# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=37

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

**Page:** 38

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## [How would I choose between \`vtkCleanPolyData\` and \`vtkStaticCleanPolyData\`?](https://discourse.vtk.org/t/how-would-i-choose-between-vtkcleanpolydata-and-vtkstaticcleanpolydata/12715)

<div class="topic-metadata">

**Author:** [@rexthor](https://discourse.vtk.org/u/rexthor)\
**Replies:** 1\
**Last updated:** [November 15, 2023, 3:58pm UTC](https://discourse.vtk.org/t/how-would-i-choose-between-vtkcleanpolydata-and-vtkstaticcleanpolydata/12715 "2023-11-15T15:58:36Z")

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How would I choose between vtkCleanPolyData and vtkStaticCleanPolyData? These seem to do the same thing, and the documentation for them is very similar.

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## [How to handle the mirroring effect](https://discourse.vtk.org/t/how-to-handle-the-mirroring-effect/12656)

<div class="topic-metadata">

**Author:** [@Limz90](https://discourse.vtk.org/u/Limz90)\
**Replies:** 8\
**Last updated:** [November 15, 2023, 12:50pm UTC](https://discourse.vtk.org/t/how-to-handle-the-mirroring-effect/12656 "2023-11-15T12:50:49Z")

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Hi there, I have to handle the mirroring effect for some of my data; to do so, i applied the scaling of -1 of the data actor but the thing is the volume data diseappears; so when I zoom in very close, it appears again. …

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## [TypeError: Could not find a suitable VTK type for object in programmable filter](https://discourse.vtk.org/t/typeerror-could-not-find-a-suitable-vtk-type-for-object-in-programmable-filter/12714)

<div class="topic-metadata">

**Author:** [@simonw](https://discourse.vtk.org/u/simonw)\
**Replies:** 5\
**Last updated:** [November 15, 2023, 8:50am UTC](https://discourse.vtk.org/t/typeerror-could-not-find-a-suitable-vtk-type-for-object-in-programmable-filter/12714 "2023-11-15T08:50:12Z")

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Dear all, consider the following python script which I execute in the Programmable Filter: from paraview import vtk, numpy\_support import numpy as np input\_array1 = inputs\[0\].PointData\['displacement'\] input\_array2 = …

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## [Can I use OpenGL compute shaders in VTK program?](https://discourse.vtk.org/t/can-i-use-opengl-compute-shaders-in-vtk-program/4055)

<div class="topic-metadata">

**Author:** [@yuxing55555](https://discourse.vtk.org/u/yuxing55555)\
**Replies:** 6\
**Last updated:** [November 14, 2023, 7:21pm UTC](https://discourse.vtk.org/t/can-i-use-opengl-compute-shaders-in-vtk-program/4055 "2023-11-14T19:21:44Z")

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VTK9.0 use OpenGL2 at backend, and use GetOpenGLVersion result is 4.4. i found vtkShader not contain compute shader. Does anyone has any example to use compute shader? thank you!

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## [Fill in contour resulting from using vtkCutter (plane) on a vtkFlyingEdges3D generated surface](https://discourse.vtk.org/t/fill-in-contour-resulting-from-using-vtkcutter-plane-on-a-vtkflyingedges3d-generated-surface/12706)

<div class="topic-metadata">

**Author:** [@Bosingwa](https://discourse.vtk.org/u/Bosingwa)\
**Replies:** 0\
**Last updated:** [November 14, 2023, 3:15pm UTC](https://discourse.vtk.org/t/fill-in-contour-resulting-from-using-vtkcutter-plane-on-a-vtkflyingedges3d-generated-surface/12706 "2023-11-14T15:15:24Z")

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Using vtkFlyingEdges3D I generated a surface based on a vtkImageData: When applying vtkCutter (with a given plane as the cutting function) I get the contour: Good so far. The problem is that now I would like to inf…

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## [Boolean Intersection going unstable](https://discourse.vtk.org/t/boolean-intersection-going-unstable/12708)

<div class="topic-metadata">

**Author:** [@NRHuntoon](https://discourse.vtk.org/u/NRHuntoon)\
**Replies:** 0\
**Last updated:** [November 14, 2023, 4:02pm UTC](https://discourse.vtk.org/t/boolean-intersection-going-unstable/12708 "2023-11-14T16:02:33Z")

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I’m using pyVista for algorithmic geometry processing, and I’ve run into a situation where the boolean\_intersection filter will get into a state where it runs in an infinite loop. This appears to be due to some issue wit…

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## [Overlaying vtkActor colour blending issue](https://discourse.vtk.org/t/overlaying-vtkactor-colour-blending-issue/12669)

<div class="topic-metadata">

**Author:** [@Bosingwa](https://discourse.vtk.org/u/Bosingwa)\
**Replies:** 3\
**Last updated:** [November 14, 2023, 3:17pm UTC](https://discourse.vtk.org/t/overlaying-vtkactor-colour-blending-issue/12669 "2023-11-14T15:17:53Z")

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I want to overlay two meshes (green and red) (vtkPolyData) on top of a 3D vtkImageData slice, with a certain degree of opacity that allows for visualizing the vtkImageData behind: However, when the green is overlayed…

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## [Activiz 9.1 display chinese](https://discourse.vtk.org/t/activiz-9-1-display-chinese/8713)

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**Author:** [@a772485252](https://discourse.vtk.org/u/a772485252)\
**Replies:** 13\
**Last updated:** [November 14, 2023, 9:09am UTC](https://discourse.vtk.org/t/activiz-9-1-display-chinese/8713 "2023-11-14T09:09:20Z")

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When I use vtkTextActor to display Chinese, the Chinese string is converted to utf8 and then to string, but the conversion fails for odd numbers. So, how to display odd numbers of Chinese in c#? vtkTextActor actor = new…

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## [The code execution cannot proceed because the following dlls were not found](https://discourse.vtk.org/t/the-code-execution-cannot-proceed-because-the-following-dlls-were-not-found/12679)

<div class="topic-metadata">

**Author:** [@Silokhin\_Ilya](https://discourse.vtk.org/u/Silokhin_Ilya)\
**Replies:** 7\
**Last updated:** [November 13, 2023, 3:15pm UTC](https://discourse.vtk.org/t/the-code-execution-cannot-proceed-because-the-following-dlls-were-not-found/12679 "2023-11-13T15:15:47Z")

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I wanted to test vtk-9.3 with an example. Example here. But when I opened .exe I got the following errors: . There is an issue with vtkRenderingFreeType, vtkInteractionStyle, vtkRenderingCore, vtkRenderingOpenG…

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## [Avoiding precision problems in VTK](https://discourse.vtk.org/t/avoiding-precision-problems-in-vtk/12681)

<div class="topic-metadata">

**Author:** [@mohaya](https://discourse.vtk.org/u/mohaya)\
**Replies:** 2\
**Last updated:** [November 13, 2023, 1:51pm UTC](https://discourse.vtk.org/t/avoiding-precision-problems-in-vtk/12681 "2023-11-13T13:51:49Z")

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It’s a common issue in graphics that large position values start to affect visuals, due to single precision floats. Some games solve this by implementing a sort of segment-offset scheme for world coordinates, where XYZ v…

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## [Exporter missing shading](https://discourse.vtk.org/t/exporter-missing-shading/12675)

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**Author:** [@wshunvx](https://discourse.vtk.org/u/wshunvx)\
**Replies:** 1\
**Last updated:** [November 10, 2023, 10:14am UTC](https://discourse.vtk.org/t/exporter-missing-shading/12675 "2023-11-10T10:14:56Z")

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exporter = vtkGLTFExporter() exporter.SetActiveRenderer(renderer) exporter.SetRenderWindow(renWin) exporter.SetFileName(filename) exporter.SaveNormalOff() exporter.SaveBatchIdOff() exporter.InlineDataOn() exporter.Write…

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## [¡How can I obtain a license for the desktop software VolView-3.4-win64-x86.exe?](https://discourse.vtk.org/t/how-can-i-obtain-a-license-for-the-desktop-software-volview-3-4-win64-x86-exe/12573)

<div class="topic-metadata">

**Author:** [@Ricardo](https://discourse.vtk.org/u/Ricardo)\
**Replies:** 6\
**Last updated:** [November 9, 2023, 5:13pm UTC](https://discourse.vtk.org/t/how-can-i-obtain-a-license-for-the-desktop-software-volview-3-4-win64-x86-exe/12573 "2023-11-09T17:13:14Z")

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I am a student and I need it for some research projects. I appreciate your help with this concern. I use this software to apply some filters and process my image, but now I get a message that I need a license to be able…

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## [Black lines on a vtkFlyingEdges3D generated isosurface](https://discourse.vtk.org/t/black-lines-on-a-vtkflyingedges3d-generated-isosurface/12665)

<div class="topic-metadata">

**Author:** [@Bosingwa](https://discourse.vtk.org/u/Bosingwa)\
**Replies:** 3\
**Last updated:** [November 9, 2023, 4:19pm UTC](https://discourse.vtk.org/t/black-lines-on-a-vtkflyingedges3d-generated-isosurface/12665 "2023-11-09T16:19:02Z")

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Does anyone know why I am seeing this weird black lines/edges when applying vtkFlyingEdges3D filter to a mask for a ROI? When using plane cutting to produce a contour this is the result:

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## [Rendering Objects in Raspberry Pi 4 FAILED](https://discourse.vtk.org/t/rendering-objects-in-raspberry-pi-4-failed/12661)

<div class="topic-metadata">

**Author:** [@Hamzeh74](https://discourse.vtk.org/u/Hamzeh74)\
**Replies:** 3\
**Last updated:** [November 9, 2023, 4:08pm UTC](https://discourse.vtk.org/t/rendering-objects-in-raspberry-pi-4-failed/12661 "2023-11-09T16:08:38Z")

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Hi :wave: :grinning: I installed the vtk 9 with following steps: $ git clone https://gitlab.kitware.com/vtk/vtk.git $ cd vtk $ mkdir build $ cd build $ cmake -DVTK\_OPENGL\_HAS\_EGL=ON -DVTK\_OPENGL\_USE\_GLES=ON $ make…

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## [How to slice a STL file and save the resultant STL file?](https://discourse.vtk.org/t/how-to-slice-a-stl-file-and-save-the-resultant-stl-file/12643)

<div class="topic-metadata">

**Author:** [@Amit](https://discourse.vtk.org/u/Amit)\
**Replies:** 4\
**Last updated:** [November 9, 2023, 10:29am UTC](https://discourse.vtk.org/t/how-to-slice-a-stl-file-and-save-the-resultant-stl-file/12643 "2023-11-09T10:29:46Z")

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Hi, I am using vtk to slice a STL file. I want to load the file and slice it and after slicing it I want to store both the halves in different STL files and save it. I am able to slice and store them in STL files but th…

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## [PVTU (multiple VTUs) to one VTU](https://discourse.vtk.org/t/pvtu-multiple-vtus-to-one-vtu/12652)

<div class="topic-metadata">

**Author:** [@ermore](https://discourse.vtk.org/u/ermore)\
**Replies:** 0\
**Last updated:** [November 9, 2023, 3:29am UTC](https://discourse.vtk.org/t/pvtu-multiple-vtus-to-one-vtu/12652 "2023-11-09T03:29:48Z")

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I use the MPI program to run out the calculation results to generate pvtu (it is made up of many vtu), and I want to turn multiple vtu files into one vtu. If I want to use C++, which vtk API can I call to implement this …

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## [Image extension format](https://discourse.vtk.org/t/image-extension-format/12647)

<div class="topic-metadata">

**Author:** [@Ricardo](https://discourse.vtk.org/u/Ricardo)\
**Replies:** 1\
**Last updated:** [November 8, 2023, 4:12pm UTC](https://discourse.vtk.org/t/image-extension-format/12647 "2023-11-08T16:12:56Z")

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What image extension does Volview accept? I have .mhd images. But I get an error that it cannot read the image. What format should my images have to be able to see them?

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## [How to render vtk objects in different thread.](https://discourse.vtk.org/t/how-to-render-vtk-objects-in-different-thread/12641)

<div class="topic-metadata">

**Author:** [@KSJ](https://discourse.vtk.org/u/KSJ)\
**Replies:** 0\
**Last updated:** [November 8, 2023, 10:41am UTC](https://discourse.vtk.org/t/how-to-render-vtk-objects-in-different-thread/12641 "2023-11-08T10:41:32Z")

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Hello Everyone, I am building an application using VTK , OpenGL and QT . I am using VTKGenericOpenGLRenderWindow for rendering. I need to execute a part of my module in different thread. I tried by using thread but sin…

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## [Applying CLAHE to vtkImageData](https://discourse.vtk.org/t/applying-clahe-to-vtkimagedata/12637)

<div class="topic-metadata">

**Author:** [@Manju](https://discourse.vtk.org/u/Manju)\
**Replies:** 0\
**Last updated:** [November 8, 2023, 5:12am UTC](https://discourse.vtk.org/t/applying-clahe-to-vtkimagedata/12637 "2023-11-08T05:12:00Z")

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I would like to apply Contrast Limited Adaptive Histogram Equalization on vtkImageData. Presently I am doing this using OpenCV function and importing the Mat data back to VTK for further processing. Is there any way to g…

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## [many "undefined references" error in building vtk on raspberry pi 4](https://discourse.vtk.org/t/many-undefined-references-error-in-building-vtk-on-raspberry-pi-4/12633)

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**Author:** [@Hamzeh74](https://discourse.vtk.org/u/Hamzeh74)\
**Replies:** 3\
**Last updated:** [November 8, 2023, 5:09am UTC](https://discourse.vtk.org/t/many-undefined-references-error-in-building-vtk-on-raspberry-pi-4/12633 "2023-11-08T05:09:43Z")

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raspberry pi 4 OS: ubuntu 20 vtk source : 7.1.1 cmake version: 2.22 when I trying to build the vtk source on raspberry pi 4 I get lot of “undefined references” error on building the: \[ 5%\] Linking CXX shared library…

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## [How to delete a cell from vtk unstructuredGrid](https://discourse.vtk.org/t/how-to-delete-a-cell-from-vtk-unstructuredgrid/12627)

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**Author:** [@Fran\_Wang](https://discourse.vtk.org/u/Fran_Wang)\
**Replies:** 2\
**Last updated:** [November 7, 2023, 7:40pm UTC](https://discourse.vtk.org/t/how-to-delete-a-cell-from-vtk-unstructuredgrid/12627 "2023-11-07T19:40:40Z")

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Hello, I have a vtkUnstructuredGrid, and what I’d like to do is delete some old cells and then add some new cells to it. But I haven’t found any way to do that. My current plan is to use vtkPolydata instead of vtkUns…

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## [Visual artifact when rendering transparent vtkQuadricLODActor](https://discourse.vtk.org/t/visual-artifact-when-rendering-transparent-vtkquadriclodactor/12119)

<div class="topic-metadata">

**Author:** [@mohaya](https://discourse.vtk.org/u/mohaya)\
**Replies:** 3\
**Last updated:** [November 7, 2023, 4:06pm UTC](https://discourse.vtk.org/t/visual-artifact-when-rendering-transparent-vtkquadriclodactor/12119 "2023-11-07T16:06:12Z")

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I am getting incorrect shading when rendering a vtkQuadricLODActor with transparency, for both levels: LOD0 and LOD1 when interacting with the scene. I tried setting the actor’s backface property, also turning the prope…

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## [icp transformation gives me different results](https://discourse.vtk.org/t/icp-transformation-gives-me-different-results/12558)

<div class="topic-metadata">

**Author:** [@Limz90](https://discourse.vtk.org/u/Limz90)\
**Replies:** 6\
**Last updated:** [November 6, 2023, 7:38am UTC](https://discourse.vtk.org/t/icp-transformation-gives-me-different-results/12558 "2023-11-06T07:38:18Z")

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Hi, I am trying to use vtkIterativeClosestPointTransform between two mesh data (it’s actually the same object and i just did a transformation on translation, rotation and scaling just to have a source object ) So, I ne…

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## [Extract surface meshes from groundtruth and deformed/predicted volumetric meshes](https://discourse.vtk.org/t/extract-surface-meshes-from-groundtruth-and-deformed-predicted-volumetric-meshes/12053)

<div class="topic-metadata">

**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 4\
**Last updated:** [November 5, 2023, 9:48am UTC](https://discourse.vtk.org/t/extract-surface-meshes-from-groundtruth-and-deformed-predicted-volumetric-meshes/12053 "2023-11-05T09:48:21Z")

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Hi, I have two volumetric meshes that have same number of nodes and connectivities (cells). The only difference is that one mesh is kind of a deformed version of the other. This means only the node positions are sligtly…

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## [Howe to set vtkSplineFilter to DOUBLE\_PRECISION?](https://discourse.vtk.org/t/howe-to-set-vtksplinefilter-to-double-precision/12437)

<div class="topic-metadata">

**Author:** [@oyster](https://discourse.vtk.org/u/oyster)\
**Replies:** 11\
**Last updated:** [November 5, 2023, 5:24am UTC](https://discourse.vtk.org/t/howe-to-set-vtksplinefilter-to-double-precision/12437 "2023-11-05T05:24:30Z")

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Hi All, I want uniformly resample a polyline using vtkSplineFilter. The input points are built with SetDataTypeToDouble(), however, the output of vtkSplineFilter is float. Thanks

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## [X11 Forwarding over SSH for remote rendering to client machine](https://discourse.vtk.org/t/x11-forwarding-over-ssh-for-remote-rendering-to-client-machine/12591)

<div class="topic-metadata">

**Author:** [@evrose54](https://discourse.vtk.org/u/evrose54)\
**Replies:** 7\
**Last updated:** [November 2, 2023, 10:37pm UTC](https://discourse.vtk.org/t/x11-forwarding-over-ssh-for-remote-rendering-to-client-machine/12591 "2023-11-02T22:37:19Z")

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Problem that’s occurring. I’ve been working with Pyvista for nearly a year now (it’s great), however I’ve noticed some limitations regarding its accessibility over ssh. I posted this issue on their repo and they recommen…

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## [mesh decimation: vtkBinnedDecimation low quality mesh result vs vtkQuadricDecimation](https://discourse.vtk.org/t/mesh-decimation-vtkbinneddecimation-low-quality-mesh-result-vs-vtkquadricdecimation/12602)

<div class="topic-metadata">

**Author:** [@hxf0223](https://discourse.vtk.org/u/hxf0223)\
**Replies:** 1\
**Last updated:** [November 2, 2023, 10:48am UTC](https://discourse.vtk.org/t/mesh-decimation-vtkbinneddecimation-low-quality-mesh-result-vs-vtkquadricdecimation/12602 "2023-11-02T10:48:20Z")

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I want to do stl file decimation in parallel, so I tried vtkBinnedDecimation. The simplified fineness is bad than what using vtkQuadricDecimation. The origin STL file is 7.3M: porsche.zip (3.0 MB) Test using vtkBinned…

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## [Convert .vtu files to .vtkjs files](https://discourse.vtk.org/t/convert-vtu-files-to-vtkjs-files/12583)

<div class="topic-metadata">

**Author:** [@inannan423](https://discourse.vtk.org/u/inannan423)\
**Replies:** 4\
**Last updated:** [November 2, 2023, 2:13am UTC](https://discourse.vtk.org/t/convert-vtu-files-to-vtkjs-files/12583 "2023-11-02T02:13:34Z")

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Hello! I noticed that in ParaView, I can export .vtu files as .vtkjs files. Can I achieve this functionality using the Python API? Thank you very much!

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## [Using vtkArrayCalculator to multiply a vector array by a single scalar value](https://discourse.vtk.org/t/using-vtkarraycalculator-to-multiply-a-vector-array-by-a-single-scalar-value/12594)

<div class="topic-metadata">

**Author:** [@bheld](https://discourse.vtk.org/u/bheld)\
**Replies:** 0\
**Last updated:** [October 31, 2023, 8:28pm UTC](https://discourse.vtk.org/t/using-vtkarraycalculator-to-multiply-a-vector-array-by-a-single-scalar-value/12594 "2023-10-31T20:28:09Z")

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It is clear how to use vtkArrayCalculator to multiply a vector array (point based) times a single scalar value. For example OutputVector = InputVector \* 2.3. But is it possible to define other variables instead of expl…

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## [Difficulty Accessing the vtkOCCTReader through the python modules](https://discourse.vtk.org/t/difficulty-accessing-the-vtkocctreader-through-the-python-modules/12588)

<div class="topic-metadata">

**Author:** [@couragious](https://discourse.vtk.org/u/couragious)\
**Replies:** 1\
**Last updated:** [November 1, 2023, 5:23pm UTC](https://discourse.vtk.org/t/difficulty-accessing-the-vtkocctreader-through-the-python-modules/12588 "2023-11-01T17:23:20Z")

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I’m working with VTK in a python environment and am running into issues accessing the OCCTReader through the python module. I’ve attempted looking in both the 9.2.6, and 9.3.0rc1 versions accessible through pypi. Is the…

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