# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=63

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

**Page:** 64

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## [how to make the height map for c++ image buffer](https://discourse.vtk.org/t/how-to-make-the-height-map-for-c-image-buffer/9921)

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**Author:** [@J\_Kim](https://discourse.vtk.org/u/J_Kim)\
**Replies:** 3\
**Last updated:** [November 24, 2022, 8:10am UTC](https://discourse.vtk.org/t/how-to-make-the-height-map-for-c-image-buffer/9921 "2022-11-24T08:10:10Z")

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Hi all I want to make the height map for c++ image buffer. to This is what I have done upto now. using vtkDelaunay2D int nImageWidth = 500, nImageHeight = 1000; BYTE\* pBuffer = new BYTE\[nImageWidth\*nImageHeight…

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## [How to catch mouse click events(right mouse button)in a VTK Chart](https://discourse.vtk.org/t/how-to-catch-mouse-click-events-right-mouse-button-in-a-vtk-chart/9876)

<div class="topic-metadata">

**Author:** [@we\_create](https://discourse.vtk.org/u/we_create)\
**Replies:** 2\
**Last updated:** [November 24, 2022, 4:13am UTC](https://discourse.vtk.org/t/how-to-catch-mouse-click-events-right-mouse-button-in-a-vtk-chart/9876 "2022-11-24T04:13:49Z")

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Hi all I just want to add userinteraction(rigth mouse click) to a vtk chart .can anyone please guide me . This is what I have done upto now.But nothing happend. class customMouseInteractorStyle : public vtkInteractorS…

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## [VTK clipping with Python](https://discourse.vtk.org/t/vtk-clipping-with-python/3352)

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**Author:** [@nikolay](https://discourse.vtk.org/u/nikolay)\
**Replies:** 7\
**Last updated:** [November 24, 2022, 1:02am UTC](https://discourse.vtk.org/t/vtk-clipping-with-python/3352 "2022-11-24T01:02:34Z")

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Hi all, I am fairly new to VTK. I am using VTK version 8.1.2, Python 3.7.5 on Windows 10. I am trying to clip a VTK image with Python similar to the screenshot below taken from Slicer: Below is the code that I manag…

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## [VTK v5.4.2 on Ubuntu (in WSL2)](https://discourse.vtk.org/t/vtk-v5-4-2-on-ubuntu-in-wsl2/9938)

<div class="topic-metadata">

**Author:** [@lbuo](https://discourse.vtk.org/u/lbuo)\
**Replies:** 3\
**Last updated:** [November 23, 2022, 1:38pm UTC](https://discourse.vtk.org/t/vtk-v5-4-2-on-ubuntu-in-wsl2/9938 "2022-11-23T13:38:23Z")

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Hello everybody. I was trying to install VTK v5.4.2 on Ubuntu (in WSL2). Those are my steps (starting from my home directory): git clone -b v5.4.2 https://gitlab.kitware.com/vtk/vtk mkdir VTK-linux cd VTK-linux ccma…

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## [Change response of render window to interactions](https://discourse.vtk.org/t/change-response-of-render-window-to-interactions/9733)

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**Author:** [@Manju](https://discourse.vtk.org/u/Manju)\
**Replies:** 2\
**Last updated:** [November 23, 2022, 8:38am UTC](https://discourse.vtk.org/t/change-response-of-render-window-to-interactions/9733 "2022-11-23T08:38:10Z")

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I am using a Qvtkwidget to display images in an application. Image interactions are enabled via render window interactor. vtkinteractorstyle image is used. Clicking and dragging on the image results in window and level c…

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## [Can we read scalars based on time dimension from NetCDF file?](https://discourse.vtk.org/t/can-we-read-scalars-based-on-time-dimension-from-netcdf-file/9927)

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**Author:** [@sherinnovation](https://discourse.vtk.org/u/sherinnovation)\
**Replies:** 0\
**Last updated:** [November 22, 2022, 12:59pm UTC](https://discourse.vtk.org/t/can-we-read-scalars-based-on-time-dimension-from-netcdf-file/9927 "2022-11-22T12:59:30Z")

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Everything is working when I load my netCDF file in paraview, wherein I am able to use the time combobox to query the scalars from any timepoint of a selected variable, which has the dimensions - (‘time’, ‘latitude’, ‘lo…

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## [write vtkInformation](https://discourse.vtk.org/t/write-vtkinformation/9915)

<div class="topic-metadata">

**Author:** [@hamid\_badi](https://discourse.vtk.org/u/hamid_badi)\
**Replies:** 0\
**Last updated:** [November 21, 2022, 10:07pm UTC](https://discourse.vtk.org/t/write-vtkinformation/9915 "2022-11-21T22:07:14Z")

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Hello, Is there a way to serialize extra keys from vtkInformation of an object ? I mean, i create an extra object key attached (instance of a class MyInfoObj which derived from vtkObjectBase) to a vtkPolyData object, I…

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## [vtkMultiBlockDataSet name](https://discourse.vtk.org/t/vtkmultiblockdataset-name/9913)

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**Author:** [@hamid\_badi](https://discourse.vtk.org/u/hamid_badi)\
**Replies:** 2\
**Last updated:** [November 21, 2022, 9:29pm UTC](https://discourse.vtk.org/t/vtkmultiblockdataset-name/9913 "2022-11-21T21:29:26Z")

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Hello, My questions are related to vtkMultiBlockDataSet : In a vtm file it’s possible to name each block using the xml attribut name, is there a way to name the vtkMultiBlockDataSet root object so that it’ll appear in…

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## [MakeKey location](https://discourse.vtk.org/t/makekey-location/9912)

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**Author:** [@hamid\_badi](https://discourse.vtk.org/u/hamid_badi)\
**Replies:** 0\
**Last updated:** [November 21, 2022, 8:12pm UTC](https://discourse.vtk.org/t/makekey-location/9912 "2022-11-21T20:12:56Z")

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Hello, I’m little but confused about vtk MakeKey, what location stands for ? Isn’t name enough to make the key unique ? Thanks.

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## [How to change dpi of saving pictures with vtkBMPWriter](https://discourse.vtk.org/t/how-to-change-dpi-of-saving-pictures-with-vtkbmpwriter/9908)

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**Author:** [@Pariss.Guo](https://discourse.vtk.org/u/Pariss.Guo)\
**Replies:** 2\
**Last updated:** [November 21, 2022, 2:04pm UTC](https://discourse.vtk.org/t/how-to-change-dpi-of-saving-pictures-with-vtkbmpwriter/9908 "2022-11-21T14:04:09Z")

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Hello， I know SetSpacing SetDimensions in vtkImageData, which set the pixel interval and the number of pixels number. And the dpi means the number of pixels per 2.54cm. If I want to set the dpi to 150, the spacing sho…

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## [vtkClipClosedSurface bad result](https://discourse.vtk.org/t/vtkclipclosedsurface-bad-result/9879)

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**Author:** [@Olivier](https://discourse.vtk.org/u/Olivier)\
**Replies:** 6\
**Last updated:** [November 20, 2022, 8:58am UTC](https://discourse.vtk.org/t/vtkclipclosedsurface-bad-result/9879 "2022-11-20T08:58:57Z")

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Hi friends, I’m facing “many” bad results with capping done by vtkClipClosedSurface + vtkContourTriangulator … vtkClipClosedSurface does a perfect job calculating the clipped triangles / lines, but capping is another s…

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## [What caused the different VolumeRender outputs between pure VTK and 3DSlicer](https://discourse.vtk.org/t/what-caused-the-different-volumerender-outputs-between-pure-vtk-and-3dslicer/9862)

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**Author:** [@zhanghc](https://discourse.vtk.org/u/zhanghc)\
**Replies:** 0\
**Last updated:** [November 17, 2022, 1:28pm UTC](https://discourse.vtk.org/t/what-caused-the-different-volumerender-outputs-between-pure-vtk-and-3dslicer/9862 "2022-11-17T13:28:35Z")

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This is a heart image rendered by pure VTK code: This is the same heart rendered by 3D Slicer: I used the same transfer functions and tried to tweak some parameters on the mapper (vtkOpenGLGPUVolumeRayCastMapper)…

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## [Different Behavior from vtkAVSucdReader + vtkGeometryFilter going from 9.0.3 to \>= 9.1](https://discourse.vtk.org/t/different-behavior-from-vtkavsucdreader-vtkgeometryfilter-going-from-9-0-3-to-9-1/9868)

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**Author:** [@ksh\_co](https://discourse.vtk.org/u/ksh_co)\
**Replies:** 0\
**Last updated:** [November 17, 2022, 11:40pm UTC](https://discourse.vtk.org/t/different-behavior-from-vtkavsucdreader-vtkgeometryfilter-going-from-9-0-3-to-9-1/9868 "2022-11-17T23:40:55Z")

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Hello I have been using python VTK, as packaged by Anaconda, for about two years now to analyze data contained in unstructured cell data (UCD) meshes. My basic read process is as follows: reader = vtkAVSucdReader() rea…

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## [vtkActor do not rotate as I want](https://discourse.vtk.org/t/vtkactor-do-not-rotate-as-i-want/9849)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 1\
**Last updated:** [November 17, 2022, 8:15pm UTC](https://discourse.vtk.org/t/vtkactor-do-not-rotate-as-i-want/9849 "2022-11-17T20:15:30Z")

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The code to reproduce my problem is: import vtkmodules.all as vtk cylinder = vtk.vtkCylinderSource() cylinder.SetCenter(0, 10, 0) cylinder.SetRadius(5) cylinder.SetHeight(10) cylinder.SetResolution(100) cylinder.Update…

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## [get a continuous line from a polydata structure](https://discourse.vtk.org/t/get-a-continuous-line-from-a-polydata-structure/9864)

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**Author:** [@PBrockmann](https://discourse.vtk.org/u/PBrockmann)\
**Replies:** 4\
**Last updated:** [November 17, 2022, 7:12pm UTC](https://discourse.vtk.org/t/get-a-continuous-line-from-a-polydata-structure/9864 "2022-11-17T19:12:19Z")

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Hi, I would like to create different continuous lines from a polydata made of cells (sparse segments). For now I have successfully found the different regions by using a vtk.vtkPolyDataConnectivityFilter(). I have a q…

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## [Mapper and PolyData Have Different Bounds](https://discourse.vtk.org/t/mapper-and-polydata-have-different-bounds/9839)

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**Author:** [@wmm](https://discourse.vtk.org/u/wmm)\
**Replies:** 0\
**Last updated:** [November 17, 2022, 2:39am UTC](https://discourse.vtk.org/t/mapper-and-polydata-have-different-bounds/9839 "2022-11-17T02:39:07Z")

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I have a vtkPolyData object controlled by a vtkActor and a vtkPolyDataMapper. In the VTK 8.x version of my app I could transform the polydata, store it back in mapper, and the bounds of the actor, mapper, and polydata w…

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## [Get scalar value at selected coordinate from interpolated polydata](https://discourse.vtk.org/t/get-scalar-value-at-selected-coordinate-from-interpolated-polydata/9808)

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**Author:** [@Waldeinsamkeit83](https://discourse.vtk.org/u/Waldeinsamkeit83)\
**Replies:** 4\
**Last updated:** [November 15, 2022, 2:08pm UTC](https://discourse.vtk.org/t/get-scalar-value-at-selected-coordinate-from-interpolated-polydata/9808 "2022-11-15T14:08:26Z")

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Hi, I used PointInterpolater example ( https://kitware.github.io/vtk-examples/site/Cxx/Meshes/PointInterpolator ) code to visualize difference between 3d scanner point cloud data and nominal CAD data. Is it possible to…

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## [vtkContext2D polygon filling disappears when zooming](https://discourse.vtk.org/t/vtkcontext2d-polygon-filling-disappears-when-zooming/9827)

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**Author:** [@Mezitor](https://discourse.vtk.org/u/Mezitor)\
**Replies:** 0\
**Last updated:** [November 15, 2022, 1:38pm UTC](https://discourse.vtk.org/t/vtkcontext2d-polygon-filling-disappears-when-zooming/9827 "2022-11-15T13:38:07Z")

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Hello! I’m using vtkContext2D as painter with DrawQuadStrip function to draw on vtkXYchart. It works fine, but when I’m zooming in filling of quads is disappearing. Only thing I found on it is correspondence with …

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## [Delete() doesn't release memory?](https://discourse.vtk.org/t/delete-doesnt-release-memory/9642)

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**Author:** [@MKRangers](https://discourse.vtk.org/u/MKRangers)\
**Replies:** 15\
**Last updated:** [November 15, 2022, 5:40am UTC](https://discourse.vtk.org/t/delete-doesnt-release-memory/9642 "2022-11-15T05:40:24Z")

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Hi VTK experts, I have a number of image stacks of which I need to crop a VOI out after I assemble them. I used vtkImageAppend\* volumeAppend = vtkImageAppend::New() to assemble these stacks forming one single volume. Th…

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## [How to find all cells connected to a list of points?](https://discourse.vtk.org/t/how-to-find-all-cells-connected-to-a-list-of-points/9765)

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**Author:** [@scotsman60](https://discourse.vtk.org/u/scotsman60)\
**Replies:** 12\
**Last updated:** [November 11, 2022, 9:24pm UTC](https://discourse.vtk.org/t/how-to-find-all-cells-connected-to-a-list-of-points/9765 "2022-11-11T21:24:04Z")

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Hello!!, How can I find the set of cells in a vtkPolyData or vtkUnstructuredGrid that are connected to a set of points? I have a vtkPolyData with a PointData field. I want to find all cells that connect to points where…

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## [Parallel (MPI) point locator](https://discourse.vtk.org/t/parallel-mpi-point-locator/9545)

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**Author:** [@a-jp1](https://discourse.vtk.org/u/a-jp1)\
**Replies:** 9\
**Last updated:** [November 10, 2022, 9:52pm UTC](https://discourse.vtk.org/t/parallel-mpi-point-locator/9545 "2022-11-10T21:52:59Z")

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Hi, I’ve made a lot of use of the vtk point locators before, I have a use case that requires me to build and perform nearest neighbour searches of point trees, distributed over MPI. Is that possible in VTK? Thanks,

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## [Shared Library Names](https://discourse.vtk.org/t/shared-library-names/9767)

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**Author:** [@henrydeere](https://discourse.vtk.org/u/henrydeere)\
**Replies:** 3\
**Last updated:** [November 9, 2022, 6:30pm UTC](https://discourse.vtk.org/t/shared-library-names/9767 "2022-11-09T18:30:35Z")

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I’ve installed vtk version 9.1.0-r4 on my linux system using the package manager, and have also compiled version 9.1.0-r4 from source The package manager installed version has libraries: libvtkCommon-9.1.so libvtkRend…

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## [Add Line on vtkXYPlotActor](https://discourse.vtk.org/t/add-line-on-vtkxyplotactor/9774)

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**Author:** [@fvitello](https://discourse.vtk.org/u/fvitello)\
**Replies:** 1\
**Last updated:** [November 9, 2022, 6:03pm UTC](https://discourse.vtk.org/t/add-line-on-vtkxyplotactor/9774 "2022-11-09T18:03:44Z")

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Hi, Is possibile to add a vertical line (with a different color) in a vtkXYPlotActor plot created from a vtkImageProbeFilter dataset? Thanks

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## [Image Profile](https://discourse.vtk.org/t/image-profile/9768)

<div class="topic-metadata">

**Author:** [@fvitello](https://discourse.vtk.org/u/fvitello)\
**Replies:** 6\
**Last updated:** [November 9, 2022, 5:18pm UTC](https://discourse.vtk.org/t/image-profile/9768 "2022-11-09T17:18:36Z")

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Hi There, I want to implement in my application the possibility to have an xy plot of the intensity values of an image along the X or the Y axis. I have tried to draw vtkLineSource on top of my image and extract the …

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## [How to get VTK9 + Qt6 working together?](https://discourse.vtk.org/t/how-to-get-vtk9-qt6-working-together/4927)

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**Author:** [@NameRakes](https://discourse.vtk.org/u/NameRakes)\
**Replies:** 19\
**Last updated:** [November 9, 2022, 9:01am UTC](https://discourse.vtk.org/t/how-to-get-vtk9-qt6-working-together/4927 "2022-11-09T09:01:50Z")

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I managed to get VTK9 to compile and work with Qt 5.15.2. But my goal is to use Qt6 which was released earlier this month. Key questions are: Can I modify CMake variables (like Qt5\_DIR, etc.) and get it to work with Qt…

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## [Clipping data with manually constructed closed surface polyData.](https://discourse.vtk.org/t/clipping-data-with-manually-constructed-closed-surface-polydata/9538)

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**Author:** [@ugis](https://discourse.vtk.org/u/ugis)\
**Replies:** 11\
**Last updated:** [November 8, 2022, 5:24pm UTC](https://discourse.vtk.org/t/clipping-data-with-manually-constructed-closed-surface-polydata/9538 "2022-11-08T17:24:56Z")

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Hi everyone, I have the following task I want to accomplish. I have results I would like to clip to a specified shape. The shape in my case is constructed via number of 2D polygon surfaces, that combined define an enclo…

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## [How to remove all actors from a renderer?](https://discourse.vtk.org/t/how-to-remove-all-actors-from-a-renderer/9763)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 1\
**Last updated:** [November 8, 2022, 12:27am UTC](https://discourse.vtk.org/t/how-to-remove-all-actors-from-a-renderer/9763 "2022-11-08T00:27:54Z")

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Is it possible to remove all actors from a renderer in VTK-9.3.0? This old post indicates that past VTK versions included vtkRenderer::RemoveAllViewProps(), but that method is no longer supported. Thanks!

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## [The program in VTK 8.1 can't work in VTK 9.2](https://discourse.vtk.org/t/the-program-in-vtk-8-1-cant-work-in-vtk-9-2/9753)

<div class="topic-metadata">

**Author:** [@supersteven](https://discourse.vtk.org/u/supersteven)\
**Replies:** 1\
**Last updated:** [November 7, 2022, 5:35pm UTC](https://discourse.vtk.org/t/the-program-in-vtk-8-1-cant-work-in-vtk-9-2/9753 "2022-11-07T17:35:25Z")

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The program is as follows, which works well in VTK8.2 : //vtkNew\<vtkGPUVolumeRayCastMapper\> volumeMapper; vtkSmartPointer\<vtkGPUVolumeRayCastMapper\> volumeMapper = vtkSmartPointer\<vtkGPUVolumeRayCastMapper\>::New(); volu…

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## [vtk: how to read ply with colors?](https://discourse.vtk.org/t/vtk-how-to-read-ply-with-colors/9749)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 0\
**Last updated:** [November 7, 2022, 5:32am UTC](https://discourse.vtk.org/t/vtk-how-to-read-ply-with-colors/9749 "2022-11-07T05:32:51Z")

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I have a ply file, which is generated from Solidworks: cube.PLY (137 KB). This ply file is colored. I want to load it, and display it with vtk. My code is: import vtkmodules.all as vtk reader = vtk.vtkPLYReader() read…

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## [vtk9 vtkLookupTable transparency](https://discourse.vtk.org/t/vtk9-vtklookuptable-transparency/9728)

<div class="topic-metadata">

**Author:** [@Nil](https://discourse.vtk.org/u/Nil)\
**Replies:** 5\
**Last updated:** [November 4, 2022, 6:35pm UTC](https://discourse.vtk.org/t/vtk9-vtklookuptable-transparency/9728 "2022-11-04T18:35:50Z")

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I’m trying to take a screenshot (vtkWindowToImageFilter) of a 4x4 toy image with a vtkLookupTable that transform NaN values into transparent values. Here’s my code: import numpy as np import vtk data = np.array( \[ …

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