# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=157

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

**Page:** 158

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## [Can't pick property after changing display setting](https://discourse.vtk.org/t/cant-pick-property-after-changing-display-setting/928)

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**Author:** [@wenyalin](https://discourse.vtk.org/u/wenyalin)\
**Replies:** 0\
**Last updated:** [May 8, 2019, 3:50am UTC](https://discourse.vtk.org/t/cant-pick-property-after-changing-display-setting/928 "2019-05-08T03:50:16Z")

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Hey guys, I’m a newbie in VTK. I got some display problem when trying to change the style of displaying image. I have a renderwindow and an observer to pick pixel when mouse hovering, the observer setup is imitated from…

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## [Error importing vtkTkRenderWindowInteractor in vtk 8.2.0](https://discourse.vtk.org/t/error-importing-vtktkrenderwindowinteractor-in-vtk-8-2-0/856)

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**Author:** [@Julie](https://discourse.vtk.org/u/Julie)\
**Replies:** 27\
**Last updated:** [May 7, 2019, 10:54pm UTC](https://discourse.vtk.org/t/error-importing-vtktkrenderwindowinteractor-in-vtk-8-2-0/856 "2019-05-07T22:54:35Z")

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Hi, everyone I am writing a simple GUI with simple inputs and vtk rendering in Python. One article about this is combing tk and vtk, namely vtkTkRenderWindowInteractor, the error and code is as below: (1) Error--------…

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## [Weird version in build output](https://discourse.vtk.org/t/weird-version-in-build-output/911)

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**Author:** [@Gilthalas](https://discourse.vtk.org/u/Gilthalas)\
**Replies:** 3\
**Last updated:** [May 6, 2019, 7:05pm UTC](https://discourse.vtk.org/t/weird-version-in-build-output/911 "2019-05-06T19:05:17Z")

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I’m working on building VTK 8.2, and for some reason, the final files that get built have a version number of 8.90, which I don’t quite understand. Any idea on what may cause this?

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## [Artifacts when using Gouraud or Phong interpolation](https://discourse.vtk.org/t/artifacts-when-using-gouraud-or-phong-interpolation/913)

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**Author:** [@Gilthalas](https://discourse.vtk.org/u/Gilthalas)\
**Replies:** 2\
**Last updated:** [May 6, 2019, 6:08pm UTC](https://discourse.vtk.org/t/artifacts-when-using-gouraud-or-phong-interpolation/913 "2019-05-06T18:08:01Z")

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I am getting odd artifacts when looking at a 3D OBJ with vtk8.2 (even though we did not see this in our tool using vtk6.3). When I choose flat shading it looks fine (but we really want the option to show both as before).…

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## [Issue with VTK in ROS Workspace](https://discourse.vtk.org/t/issue-with-vtk-in-ros-workspace/908)

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**Author:** [@mia](https://discourse.vtk.org/u/mia)\
**Replies:** 0\
**Last updated:** [May 6, 2019, 8:50am UTC](https://discourse.vtk.org/t/issue-with-vtk-in-ros-workspace/908 "2019-05-06T08:50:44Z")

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Hi everyone, I am new to Qt and ROS. I am working on Qt Creator 4.8.0 (QT with ROS plugin). I have created a catkin workspace in Qt and a mainwindow was created. And I am trying to add QVTKWidget to the mainwindow …

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## [Realtime point cloud visualization](https://discourse.vtk.org/t/realtime-point-cloud-visualization/905)

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**Author:** [@ljc19800331](https://discourse.vtk.org/u/ljc19800331)\
**Replies:** 1\
**Last updated:** [May 6, 2019, 6:00am UTC](https://discourse.vtk.org/t/realtime-point-cloud-visualization/905 "2019-05-06T06:00:01Z")

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I tried a realtime point cloud visualization code with vtk 8.1.2. This is the reference link: I tried the code with vtk 8.1.2 and vtk 6.3.0 and it only works for vtk 6.3.0. I checked multiple times and could not figu…

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## [VTK for imaging application](https://discourse.vtk.org/t/vtk-for-imaging-application/906)

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**Author:** [@Fibblefabble](https://discourse.vtk.org/u/Fibblefabble)\
**Replies:** 1\
**Last updated:** [May 6, 2019, 5:00am UTC](https://discourse.vtk.org/t/vtk-for-imaging-application/906 "2019-05-06T05:00:09Z")

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Hi all, I was hoping someone could tell me if this is the correct direction to go in for visualizing my data in VTK. I’m pretty familiar with different types of data visualization techniques, but only recently started pl…

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## [vtkTDxInteractorStyleCamera](https://discourse.vtk.org/t/vtktdxinteractorstylecamera/834)

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**Author:** [@domel](https://discourse.vtk.org/u/domel)\
**Replies:** 1\
**Last updated:** [May 4, 2019, 12:16pm UTC](https://discourse.vtk.org/t/vtktdxinteractorstylecamera/834 "2019-05-04T12:16:25Z")

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Hi, I am trying to use my 3DCONNEXION SpaceMouse Enterprise Kit. I am following the example for vtkTDxInteractorStyleCamera. However, only zoom in/out works (like wheel on mouse) and nothing else. Rotation/Panning is en…

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## [hard crash on vtk 8](https://discourse.vtk.org/t/hard-crash-on-vtk-8/894)

<div class="topic-metadata">

**Author:** [@Gilthalas](https://discourse.vtk.org/u/Gilthalas)\
**Replies:** 5\
**Last updated:** [May 3, 2019, 1:29pm UTC](https://discourse.vtk.org/t/hard-crash-on-vtk-8/894 "2019-05-03T13:29:52Z")

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We currently have an app that runs on vtk 6.3, using Java, and we’re working on getting things to run on 8.1.2. We’ve built the new libs, and updated DYLD\_LIBRARY\_PATHs accordingly to point to the new jnilibs. I’m gett…

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## [how to read the windows level / width from the dicom metadata from vtkDICOMImageReader](https://discourse.vtk.org/t/how-to-read-the-windows-level-width-from-the-dicom-metadata-from-vtkdicomimagereader/897)

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**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 1\
**Last updated:** [May 3, 2019, 12:27pm UTC](https://discourse.vtk.org/t/how-to-read-the-windows-level-width-from-the-dicom-metadata-from-vtkdicomimagereader/897 "2019-05-03T12:27:49Z")

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Dear all, I want to get the windows level and width of a series of dicoms given in the metadata of those files. But i cannot find a function in vtkDICOMImageReader to get this information. I heard that vtkDICOMReader ca…

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## [Vertex normals](https://discourse.vtk.org/t/vertex-normals/797)

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**Author:** [@graphicsmonkey](https://discourse.vtk.org/u/graphicsmonkey)\
**Replies:** 2\
**Last updated:** [May 3, 2019, 2:26am UTC](https://discourse.vtk.org/t/vertex-normals/797 "2019-05-03T02:26:04Z")

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Hi Vtk experts… When rendering a surface currently i see a banding effect and i believe it’s because Vtk is using face normals for the shading. Is there a way to generate per vertex normals? Many thanks.

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## [Missing jnilib for vtkPanel on macOS?](https://discourse.vtk.org/t/missing-jnilib-for-vtkpanel-on-macos/891)

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**Author:** [@Gilthalas](https://discourse.vtk.org/u/Gilthalas)\
**Replies:** 4\
**Last updated:** [May 2, 2019, 3:34pm UTC](https://discourse.vtk.org/t/missing-jnilib-for-vtkpanel-on-macos/891 "2019-05-02T15:34:45Z")

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We’ve been on vtk 6.3 forever, and I’m working on getting us upgraded to vtk 8.1.2. To test things, I’m trying to run some of the examples, and I run into what looks like a missing jnilib link for vtkPanel: Exception i…

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## [Volume render using ExternalVTKWidget](https://discourse.vtk.org/t/volume-render-using-externalvtkwidget/883)

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**Author:** [@Kmilo9999](https://discourse.vtk.org/u/Kmilo9999)\
**Replies:** 0\
**Last updated:** [April 30, 2019, 6:51pm UTC](https://discourse.vtk.org/t/volume-render-using-externalvtkwidget/883 "2019-04-30T18:51:20Z")

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Hello, I am trying to modify the TestGLUTRenderWindow example in order to render voume data using glut. I’m not getting anything on screen. I wonder if someone could check the code and see what I might be missing. Thank…

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## [VTK PolyData To ImageData](https://discourse.vtk.org/t/vtk-polydata-to-imagedata/863)

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**Author:** [@Tarun\_Choudhary](https://discourse.vtk.org/u/Tarun_Choudhary)\
**Replies:** 4\
**Last updated:** [April 30, 2019, 1:44pm UTC](https://discourse.vtk.org/t/vtk-polydata-to-imagedata/863 "2019-04-30T13:44:20Z")

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Dear All, I am trying to create voxel mesh (\*.vtu) from stl geometry; they all form an assembly. I have 3 stls and each of them are being converted to \*.vtu separately but when I am bringing them all together in multi…

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## [scenepicker problem](https://discourse.vtk.org/t/scenepicker-problem/880)

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**Author:** [@Andyjk1406](https://discourse.vtk.org/u/Andyjk1406)\
**Replies:** 1\
**Last updated:** [April 30, 2019, 1:32pm UTC](https://discourse.vtk.org/t/scenepicker-problem/880 "2019-04-30T13:32:47Z")

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I am trying to pick using scene picker but it doesn’t seem to find a cell or vertex, while proppicker does. How do I extract a pick position from scene picker? (Or even just a picked cell) Minimal example below, whic…

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## [vtk 8.2 MFC examples don't work](https://discourse.vtk.org/t/vtk-8-2-mfc-examples-dont-work/823)

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**Author:** [@Sean](https://discourse.vtk.org/u/Sean)\
**Replies:** 7\
**Last updated:** [April 30, 2019, 12:22pm UTC](https://discourse.vtk.org/t/vtk-8-2-mfc-examples-dont-work/823 "2019-04-30T12:22:56Z")

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I am trying to upgrade to vtk8.2.0 (VS2017) and tested it with vtkMFC examples. Now run into some problems. I just couldn’t execute any of the three projects (vtkDLG, vtkMDI, and vtkSDI) with vtk error messages: Generic…

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## [QVTKOpenGLWidget works in constuctor but not responds to signals.](https://discourse.vtk.org/t/qvtkopenglwidget-works-in-constuctor-but-not-responds-to-signals/878)

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**Author:** [@pkusunjy](https://discourse.vtk.org/u/pkusunjy)\
**Replies:** 1\
**Last updated:** [April 30, 2019, 12:07pm UTC](https://discourse.vtk.org/t/qvtkopenglwidget-works-in-constuctor-but-not-responds-to-signals/878 "2019-04-30T12:07:27Z")

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Hi, I have a QVTKOpenGLWidget in mainwindow, it’s promoted from QWidget. I need to draw something(say cylinder, .ply) in the QVTKOpenGLWidget, and when I write code in constructor, everything is ok, but when I connect r…

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## [vtk mfc examples: vtkMDI vs Win32SampleMFC](https://discourse.vtk.org/t/vtk-mfc-examples-vtkmdi-vs-win32samplemfc/869)

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**Author:** [@Kevin](https://discourse.vtk.org/u/Kevin)\
**Replies:** 0\
**Last updated:** [April 29, 2019, 2:28pm UTC](https://discourse.vtk.org/t/vtk-mfc-examples-vtkmdi-vs-win32samplemfc/869 "2019-04-29T14:28:25Z")

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I am new for vtk and trying to learn it through some examples. I saw there are two vtk examples (vtkMDI and Win32SampleMFC) and they seem for exact same functions, but quite different designs. The Win32SampleMFC with two…

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## [segfault for python importing vtk but not for vtkpython](https://discourse.vtk.org/t/segfault-for-python-importing-vtk-but-not-for-vtkpython/126)

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**Author:** [@danlipsa](https://discourse.vtk.org/u/danlipsa)\
**Replies:** 11\
**Last updated:** [April 29, 2019, 2:16pm UTC](https://discourse.vtk.org/t/segfault-for-python-importing-vtk-but-not-for-vtkpython/126 "2019-04-29T14:16:32Z")

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Hi all, I am building VTK with the latest conda-build v3 on mac. vtkpython seems to work fine, however importing vtk from python gives me a segfault. Any ideas? (See the attached information) Python 3.7.1 | packaged by…

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## [QVTKOpenGLWidget Issue on Mac OSX](https://discourse.vtk.org/t/qvtkopenglwidget-issue-on-mac-osx/828)

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**Author:** [@Andrew](https://discourse.vtk.org/u/Andrew)\
**Replies:** 1\
**Last updated:** [April 29, 2019, 8:25am UTC](https://discourse.vtk.org/t/qvtkopenglwidget-issue-on-mac-osx/828 "2019-04-29T08:25:07Z")

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Are there any QVTKOpenGLWidget examples since QVTKWidget is deprecated? I think I might be using it wrong. Here’s a little example of how I use vtkOpenGLWidget on windows (latest msvc): QVTKOpenGLWidget\* widget = new QV…

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## [vtkXdmfWriter does not write correctly for vtkPythonAlgorithm](https://discourse.vtk.org/t/vtkxdmfwriter-does-not-write-correctly-for-vtkpythonalgorithm/862)

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**Author:** [@amit112amit](https://discourse.vtk.org/u/amit112amit)\
**Replies:** 0\
**Last updated:** [April 28, 2019, 7:30pm UTC](https://discourse.vtk.org/t/vtkxdmfwriter-does-not-write-correctly-for-vtkpythonalgorithm/862 "2019-04-28T19:30:41Z")

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I wrote a custom Filter by subclassing VTKPythonAlgorithmBase following this link. When I write the output using vtkXMLPolyDataWriter class, I get correct points, lines and point-data vectors. I confirmed it by opening t…

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## [Parallel VTK 8.2 failed to build with gcc-8 on MacOS 10.14](https://discourse.vtk.org/t/parallel-vtk-8-2-failed-to-build-with-gcc-8-on-macos-10-14/854)

<div class="topic-metadata">

**Author:** [@Quang\_Ha](https://discourse.vtk.org/u/Quang_Ha)\
**Replies:** 0\
**Last updated:** [April 27, 2019, 3:38am UTC](https://discourse.vtk.org/t/parallel-vtk-8-2-failed-to-build-with-gcc-8-on-macos-10-14/854 "2019-04-27T03:38:18Z")

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I am trying to build Parallel version of VTK 8.2 using the following config: #!/bin/bash cmake \\ -D CMAKE\_INSTALL\_PREFIX:PATH=/Users/qth20/Utilities/vtk-8.2.0 \\ -D CMAKE\_INSTALL\_NAME\_DIR:STRING=/Users/qth20/Uti…

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## [Change the default events of the widgets](https://discourse.vtk.org/t/change-the-default-events-of-the-widgets/840)

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**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 0\
**Last updated:** [April 25, 2019, 1:42pm UTC](https://discourse.vtk.org/t/change-the-default-events-of-the-widgets/840 "2019-04-25T13:42:55Z")

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Hi everybody, I wonder if you know if it is possible to change the default events of the widgets. I am using the vtkBrokenLineWidget and i would like to remove the translation and change the behaviour of the orientatio…

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## [Alt key release doesn't always trigger: python 3.7, vtk8.2 and pyqt5](https://discourse.vtk.org/t/alt-key-release-doesnt-always-trigger-python-3-7-vtk8-2-and-pyqt5/826)

<div class="topic-metadata">

**Author:** [@michaelhogg](https://discourse.vtk.org/u/michaelhogg)\
**Replies:** 1\
**Last updated:** [April 25, 2019, 3:20am UTC](https://discourse.vtk.org/t/alt-key-release-doesnt-always-trigger-python-3-7-vtk8-2-and-pyqt5/826 "2019-04-25T03:20:37Z")

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Hi all, I am developing an application in Python 3.7 with PyQt5 and vtk 8.2.0 on Windows 7 / 10. I have a custom interactor class derived from vtkInteractorStyleTrackballCamera. I have added observers for KeyPressEvent …

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## [Create truncated Cone](https://discourse.vtk.org/t/create-truncated-cone/813)

<div class="topic-metadata">

**Author:** [@siaeleni](https://discourse.vtk.org/u/siaeleni)\
**Replies:** 6\
**Last updated:** [April 24, 2019, 10:26am UTC](https://discourse.vtk.org/t/create-truncated-cone/813 "2019-04-24T10:26:24Z")

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Hello, I want to display a truncated code like the following Any hint would be appreciated. Thanks

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## [visual studio - vtk 8.9 lnk2019 vtkvolume setproperty unresolve external symbol](https://discourse.vtk.org/t/visual-studio-vtk-8-9-lnk2019-vtkvolume-setproperty-unresolve-external-symbol/819)

<div class="topic-metadata">

**Author:** [@Kmilo9999](https://discourse.vtk.org/u/Kmilo9999)\
**Replies:** 1\
**Last updated:** [April 23, 2019, 6:12pm UTC](https://discourse.vtk.org/t/visual-studio-vtk-8-9-lnk2019-vtkvolume-setproperty-unresolve-external-symbol/819 "2019-04-23T18:12:48Z")

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Hello, I’m trying to render volume data using c++ / vs2015 / vtk master (I cloned it from github and built it in vs2015), but I’m getting a linker error when calling the method vtkVolume::SetProperty These are the line…

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## [Python VTK: How to use the filter vtkFeatureEdges() with a PolyData() method?](https://discourse.vtk.org/t/python-vtk-how-to-use-the-filter-vtkfeatureedges-with-a-polydata-method/818)

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**Author:** [@ramiromena](https://discourse.vtk.org/u/ramiromena)\
**Replies:** 1\
**Last updated:** [April 23, 2019, 2:45pm UTC](https://discourse.vtk.org/t/python-vtk-how-to-use-the-filter-vtkfeatureedges-with-a-polydata-method/818 "2019-04-23T14:45:41Z")

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Dear VTK community, I am trying to plot the Boundary Edges of a 3D solid. For my example, I am using a cube that is generated manually (instead of the vtkCubeSource() method) and as a part of the pipeline, the filter vt…

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## [overlapping 2 volumes in a render window](https://discourse.vtk.org/t/overlapping-2-volumes-in-a-render-window/775)

<div class="topic-metadata">

**Author:** [@Marco\_Festugato](https://discourse.vtk.org/u/Marco_Festugato)\
**Replies:** 2\
**Last updated:** [April 23, 2019, 12:30pm UTC](https://discourse.vtk.org/t/overlapping-2-volumes-in-a-render-window/775 "2019-04-23T12:30:21Z")

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Hello, I have 199 CT slices of the liver (volume 1) from which I have segmented the liver vessels (volume 2: 199 slices containing only the vessels in binary images). Now I want to overlap these 2 volumes: I want to see…

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## [Getting color codes of the points](https://discourse.vtk.org/t/getting-color-codes-of-the-points/809)

<div class="topic-metadata">

**Author:** [@sariug](https://discourse.vtk.org/u/sariug)\
**Replies:** 0\
**Last updated:** [April 22, 2019, 10:52am UTC](https://discourse.vtk.org/t/getting-color-codes-of-the-points/809 "2019-04-22T10:52:09Z")

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Hello, I used streamtracer and happily got my streamline(points). I color them with velocity magnitudes. I am using an external viewer, therefore (in order not to calculate all the look up table data, velocities and mor…

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## [how to apply MIP on 2D DICOM](https://discourse.vtk.org/t/how-to-apply-mip-on-2d-dicom/725)

<div class="topic-metadata">

**Author:** [@Aravind](https://discourse.vtk.org/u/Aravind)\
**Replies:** 1\
**Last updated:** [April 22, 2019, 7:34am UTC](https://discourse.vtk.org/t/how-to-apply-mip-on-2d-dicom/725 "2019-04-22T07:34:26Z")

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Hello - I am trying to do a MIP on the DICOM images. Not sure what I am doing wrong any help would be appreciated. Here is my code. I am unable to set up the pipeline I believe to scroll through the stack with the MIP. I…

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