# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=108

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

**Page:** 109

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## [Write to vtkImageData using parallel threads](https://discourse.vtk.org/t/write-to-vtkimagedata-using-parallel-threads/5423)

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**Author:** [@janhavi\_deshpande](https://discourse.vtk.org/u/janhavi_deshpande)\
**Replies:** 1\
**Last updated:** [March 23, 2021, 11:00am UTC](https://discourse.vtk.org/t/write-to-vtkimagedata-using-parallel-threads/5423 "2021-03-23T11:00:13Z")

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Hello, I am working in C# and I am currently using setScalarComponentFromDouble function of vtkImageData to set values to ImageData grid. This function is not thread-safe. I have also tried getting image pointer through…

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## [Questions about the Point Cloud Data representation.](https://discourse.vtk.org/t/questions-about-the-point-cloud-data-representation/969)

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**Author:** [@Kim\_William](https://discourse.vtk.org/u/Kim_William)\
**Replies:** 6\
**Last updated:** [March 23, 2021, 2:35am UTC](https://discourse.vtk.org/t/questions-about-the-point-cloud-data-representation/969 "2021-03-23T02:35:34Z")

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Hi all! I have some questions about Point Cloud Data. Question 1) The colors are represented differently depending on zoom(In my code). (zoom in) (zoom out) But ParaView shows the same color regardless of zoom. …

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## [Segm fault on Renderer render and RenderWindow Render](https://discourse.vtk.org/t/segm-fault-on-renderer-render-and-renderwindow-render/5409)

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**Author:** [@IVarha](https://discourse.vtk.org/u/IVarha)\
**Replies:** 3\
**Last updated:** [March 22, 2021, 2:41pm UTC](https://discourse.vtk.org/t/segm-fault-on-renderer-render-and-renderwindow-render/5409 "2021-03-22T14:41:34Z")

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Hello VTK community, I reusing some parts of code from “Screenshoot” sample to visualise my mesh. I receive Signal: SIGSEGV (Segmentation fault) on the line renderWindow-\>Render(); Additionally, I removed import “vtk…

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## [objects whose property is manipulated by AnimationCue don't response to the callback , but this callback response in common render. How can I make this callback respose properly in AnimationCue ?](https://discourse.vtk.org/t/objects-whose-property-is-manipulated-by-animationcue-dont-response-to-the-callback-but-this-callback-response-in-common-render-how-can-i-make-this-callback-respose-properly-in-animationcue/5419)

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**Author:** [@pi42](https://discourse.vtk.org/u/pi42)\
**Replies:** 0\
**Last updated:** [March 22, 2021, 12:02pm UTC](https://discourse.vtk.org/t/objects-whose-property-is-manipulated-by-animationcue-dont-response-to-the-callback-but-this-callback-response-in-common-render-how-can-i-make-this-callback-respose-properly-in-animationcue/5419 "2021-03-22T12:02:51Z")

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class CurtainAnimationCue : public vtkAnimationCue { public: static CurtainAnimationCue \* New() { return new CurtainAnimationCue; }; vtkTypeMacro(CurtainAnimationCue, vtkAnimationCue); public: CurtainAnimationCue() …

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## [How to overcome Failed to load vtkClientServerPython?](https://discourse.vtk.org/t/how-to-overcome-failed-to-load-vtkclientserverpython/5417)

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**Author:** [@rasunag27](https://discourse.vtk.org/u/rasunag27)\
**Replies:** 0\
**Last updated:** [March 22, 2021, 8:59am UTC](https://discourse.vtk.org/t/how-to-overcome-failed-to-load-vtkclientserverpython/5417 "2021-03-22T08:59:10Z")

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I have to run some paraview trace file in python to automate the process. For this, I have I am trying to import paraview as from paraview.simple import \* But, it is showing me an error as “Failed to load vtkClient…

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## [LNK2005 error when use VTK&OpenCV static library in VS2019](https://discourse.vtk.org/t/lnk2005-error-when-use-vtk-opencv-static-library-in-vs2019/5371)

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**Author:** [@Peiqi](https://discourse.vtk.org/u/Peiqi)\
**Replies:** 2\
**Last updated:** [March 22, 2021, 12:44am UTC](https://discourse.vtk.org/t/lnk2005-error-when-use-vtk-opencv-static-library-in-vs2019/5371 "2021-03-22T00:44:05Z")

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Conflict between vtkpng-9.0.lib and libpng.lib, but all of them must be link. VTK use vtkpng-9.0.lib and vtkfreetype-9.0.lib，and opencv must link libpng.lib and freetype.lib. I don’t know how to fix it. How to build V…

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## [vtkGeometryFilter problem](https://discourse.vtk.org/t/vtkgeometryfilter-problem/5037)

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**Author:** [@marcomusy](https://discourse.vtk.org/u/marcomusy)\
**Replies:** 20\
**Last updated:** [March 22, 2021, 12:39am UTC](https://discourse.vtk.org/t/vtkgeometryfilter-problem/5037 "2021-03-22T00:39:16Z")

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I don’t understand the behavior of vtkGeometryFilter in the case of a hexahedron - I would expect it to extract 6 faces and I get zero: import vtk reader = vtk.vtkXMLUnstructuredGridReader() reader.SetFileName('a.vtu')…

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## [Preparing minimalistic binary package for CI (use of cpack and disabling modules)](https://discourse.vtk.org/t/preparing-minimalistic-binary-package-for-ci-use-of-cpack-and-disabling-modules/4937)

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**Author:** [@dsemikin](https://discourse.vtk.org/u/dsemikin)\
**Replies:** 7\
**Last updated:** [March 22, 2021, 12:31am UTC](https://discourse.vtk.org/t/preparing-minimalistic-binary-package-for-ci-use-of-cpack-and-disabling-modules/4937 "2021-03-22T00:31:31Z")

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Hello, I have two questions (for the background see below): Question 1: I would like to pack VTK binaries using CPack. But it seems, that it is not supported (or at least not considered) because I don’t see “include(C…

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## [Using VTK with Python on Windows 10](https://discourse.vtk.org/t/using-vtk-with-python-on-windows-10/4920)

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**Author:** [@oduncu90](https://discourse.vtk.org/u/oduncu90)\
**Replies:** 5\
**Last updated:** [March 22, 2021, 12:28am UTC](https://discourse.vtk.org/t/using-vtk-with-python-on-windows-10/4920 "2021-03-22T00:28:20Z")

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I am using Python3 on Windows 10 x64. I am using python by using Msys2. I have installed several packages by using Msys2 and they work with python without problems. I have installed vtk 8.2 by using Msys2. vtk 8.2 is th…

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## [How to wrap VTK-derived C++ function for Python](https://discourse.vtk.org/t/how-to-wrap-vtk-derived-c-function-for-python/4862)

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**Author:** [@desheng](https://discourse.vtk.org/u/desheng)\
**Replies:** 4\
**Last updated:** [March 22, 2021, 12:25am UTC](https://discourse.vtk.org/t/how-to-wrap-vtk-derived-c-function-for-python/4862 "2021-03-22T00:25:17Z")

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Is there any place I can find a working example to wrap a C++ function (using VTK) to be used by Python? Searched and found this page mix VTK and SWIG Python but there is no compiling details, and this simple example on…

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## [Excess memory usage when visualising vtkCubes or other objects](https://discourse.vtk.org/t/excess-memory-usage-when-visualising-vtkcubes-or-other-objects/3923)

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**Author:** [@mastrogiorgis](https://discourse.vtk.org/u/mastrogiorgis)\
**Replies:** 4\
**Last updated:** [March 21, 2021, 10:45pm UTC](https://discourse.vtk.org/t/excess-memory-usage-when-visualising-vtkcubes-or-other-objects/3923 "2021-03-21T22:45:21Z")

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Hi, I noticed an excessive usage of memory when using vtkCubes to visualise an 8x8x2 blocks as seen in the image. The memory usage is ~ 380Mb Is there anything I can try to reduce this? Many thanks.

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## [vtkCutter no data at the boundary edge with current interpolation algorithm](https://discourse.vtk.org/t/vtkcutter-no-data-at-the-boundary-edge-with-current-interpolation-algorithm/5413)

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**Author:** [@aldis](https://discourse.vtk.org/u/aldis)\
**Replies:** 0\
**Last updated:** [March 20, 2021, 3:48am UTC](https://discourse.vtk.org/t/vtkcutter-no-data-at-the-boundary-edge-with-current-interpolation-algorithm/5413 "2021-03-20T03:48:38Z")

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Hello I have a CFD postprocessing task with \*.plt file as surface data source. After the surface data was imported via vtkTecplotReader, I tried to cut a slice at the symmetry boundary plane (Y=0 ) with “vtkCutter”. How…

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## [Measuring of rendering performance for Remote python-based Visualisation](https://discourse.vtk.org/t/measuring-of-rendering-performance-for-remote-python-based-visualisation/5404)

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**Author:** [@EMalikova](https://discourse.vtk.org/u/EMalikova)\
**Replies:** 11\
**Last updated:** [March 19, 2021, 8:21pm UTC](https://discourse.vtk.org/t/measuring-of-rendering-performance-for-remote-python-based-visualisation/5404 "2021-03-19T20:21:00Z")

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Dear All, I need to obtain an FPS performance of python-based server for remote visualisation. I have run several tests from C++ and python code on Nvidia GTX 2080 and has obtained quite different results for Mesh visua…

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## [VTK ray cast volume rendering window freeze if volumeMapper.SetImageSampleDistance less than 1.0](https://discourse.vtk.org/t/vtk-ray-cast-volume-rendering-window-freeze-if-volumemapper-setimagesampledistance-less-than-1-0/5405)

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**Author:** [@desheng](https://discourse.vtk.org/u/desheng)\
**Replies:** 0\
**Last updated:** [March 18, 2021, 9:17pm UTC](https://discourse.vtk.org/t/vtk-ray-cast-volume-rendering-window-freeze-if-volumemapper-setimagesampledistance-less-than-1-0/5405 "2021-03-18T21:17:19Z")

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Hi, I notice a confusing vtk problem: when we use vtk.vtkGPUVolumeRayCastMapper() and set volumeMapper.SetImageSampleDistance(0.5) ----or any value less than 1.0, the interactive window freeze. No response to mouse movem…

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## [How to retain watertight mesh after merging two stl using surfaceAdd?](https://discourse.vtk.org/t/how-to-retain-watertight-mesh-after-merging-two-stl-using-surfaceadd/5402)

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**Author:** [@rasunag27](https://discourse.vtk.org/u/rasunag27)\
**Replies:** 0\
**Last updated:** [March 18, 2021, 8:16am UTC](https://discourse.vtk.org/t/how-to-retain-watertight-mesh-after-merging-two-stl-using-surfaceadd/5402 "2021-03-18T08:16:15Z")

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Dear all, I have an stl mesh which is watertight mesh (Checked with surfaceCheck utility of OpenFoam). I splitted this mesh to two stl’s using Paraview filters. (STL \> GenerateNormals \> Connectivity \> Threshold \> Extr…

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## [How to split single stl file into two based on threshold in vertices?](https://discourse.vtk.org/t/how-to-split-single-stl-file-into-two-based-on-threshold-in-vertices/5401)

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**Author:** [@rasunag27](https://discourse.vtk.org/u/rasunag27)\
**Replies:** 0\
**Last updated:** [March 18, 2021, 5:53am UTC](https://discourse.vtk.org/t/how-to-split-single-stl-file-into-two-based-on-threshold-in-vertices/5401 "2021-03-18T05:53:26Z")

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Dear All, I have a watertight stl mesh which is created using pointclouds from Open3D python library. This stl file is a single file. I want this stl file to be splitted into two based on the criteria say z-coordinated …

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## [ImageData make black transparent](https://discourse.vtk.org/t/imagedata-make-black-transparent/5393)

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**Author:** [@ctfirman](https://discourse.vtk.org/u/ctfirman)\
**Replies:** 1\
**Last updated:** [March 17, 2021, 4:57pm UTC](https://discourse.vtk.org/t/imagedata-make-black-transparent/5393 "2021-03-17T16:57:41Z")

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Hi, I have an ImageData object in which I would like to replace the black area with a transparent area. I am new to VTK so sorry if this is trivial. Also is there any good python documentation regarding with working …

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## [Is it possible to overlay two raycast volumes in the same render window?](https://discourse.vtk.org/t/is-it-possible-to-overlay-two-raycast-volumes-in-the-same-render-window/2177)

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**Author:** [@msmerps](https://discourse.vtk.org/u/msmerps)\
**Replies:** 9\
**Last updated:** [March 16, 2021, 4:33am UTC](https://discourse.vtk.org/t/is-it-possible-to-overlay-two-raycast-volumes-in-the-same-render-window/2177 "2021-03-16T04:33:19Z")

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Hi everybody, I would like to render two different volumes using two different color maps in the same renderer. I can’t tell if this is currently possible in VTK. This post makes me think it is not yet possible: How…

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## [How can I get cell's type from Polydata or UGrid ?](https://discourse.vtk.org/t/how-can-i-get-cells-type-from-polydata-or-ugrid/5379)

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**Author:** [@11114](https://discourse.vtk.org/u/11114)\
**Replies:** 1\
**Last updated:** [March 14, 2021, 8:30pm UTC](https://discourse.vtk.org/t/how-can-i-get-cells-type-from-polydata-or-ugrid/5379 "2021-03-14T20:30:56Z")

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Hi, I want to get each individual cell’s type from polydata or UGrid source , I looked up the online documentation , but I didn’t find any useful method there, I think I need to do some conversion ,But don’t know how ,an…

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## [Problems encountered in multi-GPU rendering](https://discourse.vtk.org/t/problems-encountered-in-multi-gpu-rendering/5366)

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**Author:** [@Jone7](https://discourse.vtk.org/u/Jone7)\
**Replies:** 1\
**Last updated:** [March 12, 2021, 3:51pm UTC](https://discourse.vtk.org/t/problems-encountered-in-multi-gpu-rendering/5366 "2021-03-12T15:51:37Z")

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I tried to render a large scale model with VTK on two GPUs, but found that one of the GPUs was underutilized, like this: Does the VTK not support multiple GPUs? Or has it unique Settings?

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## [Store complex value in PointData](https://discourse.vtk.org/t/store-complex-value-in-pointdata/5355)

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**Author:** [@cean\_wang](https://discourse.vtk.org/u/cean_wang)\
**Replies:** 1\
**Last updated:** [March 11, 2021, 5:18pm UTC](https://discourse.vtk.org/t/store-complex-value-in-pointdata/5355 "2021-03-11T17:18:39Z")

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Hi, I want to store Complex Displacement Vector in PointData. For each point, there is Magnitude and Phase value of displacement(T) in X(T1),Y(T2) and Z(T3) axis. What is the format? Is it: T1Mag,T1Phase,T2Mag,T2Phase,…

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## [vtkPolyDataAppend of circles make holes in intersections](https://discourse.vtk.org/t/vtkpolydataappend-of-circles-make-holes-in-intersections/5367)

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**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 0\
**Last updated:** [March 11, 2021, 12:51pm UTC](https://discourse.vtk.org/t/vtkpolydataappend-of-circles-make-holes-in-intersections/5367 "2021-03-11T12:51:09Z")

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Hello, I want to delete some areas of a polydata transformed to image. It works well but it is very slow. For every circle, I make an extrusion towards the normal and I convert it into image, and substract it to the …

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## [VTK 9.0.1 Data and LargeData](https://discourse.vtk.org/t/vtk-9-0-1-data-and-largedata/5361)

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**Author:** [@robodoc](https://discourse.vtk.org/u/robodoc)\
**Replies:** 1\
**Last updated:** [March 10, 2021, 6:56pm UTC](https://discourse.vtk.org/t/vtk-9-0-1-data-and-largedata/5361 "2021-03-10T18:56:51Z")

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In updating to 9.0.1 it seems that the Data and Large Data files do not correctly untar/unzip when I attempt to extract them using 7-Zip. In the data folder I get nothing, and what I do get are hashes or uids, which are…

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## [vtk handling of python file-like objects, gzipped stls](https://discourse.vtk.org/t/vtk-handling-of-python-file-like-objects-gzipped-stls/5350)

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**Author:** [@aerogt3](https://discourse.vtk.org/u/aerogt3)\
**Replies:** 2\
**Last updated:** [March 9, 2021, 4:46pm UTC](https://discourse.vtk.org/t/vtk-handling-of-python-file-like-objects-gzipped-stls/5350 "2021-03-09T16:46:45Z")

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Hello, I am using python vtk for reading in, manipulating, and then exporting .stl files. Often these are gzipped, or download from/exported to a remote file system (amazon s3). If there any way to use vtkSTLReader and…

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## [Advice on grid formats](https://discourse.vtk.org/t/advice-on-grid-formats/5343)

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**Author:** [@Luke\_Dalessandro](https://discourse.vtk.org/u/Luke_Dalessandro)\
**Replies:** 6\
**Last updated:** [March 9, 2021, 3:07pm UTC](https://discourse.vtk.org/t/advice-on-grid-formats/5343 "2021-03-09T15:07:47Z")

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Hi all. For the last couple of years I have been using the vtkUnstructuredGrid file format as an output format for my solver infrastructure–-basically it’s storing N-dimensional \[point\]→(f0,f1,...) scalar data correspon…

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## [RegularPolygonSource shows edges](https://discourse.vtk.org/t/regularpolygonsource-shows-edges/5346)

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**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 0\
**Last updated:** [March 9, 2021, 10:01am UTC](https://discourse.vtk.org/t/regularpolygonsource-shows-edges/5346 "2021-03-09T10:01:51Z")

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Hello I have a question, I am trying to use RegularPolygonSource to paint in a 3d scene and the edge is shown. I have tried to change the properties of the actor to visibilit edges off o line width to 0 but there is no w…

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## [Manipulate a image of VTK in CUDA](https://discourse.vtk.org/t/manipulate-a-image-of-vtk-in-cuda/5339)

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**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 4\
**Last updated:** [March 8, 2021, 9:05pm UTC](https://discourse.vtk.org/t/manipulate-a-image-of-vtk-in-cuda/5339 "2021-03-08T21:05:38Z")

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Dear All, I want to manipulate a VTK image in CUDA (PyCUDA): reader1 = vtk.vtkMetaImageReader() reader1.SetFileName('c:\\\\users\\\\luisgo//catia\_pre//'+'binary2.mhd') reader1.Update() reade…

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## [How to handle cmake COMPONENTS name change between 8.2 and 9.](https://discourse.vtk.org/t/how-to-handle-cmake-components-name-change-between-8-2-and-9/5338)

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**Author:** [@Luke\_Dalessandro](https://discourse.vtk.org/u/Luke_Dalessandro)\
**Replies:** 11\
**Last updated:** [March 8, 2021, 4:57pm UTC](https://discourse.vtk.org/t/how-to-handle-cmake-components-name-change-between-8-2-and-9/5338 "2021-03-08T16:57:57Z")

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I’ve been using vtk8.2 successfully for a while now, with a basic find\_package(VTK REQUIRED COMPONENTS vtkCommonCore vtkCommonDataModel vtkIOXML) however, vtk9 changed those component names. How do I know which c…

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## [Labeled Contours](https://discourse.vtk.org/t/labeled-contours/5342)

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**Author:** [@jwhite](https://discourse.vtk.org/u/jwhite)\
**Replies:** 0\
**Last updated:** [March 8, 2021, 3:58pm UTC](https://discourse.vtk.org/t/labeled-contours/5342 "2021-03-08T15:58:45Z")

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Hello, I’m writing a program in C# that shows the stress and strain from aircraft on a slab of concrete and would like to label the contours I generate based on those values. I have the contours being drawn correctly b…

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## [Adaptive render facets in VTK?](https://discourse.vtk.org/t/adaptive-render-facets-in-vtk/5333)

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**Author:** [@GregVernon](https://discourse.vtk.org/u/GregVernon)\
**Replies:** 1\
**Last updated:** [March 7, 2021, 12:38pm UTC](https://discourse.vtk.org/t/adaptive-render-facets-in-vtk/5333 "2021-03-07T12:38:18Z")

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Is there any functionality in VTK for adaptive render facets (of nonlinear curves and surfaces) based on the current view? I know there’s the LOD functionality in ParaView, but that reduces the fidelity during view tran…

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