# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=95

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

**Page:** 96

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## [vtkLagrangianParticleTracker python commands](https://discourse.vtk.org/t/vtklagrangianparticletracker-python-commands/6477)

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**Author:** [@kal](https://discourse.vtk.org/u/kal)\
**Replies:** 13\
**Last updated:** [September 22, 2021, 10:39pm UTC](https://discourse.vtk.org/t/vtklagrangianparticletracker-python-commands/6477 "2021-09-22T22:39:45Z")

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I am trying to understand and implement how the vtkLagrangianParticleTracker (LPT) works. I tried to modify the kitchen example. Basically, replaced the vtkStreamTracer arguments with the LPT arguments. My issue is how t…

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## [Learning the difference between SetScalars vs SetVectors](https://discourse.vtk.org/t/learning-the-difference-between-setscalars-vs-setvectors/6669)

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**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 2\
**Last updated:** [September 22, 2021, 3:42pm UTC](https://discourse.vtk.org/t/learning-the-difference-between-setscalars-vs-setvectors/6669 "2021-09-22T15:42:42Z")

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I am trying to add point data like density (scalar) and velocity (vector) to point data I am trying to understand when to use which because the following example kind of threw me off. A color to me is like a vector o…

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## [Setting multiple scalars in point data](https://discourse.vtk.org/t/setting-multiple-scalars-in-point-data/6670)

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**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 2\
**Last updated:** [September 22, 2021, 3:40pm UTC](https://discourse.vtk.org/t/setting-multiple-scalars-in-point-data/6670 "2021-09-22T15:40:29Z")

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I wrote the following and trying to understand why only the density scalar is visible in the VTP file written out. What is the correct way to add multiple point data ? void example\_02() { std::string filename ("vtp\_po…

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## [reader update](https://discourse.vtk.org/t/reader-update/6668)

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**Author:** [@WZYSIUI](https://discourse.vtk.org/u/WZYSIUI)\
**Replies:** 0\
**Last updated:** [September 22, 2021, 1:40am UTC](https://discourse.vtk.org/t/reader-update/6668 "2021-09-22T01:40:50Z")

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I use the vtkImageimport interface to use the same pointer to pass in data for body drawing, the first time the pointer address grayscale range is 0 to 128, color map is 0 to 255, the second time to modify the pointer in…

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## [Rendering on Windows, black screen on Ubuntu.](https://discourse.vtk.org/t/rendering-on-windows-black-screen-on-ubuntu/6272)

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**Author:** [@ziga\_Bizjak](https://discourse.vtk.org/u/ziga_Bizjak)\
**Replies:** 1\
**Last updated:** [September 21, 2021, 1:23pm UTC](https://discourse.vtk.org/t/rendering-on-windows-black-screen-on-ubuntu/6272 "2021-09-21T13:23:06Z")

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Hi, I’m new to VTK so i apologize if this question is already answered somewhere (however i didn’t find answer online that would work for my case.) I hope this is the right forum for such a question because here we are …

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## [Unable to orveride KeyPress events in vtkInteractorStyle?](https://discourse.vtk.org/t/unable-to-orveride-keypress-events-in-vtkinteractorstyle/6659)

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**Author:** [@scotsman60](https://discourse.vtk.org/u/scotsman60)\
**Replies:** 4\
**Last updated:** [September 20, 2021, 8:50pm UTC](https://discourse.vtk.org/t/unable-to-orveride-keypress-events-in-vtkinteractorstyle/6659 "2021-09-20T20:50:07Z")

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Hello!! I’m using VTK 9.1 and Python 3.8 and I’m creating a custom InteractorStyle, derived from vtkInteractorStyleRubberBandPick, where I want to change some of the Events that drive view manipulation etc. to different…

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## [VTK Multiple Blocks in One File](https://discourse.vtk.org/t/vtk-multiple-blocks-in-one-file/6645)

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**Author:** [@AhmedAlshawi](https://discourse.vtk.org/u/AhmedAlshawi)\
**Replies:** 1\
**Last updated:** [September 18, 2021, 5:46am UTC](https://discourse.vtk.org/t/vtk-multiple-blocks-in-one-file/6645 "2021-09-18T05:46:23Z")

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Hi, I am relatively new to VTK, and I am using it with Qt. I am trying to create a vtk file (XML based) that allows me to have multiple blocks/pieces (each an unstructured grid) in a single file. I have managed to creat…

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## [Querying other vector and scalar information in VTP files ?](https://discourse.vtk.org/t/querying-other-vector-and-scalar-information-in-vtp-files/6647)

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**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 1\
**Last updated:** [September 17, 2021, 4:23am UTC](https://discourse.vtk.org/t/querying-other-vector-and-scalar-information-in-vtp-files/6647 "2021-09-17T04:23:36Z")

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Hi, I have been able to reading VTP files to query their point position and their topology/connectivity in C++. I am calling GetPoint(index) to get the position, I am able to write them out as geometry file and loading …

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## [vtkPolyData rendered upside down and reversed, why?](https://discourse.vtk.org/t/vtkpolydata-rendered-upside-down-and-reversed-why/6550)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 4\
**Last updated:** [September 16, 2021, 11:20pm UTC](https://discourse.vtk.org/t/vtkpolydata-rendered-upside-down-and-reversed-why/6550 "2021-09-16T23:20:23Z")

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I’m using VTK-8.2.0 on ubuntu 18.04.5. I’ve implemented rendering of VTK data with QtQuick via QQuickFramebufferObject, using the C++ approach described here; I subclass QQuickFramebufferObject (I call it QVtkItem) and …

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## [Changing the geometry of an actor made the picker worked incorrectly](https://discourse.vtk.org/t/changing-the-geometry-of-an-actor-made-the-picker-worked-incorrectly/2030)

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**Author:** [@tdchen](https://discourse.vtk.org/u/tdchen)\
**Replies:** 8\
**Last updated:** [September 15, 2021, 11:07pm UTC](https://discourse.vtk.org/t/changing-the-geometry-of-an-actor-made-the-picker-worked-incorrectly/2030 "2021-09-15T23:07:43Z")

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After an actor were created, its geometry were changed. In fact I just changed its polydata by splitting 1 big triangle into 3. But I found when I picked the actor, the big triangle seemed become 1 small triangle and …

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## [Limit max FPS of vtkRenderWindow](https://discourse.vtk.org/t/limit-max-fps-of-vtkrenderwindow/6641)

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**Author:** [@PWeissenbacher](https://discourse.vtk.org/u/PWeissenbacher)\
**Replies:** 1\
**Last updated:** [September 15, 2021, 9:48pm UTC](https://discourse.vtk.org/t/limit-max-fps-of-vtkrenderwindow/6641 "2021-09-15T21:48:28Z")

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Hello. The vtkRenderWindow as well as the vtkRenderWindowInteractor both provide an interface to set the DesiredUpdateRate. This ensures, that I will get at least DesiredUpdateRate (FPS). Is there a way to limit the ma…

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## [Python wrapping a VTK module file from outside VTK. Issue with supermodule](https://discourse.vtk.org/t/python-wrapping-a-vtk-module-file-from-outside-vtk-issue-with-supermodule/6500)

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**Author:** [@Karthik\_Krishnan](https://discourse.vtk.org/u/Karthik_Krishnan)\
**Replies:** 11\
**Last updated:** [September 15, 2021, 8:52pm UTC](https://discourse.vtk.org/t/python-wrapping-a-vtk-module-file-from-outside-vtk-issue-with-supermodule/6500 "2021-09-15T20:52:18Z")

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I am python wrapping a vtk class using the new way of doing it (not vtk\_wrap\_python3) as follows - vtk\_module\_wrap\_python( MODULES VTK::ModuleName SOABI “{Python{VTK\_PYTHON\_VERSION}\_SOABI}” …

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## [How to create a mesh data from vtkPoints?](https://discourse.vtk.org/t/how-to-create-a-mesh-data-from-vtkpoints/6585)

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**Author:** [@Kim\_William](https://discourse.vtk.org/u/Kim_William)\
**Replies:** 11\
**Last updated:** [September 15, 2021, 2:57am UTC](https://discourse.vtk.org/t/how-to-create-a-mesh-data-from-vtkpoints/6585 "2021-09-15T02:57:36Z")

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Hi all. I have a question about the how to create a mesh data. I’m using the VTK 9.0 with the 3D Scanner. I can represent the point cloud data with vtkGaussainMapper. Previous inquiry: Now, I would like to represen…

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## [vtkDICOM Warning on vtk Master Branch](https://discourse.vtk.org/t/vtkdicom-warning-on-vtk-master-branch/6620)

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**Author:** [@adamgranthendry](https://discourse.vtk.org/u/adamgranthendry)\
**Replies:** 2\
**Last updated:** [September 14, 2021, 12:01pm UTC](https://discourse.vtk.org/t/vtkdicom-warning-on-vtk-master-branch/6620 "2021-09-14T12:01:36Z")

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I think the vtkDICOM CMakeLists.txt is outdated and needs updating: CMake Deprecation Warning at Remote/vtkDICOM/CMakeLists.txt:5 (cmake\_minimum\_required): Compatibility with CMake \< 2.8.12 will be removed from a futu…

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## [about vtkExtractPolyDataGeometry](https://discourse.vtk.org/t/about-vtkextractpolydatageometry/6621)

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**Author:** [@loufear](https://discourse.vtk.org/u/loufear)\
**Replies:** 0\
**Last updated:** [September 14, 2021, 3:12am UTC](https://discourse.vtk.org/t/about-vtkextractpolydatageometry/6621 "2021-09-14T03:12:22Z")

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How do I get the data on the front side of the box or what I can see .The data on the back or the front is not needed

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## [Packaging/installing applications that uses VTK](https://discourse.vtk.org/t/packaging-installing-applications-that-uses-vtk/6574)

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**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 1\
**Last updated:** [September 14, 2021, 1:16am UTC](https://discourse.vtk.org/t/packaging-installing-applications-that-uses-vtk/6574 "2021-09-14T01:16:18Z")

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I have been reading about packaging application that link against VTK talking about RPATH and such. Some of the article I read is a couple of years old and I am wondering with the recent updates and module-rization of V…

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## [missing Development.Module and compiler error](https://discourse.vtk.org/t/missing-development-module-and-compiler-error/6541)

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**Author:** [@Drew](https://discourse.vtk.org/u/Drew)\
**Replies:** 1\
**Last updated:** [September 14, 2021, 1:11am UTC](https://discourse.vtk.org/t/missing-development-module-and-compiler-error/6541 "2021-09-14T01:11:52Z")

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Hello, I am running into some issues installing VTK from source. I am trying to decode the cmake error : Could NOT find Python3 (missing: Development.Module) (found version "3.8.11") and the compilation error that happen…

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## [Very confused about imdata matrix index order](https://discourse.vtk.org/t/very-confused-about-imdata-matrix-index-order/6608)

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**Author:** [@dani](https://discourse.vtk.org/u/dani)\
**Replies:** 10\
**Last updated:** [September 13, 2021, 3:36pm UTC](https://discourse.vtk.org/t/very-confused-about-imdata-matrix-index-order/6608 "2021-09-13T15:36:19Z")

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Dear, I am working in python. I am very confused about the index ordering in the matrix I do pass to imdata. I do have a numpy array named matrix, with indexes \[x,y,z\] that I pass to a vtkImageData with: imdata = vtk.…

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## [VTK color 3D image display error](https://discourse.vtk.org/t/vtk-color-3d-image-display-error/6434)

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**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 9\
**Last updated:** [September 13, 2021, 12:10pm UTC](https://discourse.vtk.org/t/vtk-color-3d-image-display-error/6434 "2021-09-13T12:10:22Z")

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Dear All, I have a 3D, MHD color image display error with VTK with interactor. The image has 2.8GBytes (raw). The problem is in Linux. My computer has 20GBytes of RAM and is i7 (Intel GPU). VTK 9.0.3 2021-08-20 11:52…

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## [problem about actor rotation](https://discourse.vtk.org/t/problem-about-actor-rotation/6616)

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**Author:** [@Noobbbb](https://discourse.vtk.org/u/Noobbbb)\
**Replies:** 0\
**Last updated:** [September 12, 2021, 2:59pm UTC](https://discourse.vtk.org/t/problem-about-actor-rotation/6616 "2021-09-12T14:59:11Z")

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Hi,i’m trying to rotate an actor around itself (the head of this machine)，bu it seem that it rotate around an axis in the world，how can i fix this ？ my code： bmHead-\>RotateWXYZ(10, 1, 0, 0);| bmHead-\>SetPosition( -th…

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## [Does vtk.js have any plans to support pointer event?](https://discourse.vtk.org/t/does-vtk-js-have-any-plans-to-support-pointer-event/6610)

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**Author:** [@gandis0713](https://discourse.vtk.org/u/gandis0713)\
**Replies:** 1\
**Last updated:** [September 11, 2021, 10:32pm UTC](https://discourse.vtk.org/t/does-vtk-js-have-any-plans-to-support-pointer-event/6610 "2021-09-11T22:32:30Z")

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I’m using vtk.js just fine. Thank you very much. We are currently implementing gestures and pen actions on tablet devices. It seems that vtk.js supports touch+mouse events. I think this alone should be enough to suppo…

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## [how to use getOrientation() / setOrientation(), returning \[undefined\]](https://discourse.vtk.org/t/how-to-use-getorientation-setorientation-returning-undefined/6612)

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**Author:** [@shanebenlolo](https://discourse.vtk.org/u/shanebenlolo)\
**Replies:** 0\
**Last updated:** [September 11, 2021, 7:08pm UTC](https://discourse.vtk.org/t/how-to-use-getorientation-setorientation-returning-undefined/6612 "2021-09-11T19:08:28Z")

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Hello, I am trying to rotate my 3d volume. I have already implemented a function which repositions the volume using the following code: shiftX({ layer, value }) { apis.forEach(api =\> { const currentPosi…

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## [HighlightSelection example not rendering properly](https://discourse.vtk.org/t/highlightselection-example-not-rendering-properly/6604)

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**Author:** [@Drew](https://discourse.vtk.org/u/Drew)\
**Replies:** 1\
**Last updated:** [September 11, 2021, 1:26am UTC](https://discourse.vtk.org/t/highlightselection-example-not-rendering-properly/6604 "2021-09-11T01:26:57Z")

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This is in regards to the Cxx example HighlightSelection which can be found at https://kitware.github.io/vtk-examples/site/Cxx/Picking/HighlightSelection/ When you select cells the user does not see those cells highlig…

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## [How to properly cleanup vtk to use it across different threads on Windows (python-vtk)](https://discourse.vtk.org/t/how-to-properly-cleanup-vtk-to-use-it-across-different-threads-on-windows-python-vtk/6380)

<div class="topic-metadata">

**Author:** [@filsilva](https://discourse.vtk.org/u/filsilva)\
**Replies:** 12\
**Last updated:** [September 10, 2021, 6:36pm UTC](https://discourse.vtk.org/t/how-to-properly-cleanup-vtk-to-use-it-across-different-threads-on-windows-python-vtk/6380 "2021-09-10T18:36:54Z")

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Hi All, For our project we (@devmessias ) need to use timers that are executed in other threads and need to call some vtk functions on them. This works fine on Linux and Mac as the same OpenGL context can be shared acr…

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## [vtkPolyDataReader: Premature EOF](https://discourse.vtk.org/t/vtkpolydatareader-premature-eof/6607)

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**Author:** [@Nezir0](https://discourse.vtk.org/u/Nezir0)\
**Replies:** 0\
**Last updated:** [September 10, 2021, 5:34pm UTC](https://discourse.vtk.org/t/vtkpolydatareader-premature-eof/6607 "2021-09-10T17:34:18Z")

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Greetings, I’m trying to implement Implicit modeling from lines spelling the word “hello.” and my code: vtkNew reader; reader-\>SetFileName(“C:/Users/ASUS/Desktop/Hello/hello.vtk”); however when running it gives me a…

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## [vtkCallbackCommand for class member functions](https://discourse.vtk.org/t/vtkcallbackcommand-for-class-member-functions/6591)

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**Author:** [@PWeissenbacher](https://discourse.vtk.org/u/PWeissenbacher)\
**Replies:** 4\
**Last updated:** [September 10, 2021, 8:24am UTC](https://discourse.vtk.org/t/vtkcallbackcommand-for-class-member-functions/6591 "2021-09-10T08:24:15Z")

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Hello VTK Community. I’m looking for a way, to register a class member function as a callback to a vtkCallbackCommand like that: class foo { public: void bar(vtkObject\* caller, unsigned long eId, void\* clientData, v…

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## [CellPicking and changing cell color using Scalars](https://discourse.vtk.org/t/cellpicking-and-changing-cell-color-using-scalars/6600)

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**Author:** [@Drew](https://discourse.vtk.org/u/Drew)\
**Replies:** 0\
**Last updated:** [September 10, 2021, 3:11am UTC](https://discourse.vtk.org/t/cellpicking-and-changing-cell-color-using-scalars/6600 "2021-09-10T03:11:10Z")

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The current CellPicking example changes a triangular part of a square cell and does this by layering actors on top of each other (at least that is what it appears to be doing). I wanted to create a simple CellPicking exa…

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## [Building VTK from source in windows for python or 'CameraOrientationWidget'](https://discourse.vtk.org/t/building-vtk-from-source-in-windows-for-python-or-cameraorientationwidget/6557)

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**Author:** [@Aymane\_Gr](https://discourse.vtk.org/u/Aymane_Gr)\
**Replies:** 4\
**Last updated:** [September 9, 2021, 11:37pm UTC](https://discourse.vtk.org/t/building-vtk-from-source-in-windows-for-python-or-cameraorientationwidget/6557 "2021-09-09T23:37:06Z")

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Hello everyone i hope you’re doing well, As a newbie, i installed vtk from python using pip install vtk. However i had an error when using cam\_orient\_manipulator = vtk.vtkCameraOrientationWidget() claiming that vtk h…

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## [Plot 3D Alpha Shape](https://discourse.vtk.org/t/plot-3d-alpha-shape/6584)

<div class="topic-metadata">

**Author:** [@Adam\_Hendry](https://discourse.vtk.org/u/Adam_Hendry)\
**Replies:** 6\
**Last updated:** [September 9, 2021, 5:12pm UTC](https://discourse.vtk.org/t/plot-3d-alpha-shape/6584 "2021-09-09T17:12:29Z")

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Problem I am trying to implement Edelsbrunner’s Algorithm for the alpha shape of a 3D point cloud in python as presented in this SO post. However, I’m having trouble plotting results. Half my sphere looks good, and the …

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## [Display Lines that not completely appear while export a render window](https://discourse.vtk.org/t/display-lines-that-not-completely-appear-while-export-a-render-window/6595)

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**Author:** [@Nicolas\_Lenoir](https://discourse.vtk.org/u/Nicolas_Lenoir)\
**Replies:** 0\
**Last updated:** [September 9, 2021, 4:36pm UTC](https://discourse.vtk.org/t/display-lines-that-not-completely-appear-while-export-a-render-window/6595 "2021-09-09T16:36:40Z")

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Hello everyone, I have some trouble with my export of a vtkRenderWindow. In fact I create a box with text and this box sometimes will not completely appear in the export image as in this example. Does any one have a…

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