# Latest

**URL:** https://discourse.vtk.org/latest.md?page=200

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

**Page:** 201

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## [Is there any plan to implement LINEAR and CUBIC interpolation in imageReslice](https://discourse.vtk.org/t/is-there-any-plan-to-implement-linear-and-cubic-interpolation-in-imagereslice/4150)

<div class="topic-metadata">

**Author:** [@kevin1](https://discourse.vtk.org/u/kevin1)\
**Replies:** 2\
**Last updated:** [September 11, 2020, 7:28am UTC](https://discourse.vtk.org/t/is-there-any-plan-to-implement-linear-and-cubic-interpolation-in-imagereslice/4150 "2020-09-11T07:28:55Z")

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VTK.JS not implement LINEAR and CUBIC in ImageReslice. The image generated by NEAREST will have obvious jaggedness and the effect is not good.

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## [Enable Multi-User int VTK.js](https://discourse.vtk.org/t/enable-multi-user-int-vtk-js/4185)

<div class="topic-metadata">

**Author:** [@Ennio\_Bolondi](https://discourse.vtk.org/u/Ennio_Bolondi)\
**Replies:** 1\
**Last updated:** [September 10, 2020, 2:45pm UTC](https://discourse.vtk.org/t/enable-multi-user-int-vtk-js/4185 "2020-09-10T14:45:10Z")

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Hi there again, I keep studying vtk.js and I’m trying to understand how to implement a Multi-User server. I followed this example which help me for creating: -front end (written in vue) -backend written in Python (ac…

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## [How to programatically manage local vtk legacy files with ParaViewWeb API?](https://discourse.vtk.org/t/how-to-programatically-manage-local-vtk-legacy-files-with-paraviewweb-api/4187)

<div class="topic-metadata">

**Author:** [@raphael553](https://discourse.vtk.org/u/raphael553)\
**Replies:** 0\
**Last updated:** [September 10, 2020, 11:38am UTC](https://discourse.vtk.org/t/how-to-programatically-manage-local-vtk-legacy-files-with-paraviewweb-api/4187 "2020-09-10T11:38:42Z")

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Hello everyone, I’ve wanted to automatically read, load and render vtk legacy unstructured grid files through ParaViewWeb API. When I try to read vtk file with VTKGeometryDataModel, I didn’t get any desired results. I’v…

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## [vtkHardwareSelector and Unstructured Grids](https://discourse.vtk.org/t/vtkhardwareselector-and-unstructured-grids/4181)

<div class="topic-metadata">

**Author:** [@raungst](https://discourse.vtk.org/u/raungst)\
**Replies:** 1\
**Last updated:** [September 10, 2020, 11:03am UTC](https://discourse.vtk.org/t/vtkhardwareselector-and-unstructured-grids/4181 "2020-09-10T11:03:33Z")

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I’m in the midst of updating my python code to use vtkHardwareSelector instead of vtkCellPicker to select cells because of slowness with vtkCellPicker as my models get larger. With vtkCellPicker, it was easy to get the c…

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## [Select only boundary edges of small holes](https://discourse.vtk.org/t/select-only-boundary-edges-of-small-holes/4180)

<div class="topic-metadata">

**Author:** [@Lucas\_A](https://discourse.vtk.org/u/Lucas_A)\
**Replies:** 1\
**Last updated:** [September 10, 2020, 4:23am UTC](https://discourse.vtk.org/t/select-only-boundary-edges-of-small-holes/4180 "2020-09-10T04:23:49Z")

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I’m using vtkFeatureEdges to extract boundary edges, but I would like to know if there is a simple way to extract only the edges where the contour of these edges has a size limit. It looks like feature edges treats every…

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## [Unwanted cutting problem in visualization](https://discourse.vtk.org/t/unwanted-cutting-problem-in-visualization/4171)

<div class="topic-metadata">

**Author:** [@neuralix](https://discourse.vtk.org/u/neuralix)\
**Replies:** 2\
**Last updated:** [September 9, 2020, 2:43pm UTC](https://discourse.vtk.org/t/unwanted-cutting-problem-in-visualization/4171 "2020-09-09T14:43:07Z")

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Hi, I’m newbie at VTK. When I try to visualize a sphere, and I adjust z value in sphere.SetCenter(0.0, 0.0, z\_value), I only can visualize cut sphere. I guess there is a viewing frame(:cube). How can I extend my viewing…

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## [vtkResampleToImage filter output save as a mhd file](https://discourse.vtk.org/t/vtkresampletoimage-filter-output-save-as-a-mhd-file/4179)

<div class="topic-metadata">

**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 0\
**Last updated:** [September 9, 2020, 11:15am UTC](https://discourse.vtk.org/t/vtkresampletoimage-filter-output-save-as-a-mhd-file/4179 "2020-09-09T11:15:22Z")

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I have created an unstructuredGrid and passed it into vtkResampleToImage filter in order to sample its point and cell data on to a uniform grid of points. Now I want to write this output as a 3D image volume i.e. in .mh…

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## [vtkScalarBarActor usage](https://discourse.vtk.org/t/vtkscalarbaractor-usage/4163)

<div class="topic-metadata">

**Author:** [@Deepa](https://discourse.vtk.org/u/Deepa)\
**Replies:** 2\
**Last updated:** [September 9, 2020, 8:57am UTC](https://discourse.vtk.org/t/vtkscalarbaractor-usage/4163 "2020-09-09T08:57:30Z")

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Hello Everyone, I’m using vedo to create a network with nodes and edges and color the nodes using the scalar values stored in an array. From what I understand, vedo uses vtkScalarBarActor to associate the scalar values …

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## [Mesh voxelization with two colours](https://discourse.vtk.org/t/mesh-voxelization-with-two-colours/4128)

<div class="topic-metadata">

**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 8\
**Last updated:** [September 9, 2020, 8:55am UTC](https://discourse.vtk.org/t/mesh-voxelization-with-two-colours/4128 "2020-09-09T08:55:56Z")

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I have created a volumetric mesh using gmsh toolkit as you can see a clipping view of it below. It has an ellipsoid inside of a box. I have used two physical groups one is to hold the data for ellipsoid and the other gro…

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## [Python version of vtkInteractorStyleDrawPolygon. How to speed up?](https://discourse.vtk.org/t/python-version-of-vtkinteractorstyledrawpolygon-how-to-speed-up/4178)

<div class="topic-metadata">

**Author:** [@michaelhogg](https://discourse.vtk.org/u/michaelhogg)\
**Replies:** 1\
**Last updated:** [September 9, 2020, 5:14am UTC](https://discourse.vtk.org/t/python-version-of-vtkinteractorstyledrawpolygon-how-to-speed-up/4178 "2020-09-09T05:14:39Z")

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Hi all, I really wanted to use a polygon (or lasso) picker in vtk using python. However, the python version does not have access to GetPolygonPoints, because it returns a vtkVector2i object which appears difficult to wr…

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## [Capping the elliptical cylinder example](https://discourse.vtk.org/t/capping-the-elliptical-cylinder-example/2949)

<div class="topic-metadata">

**Author:** [@iheartvtoolkit](https://discourse.vtk.org/u/iheartvtoolkit)\
**Replies:** 3\
**Last updated:** [September 8, 2020, 8:02pm UTC](https://discourse.vtk.org/t/capping-the-elliptical-cylinder-example/2949 "2020-09-08T20:02:09Z")

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Hello all, Given the Linear extrusion example, and the elliptical cylinder example, I produced an elliptical cylinder with a capped top and bottom. This is done by extruding towards the center of the ellipse then forwar…

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## [Is there any way I can get the corresponding image before rendering volume to the window](https://discourse.vtk.org/t/is-there-any-way-i-can-get-the-corresponding-image-before-rendering-volume-to-the-window/4172)

<div class="topic-metadata">

**Author:** [@funstuff](https://discourse.vtk.org/u/funstuff)\
**Replies:** 1\
**Last updated:** [September 8, 2020, 7:42pm UTC](https://discourse.vtk.org/t/is-there-any-way-i-can-get-the-corresponding-image-before-rendering-volume-to-the-window/4172 "2020-09-08T19:42:08Z")

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dear all， I want to know if VTK provides any method to save the image rendered by vtkSmartVolumeMapper. I know vtkWindowToImageFilter, but its implementation requires rendering data to the window,the effect is similar t…

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## [Picking objects created from geometry shader](https://discourse.vtk.org/t/picking-objects-created-from-geometry-shader/4175)

<div class="topic-metadata">

**Author:** [@filsilva](https://discourse.vtk.org/u/filsilva)\
**Replies:** 0\
**Last updated:** [September 8, 2020, 4:34pm UTC](https://discourse.vtk.org/t/picking-objects-created-from-geometry-shader/4175 "2020-09-08T16:34:13Z")

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Hi I’ve been using VTK to construct a network visualizer in Python. We are using geometry shaders to convert the lines to shaded 3D tubes and fake spheres technique to draw vertices (a fake sphere is generated in the fr…

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## [how to speedup vtkCellPicker ?](https://discourse.vtk.org/t/how-to-speedup-vtkcellpicker/4167)

<div class="topic-metadata">

**Author:** [@ericpellegrini](https://discourse.vtk.org/u/ericpellegrini)\
**Replies:** 0\
**Last updated:** [September 7, 2020, 9:11am UTC](https://discourse.vtk.org/t/how-to-speedup-vtkcellpicker/4167 "2020-09-07T09:11:29Z")

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Hi all, below is a snippet of a molecular viewer written using vtk/PyQt which I adapted from a colleague’s code. Basically, the viewer is quite efficient regarding the mouse interaction (translation, rotation, zoom). I …

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## [Invalid value in VTK](https://discourse.vtk.org/t/invalid-value-in-vtk/4165)

<div class="topic-metadata">

**Author:** [@EvanLee](https://discourse.vtk.org/u/EvanLee)\
**Replies:** 0\
**Last updated:** [September 7, 2020, 8:34am UTC](https://discourse.vtk.org/t/invalid-value-in-vtk/4165 "2020-09-07T08:34:21Z")

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Hello Everyone, I tried to store the data field information in VTK format, but there were some invalid values in the data field. How to store invalid value in VTK, thank you very much!

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## [Help with explaining differences between Paraview Glance and VTK visualisation](https://discourse.vtk.org/t/help-with-explaining-differences-between-paraview-glance-and-vtk-visualisation/4133)

<div class="topic-metadata">

**Author:** [@mattbatchelor](https://discourse.vtk.org/u/mattbatchelor)\
**Replies:** 4\
**Last updated:** [September 7, 2020, 6:45am UTC](https://discourse.vtk.org/t/help-with-explaining-differences-between-paraview-glance-and-vtk-visualisation/4133 "2020-09-07T06:45:00Z")

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I am trying to visualise some CFD data from a VTU file (exported from XFlow). When I check the results in Paraview Glance it looks like this which is correct, however when I load it in VTK and present the same cell da…

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## [Obtain new point after reslice a NIFTII image](https://discourse.vtk.org/t/obtain-new-point-after-reslice-a-niftii-image/4054)

<div class="topic-metadata">

**Author:** [@LoiseauNicolas](https://discourse.vtk.org/u/LoiseauNicolas)\
**Replies:** 7\
**Last updated:** [September 6, 2020, 8:34pm UTC](https://discourse.vtk.org/t/obtain-new-point-after-reslice-a-niftii-image/4054 "2020-09-06T20:34:42Z")

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Hello everyone and thank you for your answers, I’m a new user of VTK. And excuse my english. I have a niftii image volume with many landmarks. I want to reslice this image with an affine transformation matrix, at this …

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## [vtkMFCWindow crashes in debug mode](https://discourse.vtk.org/t/vtkmfcwindow-crashes-in-debug-mode/4147)

<div class="topic-metadata">

**Author:** [@ayush.arudra](https://discourse.vtk.org/u/ayush.arudra)\
**Replies:** 4\
**Last updated:** [September 6, 2020, 2:46pm UTC](https://discourse.vtk.org/t/vtkmfcwindow-crashes-in-debug-mode/4147 "2020-09-06T14:46:56Z")

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Hi there, I am using vtkMFCWindow object to link vtk to MFC. I create a Cstatic object and pass it on to the constructor as in m\_vtkmfcWindow = new vtkMFCWindow (pWnd); This code works well in release mode, but crashe…

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## [are scenes that mix gradient shaded and normal volume renderings common?](https://discourse.vtk.org/t/are-scenes-that-mix-gradient-shaded-and-normal-volume-renderings-common/4143)

<div class="topic-metadata">

**Author:** [@Dave\_DeMarle](https://discourse.vtk.org/u/Dave_DeMarle)\
**Replies:** 4\
**Last updated:** [September 6, 2020, 4:01am UTC](https://discourse.vtk.org/t/are-scenes-that-mix-gradient-shaded-and-normal-volume-renderings-common/4143 "2020-09-06T04:01:25Z")

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Howdy, How often do people make scenes with multiple volume rendered data sets in them and where gradient shading is turned on for some volumes but not for others? We are doing some feature planning for OSPRay and the …

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## [Optimum window and levels for vtkResliceImageViewer](https://discourse.vtk.org/t/optimum-window-and-levels-for-vtkresliceimageviewer/4157)

<div class="topic-metadata">

**Author:** [@sherinnovation](https://discourse.vtk.org/u/sherinnovation)\
**Replies:** 1\
**Last updated:** [September 5, 2020, 10:23pm UTC](https://discourse.vtk.org/t/optimum-window-and-levels-for-vtkresliceimageviewer/4157 "2020-09-05T22:23:23Z")

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I am using vtkNIFTIImageReader to read a nifti file(MRI, human head) and for displaying data I am making use of vtkResliceImageViewer. I see that different files have to different would be I am using hardcoded values fo…

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## [Activiz .net core](https://discourse.vtk.org/t/activiz-net-core/4155)

<div class="topic-metadata">

**Author:** [@MMoussa](https://discourse.vtk.org/u/MMoussa)\
**Replies:** 0\
**Last updated:** [September 5, 2020, 4:24am UTC](https://discourse.vtk.org/t/activiz-net-core/4155 "2020-09-05T04:24:31Z")

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Is Activiz only supported under .net framework, or is it supposed to work with .net core as well? I tried compiling it under .net core but got an error regarding multifile assemblies.

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## [How to colorize surface by slope?](https://discourse.vtk.org/t/how-to-colorize-surface-by-slope/4071)

<div class="topic-metadata">

**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 16\
**Last updated:** [September 4, 2020, 11:17pm UTC](https://discourse.vtk.org/t/how-to-colorize-surface-by-slope/4071 "2020-09-04T23:17:39Z")

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I’ve subclassed vtkAbstractPolyDataReader to MyReader, which reads topographic data from a file and outputs vtkPolyData containing points and polygons (triangles). I’ve written an app that uses MyReader to read a topogra…

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## [I get trouble in using vtkImageSlabReslice](https://discourse.vtk.org/t/i-get-trouble-in-using-vtkimageslabreslice/4123)

<div class="topic-metadata">

**Author:** [@funstuff](https://discourse.vtk.org/u/funstuff)\
**Replies:** 7\
**Last updated:** [September 4, 2020, 5:16am UTC](https://discourse.vtk.org/t/i-get-trouble-in-using-vtkimageslabreslice/4123 "2020-09-04T05:16:40Z")

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Dear all， I\`m using vtkImageSlabReslice to create an oblique MPR.The result is right,but there is a rotate angle in output, how to fix it ? thanks double res\[3\] = { 0 }, center\[3\] = { 0 }; center\[0\] = mPoints\[index\].…

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## [vtkWin32RenderWindowInteractor (00000212DF4DB820): No renderer defined!](https://discourse.vtk.org/t/vtkwin32renderwindowinteractor-00000212df4db820-no-renderer-defined/4124)

<div class="topic-metadata">

**Author:** [@giri\_lakshman](https://discourse.vtk.org/u/giri_lakshman)\
**Replies:** 1\
**Last updated:** [September 4, 2020, 12:21am UTC](https://discourse.vtk.org/t/vtkwin32renderwindowinteractor-00000212df4db820-no-renderer-defined/4124 "2020-09-04T00:21:11Z")

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Hi, I am working on a reading dicom images using Qt framework and VTK. I followed the below example . When i open a dicom image file from a directory, I was not able to view the image and I get the following error…

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## [FFMPEG / MPEG2 support cross-platform](https://discourse.vtk.org/t/ffmpeg-mpeg2-support-cross-platform/4125)

<div class="topic-metadata">

**Author:** [@Mathilde](https://discourse.vtk.org/u/Mathilde)\
**Replies:** 1\
**Last updated:** [September 3, 2020, 11:42pm UTC](https://discourse.vtk.org/t/ffmpeg-mpeg2-support-cross-platform/4125 "2020-09-03T23:42:38Z")

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Hello, We are using VTK export video modules for a project. On VTK \< 8 we were using vtkMPEG2Writer on Windows and vtkFFMPEGWriter on Linux and OSX. However, since VTK 8.2 vtkMPEG2Writer seems to be removed. On the …

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## [how to get the cross section perpendicular z axis base on the z user input?](https://discourse.vtk.org/t/how-to-get-the-cross-section-perpendicular-z-axis-base-on-the-z-user-input/4137)

<div class="topic-metadata">

**Author:** [@ori](https://discourse.vtk.org/u/ori)\
**Replies:** 1\
**Last updated:** [September 3, 2020, 11:14pm UTC](https://discourse.vtk.org/t/how-to-get-the-cross-section-perpendicular-z-axis-base-on-the-z-user-input/4137 "2020-09-03T23:14:38Z")

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I want read a stl file. Then capture a image of cross section perpendicular to z axis, the z value is given by user. And output the intersection to image. I already know how to read a file by https://lorensen.github.io…

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## [How to get polyline from drawn 2D image?](https://discourse.vtk.org/t/how-to-get-polyline-from-drawn-2d-image/4144)

<div class="topic-metadata">

**Author:** [@kohit](https://discourse.vtk.org/u/kohit)\
**Replies:** 3\
**Last updated:** [September 3, 2020, 10:02pm UTC](https://discourse.vtk.org/t/how-to-get-polyline-from-drawn-2d-image/4144 "2020-09-03T22:02:16Z")

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I have a grayscale image, for example, using paint brush to draw a circle(or polygon). How can I get the polydata(points and lines, which forms a circle/polygon shape) from this picture?

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## [Using regular mapper and actor instead of vtkVolumeMapper and vtkVolume](https://discourse.vtk.org/t/using-regular-mapper-and-actor-instead-of-vtkvolumemapper-and-vtkvolume/4067)

<div class="topic-metadata">

**Author:** [@samm-vs](https://discourse.vtk.org/u/samm-vs)\
**Replies:** 10\
**Last updated:** [September 3, 2020, 2:29pm UTC](https://discourse.vtk.org/t/using-regular-mapper-and-actor-instead-of-vtkvolumemapper-and-vtkvolume/4067 "2020-09-03T14:29:50Z")

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I am trying to turn on the wireframe on for a vti file but vtkVolumeProperty doesn’t seem to provide the option to setRepresentationToWireframe(), therefore I would like to render the image using the classic vtkmapper an…

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## [VMTK: Problem about multiple source/target points for vtkvmtkPolyDataCenterlines](https://discourse.vtk.org/t/vmtk-problem-about-multiple-source-target-points-for-vtkvmtkpolydatacenterlines/4136)

<div class="topic-metadata">

**Author:** [@NeuZhangQiang](https://discourse.vtk.org/u/NeuZhangQiang)\
**Replies:** 1\
**Last updated:** [September 3, 2020, 1:20pm UTC](https://discourse.vtk.org/t/vmtk-problem-about-multiple-source-target-points-for-vtkvmtkpolydatacenterlines/4136 "2020-09-03T13:20:04Z")

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I am using vmtk to extract center lines from airway, and I need some help. For example, the airway looks like: If the source point is 0, and target point is 1, the output is OK: Fig. 1 If the source point is \[1, 1…

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## [Cluster (Data visualisation)](https://discourse.vtk.org/t/cluster-data-visualisation/4142)

<div class="topic-metadata">

**Author:** [@IlhyMed](https://discourse.vtk.org/u/IlhyMed)\
**Replies:** 0\
**Last updated:** [September 3, 2020, 12:57pm UTC](https://discourse.vtk.org/t/cluster-data-visualisation/4142 "2020-09-03T12:57:59Z")

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Hi guys, I’m using VTK (c++) to visualize some results, I need that to be like a cluster (point cloud) ( which I found in vtk examples) but then I have to add the axes and also adapt the number and the colors of the clu…

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