class="topic-metadata">

**Author:** [@Aep93](https://discourse.vtk.org/u/Aep93)\
**Replies:** 4\
**Last updated:** [July 1, 2021, 8:29pm UTC](https://discourse.vtk.org/t/smoothing-of-vtkunstructuredgrids/6103 "2021-07-01T20:29:41Z")

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Hello all, This post is following my discussion in the slicer forum in the link below: Link of main discussion I want to find a way for smoothing of vtkUnstructredGrids. Any help is greatly appreciated.

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## [creating bounded plane using implicit function](https://discourse.vtk.org/t/creating-bounded-plane-using-implicit-function/6119)

<div class="topic-metadata">

**Author:** [@kicma](https://discourse.vtk.org/u/kicma)\
**Replies:** 0\
**Last updated:** [July 1, 2021, 10:08am UTC](https://discourse.vtk.org/t/creating-bounded-plane-using-implicit-function/6119 "2021-07-01T10:08:34Z")

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Hello, I manage to created bounded cylinder using vtkImplicitBoolean, vtkCylinder and two vtkPlanes. Now I’m stuck on something which I thought would be simple - creating bounded plane. I thought I would be able to crea…

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## [Questions about how to achieve fast pre selection](https://discourse.vtk.org/t/questions-about-how-to-achieve-fast-pre-selection/6113)

<div class="topic-metadata">

**Author:** [@yuhaoqiu](https://discourse.vtk.org/u/yuhaoqiu)\
**Replies:** 2\
**Last updated:** [July 1, 2021, 8:22am UTC](https://discourse.vtk.org/t/questions-about-how-to-achieve-fast-pre-selection/6113 "2021-07-01T08:22:33Z")

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Hello, I am a student, and I am trying to use vtk to render and select from more than one million units model. After reading this article: I am very interested in the feature of fast preselection. I tried to use the m…

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## [vtkImageMathematics for Image with Complex Data](https://discourse.vtk.org/t/vtkimagemathematics-for-image-with-complex-data/6078)

<div class="topic-metadata">

**Author:** [@MichelleKline](https://discourse.vtk.org/u/MichelleKline)\
**Replies:** 3\
**Last updated:** [June 30, 2021, 10:07pm UTC](https://discourse.vtk.org/t/vtkimagemathematics-for-image-with-complex-data/6078 "2021-06-30T22:07:59Z")

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Hello, I am writing code in C++ to do some mathematical operations on matrices that contain complex numbers. I am using vtk to accomplish this, primarily because the data I am working with needs to be resliced, resized,…

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## [vtkWindowedSincPolyDataFilter performance improvement](https://discourse.vtk.org/t/vtkwindowedsincpolydatafilter-performance-improvement/3262)

<div class="topic-metadata">

**Author:** [@lassoan](https://discourse.vtk.org/u/lassoan)\
**Replies:** 15\
**Last updated:** [June 30, 2021, 4:48pm UTC](https://discourse.vtk.org/t/vtkwindowedsincpolydatafilter-performance-improvement/3262 "2021-06-30T16:48:10Z")

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This topic is a follow-up of modernization/performance improvement of filters - focusing on vtkWindowedSincPolyDataFilter optimization. Here are sample VTK polydata data sets that we typically work with. They are creat…

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## [Clip volume with an arbitrary plane](https://discourse.vtk.org/t/clip-volume-with-an-arbitrary-plane/6109)

<div class="topic-metadata">

**Author:** [@tobias](https://discourse.vtk.org/u/tobias)\
**Replies:** 0\
**Last updated:** [June 30, 2021, 3:23pm UTC](https://discourse.vtk.org/t/clip-volume-with-an-arbitrary-plane/6109 "2021-06-30T15:23:31Z")

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I have a vtkVolume which I want to clip with an arbitrary plane, i.e. let a plane divide the volume and not display one of those two parts. We took a look Clip in ParaView, but it is too slow and uses a lot of memory. W…

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## [SetRepresentationTo Surface and to Wireframe simultaneously](https://discourse.vtk.org/t/setrepresentationto-surface-and-to-wireframe-simultaneously/6055)

<div class="topic-metadata">

**Author:** [@windhair10](https://discourse.vtk.org/u/windhair10)\
**Replies:** 2\
**Last updated:** [June 30, 2021, 11:49am UTC](https://discourse.vtk.org/t/setrepresentationto-surface-and-to-wireframe-simultaneously/6055 "2021-06-30T11:49:03Z")

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A new VTker’s question, is it possible to set the representation to surface with wireframe simultaneously for a import stl filestrong text? like following picture.

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## [How to set up an autobiography Center for STL files?](https://discourse.vtk.org/t/how-to-set-up-an-autobiography-center-for-stl-files/6105)

<div class="topic-metadata">

**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 0\
**Last updated:** [June 30, 2021, 11:48am UTC](https://discourse.vtk.org/t/how-to-set-up-an-autobiography-center-for-stl-files/6105 "2021-06-30T11:48:35Z")

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## [Contour filter Unstructured Grid](https://discourse.vtk.org/t/contour-filter-unstructured-grid/6086)

<div class="topic-metadata">

**Author:** [@ManuPy](https://discourse.vtk.org/u/ManuPy)\
**Replies:** 1\
**Last updated:** [June 30, 2021, 11:46am UTC](https://discourse.vtk.org/t/contour-filter-unstructured-grid/6086 "2021-06-30T11:46:08Z")

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Hi, I am new in vtk, I was wondering if there is a way to apply filters in a 3D unstructured Grid. When I have tried it just generate an empty mesh. I have been only successful in uniform grids though. I heard that exis…

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## [How to make vtkCamera to follow along a path? Similar to what we have in paraview.](https://discourse.vtk.org/t/how-to-make-vtkcamera-to-follow-along-a-path-similar-to-what-we-have-in-paraview/6097)

<div class="topic-metadata">

**Author:** [@vishalkumar2222](https://discourse.vtk.org/u/vishalkumar2222)\
**Replies:** 3\
**Last updated:** [June 30, 2021, 11:44am UTC](https://discourse.vtk.org/t/how-to-make-vtkcamera-to-follow-along-a-path-similar-to-what-we-have-in-paraview/6097 "2021-06-30T11:44:25Z")

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Hi, I have a requirement where I need to create my camera along a path. I have seen similar feature in paraview. How can I implement similar feature. Thanks,

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## [Problem Paraview/VTK](https://discourse.vtk.org/t/problem-paraview-vtk/6104)

<div class="topic-metadata">

**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 1\
**Last updated:** [June 30, 2021, 9:40am UTC](https://discourse.vtk.org/t/problem-paraview-vtk/6104 "2021-06-30T09:40:40Z")

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Dear All, When I run the example “web-project-templates-master” in Windows gives the following error: C:\\Users\\Luis.Goncalves\_ext\\novo\_botao\>"C:\\Program Files\\ParaView 5.9.1-Windows-Python3.8-msvc2017-64bit\\bin\\pvpytho…

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## [Error on linux when creating QVTKOpenGLNativeWidget](https://discourse.vtk.org/t/error-on-linux-when-creating-qvtkopenglnativewidget/6083)

<div class="topic-metadata">

**Author:** [@DLevy](https://discourse.vtk.org/u/DLevy)\
**Replies:** 11\
**Last updated:** [June 29, 2021, 1:46pm UTC](https://discourse.vtk.org/t/error-on-linux-when-creating-qvtkopenglnativewidget/6083 "2021-06-29T13:46:52Z")

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Hello, I am using VTK 9 + Qt6 in windows without any issue. I am now trying to build my application on linux, but I have errors when I instanciate the QVTKOpenGLNativeWidget and do nothing more than displaying it. …

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## [Drag and drop actors](https://discourse.vtk.org/t/drag-and-drop-actors/5620)

<div class="topic-metadata">

**Author:** [@aowen](https://discourse.vtk.org/u/aowen)\
**Replies:** 3\
**Last updated:** [June 29, 2021, 12:35pm UTC](https://discourse.vtk.org/t/drag-and-drop-actors/5620 "2021-06-29T12:35:31Z")

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Is there a way to “drag and drop” a 2D actor? I’ve seen this question come up multiple times in older forum threads, but I haven’t seen any with a posted solution. To be clear, I don’t need to rotate, pan, zoom, etc. I’…

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## [Arrow for forces](https://discourse.vtk.org/t/arrow-for-forces/6089)

<div class="topic-metadata">

**Author:** [@nparent](https://discourse.vtk.org/u/nparent)\
**Replies:** 1\
**Last updated:** [June 29, 2021, 10:57am UTC](https://discourse.vtk.org/t/arrow-for-forces/6089 "2021-06-29T10:57:08Z")

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Hi, I have a writer for a moving rod (a vtkPolyData then a vtkTubeFilter followed by a vtkPolyDataMapper and vtkPolyDataWriter). I now have detected collision in my software and I am applying a contact force when there…

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## [Example of VTK module built after VTK is built?](https://discourse.vtk.org/t/example-of-vtk-module-built-after-vtk-is-built/6099)

<div class="topic-metadata">

**Author:** [@adamrankin](https://discourse.vtk.org/u/adamrankin)\
**Replies:** 3\
**Last updated:** [June 28, 2021, 9:13pm UTC](https://discourse.vtk.org/t/example-of-vtk-module-built-after-vtk-is-built/6099 "2021-06-28T21:13:24Z")

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Hello all, Would anyone have an example of developing a VTK module in a separate project/repo?

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## [Export vtkImageSlice to .obj file](https://discourse.vtk.org/t/export-vtkimageslice-to-obj-file/5959)

<div class="topic-metadata">

**Author:** [@Uriel\_Dardik](https://discourse.vtk.org/u/Uriel_Dardik)\
**Replies:** 4\
**Last updated:** [June 28, 2021, 8:11pm UTC](https://discourse.vtk.org/t/export-vtkimageslice-to-obj-file/5959 "2021-06-28T20:11:34Z")

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