# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=20

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

**Page:** 21

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## [Is there a VTK longterme support version](https://discourse.vtk.org/t/is-there-a-vtk-longterme-support-version/14508)

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**Author:** [@Leyeti88](https://discourse.vtk.org/u/Leyeti88)\
**Replies:** 1\
**Last updated:** [August 30, 2024, 1:00pm UTC](https://discourse.vtk.org/t/is-there-a-vtk-longterme-support-version/14508 "2024-08-30T13:00:38Z")

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Hi, I am considering using VTK for a project on Ubuntu 22.04 but I don’t understand the release mechanism. On the download page there is the latest Release, the previous realease and the earlier version. As I am writti…

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## [After applying the mask, the 3D image appears jagged or aliased at the edges. Any suggestions on how to fix this](https://discourse.vtk.org/t/after-applying-the-mask-the-3d-image-appears-jagged-or-aliased-at-the-edges-any-suggestions-on-how-to-fix-this/14501)

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**Author:** [@Anton\_Botnov](https://discourse.vtk.org/u/Anton_Botnov)\
**Replies:** 2\
**Last updated:** [August 30, 2024, 8:45am UTC](https://discourse.vtk.org/t/after-applying-the-mask-the-3d-image-appears-jagged-or-aliased-at-the-edges-any-suggestions-on-how-to-fix-this/14501 "2024-08-30T08:45:03Z")

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I have a 3D image of a vertebra before applying the mask And after As you can see, the edges of the image become heavily jagged. I am considering ways to fix this. Perhaps some form of post-processing on the GPU or…

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## [Python Qt6 QML VTKRenderItem](https://discourse.vtk.org/t/python-qt6-qml-vtkrenderitem/13626)

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**Author:** [@Kai](https://discourse.vtk.org/u/Kai)\
**Replies:** 4\
**Last updated:** [August 29, 2024, 11:14am UTC](https://discourse.vtk.org/t/python-qt6-qml-vtkrenderitem/13626 "2024-08-29T11:14:56Z")

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Hi :-), I want to use VTK with Pyside6 and QML. For C++ i found an example and with QObject\* topLevel = engine.rootObjects().value(0); QQuickWindow\* window = qobject\_cast\<QQuickWindow\*\>(topLevel); window-\>show(…

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## [vtkSphere : passing a null parameter in ComputeBoundingSphere from Python](https://discourse.vtk.org/t/vtksphere-passing-a-null-parameter-in-computeboundingsphere-from-python/14473)

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**Author:** [@chir-set](https://discourse.vtk.org/u/chir-set)\
**Replies:** 10\
**Last updated:** [August 28, 2024, 11:09pm UTC](https://discourse.vtk.org/t/vtksphere-passing-a-null-parameter-in-computeboundingsphere-from-python/14473 "2024-08-28T23:09:32Z")

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Hello, I’m calling vtk.vtkSphere.ComputeBoundingSphere() from Python and stumbling on passing the hints\[2\] parameter. I don’t want to determine the 2 values of this parameter since vtkSphere does it on its own if a null…

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## [Loading vtk QML components in C++](https://discourse.vtk.org/t/loading-vtk-qml-components-in-c/14449)

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**Author:** [@amireza007](https://discourse.vtk.org/u/amireza007)\
**Replies:** 1\
**Last updated:** [August 28, 2024, 7:46pm UTC](https://discourse.vtk.org/t/loading-vtk-qml-components-in-c/14449 "2024-08-28T19:46:21Z")

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Dear VTK community, I’m very new to VTK and I am on Windows 11. I’ve been trying to integrate QML into QT. I have installed the VTK with Ninja using Cmake. However, when I want to use the components VTKRenderItem, I ge…

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## [Unable to do volume rendering on external VTK render window](https://discourse.vtk.org/t/unable-to-do-volume-rendering-on-external-vtk-render-window/14459)

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**Author:** [@CK008](https://discourse.vtk.org/u/CK008)\
**Replies:** 9\
**Last updated:** [August 28, 2024, 7:38pm UTC](https://discourse.vtk.org/t/unable-to-do-volume-rendering-on-external-vtk-render-window/14459 "2024-08-28T19:38:27Z")

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I have an existing Win32 OpenGL rendering engine. I decided to integrate VTK into it to extend it’s functionality to volume rendering. This seemed very possible with VTK’s vtkRenderingExternal module. The below is what …

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## [How to trigger QQuickVTKItem::initializeVTK()?](https://discourse.vtk.org/t/how-to-trigger-qquickvtkitem-initializevtk/14490)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 3\
**Last updated:** [August 28, 2024, 7:31pm UTC](https://discourse.vtk.org/t/how-to-trigger-qquickvtkitem-initializevtk/14490 "2024-08-28T19:31:34Z")

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I’ve subclassed QQuickVTKItem to display topographic data stored in a file. The QQuickVTKItem::initializeVTK() method sets up the pipeline elements which in my case includes calling vtkAbstractPolyDataReader::SetFile() a…

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## [Error compiling ex\_field\_utils.c building vtk](https://discourse.vtk.org/t/error-compiling-ex-field-utils-c-building-vtk/14442)

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**Author:** [@gib](https://discourse.vtk.org/u/gib)\
**Replies:** 9\
**Last updated:** [August 27, 2024, 10:36pm UTC](https://discourse.vtk.org/t/error-compiling-ex-field-utils-c-building-vtk/14442 "2024-08-27T22:36:22Z")

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I am using VS 2019 to build the vtk-9.3 source code I fetched from https://gitlab.kitware.com/vtk. The errors are in line 30 of ex\_field\_utils.c" static size\_t my\_strlcat(char \*restrict dst, const char \*restrict src, …

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## [VTK9.3.0 compiled libraries can not be found in OpenCascade](https://discourse.vtk.org/t/vtk9-3-0-compiled-libraries-can-not-be-found-in-opencascade/14486)

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**Author:** [@riverandroad](https://discourse.vtk.org/u/riverandroad)\
**Replies:** 1\
**Last updated:** [August 27, 2024, 8:43am UTC](https://discourse.vtk.org/t/vtk9-3-0-compiled-libraries-can-not-be-found-in-opencascade/14486 "2024-08-27T08:43:16Z")

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On my laptop with arch linux OS, I want to use vtk in OpenCascade (OCCT 7.8.0), so i download vtk with the lateset release vtk 9.3.1 and compiled it, installed the files and the libs in my specific directory. But the com…

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## [Correct usage of FetchContent\_Declare() and FetchContent\_MakeAvailable() for building VTK](https://discourse.vtk.org/t/correct-usage-of-fetchcontent-declare-and-fetchcontent-makeavailable-for-building-vtk/14470)

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**Author:** [@fraxer](https://discourse.vtk.org/u/fraxer)\
**Replies:** 3\
**Last updated:** [August 26, 2024, 1:55pm UTC](https://discourse.vtk.org/t/correct-usage-of-fetchcontent-declare-and-fetchcontent-makeavailable-for-building-vtk/14470 "2024-08-26T13:55:20Z")

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Hi, I try building VTK using the FetchContent feature of CMake, but without success. What is the correct way to work wit FetchContent in the case of VTK? My intuition would have been that FetchContent\_MakeAvailable() p…

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## [how to resolve the issue in vtkEuclideanClusterExtraction?](https://discourse.vtk.org/t/how-to-resolve-the-issue-in-vtkeuclideanclusterextraction/14477)

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**Author:** [@erya123](https://discourse.vtk.org/u/erya123)\
**Replies:** 1\
**Last updated:** [August 26, 2024, 1:49pm UTC](https://discourse.vtk.org/t/how-to-resolve-the-issue-in-vtkeuclideanclusterextraction/14477 "2024-08-26T13:49:59Z")

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After running the following code, why does the statement print(f"Cluster {cluster\_index} has {num\_points} points.") output the coordinates of the 50 points from the first iteration again during the second iteration of th…

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## [Using VTK in QT using Cmake](https://discourse.vtk.org/t/using-vtk-in-qt-using-cmake/14478)

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**Author:** [@amireza007](https://discourse.vtk.org/u/amireza007)\
**Replies:** 1\
**Last updated:** [August 26, 2024, 1:47pm UTC](https://discourse.vtk.org/t/using-vtk-in-qt-using-cmake/14478 "2024-08-26T13:47:59Z")

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Hello, I’m on Windows 11 and have been really struggling to include VTK into the QT. I am very new to VTK. I have built and installed VTK (via ninja) by enabling the following configurations set using cmake-gui: VTK\_G…

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## [vtkMultiVolume::GetBounds() return wrong bound when sub volume set position](https://discourse.vtk.org/t/vtkmultivolume-getbounds-return-wrong-bound-when-sub-volume-set-position/14483)

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**Author:** [@hgyxbll](https://discourse.vtk.org/u/hgyxbll)\
**Replies:** 0\
**Last updated:** [August 26, 2024, 9:39am UTC](https://discourse.vtk.org/t/vtkmultivolume-getbounds-return-wrong-bound-when-sub-volume-set-position/14483 "2024-08-26T09:39:25Z")

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I have one vtkMultiVolume which have three volume. the three volume have same size and same pos. e.g. 200x300x400. when not set position, GetBounds() will return right. when the three volume set small pos(e.g. pos(10,…

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## [explanation of vtkSignedDistance() function ?](https://discourse.vtk.org/t/explanation-of-vtksigneddistance-function/14481)

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**Author:** [@angusi](https://discourse.vtk.org/u/angusi)\
**Replies:** 0\
**Last updated:** [August 26, 2024, 8:31am UTC](https://discourse.vtk.org/t/explanation-of-vtksigneddistance-function/14481 "2024-08-26T08:31:47Z")

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Hi, I’m a new VTK user wanting to find the distance from a vtkPolyData surface to the points of a structured vtkImageData grid… My problem is in understanding the logic beneath vtkSignedDistance, if anyone can help! co…

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## [Running TestWin32OpenGLDXRenderWindow.cxx test case report error?](https://discourse.vtk.org/t/running-testwin32opengldxrenderwindow-cxx-test-case-report-error/14467)

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**Author:** [@Don](https://discourse.vtk.org/u/Don)\
**Replies:** 1\
**Last updated:** [August 24, 2024, 12:27pm UTC](https://discourse.vtk.org/t/running-testwin32opengldxrenderwindow-cxx-test-case-report-error/14467 "2024-08-24T12:27:15Z")

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Hi, there, I am looking for how to use the vtkWin32OpenGLDXRenderWindow class, and I found a test case from the VTK official code site: Rendering/OpenGL2/Testing/Cxx/TestWin32OpenGLDXRenderWindow.cxx But when I follo…

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## [Unable to build vtk 8 on ubuntu 22.04](https://discourse.vtk.org/t/unable-to-build-vtk-8-on-ubuntu-22-04/14453)

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**Author:** [@sabyasachi\_chatterje](https://discourse.vtk.org/u/sabyasachi_chatterje)\
**Replies:** 3\
**Last updated:** [August 22, 2024, 9:17pm UTC](https://discourse.vtk.org/t/unable-to-build-vtk-8-on-ubuntu-22-04/14453 "2024-08-22T21:17:59Z")

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Hello, I am trying to build VTK-8.2.0 on ubuntu 22.04 following the instructions on VTK/Configure and Build - KitwarePublic. Fyi, the gcc version is 11.4.0 and python version is 3.10.12. After following all the steps,…

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## [how to speed up vtkRenderWindow-\>Render()](https://discourse.vtk.org/t/how-to-speed-up-vtkrenderwindow-render/14434)

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**Author:** [@Vicore.Nv](https://discourse.vtk.org/u/Vicore.Nv)\
**Replies:** 2\
**Last updated:** [August 22, 2024, 3:21am UTC](https://discourse.vtk.org/t/how-to-speed-up-vtkrenderwindow-render/14434 "2024-08-22T03:21:01Z")

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I have an Qt(5.15.2) application which display pointcloud using vtk9.1 and pcl1.12, and I need to update pointCloud at about 30fps, each PointCloud has about 100K points ,But I found that calling vtkRenderWindow-\>Render…

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## [Segfault when calling StartAppend() in vtkUnsignedDistance()](https://discourse.vtk.org/t/segfault-when-calling-startappend-in-vtkunsigneddistance/14402)

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**Author:** [@fraseyboo](https://discourse.vtk.org/u/fraseyboo)\
**Replies:** 7\
**Last updated:** [August 21, 2024, 1:21pm UTC](https://discourse.vtk.org/t/segfault-when-calling-startappend-in-vtkunsigneddistance/14402 "2024-08-21T13:21:41Z")

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So I’m trying to use the Append() function in vtkSignedDistance / vtkUnsignedDistance which allows for polydata to be incrementally added which is supposedly supported from the documentation, when initially calling Start…

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## [Point Cloud Rending](https://discourse.vtk.org/t/point-cloud-rending/14444)

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**Author:** [@metamurk](https://discourse.vtk.org/u/metamurk)\
**Replies:** 2\
**Last updated:** [August 21, 2024, 8:51am UTC](https://discourse.vtk.org/t/point-cloud-rending/14444 "2024-08-21T08:51:40Z")

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Hello together, I’m rendering medium size point clouds (up to 20m points) with vtk. I’m ussing gaussian splatting for rendering. I have to issues: When I zoom out, my point cloud disappeares relativly fast. How can I…

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## [Tree edges are rendered incorrectly in vtkCocoa after calling SetLineWidth()](https://discourse.vtk.org/t/tree-edges-are-rendered-incorrectly-in-vtkcocoa-after-calling-setlinewidth/14436)

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**Author:** [@fraseyboo](https://discourse.vtk.org/u/fraseyboo)\
**Replies:** 0\
**Last updated:** [August 20, 2024, 10:56pm UTC](https://discourse.vtk.org/t/tree-edges-are-rendered-incorrectly-in-vtkcocoa-after-calling-setlinewidth/14436 "2024-08-20T22:56:36Z")

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So there appears to be an obscure bug present in the vtkCocoa renderer (used in MacOS) which happens in vtkGraphLayoutView. Modifying the line width of the graph edges breaks the render. It appears that all rectangles in…

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## [size of vtkImageStencil output image not the same as input image](https://discourse.vtk.org/t/size-of-vtkimagestencil-output-image-not-the-same-as-input-image/14429)

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**Author:** [@Thomas78](https://discourse.vtk.org/u/Thomas78)\
**Replies:** 2\
**Last updated:** [August 20, 2024, 7:28am UTC](https://discourse.vtk.org/t/size-of-vtkimagestencil-output-image-not-the-same-as-input-image/14429 "2024-08-20T07:28:33Z")

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I need help with vtkImageStencil. The attached program is doing the following: loading a 3D image (CT-scan data) applying a threshold creating polydata via vtkFlyingEdges3D (MarchingCube alg.) using vtkPolyDataToImage…

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## [Cannot call SetScalar()](https://discourse.vtk.org/t/cannot-call-setscalar/14419)

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**Author:** [@Taco\_Z](https://discourse.vtk.org/u/Taco_Z)\
**Replies:** 2\
**Last updated:** [August 20, 2024, 5:09am UTC](https://discourse.vtk.org/t/cannot-call-setscalar/14419 "2024-08-20T05:09:58Z")

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I’m new to VTK and I try to use VTK9.1 + QT6 to display points cloud. I found tutorials and examples for displaying points cloud with different color by calling SetScalar(). Here’s the code: vtkSmartPointer points = v…

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## [Can I avoid or filter out degenerate cells when generating polydata?](https://discourse.vtk.org/t/can-i-avoid-or-filter-out-degenerate-cells-when-generating-polydata/14411)

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**Author:** [@rexthor](https://discourse.vtk.org/u/rexthor)\
**Replies:** 6\
**Last updated:** [August 17, 2024, 5:54am UTC](https://discourse.vtk.org/t/can-i-avoid-or-filter-out-degenerate-cells-when-generating-polydata/14411 "2024-08-17T05:54:53Z")

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I’m generating things that are topologically tubes (they aren’t cylinders). I was trying to accomplish this as below - but I get degenerate cells (cell labeled as vtkQuad, but has no area - i.e., it is a line, I think ce…

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## [When reading the CGNS file, an incorrect topology result was obtained, but there was no problem using Paraview to read it. What could be the reason for this?](https://discourse.vtk.org/t/when-reading-the-cgns-file-an-incorrect-topology-result-was-obtained-but-there-was-no-problem-using-paraview-to-read-it-what-could-be-the-reason-for-this/14424)

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**Author:** [@realwhzc](https://discourse.vtk.org/u/realwhzc)\
**Replies:** 0\
**Last updated:** [August 16, 2024, 11:40am UTC](https://discourse.vtk.org/t/when-reading-the-cgns-file-an-incorrect-topology-result-was-obtained-but-there-was-no-problem-using-paraview-to-read-it-what-could-be-the-reason-for-this/14424 "2024-08-16T11:40:11Z")

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I use the following code to read CGNS files： vtkNew\<vtkCGNSReader\> reader; reader-\>SetFileName(toUTF8(filename).c\_str()); reader-\>UpdateInformation(); reader-\>EnableAllBases(); reader-\>EnableAllFamil…

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## [Using a Picker to get grid index inside MultiBlockDataSet](https://discourse.vtk.org/t/using-a-picker-to-get-grid-index-inside-multiblockdataset/14420)

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**Author:** [@auffii](https://discourse.vtk.org/u/auffii)\
**Replies:** 0\
**Last updated:** [August 15, 2024, 6:27pm UTC](https://discourse.vtk.org/t/using-a-picker-to-get-grid-index-inside-multiblockdataset/14420 "2024-08-15T18:27:59Z")

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Hi, I’ve been trying to figure this out for a while without success. I have multiple StructuredGrids in a MultiBlockDataSet with associated PolyData/Mapper/Actor and when I pick a cell via CellPicker I would like it to…

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## [Different Volume Calculation Results](https://discourse.vtk.org/t/different-volume-calculation-results/14417)

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**Author:** [@dzzhang](https://discourse.vtk.org/u/dzzhang)\
**Replies:** 2\
**Last updated:** [August 15, 2024, 5:12pm UTC](https://discourse.vtk.org/t/different-volume-calculation-results/14417 "2024-08-15T17:12:59Z")

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I have a binary mask, I loaded it in 3D slicer as a segmentation file, and in Data module, I used “export visible segments to model”. Then in Models module, I can see the model volume is 55349.06 mm^3 (none smooth). T…

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## [The direction of vtkImageData make something wrong.](https://discourse.vtk.org/t/the-direction-of-vtkimagedata-make-something-wrong/4997)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 4\
**Last updated:** [August 15, 2024, 6:52am UTC](https://discourse.vtk.org/t/the-direction-of-vtkimagedata-make-something-wrong/4997 "2024-08-15T06:52:43Z")

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I have a code to show a image: from vtk.util.numpy\_support import vtk\_to\_numpy, numpy\_to\_vtk import vtk import numpy as np def numpyToVTK(data): flat\_data\_array = data.transpose(2,1,0).flatten() vtk\_data\_array …

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## [How to understand this use of New() within a struct?](https://discourse.vtk.org/t/how-to-understand-this-use-of-new-within-a-struct/14412)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 4\
**Last updated:** [August 14, 2024, 5:33pm UTC](https://discourse.vtk.org/t/how-to-understand-this-use-of-new-within-a-struct/14412 "2024-08-14T17:33:11Z")

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I’ve usually seen New() used as follows: vtkPolyData \*pd = vtkPolyData::New(); But I’ve encountered a syntax I haven’t seen before: what does New() do in the following struct? struct MyItem { struct Data : vtkObje…

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## [QQuickVTKItem and vtkUserData question](https://discourse.vtk.org/t/qquickvtkitem-and-vtkuserdata-question/14400)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 1\
**Last updated:** [August 13, 2024, 10:18pm UTC](https://discourse.vtk.org/t/qquickvtkitem-and-vtkuserdata-question/14400 "2024-08-13T22:18:38Z")

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QQuickVTKItem documentation says this for method initializeVTK(): All VTK objects must be stored in the vtkUserData object returned from this method. They will be destroyed if the underlying QSGNode (which must contain…

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## [segfault in vtkOpenGLRenderWindow::OpenGLInitState()](https://discourse.vtk.org/t/segfault-in-vtkopenglrenderwindow-openglinitstate/14366)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 21\
**Last updated:** [August 13, 2024, 7:55pm UTC](https://discourse.vtk.org/t/segfault-in-vtkopenglrenderwindow-openglinitstate/14366 "2024-08-13T19:55:13Z")

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I’m running VTK-9.3.1 on ubuntu-22.04 My application instantiates a vtkGenericOpenGLRenderWindow and invokes vtkOpenGLRenderWindow::OpenGLInitState(): renderWindow\_ = vtkSmartPointer\<vtkGenericOpenGLRenderWindow\>:…

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