# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=137

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

**Page:** 138

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## [how to get a vtkDataSet from the vtkSmartPointer](https://discourse.vtk.org/t/how-to-get-a-vtkdataset-from-the-vtksmartpointer/2848)

<div class="topic-metadata">

**Author:** [@1116](https://discourse.vtk.org/u/1116)\
**Replies:** 1\
**Last updated:** [March 18, 2020, 11:46am UTC](https://discourse.vtk.org/t/how-to-get-a-vtkdataset-from-the-vtksmartpointer/2848 "2020-03-18T11:46:15Z")

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Hello, I have a vtkSmartPointer such like this: vtkSmartPointer sphereSource = vtkSmartPointer::New(); How could I get a vtkDataSet from the sphereSource? It seems there is a vtkDataSet::SafeDownCast function, but I’m…

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## [renderer renders with wrong order with opacity](https://discourse.vtk.org/t/renderer-renders-with-wrong-order-with-opacity/2833)

<div class="topic-metadata">

**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 2\
**Last updated:** [March 17, 2020, 3:16pm UTC](https://discourse.vtk.org/t/renderer-renders-with-wrong-order-with-opacity/2833 "2020-03-17T15:16:41Z")

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Hello, I have a problem with the order of the rendering. I have a render and i render a dicom volume and some geometric polydatas like a cube. The problem is that if i add some oppacity in the cube, some parts dissappe…

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## [VTK\_Group\_Qt cmake error](https://discourse.vtk.org/t/vtk-group-qt-cmake-error/2826)

<div class="topic-metadata">

**Author:** [@Tracy\_Nk](https://discourse.vtk.org/u/Tracy_Nk)\
**Replies:** 4\
**Last updated:** [March 17, 2020, 2:46pm UTC](https://discourse.vtk.org/t/vtk-group-qt-cmake-error/2826 "2020-03-17T14:46:50Z")

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I’m trying to configure VTK\_Group\_Qt for my VTK build on cmake however i’m experiencing the following error (i have tried putting the directory of my Qt download but it doesnt make a difference): Qt directory: C:\\Qt\\5…

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## [Error when compiling master branch with GUISupportQtOpenGL](https://discourse.vtk.org/t/error-when-compiling-master-branch-with-guisupportqtopengl/2132)

<div class="topic-metadata">

**Author:** [@cesss](https://discourse.vtk.org/u/cesss)\
**Replies:** 3\
**Last updated:** [March 17, 2020, 2:45pm UTC](https://discourse.vtk.org/t/error-when-compiling-master-branch-with-guisupportqtopengl/2132 "2020-03-17T14:45:46Z")

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When building master with VTK\_MODULE\_ENABLE\_VTK\_GUISupportQtOpenGL I’m getting the following error (I have Qt 5.12.0 if that matters): src/VTK/2019-11-24/GUISupport/QtOpenGL/QVTKWidget2.cxx:488:21: error: no member nam…

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## [mirroring and normals](https://discourse.vtk.org/t/mirroring-and-normals/2767)

<div class="topic-metadata">

**Author:** [@andreasbuykx](https://discourse.vtk.org/u/andreasbuykx)\
**Replies:** 3\
**Last updated:** [March 17, 2020, 11:45am UTC](https://discourse.vtk.org/t/mirroring-and-normals/2767 "2020-03-17T11:45:00Z")

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I have an actor with point normals, and I want to mirror it in X and Y directions. My approach is illustrated in attached python script mirroring.py (1.6 KB) The output shows two of the mirrors in black instead of the …

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## [VtkSphereSource with evenly distributed points](https://discourse.vtk.org/t/vtkspheresource-with-evenly-distributed-points/2824)

<div class="topic-metadata">

**Author:** [@vianamp](https://discourse.vtk.org/u/vianamp)\
**Replies:** 1\
**Last updated:** [March 17, 2020, 10:28am UTC](https://discourse.vtk.org/t/vtkspheresource-with-evenly-distributed-points/2824 "2020-03-17T10:28:48Z")

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Does anyone have an implementation of vtkSphereSource with evenly distributed points to share? Thanks,

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## [vtkIntegrateAttributes not available](https://discourse.vtk.org/t/vtkintegrateattributes-not-available/2751)

<div class="topic-metadata">

**Author:** [@Jamargi](https://discourse.vtk.org/u/Jamargi)\
**Replies:** 2\
**Last updated:** [March 17, 2020, 9:12am UTC](https://discourse.vtk.org/t/vtkintegrateattributes-not-available/2751 "2020-03-17T09:12:35Z")

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Good morning, I am trying to integrate some arrays within a .VTK, and found about the “vtkIntegrateAttributes”, but on python that module seems to not exist. I am using vtk8.1 with python2.7. What could be the problem? …

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## [QVTKRenderWindowInteractor cause problem to draw vktDistanceWidget on vtkImageReslice](https://discourse.vtk.org/t/qvtkrenderwindowinteractor-cause-problem-to-draw-vktdistancewidget-on-vtkimagereslice/2831)

<div class="topic-metadata">

**Author:** [@kimia.af1998](https://discourse.vtk.org/u/kimia.af1998)\
**Replies:** 0\
**Last updated:** [March 17, 2020, 8:31am UTC](https://discourse.vtk.org/t/qvtkrenderwindowinteractor-cause-problem-to-draw-vktdistancewidget-on-vtkimagereslice/2831 "2020-03-17T08:31:50Z")

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Hi. I’ve been displaying DICOM series slices(vtkImageReslice output) on QVTKRenderWindowInteractor but when I want to use vtkDistanceWidget to measure two selected points by mouse event, It doesn’t work and nothing appe…

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## [VTK-9.0.0.rc1 archive is broken](https://discourse.vtk.org/t/vtk-9-0-0-rc1-archive-is-broken/2764)

<div class="topic-metadata">

**Author:** [@danlipsa](https://discourse.vtk.org/u/danlipsa)\
**Replies:** 4\
**Last updated:** [March 17, 2020, 2:17am UTC](https://discourse.vtk.org/t/vtk-9-0-0-rc1-archive-is-broken/2764 "2020-03-17T02:17:18Z")

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Hi, I downloaded the RC1 archives from https://vtk.org/download/ and both the tar.gz and the zip seem broken: \[~/Downloads\]$ tar xzf VTK-9.0.0.rc1.tar.gz tar: Unexpected EOF in archive tar: Unexpected EOF in archiv…

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## [is it possible to call a python script in a C++ program](https://discourse.vtk.org/t/is-it-possible-to-call-a-python-script-in-a-c-program/2710)

<div class="topic-metadata">

**Author:** [@embeddedmz](https://discourse.vtk.org/u/embeddedmz)\
**Replies:** 4\
**Last updated:** [March 16, 2020, 5:32pm UTC](https://discourse.vtk.org/t/is-it-possible-to-call-a-python-script-in-a-c-program/2710 "2020-03-16T17:32:32Z")

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Hi, In ParaView’s Catalyst, one can write a Python script and call it from a C++ context, I wonder if this feature can be achieved in pure VTK ? Thanks.

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## [No rule to make target '/usr/include/python3.6/context.h'](https://discourse.vtk.org/t/no-rule-to-make-target-usr-include-python3-6-context-h/2805)

<div class="topic-metadata">

**Author:** [@jiapei100](https://discourse.vtk.org/u/jiapei100)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 5:21pm UTC](https://discourse.vtk.org/t/no-rule-to-make-target-usr-include-python3-6-context-h/2805 "2020-03-16T17:21:00Z")

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Failed to build VTK with the following ERROR messages: \[ 22%\] Built target vtkFiltersPython-hierarchy make -f CMakeFiles/vtkFiltersPythonPython.dir/build.make CMakeFiles/vtkFiltersPythonPython.dir/depend make\[2\]: Enteri…

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## [getting/building libs for r/w vtk and xdmf geometry formats](https://discourse.vtk.org/t/getting-building-libs-for-r-w-vtk-and-xdmf-geometry-formats/2720)

<div class="topic-metadata">

**Author:** [@kcris](https://discourse.vtk.org/u/kcris)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 5:06pm UTC](https://discourse.vtk.org/t/getting-building-libs-for-r-w-vtk-and-xdmf-geometry-formats/2720 "2020-03-16T17:06:34Z")

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Hi, I plan to use vtk libraries for reading/writing various vtk geometry formats (vtk text formats, xdms formats). Vtk sourcecode is huge and I am a bit lost, there are literally hundreds of modules. And I am just get…

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## [Can .vtk files be used to visualise solutions on 1D meshes?](https://discourse.vtk.org/t/can-vtk-files-be-used-to-visualise-solutions-on-1d-meshes/2830)

<div class="topic-metadata">

**Author:** [@krishnakumar](https://discourse.vtk.org/u/krishnakumar)\
**Replies:** 0\
**Last updated:** [March 16, 2020, 4:30pm UTC](https://discourse.vtk.org/t/can-vtk-files-be-used-to-visualise-solutions-on-1d-meshes/2830 "2020-03-16T16:30:34Z")

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I have a standard diffusion equation solved using a finite element software on a 1D mesh for the concentration values. Can I visualise this using the .vtk or .vtu files? Krishna

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## [vtkXdmf3Writer not in python pypi distribution ?](https://discourse.vtk.org/t/vtkxdmf3writer-not-in-python-pypi-distribution/2470)

<div class="topic-metadata">

**Author:** [@blignyc](https://discourse.vtk.org/u/blignyc)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 3:52pm UTC](https://discourse.vtk.org/t/vtkxdmf3writer-not-in-python-pypi-distribution/2470 "2020-03-16T15:52:19Z")

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Hello, I just installed the python vtk package on my machine, using « pip install vtk » in a virtual env. I work with MacOS 10, python 3.7 I tried to use the vtkXdmf3Writer class, but I got an error : module ‘vtk’ ha…

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## [Ospray material library from python](https://discourse.vtk.org/t/ospray-material-library-from-python/2459)

<div class="topic-metadata">

**Author:** [@gilcu2](https://discourse.vtk.org/u/gilcu2)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 3:48pm UTC](https://discourse.vtk.org/t/ospray-material-library-from-python/2459 "2020-03-16T15:48:58Z")

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Hello, I am trying to load an mtl file from python following the C++ code like this: import vtkmodules.vtkRenderingRayTracing as vtkrt osprayMtlLibrary = vtkrt.vtkOSPRayMaterialLibrary() osprayM…

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## [Cmake error in vtkeigen when building from source](https://discourse.vtk.org/t/cmake-error-in-vtkeigen-when-building-from-source/2451)

<div class="topic-metadata">

**Author:** [@Patrick\_Mineault](https://discourse.vtk.org/u/Patrick_Mineault)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 3:44pm UTC](https://discourse.vtk.org/t/cmake-error-in-vtkeigen-when-building-from-source/2451 "2020-03-16T15:44:11Z")

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I’m trying to build vtk from source on Ubuntu since I’m having trouble accessing vtkXdmfReader in pre-built libraries. Following the instructions here: https://vtk.org/Wiki/VTK/Building/Linux, when running this series of…

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## [Cannot interact with basic QT/VTK application](https://discourse.vtk.org/t/cannot-interact-with-basic-qt-vtk-application/2447)

<div class="topic-metadata">

**Author:** [@ian.liu88](https://discourse.vtk.org/u/ian.liu88)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 3:36pm UTC](https://discourse.vtk.org/t/cannot-interact-with-basic-qt-vtk-application/2447 "2020-03-16T15:36:55Z")

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I have the following snippet which is correctly displaying a cone shape on screen, but I can’t interact with it, ie pan, rotate, zoom, etc. Should I expect it to be interactive? import sys import PySide2 from PySide2.Qt…

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## [Does vtkSmartPointer support std::move](https://discourse.vtk.org/t/does-vtksmartpointer-support-std-move/2771)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 4\
**Last updated:** [March 13, 2020, 11:22pm UTC](https://discourse.vtk.org/t/does-vtksmartpointer-support-std-move/2771 "2020-03-13T23:22:54Z")

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As vtkSmartPointer is similar to std::shared\_ptr. I use std::move to vtkSmartPointer object. But I find the pointer of the object is NOT null after std::move. Does vtkSmartPointer support std::move? If supported, what’…

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## [How to get specific number of seed points using seedwidgetwithcustomcallback?](https://discourse.vtk.org/t/how-to-get-specific-number-of-seed-points-using-seedwidgetwithcustomcallback/2814)

<div class="topic-metadata">

**Author:** [@Pooja](https://discourse.vtk.org/u/Pooja)\
**Replies:** 1\
**Last updated:** [March 13, 2020, 3:07pm UTC](https://discourse.vtk.org/t/how-to-get-specific-number-of-seed-points-using-seedwidgetwithcustomcallback/2814 "2020-03-13T15:07:10Z")

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Hello, I used seedwidgetwithcustomcallback to get seed points of dicom image. But I need only 3 seeds and after that it should not take new point. Could someone please tell me how to do it? It seems PlacePointEvent u…

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## [I cannot use filter for calculation Hausdorff distance](https://discourse.vtk.org/t/i-cannot-use-filter-for-calculation-hausdorff-distance/2339)

<div class="topic-metadata">

**Author:** [@Inna\_Daymand](https://discourse.vtk.org/u/Inna_Daymand)\
**Replies:** 4\
**Last updated:** [March 13, 2020, 10:30am UTC](https://discourse.vtk.org/t/i-cannot-use-filter-for-calculation-hausdorff-distance/2339 "2020-03-13T10:30:24Z")

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I have VTK 8.2.0 build I want to use vtkHausdorffDistancePointSetFilter filter in my python program according to example https://lorensen.github.io/VTKExamples/site/Python/PolyData/AlignTwoPolyDatas/ but I am getting …

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## [The vtkPolyData can not be Deleted After some DeleteCell...](https://discourse.vtk.org/t/the-vtkpolydata-can-not-be-deleted-after-some-deletecell/2804)

<div class="topic-metadata">

**Author:** [@tdchen](https://discourse.vtk.org/u/tdchen)\
**Replies:** 3\
**Last updated:** [March 13, 2020, 12:00am UTC](https://discourse.vtk.org/t/the-vtkpolydata-can-not-be-deleted-after-some-deletecell/2804 "2020-03-13T00:00:59Z")

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Hi vtkers I have made a function to simplify a triangle mesh: void UpdateTriangles(vtkIdType ia, vtkIdType ib, vtkPolyData \*pTriangles); The ia and ib are vertex IDs of an edge and pTriangles points to a triangle mesh…

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## [How to render (visualize) histogram of 3D image](https://discourse.vtk.org/t/how-to-render-visualize-histogram-of-3d-image/2809)

<div class="topic-metadata">

**Author:** [@RomyM](https://discourse.vtk.org/u/RomyM)\
**Replies:** 1\
**Last updated:** [March 12, 2020, 5:10pm UTC](https://discourse.vtk.org/t/how-to-render-visualize-histogram-of-3d-image/2809 "2020-03-12T17:10:30Z")

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Hey, I try to visualize my histogram in order to check peaks in my image (and later on to segment those pixels). However, I try to render it with ren.AddActor(plot), but it only shows a black screen (I think here is the…

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## [Align two volumes with different spacing and origin](https://discourse.vtk.org/t/align-two-volumes-with-different-spacing-and-origin/2741)

<div class="topic-metadata">

**Author:** [@Darya\_Berezniak](https://discourse.vtk.org/u/Darya_Berezniak)\
**Replies:** 18\
**Last updated:** [March 11, 2020, 4:46am UTC](https://discourse.vtk.org/t/align-two-volumes-with-different-spacing-and-origin/2741 "2020-03-11T04:46:58Z")

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I have two data sets: a CT volume (Dicom or Nii format) and a segmentation (Nii or Nrrd format) created in Slicer3D. I need to display both of them with correct position of the segmentation. But these two data sets have …

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## [Calculating Wall shear Stress and Mapping value to isosurface skin.](https://discourse.vtk.org/t/calculating-wall-shear-stress-and-mapping-value-to-isosurface-skin/2800)

<div class="topic-metadata">

**Author:** [@LimTzeSuen](https://discourse.vtk.org/u/LimTzeSuen)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 11:56pm UTC](https://discourse.vtk.org/t/calculating-wall-shear-stress-and-mapping-value-to-isosurface-skin/2800 "2020-03-10T23:56:08Z")

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Greetings all, I’m new to VTK. I’m trying to calculate Wall Shear Stress on a 3D MRI Velocity Dataset. I’ve done the noise filtering, and generated a 3D velocity volume and the construction of vessel skin by using vtkMar…

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## [Why VTK filters behave strangely when I feed my dataset to them?](https://discourse.vtk.org/t/why-vtk-filters-behave-strangely-when-i-feed-my-dataset-to-them/2795)

<div class="topic-metadata">

**Author:** [@myousefi2016](https://discourse.vtk.org/u/myousefi2016)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 6:26pm UTC](https://discourse.vtk.org/t/why-vtk-filters-behave-strangely-when-i-feed-my-dataset-to-them/2795 "2020-03-10T18:26:29Z")

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I have vtkUnstructuredGrid that has a vector array in it. All the cell types in this vtkUnstructuredGrid are VTK\_VOXEL and my vector array is attributed to the cells (i.e. cell data). Now I want to extract the cell cente…

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## [Problem Clipping Unstructured Grid with Quadratic Quad Element](https://discourse.vtk.org/t/problem-clipping-unstructured-grid-with-quadratic-quad-element/2790)

<div class="topic-metadata">

**Author:** [@alx](https://discourse.vtk.org/u/alx)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 12:54pm UTC](https://discourse.vtk.org/t/problem-clipping-unstructured-grid-with-quadratic-quad-element/2790 "2020-03-10T12:54:41Z")

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I am having trouble to correctly clip an unstructured grid with vtkClipDataSet. For cells of type VTK\_QUADRATIC\_TRIANGLE the cell data seems to be clipped correctly but for VTK\_QUADRATIC\_QUAD cells the clipping messes …

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## [OSPRay 2.0 & VTK 9.0 ?](https://discourse.vtk.org/t/ospray-2-0-vtk-9-0/2789)

<div class="topic-metadata">

**Author:** [@rossetantoine](https://discourse.vtk.org/u/rossetantoine)\
**Replies:** 1\
**Last updated:** [March 10, 2020, 12:19pm UTC](https://discourse.vtk.org/t/ospray-2-0-vtk-9-0/2789 "2020-03-10T12:19:50Z")

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OSPRay 2.0 (https://www.ospray.org) is available since a few weeks. Do you know if it will supported in VTK 9.0? Or a time frame? Thanks !

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## [vtkMarchingCube error...](https://discourse.vtk.org/t/vtkmarchingcube-error/2775)

<div class="topic-metadata">

**Author:** [@Yongun\_Lee](https://discourse.vtk.org/u/Yongun_Lee)\
**Replies:** 4\
**Last updated:** [March 10, 2020, 2:00am UTC](https://discourse.vtk.org/t/vtkmarchingcube-error/2775 "2020-03-10T02:00:24Z")

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I’ve attached the code I wrote below. I want to know the reason. No problem with 64bit, but with 32bit the same problem. SkinExtractor-\> SetValue (0, value); Set the value value to 250.0. vtkSmartPointer\<vtkNamedColor…

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## [run vtk application using putty and xserver](https://discourse.vtk.org/t/run-vtk-application-using-putty-and-xserver/2785)

<div class="topic-metadata">

**Author:** [@benjamin](https://discourse.vtk.org/u/benjamin)\
**Replies:** 0\
**Last updated:** [March 9, 2020, 10:24pm UTC](https://discourse.vtk.org/t/run-vtk-application-using-putty-and-xserver/2785 "2020-03-09T22:24:24Z")

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Hello, I have compiled the arrow example using vtk 7.1.0 library in a hpc cluster using a putty window in my pc. My problem is when I run the arrow example, a window to visualize the arrow (a visualization of the arrow…

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## [Is there a way to convert a view of a 3D Actor (for example: a view in the X-Z direction) to a 2D Actor.](https://discourse.vtk.org/t/is-there-a-way-to-convert-a-view-of-a-3d-actor-for-example-a-view-in-the-x-z-direction-to-a-2d-actor/2684)

<div class="topic-metadata">

**Author:** [@kknnnyy](https://discourse.vtk.org/u/kknnnyy)\
**Replies:** 7\
**Last updated:** [March 9, 2020, 9:35pm UTC](https://discourse.vtk.org/t/is-there-a-way-to-convert-a-view-of-a-3d-actor-for-example-a-view-in-the-x-z-direction-to-a-2d-actor/2684 "2020-03-09T21:35:52Z")

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I need to get a 3D view in the X-Y, X-Z, Y-Z directions, so I need to convert a 3D Actor to a 2D Actor. How to get a 2D view (not locking the 3d Actor camera)

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