# Development

**URL:** https://discourse.vtk.org/c/development/7.md?page=11

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

**Page:** 12

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## [How to add a widget in a view with rotation](https://discourse.vtk.org/t/how-to-add-a-widget-in-a-view-with-rotation/14151)

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**Author:** [@Juan\_Augusto\_Tardivo](https://discourse.vtk.org/u/Juan_Augusto_Tardivo)\
**Replies:** 1\
**Last updated:** [July 2, 2024, 1:46pm UTC](https://discourse.vtk.org/t/how-to-add-a-widget-in-a-view-with-rotation/14151 "2024-07-02T13:46:46Z")

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I am creating a component that renders 2D images and STL file. In both cases or at least in the STL files I need to have interaction, for example zoom and rotate. I have this code: const render2D = async (vtk2DRefs, i…

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## [GeneralTransform that has a GeoProjection does not correctly perform inverse](https://discourse.vtk.org/t/generaltransform-that-has-a-geoprojection-does-not-correctly-perform-inverse/14150)

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**Author:** [@robynsb](https://discourse.vtk.org/u/robynsb)\
**Replies:** 1\
**Last updated:** [July 1, 2024, 2:07pm UTC](https://discourse.vtk.org/t/generaltransform-that-has-a-geoprojection-does-not-correctly-perform-inverse/14150 "2024-07-01T14:07:31Z")

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Heyy, when trying to take the inverse of a GeneralTransform that contains a GeoProjection it seems like the GeoProjection is “skipped” in the inverse transform. I believe this is a bug. Below is my code to reproduce. I …

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## [After moving the geometric model, it becomes invisible from certain viewpoints, and at the same time, it cannot be picked.](https://discourse.vtk.org/t/after-moving-the-geometric-model-it-becomes-invisible-from-certain-viewpoints-and-at-the-same-time-it-cannot-be-picked/14135)

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**Author:** [@yuanhui](https://discourse.vtk.org/u/yuanhui)\
**Replies:** 1\
**Last updated:** [June 28, 2024, 8:17am UTC](https://discourse.vtk.org/t/after-moving-the-geometric-model-it-becomes-invisible-from-certain-viewpoints-and-at-the-same-time-it-cannot-be-picked/14135 "2024-06-28T08:17:19Z")

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After relocating the geometric model within the scene, an issue has surfaced where the model is not rendered and thus appears invisible when viewed from specific angles. Concurrently, attempts to interact with the model …

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## [vtkOpenFOAMReader: reading OpenFOAM-11 particle data?](https://discourse.vtk.org/t/vtkopenfoamreader-reading-openfoam-11-particle-data/14132)

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**Author:** [@nchowlett](https://discourse.vtk.org/u/nchowlett)\
**Replies:** 0\
**Last updated:** [June 28, 2024, 7:29am UTC](https://discourse.vtk.org/t/vtkopenfoamreader-reading-openfoam-11-particle-data/14132 "2024-06-28T07:29:29Z")

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Heya! I’m having an issues reading lagrangian data using vtkOpenFOAMReader via Python. I can’t even see any lagrangian arrays even tho particle files are present in each time-step directory (see code below). I used OpenF…

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## [Offscreen rendering in QtQuick application](https://discourse.vtk.org/t/offscreen-rendering-in-qtquick-application/14120)

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**Author:** [@m-diers](https://discourse.vtk.org/u/m-diers)\
**Replies:** 0\
**Last updated:** [June 26, 2024, 3:32pm UTC](https://discourse.vtk.org/t/offscreen-rendering-in-qtquick-application/14120 "2024-06-26T15:32:36Z")

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Hello, I have a problem adapting an application under linux to qtquick with vtk offscreen rendering to generate graphics in png format. The rendering should not work visually via a QVtk element, but completely detached…

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## [Bug: Render VTK window offscreen in Apple vtkCocoaGLView](https://discourse.vtk.org/t/bug-render-vtk-window-offscreen-in-apple-vtkcocoaglview/14099)

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**Author:** [@JeffreyWardman](https://discourse.vtk.org/u/JeffreyWardman)\
**Replies:** 1\
**Last updated:** [June 26, 2024, 12:57am UTC](https://discourse.vtk.org/t/bug-render-vtk-window-offscreen-in-apple-vtkcocoaglview/14099 "2024-06-26T00:57:53Z")

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I have a library which renders fine and without segfaults on arm64 mac and for linux and windows. I have a QT application which uses this library and works fine for linux and windows but not for mac. In the library, I …

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## [Loading 3D volume performance](https://discourse.vtk.org/t/loading-3d-volume-performance/14050)

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**Author:** [@tomasbkk](https://discourse.vtk.org/u/tomasbkk)\
**Replies:** 8\
**Last updated:** [June 23, 2024, 4:39am UTC](https://discourse.vtk.org/t/loading-3d-volume-performance/14050 "2024-06-23T04:39:49Z")

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I’m very new to VTK and 3D programming overall and have been tasked to create a 3D volume viewer which receives volumes consecutively and displays them as they’re received. I have used https://examples.vtk.org/site/Cxx/…

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## [Undocumented behavior for scalar bars](https://discourse.vtk.org/t/undocumented-behavior-for-scalar-bars/14102)

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**Author:** [@whereismymoney](https://discourse.vtk.org/u/whereismymoney)\
**Replies:** 0\
**Last updated:** [June 21, 2024, 8:15pm UTC](https://discourse.vtk.org/t/undocumented-behavior-for-scalar-bars/14102 "2024-06-21T20:15:24Z")

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This information is for people working with vtkScalarBarActor vtkScalarBarWidget vtkScalarBarRepresentation My experiments indicate that if you want to change the orientation, then you must call vtkScalarBarRepresen…

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## [Plot Tree Timing with MPI](https://discourse.vtk.org/t/plot-tree-timing-with-mpi/14096)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 3\
**Last updated:** [June 21, 2024, 3:19pm UTC](https://discourse.vtk.org/t/plot-tree-timing-with-mpi/14096 "2024-06-21T15:19:16Z")

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Hello, I developed a code to run the tree timing code with MPI. I am not familiar with MPI so I get segmentation fault when I call the function. Thanks Rafael Scatena //#ifdef ENABLE\_MPI struct ParallelIsoArgs\_tmp { …

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## [Can we use vtkprobefilter to extract data along a curve in a volume?](https://discourse.vtk.org/t/can-we-use-vtkprobefilter-to-extract-data-along-a-curve-in-a-volume/14038)

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**Author:** [@Kiran\_shaji](https://discourse.vtk.org/u/Kiran_shaji)\
**Replies:** 3\
**Last updated:** [June 20, 2024, 6:58pm UTC](https://discourse.vtk.org/t/can-we-use-vtkprobefilter-to-extract-data-along-a-curve-in-a-volume/14038 "2024-06-20T18:58:42Z")

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I’m trying to extract pixel values from each slice in a stack of slices by drawing a contour curve. I’m getting a curve like this. How can I extract the pixel values which are inside the curve line? This is my code vtk…

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## [Please do not backport to \`release\` or \`paraview/release\` branches until Wednesday, June 19](https://discourse.vtk.org/t/please-do-not-backport-to-release-or-paraview-release-branches-until-wednesday-june-19/14067)

<div class="topic-metadata">

**Author:** [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)\
**Replies:** 1\
**Last updated:** [June 20, 2024, 3:04pm UTC](https://discourse.vtk.org/t/please-do-not-backport-to-release-or-paraview-release-branches-until-wednesday-june-19/14067 "2024-06-20T15:04:12Z")

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Dear VTK developers To aid the ParaView release process, please hold off on backporting to release or paraview/release branches until at least Wednesday, June 19. A short pause is needed to advance the paraview/release …

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## [how to convert a vtk binary file in vtk ascii file using python?](https://discourse.vtk.org/t/how-to-convert-a-vtk-binary-file-in-vtk-ascii-file-using-python/14084)

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**Author:** [@damien-mattei](https://discourse.vtk.org/u/damien-mattei)\
**Replies:** 0\
**Last updated:** [June 19, 2024, 1:45pm UTC](https://discourse.vtk.org/t/how-to-convert-a-vtk-binary-file-in-vtk-ascii-file-using-python/14084 "2024-06-19T13:45:41Z")

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hello, all is in the title… but i’m not sure i’m on the good server … regards, damien

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## [How to compute 64 bit integer in vtkShaderProgram?](https://discourse.vtk.org/t/how-to-compute-64-bit-integer-in-vtkshaderprogram/14046)

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**Author:** [@Michael\_Jackson](https://discourse.vtk.org/u/Michael_Jackson)\
**Replies:** 2\
**Last updated:** [June 17, 2024, 5:37pm UTC](https://discourse.vtk.org/t/how-to-compute-64-bit-integer-in-vtkshaderprogram/14046 "2024-06-17T17:37:08Z")

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I’m really don’t know what I am doing when it comes to OpenGL and OpenGL Shader and all of that but I have a custom piece of code that was written for us: std::string FSSource = shaders\[vtkShader::Fragment\]-\>GetSour…

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## [Neighbour points of current point](https://discourse.vtk.org/t/neighbour-points-of-current-point/14063)

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**Author:** [@Northern\_Condor](https://discourse.vtk.org/u/Northern_Condor)\
**Replies:** 0\
**Last updated:** [June 17, 2024, 11:09am UTC](https://discourse.vtk.org/t/neighbour-points-of-current-point/14063 "2024-06-17T11:09:52Z")

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Hello! How to get the neighbour points of the current point in VTK? I am aware of quering the Cell. which this point belongs to, and than quering the points of these cells, however, due to the existence of elements of …

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## [Filter vtkSubdivideTetra results in negative volumes](https://discourse.vtk.org/t/filter-vtksubdividetetra-results-in-negative-volumes/14054)

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**Author:** [@sfladi](https://discourse.vtk.org/u/sfladi)\
**Replies:** 0\
**Last updated:** [June 14, 2024, 12:14pm UTC](https://discourse.vtk.org/t/filter-vtksubdividetetra-results-in-negative-volumes/14054 "2024-06-14T12:14:12Z")

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When using the vtkSubdivideTetra filter, half of the resulting tetrahedral cells have negative volume, resulting in a zero or close to zero volume for the whole mesh. This probably has to do with with the ordering of ve…

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## [Simulation of a line cutting a mesh, English and Spanish](https://discourse.vtk.org/t/simulation-of-a-line-cutting-a-mesh-english-and-spanish/14003)

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**Author:** [@Miguelrevine](https://discourse.vtk.org/u/Miguelrevine)\
**Replies:** 2\
**Last updated:** [June 14, 2024, 10:18am UTC](https://discourse.vtk.org/t/simulation-of-a-line-cutting-a-mesh-english-and-spanish/14003 "2024-06-14T10:18:22Z")

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\[EN\] Good morning, I am trying to simulate the passage of a trajectory through a mesh. This trajectory has a series of points and movements, each movement goes from one point to the next and has a determined speed. My f…

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## [How to set width of vtkAxisActor2D?](https://discourse.vtk.org/t/how-to-set-width-of-vtkaxisactor2d/14047)

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**Author:** [@Konradlk](https://discourse.vtk.org/u/Konradlk)\
**Replies:** 0\
**Last updated:** [June 13, 2024, 9:23pm UTC](https://discourse.vtk.org/t/how-to-set-width-of-vtkaxisactor2d/14047 "2024-06-13T21:23:12Z")

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I am using vtkLegendScaleActor as following: scaleActor = vtkSmartPointer\<vtkLegendScaleActor\>::New(); scaleActor-\>RightAxisVisibilityOff(); scaleActor-\>LeftAxisVisibilityOff(); scaleActor-\>TopAxisVisibi…

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## [Updates to the VTK coding conventions](https://discourse.vtk.org/t/updates-to-the-vtk-coding-conventions/13997)

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**Author:** [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)\
**Replies:** 2\
**Last updated:** [June 13, 2024, 3:44pm UTC](https://discourse.vtk.org/t/updates-to-the-vtk-coding-conventions/13997 "2024-06-13T15:44:50Z")

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I just merged some updates to the VTK coding conventions in this merge request. The main changes are: Discourage default arguments in C++ function definitions. Remove prohibitions due to VS 2013 because VS 2013 is no l…

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## [The extent of vtkResliceCursorRepresentation output.](https://discourse.vtk.org/t/the-extent-of-vtkreslicecursorrepresentation-output/13978)

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**Author:** [@leo](https://discourse.vtk.org/u/leo)\
**Replies:** 2\
**Last updated:** [June 7, 2024, 2:31am UTC](https://discourse.vtk.org/t/the-extent-of-vtkreslicecursorrepresentation-output/13978 "2024-06-07T02:31:25Z")

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The vtkResliceCursorRepresentation::UpdateReslicePlane() sets extentX/extentY to a power of 2 may cause the program to slow down when the center is moved to the edge of the image, where extent may be 2048. I would like t…

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## [About VTK continuous integration](https://discourse.vtk.org/t/about-vtk-continuous-integration/13992)

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**Author:** [@mwestphal](https://discourse.vtk.org/u/mwestphal)\
**Replies:** 2\
**Last updated:** [June 6, 2024, 1:40pm UTC](https://discourse.vtk.org/t/about-vtk-continuous-integration/13992 "2024-06-06T13:40:16Z")

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Currently, a full run of VTK continuous integration take more than 24 hours because of long queue time in VTK merge request. While we try to reduce queue time by selecting which job should run, we recently introduced a …

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## [vtk9.3 vtkGPUVolumeRayCastMapper can not allocate memory](https://discourse.vtk.org/t/vtk9-3-vtkgpuvolumeraycastmapper-can-not-allocate-memory/13990)

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**Author:** [@qs10086](https://discourse.vtk.org/u/qs10086)\
**Replies:** 0\
**Last updated:** [June 6, 2024, 2:26am UTC](https://discourse.vtk.org/t/vtk9-3-vtkgpuvolumeraycastmapper-can-not-allocate-memory/13990 "2024-06-06T02:26:52Z")

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vtkSmartPointer\<vtkGPUVolumeRayCastMapper\> volumeMapper = vtkSmartPointer\<vtkGPUVolumeRayCastMapper\>::New();

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## [Polydata Plane Cuter to make a volume render](https://discourse.vtk.org/t/polydata-plane-cuter-to-make-a-volume-render/13988)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 0\
**Last updated:** [June 5, 2024, 9:53pm UTC](https://discourse.vtk.org/t/polydata-plane-cuter-to-make-a-volume-render/13988 "2024-06-05T21:53:14Z")

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Hello, I am using vtk with EGL offscreen rendering due to software limitations. I am rendering patients and I would like to cut them in half and visualize only from the middle of the patient till the end so I could see …

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## [setting color and textures in vtkGLTFExporter](https://discourse.vtk.org/t/setting-color-and-textures-in-vtkgltfexporter/13954)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 2\
**Last updated:** [June 4, 2024, 5:41pm UTC](https://discourse.vtk.org/t/setting-color-and-textures-in-vtkgltfexporter/13954 "2024-06-04T17:41:08Z")

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Hello, I have a triangle mesh with 2 scalar fields for each triangle. I would like to export the mesh to a gltf file. I was thinking in put the 2 scalar fields in the color or texture coordinates and then export with vt…

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## [Resizing canvas using interactor (WASM with threading)](https://discourse.vtk.org/t/resizing-canvas-using-interactor-wasm-with-threading/13962)

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**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 3\
**Last updated:** [June 4, 2024, 3:15pm UTC](https://discourse.vtk.org/t/resizing-canvas-using-interactor-wasm-with-threading/13962 "2024-06-04T15:15:49Z")

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I have replicated the setup from vtkWasmBenchmarks, where I use vtkRenderWindowInteractor::InteractorManagesTheEventLoop = false. It works perfectly. I followed the latest build instructions for VTK+WASM (updated a week…

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## [Need help on contributing a vtk example](https://discourse.vtk.org/t/need-help-on-contributing-a-vtk-example/13966)

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**Author:** [@MJamal](https://discourse.vtk.org/u/MJamal)\
**Replies:** 6\
**Last updated:** [June 4, 2024, 1:59pm UTC](https://discourse.vtk.org/t/need-help-on-contributing-a-vtk-example/13966 "2024-06-04T13:59:23Z")

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Hello, I’ve developed a cool VTK example of a stylized, animated atom structure. The example demonstrates the use of several classes, such as vtkEllipseArcSource and vtkLegendBoxActor. I’ve looked through the official …

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## [Getting rid of modules FiltersParallelDIY2 and FiltersParallel?](https://discourse.vtk.org/t/getting-rid-of-modules-filtersparalleldiy2-and-filtersparallel/13972)

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**Author:** [@Yohann\_Bearzi](https://discourse.vtk.org/u/Yohann_Bearzi)\
**Replies:** 2\
**Last updated:** [June 4, 2024, 7:47am UTC](https://discourse.vtk.org/t/getting-rid-of-modules-filtersparalleldiy2-and-filtersparallel/13972 "2024-06-04T07:47:24Z")

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The current module architecture around filters using DIY necessitates placing these filters in FiltersParallelDIY2 or in a module for which FiltersParallelDIY2 doesn’t depend on, to avoid cyclic dependencies. Some filter…

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## [vtkLinearCellExtrusionFilter not giving output](https://discourse.vtk.org/t/vtklinearcellextrusionfilter-not-giving-output/13977)

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**Author:** [@marchirschvogel](https://discourse.vtk.org/u/marchirschvogel)\
**Replies:** 0\
**Last updated:** [June 4, 2024, 7:27am UTC](https://discourse.vtk.org/t/vtklinearcellextrusionfilter-not-giving-output/13977 "2024-06-04T07:27:06Z")

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Dear VTK community! I want to make use of the vtkLinearCellExtrusionFilter to extrude Polydata to 3D unstructured grid data, which the filter is supposed to do. However, it seems that I cannot retrieve the filter’s outp…

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## [Error While Linking with Anari Library](https://discourse.vtk.org/t/error-while-linking-with-anari-library/13947)

<div class="topic-metadata">

**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 4\
**Last updated:** [June 3, 2024, 1:44pm UTC](https://discourse.vtk.org/t/error-while-linking-with-anari-library/13947 "2024-06-03T13:44:27Z")

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Hello, I get this error while I try to perform a render pass with anari and then render: 2024-05-27 22:34:34.125 ( 70.237s) \[ 7F3A0625F5C0\]vtkAnariRendererNode.cx:603 ERR| \[ANARI::FATAL\] 'environment' library se…

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## [Flicker effect/black screen issue with QVTKOpenGLNativeWidget](https://discourse.vtk.org/t/flicker-effect-black-screen-issue-with-qvtkopenglnativewidget/3855)

<div class="topic-metadata">

**Author:** [@santichialvo](https://discourse.vtk.org/u/santichialvo)\
**Replies:** 10\
**Last updated:** [June 1, 2024, 7:31pm UTC](https://discourse.vtk.org/t/flicker-effect-black-screen-issue-with-qvtkopenglnativewidget/3855 "2024-06-01T19:31:34Z")

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Hi, I hope you are well. We have an application where we use Qt and VTK. We’ve recently upgraded our application to VTK 9.0, first of all, thanks for these new functionalities, such as PBR. They are amazing. Due to this…

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## [OpenXR Meta Quest2 Controller Profile Missing](https://discourse.vtk.org/t/openxr-meta-quest2-controller-profile-missing/12617)

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**Author:** [@Hasnain\_Raza](https://discourse.vtk.org/u/Hasnain_Raza)\
**Replies:** 3\
**Last updated:** [May 31, 2024, 7:19am UTC](https://discourse.vtk.org/t/openxr-meta-quest2-controller-profile-missing/12617 "2024-05-31T07:19:46Z")

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When using the OpenXR Interface in ParaView using OpenVR with the Meta Quest 2 headset, my controllers are rendered with an actual Quest 2 controller model and they are able to perform the supported range of motions such…

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