# Latest

**URL:** https://discourse.vtk.org/latest.md?page=101

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

**Page:** 102

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## [vtkTextActor (0x26049358): Failed getting the TextRenderer instance!](https://discourse.vtk.org/t/vtktextactor-0x26049358-failed-getting-the-textrenderer-instance/1931)

<div class="topic-metadata">

**Author:** [@KeyboardMan](https://discourse.vtk.org/u/KeyboardMan)\
**Replies:** 6\
**Last updated:** [January 19, 2023, 6:47am UTC](https://discourse.vtk.org/t/vtktextactor-0x26049358-failed-getting-the-textrenderer-instance/1931 "2023-01-19T06:47:30Z")

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## [About vtkCornerAnnotation rendering slow](https://discourse.vtk.org/t/about-vtkcornerannotation-rendering-slow/10493)

<div class="topic-metadata">

**Author:** [@marlon.ma](https://discourse.vtk.org/u/marlon.ma)\
**Replies:** 0\
**Last updated:** [January 19, 2023, 1:28am UTC](https://discourse.vtk.org/t/about-vtkcornerannotation-rendering-slow/10493 "2023-01-19T01:28:06Z")

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I finished an mpr display, but I found a problem where I used the vtkCornerAnnotation class to synchronize the window width display in each window when adjusting the window width. However, I found that the rendering spee…

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## [Using C++ code in VTK.js](https://discourse.vtk.org/t/using-c-code-in-vtk-js/7271)

<div class="topic-metadata">

**Author:** [@shrikant](https://discourse.vtk.org/u/shrikant)\
**Replies:** 8\
**Last updated:** [January 18, 2023, 10:53pm UTC](https://discourse.vtk.org/t/using-c-code-in-vtk-js/7271 "2023-01-18T22:53:48Z")

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Hi, I am trying to use my existing C++ code in VTK.js. I saw Emscripten related examples. However, it uses the docker. I simply wanted to C++ code in VTK.js and on Windows platform. is there any other way to accomplis…

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## [vtkvoroni2d doesn't work probably](https://discourse.vtk.org/t/vtkvoroni2d-doesnt-work-probably/10478)

<div class="topic-metadata">

**Author:** [@AndreAhmed](https://discourse.vtk.org/u/AndreAhmed)\
**Replies:** 8\
**Last updated:** [January 18, 2023, 11:42am UTC](https://discourse.vtk.org/t/vtkvoroni2d-doesnt-work-probably/10478 "2023-01-18T11:42:33Z")

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I’m trying to generate a grid of voroni2D, here is the code, and the output, is really weird int i = 0; while (i \< 1000) { float pt\_x = rand\_FloatRange(0, 1); float pt\_y = rand\_FloatRange(0, 1); points\_voron…

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## [Blank scrren using imgui-vtk](https://discourse.vtk.org/t/blank-scrren-using-imgui-vtk/10488)

<div class="topic-metadata">

**Author:** [@claid00](https://discourse.vtk.org/u/claid00)\
**Replies:** 0\
**Last updated:** [January 18, 2023, 7:25am UTC](https://discourse.vtk.org/t/blank-scrren-using-imgui-vtk/10488 "2023-01-18T07:25:11Z")

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Dear all developers, I’m developing 3d visualizer using imgui-vtk. Standalone project for 3d visualizer with imgui-vtk works fine, but it does NOT when I integrate other project. The other project has developed by onl…

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## [VTK for Android](https://discourse.vtk.org/t/vtk-for-android/5604)

<div class="topic-metadata">

**Author:** [@timt](https://discourse.vtk.org/u/timt)\
**Replies:** 10\
**Last updated:** [January 18, 2023, 12:15am UTC](https://discourse.vtk.org/t/vtk-for-android/5604 "2023-01-18T00:15:00Z")

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I am currently trying to build any recent version of VTK with any recent version of Android using: cmake -S vtk -B vtk-android-build -GNinja -DVTK\_ANDROID\_BUILD=ON cmake --build vtk-android-build I have tried the follo…

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## [how to create a 3d surface and display it in vtk](https://discourse.vtk.org/t/how-to-create-a-3d-surface-and-display-it-in-vtk/10461)

<div class="topic-metadata">

**Author:** [@we\_create](https://discourse.vtk.org/u/we_create)\
**Replies:** 1\
**Last updated:** [January 17, 2023, 5:24pm UTC](https://discourse.vtk.org/t/how-to-create-a-3d-surface-and-display-it-in-vtk/10461 "2023-01-17T17:24:40Z")

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Right now I have 3 curves and what I what is to make a surface from this curves.Is there any way to do this (any predifined class or filter).If so can anybody plz guide me.

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## [Measure, segment.](https://discourse.vtk.org/t/measure-segment/10424)

<div class="topic-metadata">

**Author:** [@jane](https://discourse.vtk.org/u/jane)\
**Replies:** 1\
**Last updated:** [January 17, 2023, 3:14pm UTC](https://discourse.vtk.org/t/measure-segment/10424 "2023-01-17T15:14:00Z")

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I display the 3D results on the front end through the remoteview, can I interoperate through the three.js? For example, measuring, segmenting, etc.

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## [How modify the scalars of the volume?](https://discourse.vtk.org/t/how-modify-the-scalars-of-the-volume/10434)

<div class="topic-metadata">

**Author:** [@YagoM](https://discourse.vtk.org/u/YagoM)\
**Replies:** 1\
**Last updated:** [January 17, 2023, 3:10pm UTC](https://discourse.vtk.org/t/how-modify-the-scalars-of-the-volume/10434 "2023-01-17T15:10:33Z")

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Hi! I’m trying to hide/turn transparent some specific points from the vtkVolume. How can i achieve this? Actually i’m trying to modify the scalar values of this points to a specific value (for example “-3024”) and the p…

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## [Whether the properties of the volume drawing map, such as gradient opacity, can be changed during interaction. If so, how?](https://discourse.vtk.org/t/whether-the-properties-of-the-volume-drawing-map-such-as-gradient-opacity-can-be-changed-during-interaction-if-so-how/10460)

<div class="topic-metadata">

**Author:** [@zbz](https://discourse.vtk.org/u/zbz)\
**Replies:** 1\
**Last updated:** [January 17, 2023, 2:28pm UTC](https://discourse.vtk.org/t/whether-the-properties-of-the-volume-drawing-map-such-as-gradient-opacity-can-be-changed-during-interaction-if-so-how/10460 "2023-01-17T14:28:52Z")

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Whether the properties of the volume drawing map, such as gradient opacity, can be changed during interaction. If so, how?

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## [Out of memory for huge volume](https://discourse.vtk.org/t/out-of-memory-for-huge-volume/10118)

<div class="topic-metadata">

**Author:** [@WilliManFR](https://discourse.vtk.org/u/WilliManFR)\
**Replies:** 12\
**Last updated:** [January 17, 2023, 11:25am UTC](https://discourse.vtk.org/t/out-of-memory-for-huge-volume/10118 "2023-01-17T11:25:58Z")

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Hello, I am a student. I am currently working on a project, where I have to generate a large cube composed of small cubes. For this, I generated csv files for vertices, edges, faces and also tetrahedra. Then in VTK I cr…

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## [Unable to move around in VR](https://discourse.vtk.org/t/unable-to-move-around-in-vr/10450)

<div class="topic-metadata">

**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 2\
**Last updated:** [January 17, 2023, 8:34am UTC](https://discourse.vtk.org/t/unable-to-move-around-in-vr/10450 "2023-01-17T08:34:58Z")

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I’ve managed to build a VTK python wheel with OpenVR enabled and I’m toying with the following example. I’m unable to move around the scene. The sphere renders, but I cannot fly around or translate. I notice an error o…

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## [\[OpenVR\] Set scale or motion factor from UI crashes](https://discourse.vtk.org/t/openvr-set-scale-or-motion-factor-from-ui-crashes/10474)

<div class="topic-metadata">

**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 1\
**Last updated:** [January 17, 2023, 8:33am UTC](https://discourse.vtk.org/t/openvr-set-scale-or-motion-factor-from-ui-crashes/10474 "2023-01-17T08:33:39Z")

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If I try to use the UI to change the Scale Factor or Motion Factor, the VR app crashes without any error messages… I’ve also tried programmatically calling SetPhysicalScale(), but that has seemingly no affect. Any tips …

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## [Render Window Screenshot Capture with svg elements (e.g. LabelWidget)](https://discourse.vtk.org/t/render-window-screenshot-capture-with-svg-elements-e-g-labelwidget/10464)

<div class="topic-metadata">

**Author:** [@Kalsyc](https://discourse.vtk.org/u/Kalsyc)\
**Replies:** 3\
**Last updated:** [January 17, 2023, 7:59am UTC](https://discourse.vtk.org/t/render-window-screenshot-capture-with-svg-elements-e-g-labelwidget/10464 "2023-01-17T07:59:21Z")

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Hi vtk community and maintainers, I would like to ask for help with regard to a screenshot capture for a render window with svg inline elements. For example, let’s say for vtk.js, I would like to screenshot both the bac…

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## [vtkRenderWindow Render method on server](https://discourse.vtk.org/t/vtkrenderwindow-render-method-on-server/10440)

<div class="topic-metadata">

**Author:** [@RAUMIK\_RANA](https://discourse.vtk.org/u/RAUMIK_RANA)\
**Replies:** 4\
**Last updated:** [January 17, 2023, 4:22am UTC](https://discourse.vtk.org/t/vtkrenderwindow-render-method-on-server/10440 "2023-01-17T04:22:44Z")

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vtkRenderWindow Render method on Linux server not working getting below error vtkXOpenGLRenderWindow.:464 ERR| vtkXOpenGLRenderWindow (0x55edd2d73ce0): bad X server connection. DISPLAY=

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## [VR scenes are rotated](https://discourse.vtk.org/t/vr-scenes-are-rotated/10451)

<div class="topic-metadata">

**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 4\
**Last updated:** [January 16, 2023, 9:03pm UTC](https://discourse.vtk.org/t/vr-scenes-are-rotated/10451 "2023-01-16T21:03:21Z")

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Whenever rendering with OpenVR, the scene is rotated. This is clearly visible with an vtkAxesActor. The Z axis is parallel to the floor… this is not expected. import vtk from vtkmodules.vtkRenderingOpenVR import ( …

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## [How to add Dates to X-Axis of Line Plot](https://discourse.vtk.org/t/how-to-add-dates-to-x-axis-of-line-plot/10466)

<div class="topic-metadata">

**Author:** [@DavidA](https://discourse.vtk.org/u/DavidA)\
**Replies:** 0\
**Last updated:** [January 16, 2023, 10:51am UTC](https://discourse.vtk.org/t/how-to-add-dates-to-x-axis-of-line-plot/10466 "2023-01-16T10:51:53Z")

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I followed the examples provided on the vtk.org website and am able to create line plots, scatter plots, etc. but so far I have only been able to have a running number along the X-Axis. I would like to change the running…

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## [vtkInteractorStyleRubberBand2D inverted pan controls](https://discourse.vtk.org/t/vtkinteractorstylerubberband2d-inverted-pan-controls/10462)

<div class="topic-metadata">

**Author:** [@gbene](https://discourse.vtk.org/u/gbene)\
**Replies:** 0\
**Last updated:** [January 16, 2023, 9:42am UTC](https://discourse.vtk.org/t/vtkinteractorstylerubberband2d-inverted-pan-controls/10462 "2023-01-16T09:42:42Z")

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Hi all! I was experimenting with the vtkInteractorStyleRubberBand2D interactor and I have encountered a strange behavior. It seems that when changing the camera’s position to \[0, 0, -1\] (view from below), the the horizo…

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## [how to create a polydata when points(x,y,z) are given.](https://discourse.vtk.org/t/how-to-create-a-polydata-when-points-x-y-z-are-given/10387)

<div class="topic-metadata">

**Author:** [@we\_create](https://discourse.vtk.org/u/we_create)\
**Replies:** 5\
**Last updated:** [January 16, 2023, 8:31am UTC](https://discourse.vtk.org/t/how-to-create-a-polydata-when-points-x-y-z-are-given/10387 "2023-01-16T08:31:59Z")

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Hi all, can anybody guide me with creating a poly data when x,y,z. I have the points in a text format.Do we have predifined class and if there is any can anybody guide me with creating the polydata(a 3d view) with poin…

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## [using CellPicker with Trame "Surface Picking" example](https://discourse.vtk.org/t/using-cellpicker-with-trame-surface-picking-example/10404)

<div class="topic-metadata">

**Author:** [@Robert\_Collar](https://discourse.vtk.org/u/Robert_Collar)\
**Replies:** 4\
**Last updated:** [January 16, 2023, 1:29am UTC](https://discourse.vtk.org/t/using-cellpicker-with-trame-surface-picking-example/10404 "2023-01-16T01:29:04Z")

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Hi VTK Community! In the “Surface Picking” Trame example, found here, a user can “pick” locations on the screen and the closest point in the racecar mesh is selected and indicated with a cone pointer + tooltip. As far a…

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## [How to highlight a smooth region on a polygonal mesh](https://discourse.vtk.org/t/how-to-highlight-a-smooth-region-on-a-polygonal-mesh/1813)

<div class="topic-metadata">

**Author:** [@eustache](https://discourse.vtk.org/u/eustache)\
**Replies:** 9\
**Last updated:** [January 15, 2023, 8:47pm UTC](https://discourse.vtk.org/t/how-to-highlight-a-smooth-region-on-a-polygonal-mesh/1813 "2023-01-15T20:47:25Z")

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The goal is to highlight a smooth region on a polygonal mesh. I am investigating two different techniques: select cells on the surface of the mesh itself and apply some texture on them, but then I can’t have smooth bor…

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## [How to make a poly data more dense?](https://discourse.vtk.org/t/how-to-make-a-poly-data-more-dense/10459)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 3\
**Last updated:** [January 15, 2023, 4:31pm UTC](https://discourse.vtk.org/t/how-to-make-a-poly-data-more-dense/10459 "2023-01-15T16:31:55Z")

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For example, I have a poly data: How can I make it more dense? The dense means more point in the circle. I expect the following poly data: Is there any filter to make poly data more dense? Any suggestion is apprec…

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## [Visualise the errors as relative to the magnitude of the deformation](https://discourse.vtk.org/t/visualise-the-errors-as-relative-to-the-magnitude-of-the-deformation/10418)

<div class="topic-metadata">

**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 7\
**Last updated:** [January 15, 2023, 12:49pm UTC](https://discourse.vtk.org/t/visualise-the-errors-as-relative-to-the-magnitude-of-the-deformation/10418 "2023-01-15T12:49:31Z")

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I have two volumetric liver meshes (groundturht and predicted versions) in .vtk format (i.e. ground-truth and predicted versions) and I want to visualise the errors as relative to the magnitude of the deformation on the …

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## [Resampling and ploting multiple slices from a vtkPolydata](https://discourse.vtk.org/t/resampling-and-ploting-multiple-slices-from-a-vtkpolydata/10443)

<div class="topic-metadata">

**Author:** [@Jishnu](https://discourse.vtk.org/u/Jishnu)\
**Replies:** 5\
**Last updated:** [January 15, 2023, 7:05am UTC](https://discourse.vtk.org/t/resampling-and-ploting-multiple-slices-from-a-vtkpolydata/10443 "2023-01-15T07:05:29Z")

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I have a vtkPolydata with 3D coordinates of the vertex of the grid as points and Temperature at each point stored as point field data. I want to plot the Temperature distribution at different elevations. I am using Pytho…

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## [vtkWin32OpenGLRenderWindow: GLEW could not be initialized: Missing GL version](https://discourse.vtk.org/t/vtkwin32openglrenderwindow-glew-could-not-be-initialized-missing-gl-version/7517)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 5\
**Last updated:** [January 14, 2023, 1:31pm UTC](https://discourse.vtk.org/t/vtkwin32openglrenderwindow-glew-could-not-be-initialized-missing-gl-version/7517 "2023-01-14T13:31:13Z")

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I meet a bug: The code to reproduce this bug is: vtkSmartPointer\<vtkSphereSource\> source = vtkSmartPointer\<vtkSphereSource\>::New(); source-\>Update(); vtkSmartPointer\<vtkPolyDataMapper\> mapper = vtkSmartPointer\<vtkPo…

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## [How to save the 3D medical image reconstructed by the volume drawing algorithm as a PLY file to the local computer](https://discourse.vtk.org/t/how-to-save-the-3d-medical-image-reconstructed-by-the-volume-drawing-algorithm-as-a-ply-file-to-the-local-computer/9982)

<div class="topic-metadata">

**Author:** [@mmXIO](https://discourse.vtk.org/u/mmXIO)\
**Replies:** 12\
**Last updated:** [January 14, 2023, 5:00am UTC](https://discourse.vtk.org/t/how-to-save-the-3d-medical-image-reconstructed-by-the-volume-drawing-algorithm-as-a-ply-file-to-the-local-computer/9982 "2023-01-14T05:00:58Z")

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How to save the 3D medical image reconstructed by the volume drawing algorithm as a PLY file to the local computer

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## [Is it possible to achieve bloom/glow effect in VTK?](https://discourse.vtk.org/t/is-it-possible-to-achieve-bloom-glow-effect-in-vtk/10438)

<div class="topic-metadata">

**Author:** [@sherinnovation](https://discourse.vtk.org/u/sherinnovation)\
**Replies:** 1\
**Last updated:** [January 13, 2023, 9:07pm UTC](https://discourse.vtk.org/t/is-it-possible-to-achieve-bloom-glow-effect-in-vtk/10438 "2023-01-13T21:07:56Z")

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I have some points and lines in my scene, and I want to get a glow effect displayed for those lines and points. If there are no builtin classes in VTK to achieve this, what are the alternate options to achieve this? Any …

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## [How to improve noises of displaying 2D DICOM slices with rendering vtk and make it more clear ?](https://discourse.vtk.org/t/how-to-improve-noises-of-displaying-2d-dicom-slices-with-rendering-vtk-and-make-it-more-clear/1843)

<div class="topic-metadata">

**Author:** [@kimia.af1998](https://discourse.vtk.org/u/kimia.af1998)\
**Replies:** 16\
**Last updated:** [January 13, 2023, 1:18pm UTC](https://discourse.vtk.org/t/how-to-improve-noises-of-displaying-2d-dicom-slices-with-rendering-vtk-and-make-it-more-clear/1843 "2023-01-13T13:18:37Z")

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Here is my code to display 2d slices of DICOM volume using vtk renderer with python : # Read DICOM images self.reader = vtk.vtkDICOMImageReader() self.reader.SetDirectoryName(folder) self.reader.Update()…

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## [vtkClipPolyData leaving some edges](https://discourse.vtk.org/t/vtkclippolydata-leaving-some-edges/10442)

<div class="topic-metadata">

**Author:** [@nico-arnold](https://discourse.vtk.org/u/nico-arnold)\
**Replies:** 0\
**Last updated:** [January 13, 2023, 12:09pm UTC](https://discourse.vtk.org/t/vtkclippolydata-leaving-some-edges/10442 "2023-01-13T12:09:38Z")

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Hello everybody, I am using Vedo and VTK to cut up a flat 3D model into different regions to do some selective mesh refinement and transformations later. For that, I need to extract regions that are going to be transfor…

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## [vtkRenderLargeImage restarting celery on server](https://discourse.vtk.org/t/vtkrenderlargeimage-restarting-celery-on-server/10437)

<div class="topic-metadata">

**Author:** [@RAUMIK\_RANA](https://discourse.vtk.org/u/RAUMIK_RANA)\
**Replies:** 0\
**Last updated:** [January 13, 2023, 6:31am UTC](https://discourse.vtk.org/t/vtkrenderlargeimage-restarting-celery-on-server/10437 "2023-01-13T06:31:21Z")

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I want to take screentshot of renderWindow. So I am using “vtkRenderLargeImage” for that I have used offScringRenderig. renderWindow.SetOffScreenRendering(1) w2Image = vtk.vtkRenderLargeImage() w2Image.SetInput(inRen…

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