# Latest

**URL:** https://discourse.vtk.org/latest.md?page=107

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

**Page:** 108

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## [vtkTexture repeat BUG: unexpected-extra repeat with squeezed shape](https://discourse.vtk.org/t/vtktexture-repeat-bug-unexpected-extra-repeat-with-squeezed-shape/10041)

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**Author:** [@yujhuang](https://discourse.vtk.org/u/yujhuang)\
**Replies:** 4\
**Last updated:** [December 7, 2022, 3:11am UTC](https://discourse.vtk.org/t/vtktexture-repeat-bug-unexpected-extra-repeat-with-squeezed-shape/10041 "2022-12-07T03:11:08Z")

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single Texture sample: when we zoom in, we can see that there is squeezed repeats along rows of textures: so I tried to repeat vtkTexture on a tubeActor, but there appears glitches, which I am pretty sure are sq…

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## [about vtk continuous display](https://discourse.vtk.org/t/about-vtk-continuous-display/10097)

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**Author:** [@marlon.ma](https://discourse.vtk.org/u/marlon.ma)\
**Replies:** 0\
**Last updated:** [December 7, 2022, 2:19am UTC](https://discourse.vtk.org/t/about-vtk-continuous-display/10097 "2022-12-07T02:19:04Z")

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I want vtk to display images continuously, because I am tracking the registration process, but my code will not respond to the image window when running. What should I do？ void Updata() { i++; cout \<\< i \<\< endl; v…

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## [Opacity value\<1.0 become invisible](https://discourse.vtk.org/t/opacity-value-1-0-become-invisible/9944)

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**Author:** [@Panda12197](https://discourse.vtk.org/u/Panda12197)\
**Replies:** 10\
**Last updated:** [December 6, 2022, 11:49pm UTC](https://discourse.vtk.org/t/opacity-value-1-0-become-invisible/9944 "2022-12-06T23:49:17Z")

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Hello Everyone, I am trying this example (Opacity) on Ubuntu 18.04 and VTK 8.2.0. The object is disappeared when I set the opacity value\<1.0. When both of the opacity values are less than 1.0, cubeActor-\>GetPropert…

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## [How to represent missing z-values in VtkPoints?](https://discourse.vtk.org/t/how-to-represent-missing-z-values-in-vtkpoints/9727)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 6\
**Last updated:** [December 6, 2022, 5:40pm UTC](https://discourse.vtk.org/t/how-to-represent-missing-z-values-in-vtkpoints/9727 "2022-12-06T17:40:54Z")

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I am using VTK-9.3.0. My C++ application builds a VtkPoints collection (variable ‘gridPoints\_’) from topography data. for (row = 0; row \< nRows; row++) { for (col = 0; col \< nCols; col++) { # Get x, y, and z. Note…

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## [Again clarification about quad node ordering](https://discourse.vtk.org/t/again-clarification-about-quad-node-ordering/10094)

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**Author:** [@philippeVerney](https://discourse.vtk.org/u/philippeVerney)\
**Replies:** 0\
**Last updated:** [December 6, 2022, 5:28pm UTC](https://discourse.vtk.org/t/again-clarification-about-quad-node-ordering/10094 "2022-12-06T17:28:18Z")

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Hi all, Following Clarification about quad node ordering, I made some experiments and here is a snapshot This image shows two surfaces where the colors correspond to the Y component of the normal computed by the vtk…

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## [Deriving coordinates for display (pixel) values](https://discourse.vtk.org/t/deriving-coordinates-for-display-pixel-values/9364)

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**Author:** [@llobera](https://discourse.vtk.org/u/llobera)\
**Replies:** 7\
**Last updated:** [December 6, 2022, 5:26pm UTC](https://discourse.vtk.org/t/deriving-coordinates-for-display-pixel-values/9364 "2022-12-06T17:26:59Z")

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I have a few related questions. The first one is the main question I am trying to work through. I am trying to obtain (as exact as it is possible) the coordinates for each pixel in a display(). I know how to convert z-b…

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## [borehole/well log](https://discourse.vtk.org/t/borehole-well-log/9948)

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**Author:** [@bistek](https://discourse.vtk.org/u/bistek)\
**Replies:** 7\
**Last updated:** [December 6, 2022, 3:34pm UTC](https://discourse.vtk.org/t/borehole-well-log/9948 "2022-12-06T15:34:09Z")

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Hello, we are building a geological visualization application and we need to visualize borehole/well logs, i.e. parameters recorded along a borehole or a well in the subsurface. The borehole geometry is represented by a …

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## [vtk.js off-screen rendering](https://discourse.vtk.org/t/vtk-js-off-screen-rendering/10045)

<div class="topic-metadata">

**Author:** [@JohnSkinner](https://discourse.vtk.org/u/JohnSkinner)\
**Replies:** 7\
**Last updated:** [December 6, 2022, 2:32pm UTC](https://discourse.vtk.org/t/vtk-js-off-screen-rendering/10045 "2022-12-06T14:32:21Z")

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I have a need to capture a set of renderings from one of my viz app’s renderWindow, but at a different resolution. My current approach is to attempt to use offscreen canvas via RenderWindow’s useOffscreen=true property. …

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## [How to store time series array of scalars?](https://discourse.vtk.org/t/how-to-store-time-series-array-of-scalars/10089)

<div class="topic-metadata">

**Author:** [@Reshma\_R\_S](https://discourse.vtk.org/u/Reshma_R_S)\
**Replies:** 0\
**Last updated:** [December 6, 2022, 1:21pm UTC](https://discourse.vtk.org/t/how-to-store-time-series-array-of-scalars/10089 "2022-12-06T13:21:32Z")

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I have a netCDF file with geospatial temporal data. From the vtk NETCDF reader, without having to do an Update() on the reader, I am able to get the scalars from different time points using the following code: timeIndex…

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## [Data Visualization](https://discourse.vtk.org/t/data-visualization/10060)

<div class="topic-metadata">

**Author:** [@Frankenstein](https://discourse.vtk.org/u/Frankenstein)\
**Replies:** 4\
**Last updated:** [December 6, 2022, 2:01pm UTC](https://discourse.vtk.org/t/data-visualization/10060 "2022-12-06T14:01:10Z")

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Hi,guys,I am using VTK(c++) to visualize some results,I need to visualize the distribution of oil film forces on a cylinder surface， just like this picture.I already have a two-dimensional array of pressure data that …

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## ['vtkScalarBarActor' show error with vtkGenericOpenGLRenderWindow](https://discourse.vtk.org/t/vtkscalarbaractor-show-error-with-vtkgenericopenglrenderwindow/10083)

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**Author:** [@domusonway](https://discourse.vtk.org/u/domusonway)\
**Replies:** 0\
**Last updated:** [December 6, 2022, 8:16am UTC](https://discourse.vtk.org/t/vtkscalarbaractor-show-error-with-vtkgenericopenglrenderwindow/10083 "2022-12-06T08:16:53Z")

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I want to add vtkScalarBarActor in vtk widget under qt , but I have a problem. When using vtkGenericOpenGLRenderWindow, the displayed color bar has no color, and the label is normal. But if I switch vtkGenericOpenGLRende…

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## [How to clone a vtkPolyDataReader](https://discourse.vtk.org/t/how-to-clone-a-vtkpolydatareader/9952)

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**Author:** [@peeling](https://discourse.vtk.org/u/peeling)\
**Replies:** 4\
**Last updated:** [December 6, 2022, 9:46am UTC](https://discourse.vtk.org/t/how-to-clone-a-vtkpolydatareader/9952 "2022-12-06T09:46:19Z")

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Hello, I need to clone / duplicate a vtkPolyDataReader after reading my VTK file (Mesh), Just after reading my Mesh I want to duplicate the Mesh polyData in two variables to then apply a different transform to each var…

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## [An error about openxr demo?](https://discourse.vtk.org/t/an-error-about-openxr-demo/10065)

<div class="topic-metadata">

**Author:** [@Rain-BBking](https://discourse.vtk.org/u/Rain-BBking)\
**Replies:** 3\
**Last updated:** [December 6, 2022, 6:25am UTC](https://discourse.vtk.org/t/an-error-about-openxr-demo/10065 "2022-12-06T06:25:16Z")

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I’m writing a project recently that needs to achieve VR effect. I’m going to use vtkOpenXRRenderWindow to implement it, but I had a problem when I used the official demo( Rendering/OpenXR/Testing/Cxx/TestOpenXRInitializa…

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## [SetInterpolationToFlat do not work](https://discourse.vtk.org/t/setinterpolationtoflat-do-not-work/10015)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 7\
**Last updated:** [December 6, 2022, 1:43am UTC](https://discourse.vtk.org/t/setinterpolationtoflat-do-not-work/10015 "2022-12-06T01:43:45Z")

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I am using SetInterpolationToFlat, but I find it do not work. The code to reproduce my question is: import vtkmodules.all as vtk nodes = \[ \[ 3.56000000e+02, 2.56000000e+02, 0.00000000e+00\], \[ 1.56000000e+02,…

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## [why I can't include header file 'itkVTKImageToImageFilter.h'](https://discourse.vtk.org/t/why-i-cant-include-header-file-itkvtkimagetoimagefilter-h/10076)

<div class="topic-metadata">

**Author:** [@Sterben\_01](https://discourse.vtk.org/u/Sterben_01)\
**Replies:** 3\
**Last updated:** [December 5, 2022, 8:25pm UTC](https://discourse.vtk.org/t/why-i-cant-include-header-file-itkvtkimagetoimagefilter-h/10076 "2022-12-05T20:25:19Z")

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Hi! I want to convert vtkImageData to itk::Image, so I found a class called itk::VTKImageToImageFilter But after I included the header file include \<itkVTKImageToImageFilter.h\>, it pops some error like ： /home/zhaoz22…

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## [How to show a messagebox by click on an object with Activiz](https://discourse.vtk.org/t/how-to-show-a-messagebox-by-click-on-an-object-with-activiz/10077)

<div class="topic-metadata">

**Author:** [@ranrui04](https://discourse.vtk.org/u/ranrui04)\
**Replies:** 0\
**Last updated:** [December 5, 2022, 8:03pm UTC](https://discourse.vtk.org/t/how-to-show-a-messagebox-by-click-on-an-object-with-activiz/10077 "2022-12-05T20:03:21Z")

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Hello! I wanted to popup a message box by clicking on a vtkRectangularButtonSouce or other type of object. I didn’t find any C# examples that would help. I’d appreciate it if someone could point me to the right directio…

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## [How to use Eigen inside VTK](https://discourse.vtk.org/t/how-to-use-eigen-inside-vtk/10047)

<div class="topic-metadata">

**Author:** [@Ruooo](https://discourse.vtk.org/u/Ruooo)\
**Replies:** 1\
**Last updated:** [December 5, 2022, 4:08pm UTC](https://discourse.vtk.org/t/how-to-use-eigen-inside-vtk/10047 "2022-12-05T16:08:34Z")

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Hi, I’m trying to use Eigen for some geometry computing, but I don’t know how to use the VTK third-party module and how to include the Eigen header. For now, In CMakeLists, I put vtkeigen in the find\_package, and includ…

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## [How to expand the model bounding box in VTK.JS](https://discourse.vtk.org/t/how-to-expand-the-model-bounding-box-in-vtk-js/10063)

<div class="topic-metadata">

**Author:** [@sunlin0oo](https://discourse.vtk.org/u/sunlin0oo)\
**Replies:** 4\
**Last updated:** [December 5, 2022, 3:11pm UTC](https://discourse.vtk.org/t/how-to-expand-the-model-bounding-box-in-vtk-js/10063 "2022-12-05T15:11:52Z")

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I can get the boundary value of the model through mapper.getBounds(), which I understand is the value of the bounding box. Right now I scale up (shrink) the model coordinates through the shader, causing parts of it to b…

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## [Forward Declaration error when using Qt](https://discourse.vtk.org/t/forward-declaration-error-when-using-qt/10066)

<div class="topic-metadata">

**Author:** [@nnzzll](https://discourse.vtk.org/u/nnzzll)\
**Replies:** 1\
**Last updated:** [December 5, 2022, 2:46pm UTC](https://discourse.vtk.org/t/forward-declaration-error-when-using-qt/10066 "2022-12-05T14:46:48Z")

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Here is a simple example for my problem: // test.h #include \<QObject\> #include \<vtkSmartPointer.h\> class vtkImageData; class test : public QObject { private: vtkSmartPointer\<vtkImageData\> img = vtkSmartPointer\<vtkI…

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## [How to quote/reference VTK in commercial applications ?](https://discourse.vtk.org/t/how-to-quote-reference-vtk-in-commercial-applications/10057)

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**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 1\
**Last updated:** [December 5, 2022, 9:23am UTC](https://discourse.vtk.org/t/how-to-quote-reference-vtk-in-commercial-applications/10057 "2022-12-05T09:23:32Z")

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Hi, I am compiling VTK and linking my application to the VTK libraries. I am considering providing my application as a commercial offering. I have been reading the following page https://vtk.org/about/ especially the …

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## [Scipy cookbook example not compatible with vtk 8](https://discourse.vtk.org/t/scipy-cookbook-example-not-compatible-with-vtk-8/1144)

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**Author:** [@joa](https://discourse.vtk.org/u/joa)\
**Replies:** 3\
**Last updated:** [December 5, 2022, 5:56am UTC](https://discourse.vtk.org/t/scipy-cookbook-example-not-compatible-with-vtk-8/1144 "2022-12-05T05:56:00Z")

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Hello everyone, I’m trying to get familiar with vtk in python. I’d like to do ray tracing using vtk 8. So I found the following example at https://vtk.org/Wiki/VTK/Examples/Python/vtkWithNumpy (reproducing it to free…

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## [How can I determine which handle of a vtkLineWidget2 is active and get it's current position?](https://discourse.vtk.org/t/how-can-i-determine-which-handle-of-a-vtklinewidget2-is-active-and-get-its-current-position/10061)

<div class="topic-metadata">

**Author:** [@scotsman60](https://discourse.vtk.org/u/scotsman60)\
**Replies:** 3\
**Last updated:** [December 4, 2022, 9:01pm UTC](https://discourse.vtk.org/t/how-can-i-determine-which-handle-of-a-vtklinewidget2-is-active-and-get-its-current-position/10061 "2022-12-04T21:01:50Z")

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Hello!!! I’m trying to use vtkLineWidget2 in such a way that the ends of the line “snap” to the nearest point under the cursor. Positioning a handle is easy enough, but I can’t figure out how to determine which handle i…

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## [Color a mesh by height and width](https://discourse.vtk.org/t/color-a-mesh-by-height-and-width/9965)

<div class="topic-metadata">

**Author:** [@Hamid\_Fsian](https://discourse.vtk.org/u/Hamid_Fsian)\
**Replies:** 1\
**Last updated:** [December 4, 2022, 3:10pm UTC](https://discourse.vtk.org/t/color-a-mesh-by-height-and-width/9965 "2022-12-04T15:10:49Z")

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Dear Community, I am trying to color an object based on the width of this later. I tried to inspire myself from this code But this later is for the height. And I want to set a color map based on the width for each z-sli…

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## [Fit splines to center of irregular 3d tube](https://discourse.vtk.org/t/fit-splines-to-center-of-irregular-3d-tube/9972)

<div class="topic-metadata">

**Author:** [@s195t](https://discourse.vtk.org/u/s195t)\
**Replies:** 1\
**Last updated:** [December 4, 2022, 3:06pm UTC](https://discourse.vtk.org/t/fit-splines-to-center-of-irregular-3d-tube/9972 "2022-12-04T15:06:11Z")

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Dear everyone, I have a dataset with multiple structures which are shaped like irregular 3d tubes, I was wondering if it is possible to fit a spline through the approximate center of such structures (I have both isosurf…

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## [Color a vtk object by width](https://discourse.vtk.org/t/color-a-vtk-object-by-width/9969)

<div class="topic-metadata">

**Author:** [@Hamid\_Fsian](https://discourse.vtk.org/u/Hamid_Fsian)\
**Replies:** 1\
**Last updated:** [December 4, 2022, 2:56pm UTC](https://discourse.vtk.org/t/color-a-vtk-object-by-width/9969 "2022-12-04T14:56:46Z")

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Dear Community, I am trying to color a 3D object by parsing each slice and affect a color if the width is \> to a certain thershold. Or \< to another one Below the code that I try to modify in order to fit my needs. but …

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## [How to area pick actors?](https://discourse.vtk.org/t/how-to-area-pick-actors/9961)

<div class="topic-metadata">

**Author:** [@rockydut](https://discourse.vtk.org/u/rockydut)\
**Replies:** 1\
**Last updated:** [December 4, 2022, 2:43pm UTC](https://discourse.vtk.org/t/how-to-area-pick-actors/9961 "2022-12-04T14:43:56Z")

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There are many actors, and I want to area pick some actors. The area defined by mouse can be get from: vtkPlanes\* frustum = static\_cast\<vtkAreaPicker\*\>(GetInteractor()-\>GetPicker())-\>GetFrustum(); The problem is how t…

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## [Does vtkNew is as same as vtkSmartPointer?](https://discourse.vtk.org/t/does-vtknew-is-as-same-as-vtksmartpointer/10039)

<div class="topic-metadata">

**Author:** [@Sterben\_01](https://discourse.vtk.org/u/Sterben_01)\
**Replies:** 6\
**Last updated:** [December 4, 2022, 12:34am UTC](https://discourse.vtk.org/t/does-vtknew-is-as-same-as-vtksmartpointer/10039 "2022-12-04T00:34:10Z")

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Hi, I’m a beginner of VTK. I faced an special issue about vtkNew and vtkSmartPointer I have such code: #include \<vtkNIFTIImageReader.h\> #include \<vtkNIFTIImageWriter.h\> #include \<vtkCamera.h\> #include \<vtkImageActor.h\> …

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## [VTK 9.0 artifacts after upgrade using vcpkg](https://discourse.vtk.org/t/vtk-9-0-artifacts-after-upgrade-using-vcpkg/9828)

<div class="topic-metadata">

**Author:** [@ErwanD](https://discourse.vtk.org/u/ErwanD)\
**Replies:** 5\
**Last updated:** [December 3, 2022, 5:15pm UTC](https://discourse.vtk.org/t/vtk-9-0-artifacts-after-upgrade-using-vcpkg/9828 "2022-12-03T17:15:51Z")

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Hi, I got multiple artifacts on vtk canvas. I didn´t have this issue before I changed vcpkg commit and vtk version. Here is an overview of my problem : I´m using : Vcpkg commit is : 779ce74ef VTK version : 9.0.3-…

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## [Image viewer / points - Dicom dataset.](https://discourse.vtk.org/t/image-viewer-points-dicom-dataset/10050)

<div class="topic-metadata">

**Author:** [@St\_Luk](https://discourse.vtk.org/u/St_Luk)\
**Replies:** 1\
**Last updated:** [December 3, 2022, 4:26am UTC](https://discourse.vtk.org/t/image-viewer-points-dicom-dataset/10050 "2022-12-03T04:26:55Z")

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Hi everyone, I need to take manually some coordinates from a dataset DICOM. The idea is developed some image viewer to see the images and then with the cursor place two points and generate a json file of them. Is it po…

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## [Visualization](https://discourse.vtk.org/t/visualization/10052)

<div class="topic-metadata">

**Author:** [@Frankenstein](https://discourse.vtk.org/u/Frankenstein)\
**Replies:** 0\
**Last updated:** [December 3, 2022, 3:59am UTC](https://discourse.vtk.org/t/visualization/10052 "2022-12-03T03:59:25Z")

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I wanted to visualize the pressure distribution of a sliding bearing, but I didn’t know how to start making such an image in VTK, and all I had was bearing data and two-dimensional pressure data. .just like this image,I…

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