# Latest

**URL:** https://discourse.vtk.org/latest.md?page=215

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

**Page:** 216

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## [vtkCamera - What coordinate system for setting variables?](https://discourse.vtk.org/t/vtkcamera-what-coordinate-system-for-setting-variables/3173)

<div class="topic-metadata">

**Author:** [@tchen87](https://discourse.vtk.org/u/tchen87)\
**Replies:** 1\
**Last updated:** [May 1, 2020, 12:29pm UTC](https://discourse.vtk.org/t/vtkcamera-what-coordinate-system-for-setting-variables/3173 "2020-05-01T12:29:42Z")

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I’m attempting to use vtkCamera for my stereo rendering application, with OffAxisProjection. The display I’m using is tilted at an angle, so I wanted to get clarity on the proper coordinate system to use for the various …

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## [is there any way to check mesh is watertight?](https://discourse.vtk.org/t/is-there-any-way-to-check-mesh-is-watertight/3169)

<div class="topic-metadata">

**Author:** [@srbn.ghosh99](https://discourse.vtk.org/u/srbn.ghosh99)\
**Replies:** 3\
**Last updated:** [April 30, 2020, 10:02pm UTC](https://discourse.vtk.org/t/is-there-any-way-to-check-mesh-is-watertight/3169 "2020-04-30T22:02:27Z")

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Hi, I have used PolyDataConnectivityFilter to get rid of disconnected vertices. Is that enough to check if the mesh is watertight? Or I need to use any other filter to check if the mesh is watertight? Could you sugges…

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## [vtkScalarBarActor](https://discourse.vtk.org/t/vtkscalarbaractor/3186)

<div class="topic-metadata">

**Author:** [@VannieZ](https://discourse.vtk.org/u/VannieZ)\
**Replies:** 0\
**Last updated:** [April 30, 2020, 6:07pm UTC](https://discourse.vtk.org/t/vtkscalarbaractor/3186 "2020-04-30T18:07:48Z")

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Hello, I am using ActiViz Edition 5.8.0 I am trying to set colorbar values which are always between \[0,1\] (it would be okay, plot looks perfect with many colors on it, but for my subject it is very important to have co…

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## [vtkimageViewer2 can't Render the DicomSeries](https://discourse.vtk.org/t/vtkimageviewer2-cant-render-the-dicomseries/3171)

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**Author:** [@Amnesie](https://discourse.vtk.org/u/Amnesie)\
**Replies:** 3\
**Last updated:** [April 30, 2020, 5:00pm UTC](https://discourse.vtk.org/t/vtkimageviewer2-cant-render-the-dicomseries/3171 "2020-04-30T17:00:43Z")

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Hello everyone , I used ITK to create a Dicomseries from a Raw Volumen pure .raw data not include mhd or any header i just add some tags by manual ,so the Dicomseries dont have much Dicom-Tags. Then i try to render the…

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## [AVIWriter on Ubuntu](https://discourse.vtk.org/t/aviwriter-on-ubuntu/3183)

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**Author:** [@FabianSchuetze](https://discourse.vtk.org/u/FabianSchuetze)\
**Replies:** 1\
**Last updated:** [April 30, 2020, 2:51pm UTC](https://discourse.vtk.org/t/aviwriter-on-ubuntu/3183 "2020-04-30T14:51:38Z")

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I would like to use the VTKAVIWriter.h on Ubuntu but do unfortunately not know how to do that. I indeed find the header in the source files but its not among the installed files after compilation. I looked for compile …

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## [Compile Error: Definition Provided for Explicit instantiation](https://discourse.vtk.org/t/compile-error-definition-provided-for-explicit-instantiation/3176)

<div class="topic-metadata">

**Author:** [@FabianSchuetze](https://discourse.vtk.org/u/FabianSchuetze)\
**Replies:** 5\
**Last updated:** [April 30, 2020, 8:58am UTC](https://discourse.vtk.org/t/compile-error-definition-provided-for-explicit-instantiation/3176 "2020-04-30T08:58:21Z")

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When compiling software that includes vtkFloatArray.h with Qtcreator and gcc 9.3 as compiler on Ubuntu 20.04 I receive the following error: /usr/local/include/vtk-8.2/vtkFloatArray.h:38:3: error: definition provided for…

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## [Help to port a VTK Python library to VTK.js](https://discourse.vtk.org/t/help-to-port-a-vtk-python-library-to-vtk-js/3181)

<div class="topic-metadata">

**Author:** [@adamjamesturner93](https://discourse.vtk.org/u/adamjamesturner93)\
**Replies:** 0\
**Last updated:** [April 30, 2020, 7:45am UTC](https://discourse.vtk.org/t/help-to-port-a-vtk-python-library-to-vtk-js/3181 "2020-04-30T07:45:05Z")

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Good morning, I am trying to create a web application for a Hospital Lab who has asked for some help. The basic requirement is to render an STL file and then create a pressure map from a series of 144 pressure values fo…

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## [Write scene from Vtk PolyData to PNG File](https://discourse.vtk.org/t/write-scene-from-vtk-polydata-to-png-file/3057)

<div class="topic-metadata">

**Author:** [@goflo](https://discourse.vtk.org/u/goflo)\
**Replies:** 4\
**Last updated:** [April 30, 2020, 7:42am UTC](https://discourse.vtk.org/t/write-scene-from-vtk-polydata-to-png-file/3057 "2020-04-30T07:42:00Z")

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Hi, I have VTK PolyData XML files which are generated by a .NET Core Webservice. I’m building now an other .NET Service which will generate PDF reports. Part of this reports are a few images from the 3D model. I need to…

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## [INTERPOLATE ON STL: Plotting scalar field on 50 points on An 70000-points STL surface](https://discourse.vtk.org/t/interpolate-on-stl-plotting-scalar-field-on-50-points-on-an-70000-points-stl-surface/450)

<div class="topic-metadata">

**Author:** [@Hosam](https://discourse.vtk.org/u/Hosam)\
**Replies:** 18\
**Last updated:** [April 29, 2020, 1:26am UTC](https://discourse.vtk.org/t/interpolate-on-stl-plotting-scalar-field-on-50-points-on-an-70000-points-stl-surface/450 "2020-04-29T01:26:46Z")

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Hello, I have an STL surface file. The data were sampled on 50 selected points only (wind tunnel test). I want to visualize the field as a contour on the STL file. I know basic stuff on how to use VTK python library.…

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## [How to have multiple polylines in polydata?](https://discourse.vtk.org/t/how-to-have-multiple-polylines-in-polydata/3170)

<div class="topic-metadata">

**Author:** [@dzenanz](https://discourse.vtk.org/u/dzenanz)\
**Replies:** 7\
**Last updated:** [April 28, 2020, 5:57pm UTC](https://discourse.vtk.org/t/how-to-have-multiple-polylines-in-polydata/3170 "2020-04-28T17:57:06Z")

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I am starting from this example and I want to extend it to put multiple lines in a single polydata. My attempt is below. It results in an empty render window, whereas I expect some lines to be visible. What am I doing wr…

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## [Force flushing on vtkWebApplication rendering](https://discourse.vtk.org/t/force-flushing-on-vtkwebapplication-rendering/3167)

<div class="topic-metadata">

**Author:** [@BotellaA](https://discourse.vtk.org/u/BotellaA)\
**Replies:** 5\
**Last updated:** [April 28, 2020, 3:36pm UTC](https://discourse.vtk.org/t/force-flushing-on-vtkwebapplication-rendering/3167 "2020-04-28T15:36:20Z")

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I am using the RPC “viewport.image.push” combined with a manual camera update to query for an image of the updated rendering. It takes more than 1s in localhost configuration to get the image. I looked at the explanation…

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## [Any guides for building VTK on Ubuntu 18.04 using WSL?](https://discourse.vtk.org/t/any-guides-for-building-vtk-on-ubuntu-18-04-using-wsl/2999)

<div class="topic-metadata">

**Author:** [@Ahmed\_Salih](https://discourse.vtk.org/u/Ahmed_Salih)\
**Replies:** 14\
**Last updated:** [April 28, 2020, 1:58pm UTC](https://discourse.vtk.org/t/any-guides-for-building-vtk-on-ubuntu-18-04-using-wsl/2999 "2020-04-28T13:58:19Z")

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Hello! I am trying to build VTK 8.1 for Linux basically in WSL, because I want to incorporate this functionality showcasen here in my own code; https://lorensen.github.io/VTKExamples/site/Cxx/IO/WriteVTP/ I am strugg…

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## [Multiple Scalars per Cell or Face](https://discourse.vtk.org/t/multiple-scalars-per-cell-or-face/2493)

<div class="topic-metadata">

**Author:** [@akaszynski](https://discourse.vtk.org/u/akaszynski)\
**Replies:** 9\
**Last updated:** [April 28, 2020, 1:24pm UTC](https://discourse.vtk.org/t/multiple-scalars-per-cell-or-face/2493 "2020-04-28T13:24:05Z")

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Hello, Aside from array scalars, VTK currently supports point or cell scalars, which means either the scalars array needs to match the number of points or cells. I’d like to plot scalars such that each point of each ce…

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## [Should I enable or disable the VTK\_USE\_SYSTEM\_\* options when using cmake to config vtk.](https://discourse.vtk.org/t/should-i-enable-or-disable-the-vtk-use-system-options-when-using-cmake-to-config-vtk/3166)

<div class="topic-metadata">

**Author:** [@Hongyi\_Zhao](https://discourse.vtk.org/u/Hongyi_Zhao)\
**Replies:** 2\
**Last updated:** [April 27, 2020, 11:54pm UTC](https://discourse.vtk.org/t/should-i-enable-or-disable-the-vtk-use-system-options-when-using-cmake-to-config-vtk/3166 "2020-04-27T23:54:21Z")

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Hi, There are many VTK\_USE\_SYSTEM\_\* options when compiling vtk, say the following ones: -DVTK\_USE\_SYSTEM\_LIBRARIES=ON \\ -DVTK\_USE\_SYSTEM\_LIBPROJ4=OFF \\ -DVTK\_USE\_SYSTEM\_GL2PS=O…

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## [Custom image filter](https://discourse.vtk.org/t/custom-image-filter/3165)

<div class="topic-metadata">

**Author:** [@ShaneKirkbride](https://discourse.vtk.org/u/ShaneKirkbride)\
**Replies:** 0\
**Last updated:** [April 27, 2020, 8:38pm UTC](https://discourse.vtk.org/t/custom-image-filter/3165 "2020-04-27T20:38:47Z")

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I’d like to make a custom image filter. I did see the gauss filter. Similar to imfilter in matlab. I’d like to define my H matrix. I didn’t find anything on a search. Can I do this with vtk? Here is the link to imfilte…

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## [Is PV MultiSlice view available in vtk python](https://discourse.vtk.org/t/is-pv-multislice-view-available-in-vtk-python/3164)

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**Author:** [@terryturton](https://discourse.vtk.org/u/terryturton)\
**Replies:** 2\
**Last updated:** [April 27, 2020, 7:25pm UTC](https://discourse.vtk.org/t/is-pv-multislice-view-available-in-vtk-python/3164 "2020-04-27T19:25:40Z")

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Can I get the PV multislice view (https://kitware.github.io/paraview-docs/latest/cxx/DesignSliceView.html) easily using vtk python? Thanks.

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## [How to set colors for PointData of vtkStructuredGrid example](https://discourse.vtk.org/t/how-to-set-colors-for-pointdata-of-vtkstructuredgrid-example/3159)

<div class="topic-metadata">

**Author:** [@kerim](https://discourse.vtk.org/u/kerim)\
**Replies:** 2\
**Last updated:** [April 27, 2020, 12:39pm UTC](https://discourse.vtk.org/t/how-to-set-colors-for-pointdata-of-vtkstructuredgrid-example/3159 "2020-04-27T12:39:55Z")

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Hi, I’m beginner. I read tutorial and watch examples but some basic questions still actual. So here is simple example of vtkStructuredGrid. I’m trying to add data to the points and display this data as color. The probl…

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## [vtk filter for OpenFOAM](https://discourse.vtk.org/t/vtk-filter-for-openfoam/3141)

<div class="topic-metadata">

**Author:** [@matsubaraDaisuke](https://discourse.vtk.org/u/matsubaraDaisuke)\
**Replies:** 1\
**Last updated:** [April 27, 2020, 6:11am UTC](https://discourse.vtk.org/t/vtk-filter-for-openfoam/3141 "2020-04-27T06:11:22Z")

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I want to filter a pressure by thresholding using python-vtk import vtk filename = "a.foam" reader = vtk.vtkOpenFOAMReader() reader.SetFileName(filename) reader.CreateCellToPointOn() reader.DecomposePolyhedraOn() reade…

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## [Creating a graph in VTK](https://discourse.vtk.org/t/creating-a-graph-in-vtk/3150)

<div class="topic-metadata">

**Author:** [@Deepa](https://discourse.vtk.org/u/Deepa)\
**Replies:** 1\
**Last updated:** [April 26, 2020, 7:07pm UTC](https://discourse.vtk.org/t/creating-a-graph-in-vtk/3150 "2020-04-26T19:07:12Z")

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(topic withdrawn by author, will be automatically deleted in 24 hours unless flagged)

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## [Update a vtkCutter with a qslider - c++](https://discourse.vtk.org/t/update-a-vtkcutter-with-a-qslider-c/3149)

<div class="topic-metadata">

**Author:** [@armel.demontgros](https://discourse.vtk.org/u/armel.demontgros)\
**Replies:** 2\
**Last updated:** [April 26, 2020, 12:27am UTC](https://discourse.vtk.org/t/update-a-vtkcutter-with-a-qslider-c/3149 "2020-04-26T00:27:56Z")

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Hi I am fairly new to VTK and trying to push it as much as I can. I am trying to update the cuttling plane value with a qslider. I have a slice on a vtk in a QVTKOpenGLNativeWidget setup as exmVTK::exmVTK(QWidget\* pare…

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## [Creating a graph in VTK using ConstructGraph](https://discourse.vtk.org/t/creating-a-graph-in-vtk-using-constructgraph/3157)

<div class="topic-metadata">

**Author:** [@Deepa](https://discourse.vtk.org/u/Deepa)\
**Replies:** 0\
**Last updated:** [April 25, 2020, 12:39pm UTC](https://discourse.vtk.org/t/creating-a-graph-in-vtk-using-constructgraph/3157 "2020-04-25T12:39:08Z")

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I want to create a graph using VTK class https://lorensen.github.io/VTKExamples/site/Python/Graphs/ConstructGraph/ def main(): g = vtk.vtkMutableUndirectedGraph() v1 = g.AddVertex() v2 = g.AddVertex() …

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## [how to extend vtkImagePlaneWidget bounds](https://discourse.vtk.org/t/how-to-extend-vtkimageplanewidget-bounds/3151)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 0\
**Last updated:** [April 25, 2020, 6:01am UTC](https://discourse.vtk.org/t/how-to-extend-vtkimageplanewidget-bounds/3151 "2020-04-25T06:01:53Z")

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I’ve implemented MPR by using vtkImagePlaneWidget. I rotate one plane widget by changing its normal in the source code. But the bounds of the plane can not extend to the sagittal plane(the plane with red border), showed …

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## [vtk image connectivity filter](https://discourse.vtk.org/t/vtk-image-connectivity-filter/3133)

<div class="topic-metadata">

**Author:** [@srbn.ghosh99](https://discourse.vtk.org/u/srbn.ghosh99)\
**Replies:** 11\
**Last updated:** [April 24, 2020, 6:42pm UTC](https://discourse.vtk.org/t/vtk-image-connectivity-filter/3133 "2020-04-24T18:42:21Z")

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Hi, I have labeled 3D image with two different pixel values. I want to apply image connectivity filter to remove the other noises which are creating problems to create a simple surface extraction in the next level. I c…

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## [How to interpret the output of CellData\['Topology'\]](https://discourse.vtk.org/t/how-to-interpret-the-output-of-celldata-topology/3145)

<div class="topic-metadata">

**Author:** [@Deepa](https://discourse.vtk.org/u/Deepa)\
**Replies:** 3\
**Last updated:** [April 24, 2020, 6:29pm UTC](https://discourse.vtk.org/t/how-to-interpret-the-output-of-celldata-topology/3145 "2020-04-24T18:29:05Z")

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I’ve the following VTK object obtained from vmtk.NetworkExtraction pprint(network\_dsa.CellData\[‘Topology’\]) gives VTKArray(\[\[0, 1\], \[0, 2\], \[0, 2\], \[0, 1\], \[0, 3\], \[0, 3\], \[0, 4\], \[0, 5\], \[0, 5\], \[1, 6\], \[4,…

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## [Error in displaying the layout of a graph obtained from vmtkNetworkExtraction](https://discourse.vtk.org/t/error-in-displaying-the-layout-of-a-graph-obtained-from-vmtknetworkextraction/3139)

<div class="topic-metadata">

**Author:** [@Deepa](https://discourse.vtk.org/u/Deepa)\
**Replies:** 1\
**Last updated:** [April 24, 2020, 3:13pm UTC](https://discourse.vtk.org/t/error-in-displaying-the-layout-of-a-graph-obtained-from-vmtknetworkextraction/3139 "2020-04-24T15:13:51Z")

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Hi All, I’m referring to the examples available here to display a graph . The graph has been obtained from the following code and the input file is available here. reader = vmtkscripts.vmtkSurfaceReader() reader.Input…

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## [vtk python from pip: vtkReebGraphToJoinSplitTree is not found.](https://discourse.vtk.org/t/vtk-python-from-pip-vtkreebgraphtojoinsplittree-is-not-found/3143)

<div class="topic-metadata">

**Author:** [@jaswantp](https://discourse.vtk.org/u/jaswantp)\
**Replies:** 3\
**Last updated:** [April 24, 2020, 2:59pm UTC](https://discourse.vtk.org/t/vtk-python-from-pip-vtkreebgraphtojoinsplittree-is-not-found/3143 "2020-04-24T14:59:55Z")

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I’m using vtk python from pip, it is 8.1.2. Unable to find this attribute. Any suggestions? Is this function not available in 8.1.2? \>\>\> import vtk …

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## [Compile error 9.0RC3, VS 2017, Windows 10, snprintf](https://discourse.vtk.org/t/compile-error-9-0rc3-vs-2017-windows-10-snprintf/3136)

<div class="topic-metadata">

**Author:** [@biagas](https://discourse.vtk.org/u/biagas)\
**Replies:** 1\
**Last updated:** [April 24, 2020, 1:51pm UTC](https://discourse.vtk.org/t/compile-error-9-0rc3-vs-2017-windows-10-snprintf/3136 "2020-04-24T13:51:27Z")

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I am using CMake 3.12.2, VS 2017 15.9.22 on a Windows 10 machine. When I compile, I get errors in libxml2 and tiff: Macro redefinition of 'snprintf' conflicts with Standard Library definition. I have traced it to Thir…

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## [How to use vtkImageConnectivityFilter](https://discourse.vtk.org/t/how-to-use-vtkimageconnectivityfilter/3142)

<div class="topic-metadata">

**Author:** [@NeuZhangQiang](https://discourse.vtk.org/u/NeuZhangQiang)\
**Replies:** 1\
**Last updated:** [April 24, 2020, 12:36pm UTC](https://discourse.vtk.org/t/how-to-use-vtkimageconnectivityfilter/3142 "2020-04-24T12:36:45Z")

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I need to use the vtkImageConnectivityFilter, and I want to use the SetExtractionModeToSeededRegions method. But, I don’t know how to provide the seed (such as (50, 50)). Could somebody provide a demo? For example: the…

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## [The operation is insecure](https://discourse.vtk.org/t/the-operation-is-insecure/3076)

<div class="topic-metadata">

**Author:** [@xuexl](https://discourse.vtk.org/u/xuexl)\
**Replies:** 3\
**Last updated:** [April 24, 2020, 2:14am UTC](https://discourse.vtk.org/t/the-operation-is-insecure/3076 "2020-04-24T02:14:22Z")

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When i open the website which is test the vtkjs in the firefox, the page can not show normally, and there are something errors like in the picture. and the chrome can not show normally too, but the errors are not the …

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## [vtkNew and vtkSmartPointer](https://discourse.vtk.org/t/vtknew-and-vtksmartpointer/469)

<div class="topic-metadata">

**Author:** [@lorensen](https://discourse.vtk.org/u/lorensen)\
**Replies:** 34\
**Last updated:** [April 23, 2020, 8:52pm UTC](https://discourse.vtk.org/t/vtknew-and-vtksmartpointer/469 "2020-04-23T20:52:35Z")

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Folks, We have had on and off discussions about which to use. Both can be used pretty much interchangeably. vtkNew is not friendly with some STL containers. But this is not a major issue for vtk since STL containers a…

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