# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=72

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

**Page:** 73

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## [plotting grid data on chart scene](https://discourse.vtk.org/t/plotting-grid-data-on-chart-scene/8915)

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**Author:** [@Odera\_Dim](https://discourse.vtk.org/u/Odera_Dim)\
**Replies:** 2\
**Last updated:** [July 12, 2022, 4:12pm UTC](https://discourse.vtk.org/t/plotting-grid-data-on-chart-scene/8915 "2022-07-12T16:12:01Z")

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Hi all, I am trying to plot some figures using the vtk bindings in python. My figure is a simple 10 x 10 square grid with colors for each cell of the grid being colored based on an array of 100 values. I was able to ach…

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## [Cannot build vtkrenderingExternal on windows](https://discourse.vtk.org/t/cannot-build-vtkrenderingexternal-on-windows/8921)

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**Author:** [@edwardAllen](https://discourse.vtk.org/u/edwardAllen)\
**Replies:** 4\
**Last updated:** [July 12, 2022, 9:37am UTC](https://discourse.vtk.org/t/cannot-build-vtkrenderingexternal-on-windows/8921 "2022-07-12T09:37:09Z")

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This is external dependencies : This is build options : I can find three dependencies in cmake output . But the flag //Request building vtkRenderingExternal Module\_vtkRenderingExternal:BOOL=OFF It always OFF, e…

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## [Is it possible to visualize the point cloud in QVTKOpenGLWidget?](https://discourse.vtk.org/t/is-it-possible-to-visualize-the-point-cloud-in-qvtkopenglwidget/8534)

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**Author:** [@Panda12197](https://discourse.vtk.org/u/Panda12197)\
**Replies:** 23\
**Last updated:** [July 12, 2022, 7:04am UTC](https://discourse.vtk.org/t/is-it-possible-to-visualize-the-point-cloud-in-qvtkopenglwidget/8534 "2022-07-12T07:04:09Z")

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I try to visualize the LiDAR point cloud in QVTKOpenGLWidget. In real time visualization, the program crash immediately after the widget appear. Is it possible to visualize the point cloud in QVTKOpenGLWidget? The main…

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## [Compilation errors building vtk\_examples](https://discourse.vtk.org/t/compilation-errors-building-vtk-examples/8917)

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**Author:** [@DStranz](https://discourse.vtk.org/u/DStranz)\
**Replies:** 14\
**Last updated:** [July 12, 2022, 6:15am UTC](https://discourse.vtk.org/t/compilation-errors-building-vtk-examples/8917 "2022-07-12T06:15:04Z")

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I have downloaded VTK 9.2.0.rc1 and built it using Visual Studio 2022 without errors. I also downloaded vtk\_examples (as of July 8) from github. In trying to build vtk\_examples using VS 2022, the projects in the Geomet…

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## [VTK 9.1 vtkResampleToImage() seg faults core dumps on CentOS 7](https://discourse.vtk.org/t/vtk-9-1-vtkresampletoimage-seg-faults-core-dumps-on-centos-7/8931)

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**Author:** [@synthetic\_person](https://discourse.vtk.org/u/synthetic_person)\
**Replies:** 0\
**Last updated:** [July 11, 2022, 7:13pm UTC](https://discourse.vtk.org/t/vtk-9-1-vtkresampletoimage-seg-faults-core-dumps-on-centos-7/8931 "2022-07-11T19:13:44Z")

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Hello, my python script fails with Segmentation fault (core dumped) when I try to convert an unstructured grid into a 3D volume using vtkResampleToImage() import vtkmodules.all as vtk ... resample = vtk.vtkResampleToI…

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## [vtkLineIntegralConvolution2D](https://discourse.vtk.org/t/vtklineintegralconvolution2d/8926)

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**Author:** [@s195t](https://discourse.vtk.org/u/s195t)\
**Replies:** 0\
**Last updated:** [July 11, 2022, 11:32am UTC](https://discourse.vtk.org/t/vtklineintegralconvolution2d/8926 "2022-07-11T11:32:30Z")

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Dear everyone, I am trying to render/screenshot/export some LIC on a vtk object of a plane, apparently the vtkLineIntegralConvolution2D should do the trick. However even looking in the examples/LIC/Python folder on the …

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## [Compilation related issues, especially on mac m1 devices](https://discourse.vtk.org/t/compilation-related-issues-especially-on-mac-m1-devices/8855)

<div class="topic-metadata">

**Author:** [@edwardAllen](https://discourse.vtk.org/u/edwardAllen)\
**Replies:** 6\
**Last updated:** [July 11, 2022, 8:32am UTC](https://discourse.vtk.org/t/compilation-related-issues-especially-on-mac-m1-devices/8855 "2022-07-11T08:32:43Z")

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I am trying to compiling this project on mac m1 pro device , and there are some problems I had encountered. 1 If I want build vtkExternalOpenglRenderWindow, I need to change CMakeCache.txt file to make some option abou…

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## [Crash when starting vtkRenderer](https://discourse.vtk.org/t/crash-when-starting-vtkrenderer/8851)

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**Author:** [@Stuart\_Brorson](https://discourse.vtk.org/u/Stuart_Brorson)\
**Replies:** 5\
**Last updated:** [July 10, 2022, 1:42pm UTC](https://discourse.vtk.org/t/crash-when-starting-vtkrenderer/8851 "2022-07-10T13:42:55Z")

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Hello, I am working on a program which computes a particular polynomial in the complex plane, then uses VTK to make a colorized 2D plot of the polynomial. My program is written in C++ and uses VTK-9.X for visualizat…

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## [How do I get a 2D Boolean?](https://discourse.vtk.org/t/how-do-i-get-a-2d-boolean/8896)

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**Author:** [@ldk7972](https://discourse.vtk.org/u/ldk7972)\
**Replies:** 1\
**Last updated:** [July 9, 2022, 10:00pm UTC](https://discourse.vtk.org/t/how-do-i-get-a-2d-boolean/8896 "2022-07-09T22:00:47Z")

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hi. I created a polygon using vtkPoints. And we want to make it a boolean. What should I do? I guess vtkBooleanOperationPolyDataFilter doesn’t work.

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## [Crashed on vtkOpenGLFramebufferObject::PopulateFramebuffer function](https://discourse.vtk.org/t/crashed-on-vtkopenglframebufferobject-populateframebuffer-function/8911)

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**Author:** [@edwardAllen](https://discourse.vtk.org/u/edwardAllen)\
**Replies:** 8\
**Last updated:** [July 8, 2022, 8:26am UTC](https://discourse.vtk.org/t/crashed-on-vtkopenglframebufferobject-populateframebuffer-function/8911 "2022-07-08T08:26:40Z")

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The whole code is build for Qt 6.x and Vtk 9.2 , and it crashed in function vtkOpenGLFramebufferObject::PopulateFramebuffer – \> vtkOpenGLFramebufferObject::Bind() → vtkOpenGLFramebufferObject::CreateFBO → glGenFrameb…

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## [vtkLoopSubdivisionFilter doesn't work properly](https://discourse.vtk.org/t/vtkloopsubdivisionfilter-doesnt-work-properly/8893)

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**Author:** [@esmitt](https://discourse.vtk.org/u/esmitt)\
**Replies:** 6\
**Last updated:** [July 7, 2022, 11:52pm UTC](https://discourse.vtk.org/t/vtkloopsubdivisionfilter-doesnt-work-properly/8893 "2022-07-07T23:52:34Z")

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Hello! this is my first post due that I am having a problem: I am using this example: https://kitware.github.io/vtk-examples/site/Cxx/Meshes/Subdivision/ replacing my OBJ file (a simple one based on triangles, vertex, …

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## [Howto wrap a class that does not subclass vtkObject](https://discourse.vtk.org/t/howto-wrap-a-class-that-does-not-subclass-vtkobject/8889)

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**Author:** [@jensgw](https://discourse.vtk.org/u/jensgw)\
**Replies:** 12\
**Last updated:** [July 7, 2022, 5:11pm UTC](https://discourse.vtk.org/t/howto-wrap-a-class-that-does-not-subclass-vtkobject/8889 "2022-07-07T17:11:15Z")

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Hi there, as far as I can tell, subclassing from vtkObject automatically includes the class in the wrapping process. How do you tell the wrapper to also include additional classes that do not subclass vtkObject? Best …

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## [Adding multiple hexahedrons using a single actor/renderer in QVTKOpenGLNativeWidget](https://discourse.vtk.org/t/adding-multiple-hexahedrons-using-a-single-actor-renderer-in-qvtkopenglnativewidget/8909)

<div class="topic-metadata">

**Author:** [@ujjwala](https://discourse.vtk.org/u/ujjwala)\
**Replies:** 0\
**Last updated:** [July 7, 2022, 3:36pm UTC](https://discourse.vtk.org/t/adding-multiple-hexahedrons-using-a-single-actor-renderer-in-qvtkopenglnativewidget/8909 "2022-07-07T15:36:27Z")

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Hi, I’m new to VTK. I’m trying to add multiple cubes/hexahedrons using a single actor and single renderer. The issue I’m running into is that if I have just one polygon in my list the hexahedron is rendered correctly. W…

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## [VTK generate document failed](https://discourse.vtk.org/t/vtk-generate-document-failed/8898)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 1\
**Last updated:** [July 7, 2022, 2:35pm UTC](https://discourse.vtk.org/t/vtk-generate-document-failed/8898 "2022-07-07T14:35:13Z")

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I want to generate document for VTK, and I turn VTK\_BUILD\_DOCUMENTATION ON. The building is OK, but bug is reported when I want to install it: 107\>CMake Error at Utilities/Doxygen/cmake\_install.cmake:70 (file): 107\> f…

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## [Getting blue slice instead of grayscale vtkCutter](https://discourse.vtk.org/t/getting-blue-slice-instead-of-grayscale-vtkcutter/8903)

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**Author:** [@olry](https://discourse.vtk.org/u/olry)\
**Replies:** 0\
**Last updated:** [July 7, 2022, 1:26pm UTC](https://discourse.vtk.org/t/getting-blue-slice-instead-of-grayscale-vtkcutter/8903 "2022-07-07T13:26:19Z")

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Hi everyone! I’m reading uint16 numpy array using vtkImageImport and them try to cut one slice from this volume but I get a blue image only, whreas the volume is rendered in grayscale as needed. Could anyone please sugg…

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## [surface rendering artifacts](https://discourse.vtk.org/t/surface-rendering-artifacts/8875)

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**Author:** [@Dean](https://discourse.vtk.org/u/Dean)\
**Replies:** 3\
**Last updated:** [July 6, 2022, 5:32pm UTC](https://discourse.vtk.org/t/surface-rendering-artifacts/8875 "2022-07-06T17:32:04Z")

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I am working on transitioning legacy VTK code (5.6) to 9.1+ and am encountering rendering artifacts when visualizing a triangulated, mostly flat, 3D surface. The artifact does not occur with our legacy code but does w…

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## [Linear Algebra Application with VTK: Warps and Morphs](https://discourse.vtk.org/t/linear-algebra-application-with-vtk-warps-and-morphs/8880)

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**Author:** [@Freya\_the\_Goddess](https://discourse.vtk.org/u/Freya_the_Goddess)\
**Replies:** 1\
**Last updated:** [July 6, 2022, 11:57am UTC](https://discourse.vtk.org/t/linear-algebra-application-with-vtk-warps-and-morphs/8880 "2022-07-06T11:57:58Z")

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Hi all, I am reading Linear Algebra book and I am wondering, is VTK capable of doing warps and morphs? The example is attached (a picture of a projection how someone will get old). Anyone ever done similar thing here? …

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## [How to rename a plot after adding it to a chart](https://discourse.vtk.org/t/how-to-rename-a-plot-after-adding-it-to-a-chart/8873)

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**Author:** [@manatee](https://discourse.vtk.org/u/manatee)\
**Replies:** 0\
**Last updated:** [July 5, 2022, 2:08pm UTC](https://discourse.vtk.org/t/how-to-rename-a-plot-after-adding-it-to-a-chart/8873 "2022-07-05T14:08:39Z")

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Hi all, I’m trying to rename a plot after it has been added to a chart. How can this be done? I tried changing the underlying vtkFloatArray name, but this produces no name change and the error vtkPlotPoints: No Y column…

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## [Plotting in VTK: vtkXYPlotActor and vtkBarChartActor vs vtkChart](https://discourse.vtk.org/t/plotting-in-vtk-vtkxyplotactor-and-vtkbarchartactor-vs-vtkchart/8861)

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**Author:** [@spencermanwell](https://discourse.vtk.org/u/spencermanwell)\
**Replies:** 0\
**Last updated:** [July 4, 2022, 3:41pm UTC](https://discourse.vtk.org/t/plotting-in-vtk-vtkxyplotactor-and-vtkbarchartactor-vs-vtkchart/8861 "2022-07-04T15:41:28Z")

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I am hoping to get some guidance on the different pipeline options for plotting in VTK. I have some familiarity generating plots by creation of an vtkXYPlotActor, but it’s usage is not abstract enough as I would like to …

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## [physics based rendering brightness](https://discourse.vtk.org/t/physics-based-rendering-brightness/8858)

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**Author:** [@andreasbuykx](https://discourse.vtk.org/u/andreasbuykx)\
**Replies:** 5\
**Last updated:** [July 4, 2022, 10:32am UTC](https://discourse.vtk.org/t/physics-based-rendering-brightness/8858 "2022-07-04T10:32:28Z")

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I’m experimenting with PBR, and notice that the model appears significantly less bright compared to the default gouraud interpolation. Is my only option to add more lights? The (default) value of the light intensi…

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## [How to create a fixed 2D vtkActor on the top of the 3D vtkActors](https://discourse.vtk.org/t/how-to-create-a-fixed-2d-vtkactor-on-the-top-of-the-3d-vtkactors/8836)

<div class="topic-metadata">

**Author:** [@Ruooo](https://discourse.vtk.org/u/Ruooo)\
**Replies:** 2\
**Last updated:** [July 4, 2022, 7:54am UTC](https://discourse.vtk.org/t/how-to-create-a-fixed-2d-vtkactor-on-the-top-of-the-3d-vtkactors/8836 "2022-07-04T07:54:29Z")

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Hi all, I’m trying to put a 2D vtkActor on the display coordinate, no matter how other 3D vtkActors’ camera moved, this 2D vtkActor should be in a fixed position in the scene. Currently, this 2D vtkActor is a 2D plane w…

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## [Does VTK support wsl?](https://discourse.vtk.org/t/does-vtk-support-wsl/3661)

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**Author:** [@Yue\_JIN](https://discourse.vtk.org/u/Yue_JIN)\
**Replies:** 4\
**Last updated:** [July 4, 2022, 2:23am UTC](https://discourse.vtk.org/t/does-vtk-support-wsl/3661 "2022-07-04T02:23:58Z")

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I’ve installed VTK 8.2.0 in WSL 2. But when I tried to run an example, it showed: ERROR: In /mnt/d/Toolkits/VTK-8.2.0/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx, line 747 vtkXOpenGLRenderWindow (0x55d2f37462f0): Unabl…

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## [VTK 9.1 + GUISupportQtQUICK + Qt5](https://discourse.vtk.org/t/vtk-9-1-guisupportqtquick-qt5/8084)

<div class="topic-metadata">

**Author:** [@Parisa\_Rabbani](https://discourse.vtk.org/u/Parisa_Rabbani)\
**Replies:** 3\
**Last updated:** [July 4, 2022, 2:02am UTC](https://discourse.vtk.org/t/vtk-9-1-guisupportqtquick-qt5/8084 "2022-07-04T02:02:06Z")

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Hi! I built VTK 9.1 on windows 10 with GUISupportQtQuick enabled and QT 5. The build is done without any error. However, I am not able to import VTK in qml. Here is the error I get: I have defined the environment var…

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## [Stereo problem with GPU Volume Mappers](https://discourse.vtk.org/t/stereo-problem-with-gpu-volume-mappers/7512)

<div class="topic-metadata">

**Author:** [@maximas](https://discourse.vtk.org/u/maximas)\
**Replies:** 1\
**Last updated:** [July 2, 2022, 5:52pm UTC](https://discourse.vtk.org/t/stereo-problem-with-gpu-volume-mappers/7512 "2022-07-02T17:52:19Z")

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I want to use stereo anaglyph with vtkOpenGLGPUVolumeRayCastMapper or vtkGPUVolumeRayCastMapper but stereo doesn’t work with GPU mappers. Stereo works perfectly fine with vtkFixedPointVolumeRayCastMapper. Attached scre…

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## [How can I move the vertices by clicking with the mouse?](https://discourse.vtk.org/t/how-can-i-move-the-vertices-by-clicking-with-the-mouse/8826)

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**Author:** [@ldk7972](https://discourse.vtk.org/u/ldk7972)\
**Replies:** 1\
**Last updated:** [July 1, 2022, 7:54pm UTC](https://discourse.vtk.org/t/how-can-i-move-the-vertices-by-clicking-with-the-mouse/8826 "2022-07-01T19:54:41Z")

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please give me hint

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## [Binary DataArray in XML using python/numpy: what are the leading int32 values?](https://discourse.vtk.org/t/binary-dataarray-in-xml-using-python-numpy-what-are-the-leading-int32-values/8013)

<div class="topic-metadata">

**Author:** [@bva99](https://discourse.vtk.org/u/bva99)\
**Replies:** 19\
**Last updated:** [March 22, 2022, 4:06pm UTC](https://discourse.vtk.org/t/binary-dataarray-in-xml-using-python-numpy-what-are-the-leading-int32-values/8013 "2022-03-22T16:06:30Z")

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I am writing a python function that saves the CellArrays of an ImageData representation from a numpy array to a binary XML .vti file. I have read this VTK support question, but I don’t believe a solution was actually fou…

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## [Coloring a vtkUnstructuredGrid by vector magnitude](https://discourse.vtk.org/t/coloring-a-vtkunstructuredgrid-by-vector-magnitude/8840)

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**Author:** [@hye00525](https://discourse.vtk.org/u/hye00525)\
**Replies:** 1\
**Last updated:** [July 1, 2022, 7:53am UTC](https://discourse.vtk.org/t/coloring-a-vtkunstructuredgrid-by-vector-magnitude/8840 "2022-07-01T07:53:21Z")

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hello, i’m trying to Coloring a vtkUnstructuredGrid by vector magnitude The value I want to use for coloring is “VECTORS solution double” value in the file below. I want to color my vtkUnstructuredGrid using its magnit…

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## [Rendering artifact](https://discourse.vtk.org/t/rendering-artifact/8830)

<div class="topic-metadata">

**Author:** [@rprueckl](https://discourse.vtk.org/u/rprueckl)\
**Replies:** 0\
**Last updated:** [June 29, 2022, 2:58pm UTC](https://discourse.vtk.org/t/rendering-artifact/8830 "2022-06-29T14:58:28Z")

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Dear all, I am writing extensions for 3D Slicer and encountered some rendering artifacts: I manually load an obj and a texture and want to display this. The result is as follows: When I use the same code, but add th…

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## [Draw polygon and highlight points inside the polygon](https://discourse.vtk.org/t/draw-polygon-and-highlight-points-inside-the-polygon/8682)

<div class="topic-metadata">

**Author:** [@mdc93](https://discourse.vtk.org/u/mdc93)\
**Replies:** 8\
**Last updated:** [June 28, 2022, 1:09pm UTC](https://discourse.vtk.org/t/draw-polygon-and-highlight-points-inside-the-polygon/8682 "2022-06-28T13:09:34Z")

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Hello everybody, I would like to have some suggestions on how to implement the following: I have a STL file and I would like to allow the user to draw a closed polygon and pick points of the mesh inside the closed cont…

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## [Installing and using FFmpeg with VTK9.1.0](https://discourse.vtk.org/t/installing-and-using-ffmpeg-with-vtk9-1-0/8803)

<div class="topic-metadata">

**Author:** [@vyvex](https://discourse.vtk.org/u/vyvex)\
**Replies:** 6\
**Last updated:** [June 28, 2022, 10:09am UTC](https://discourse.vtk.org/t/installing-and-using-ffmpeg-with-vtk9-1-0/8803 "2022-06-28T10:09:58Z")

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Hello everyone, i am trying to use ffmpeg to export a video of a data visualisation i’ve written but so far i have not been successful in getting vtk to be able to use ffmpeg. I am using Ubuntu 22.04 LTS and VTK9.1.0. …

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