# Latest

**URL:** https://discourse.vtk.org/latest.md?page=203

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

**Page:** 204

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## [Convert .vtk file into nifti format](https://discourse.vtk.org/t/convert-vtk-file-into-nifti-format/3997)

<div class="topic-metadata">

**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 3\
**Last updated:** [August 17, 2020, 4:00pm UTC](https://discourse.vtk.org/t/convert-vtk-file-into-nifti-format/3997 "2020-08-17T16:00:39Z")

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I have first created a vtkParametricEllipsoid (i.e. a surface mesh). I here used trimesh library since it contains a functionality to generate a 3D volume mesh by passing a surface mesh (for that they used gmsh library).…

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## [Save vtk file in old format](https://discourse.vtk.org/t/save-vtk-file-in-old-format/3987)

<div class="topic-metadata">

**Author:** [@Yakov](https://discourse.vtk.org/u/Yakov)\
**Replies:** 1\
**Last updated:** [August 16, 2020, 7:24pm UTC](https://discourse.vtk.org/t/save-vtk-file-in-old-format/3987 "2020-08-16T19:24:20Z")

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If there is a way to save a file in old vtk 3.0 format(except using an old vtk version)?

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## [How can I programmatically set individual voxels?](https://discourse.vtk.org/t/how-can-i-programmatically-set-individual-voxels/3988)

<div class="topic-metadata">

**Author:** [@inhahe](https://discourse.vtk.org/u/inhahe)\
**Replies:** 0\
**Last updated:** [August 16, 2020, 4:36pm UTC](https://discourse.vtk.org/t/how-can-i-programmatically-set-individual-voxels/3988 "2020-08-16T16:36:53Z")

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I want to do some volumetric rendering of a volume I create by setting individual points, not from loading a file and not from using primitives like the cylinder, cone, sphere, etc. How can I do this? Also, is it bad if…

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## [Create volumetric mesh](https://discourse.vtk.org/t/create-volumetric-mesh/3984)

<div class="topic-metadata">

**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 1\
**Last updated:** [August 15, 2020, 5:37pm UTC](https://discourse.vtk.org/t/create-volumetric-mesh/3984 "2020-08-15T17:37:07Z")

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I need to create a volumetric ellipsoid. VTK appears to provide a number of ways to create a mesh representing the surface of a 3D object. Therefore I used the example given in \[1\] to first create a vtkParametricEllipso…

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## [Can't access VTK classes or methods in python](https://discourse.vtk.org/t/cant-access-vtk-classes-or-methods-in-python/3913)

<div class="topic-metadata">

**Author:** [@epaj95](https://discourse.vtk.org/u/epaj95)\
**Replies:** 1\
**Last updated:** [August 14, 2020, 4:04pm UTC](https://discourse.vtk.org/t/cant-access-vtk-classes-or-methods-in-python/3913 "2020-08-14T16:04:30Z")

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Hello all, I’m having a strange issue using VTK in python. I have created a conda environment and installed VTK 8.1 from the anaconda channel. In VScode, I’ve set the python interpreter to this conda env, and can import…

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## [How to use a Custom LookupTable, vtkThresholdPoints with vtkGlyph3DMapper](https://discourse.vtk.org/t/how-to-use-a-custom-lookuptable-vtkthresholdpoints-with-vtkglyph3dmapper/3979)

<div class="topic-metadata">

**Author:** [@Seun](https://discourse.vtk.org/u/Seun)\
**Replies:** 0\
**Last updated:** [August 14, 2020, 2:19pm UTC](https://discourse.vtk.org/t/how-to-use-a-custom-lookuptable-vtkthresholdpoints-with-vtkglyph3dmapper/3979 "2020-08-14T14:19:33Z")

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Hi everyone, I’ve got this issue working with vtkGlyph3DMapper. Basically, I’ve got a polydata populated with points of which each individual point has a value (magnitude) associated with it. This array of magnitude is …

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## [How split image data with plane form DICOM images](https://discourse.vtk.org/t/how-split-image-data-with-plane-form-dicom-images/3955)

<div class="topic-metadata">

**Author:** [@11112](https://discourse.vtk.org/u/11112)\
**Replies:** 5\
**Last updated:** [August 14, 2020, 10:01am UTC](https://discourse.vtk.org/t/how-split-image-data-with-plane-form-dicom-images/3955 "2020-08-14T10:01:54Z")

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I already have a series of DICOM images as CT of verts, I read it with vtkDICOMReader. And use volume ray cast to transform as 3D image. Now I need to split each vert by plane, and get slice of 3 dimensions. How can I…

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## [vtk Streamlines from numpy array](https://discourse.vtk.org/t/vtk-streamlines-from-numpy-array/3977)

<div class="topic-metadata">

**Author:** [@prateekm](https://discourse.vtk.org/u/prateekm)\
**Replies:** 0\
**Last updated:** [August 14, 2020, 8:28am UTC](https://discourse.vtk.org/t/vtk-streamlines-from-numpy-array/3977 "2020-08-14T08:28:18Z")

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I m new to vtk I want to generate vtk streamlines from data stored in numpy array …how can I do that?? Thanks in advance.

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## [Formatting Own Data into vtk Supported Format](https://discourse.vtk.org/t/formatting-own-data-into-vtk-supported-format/3928)

<div class="topic-metadata">

**Author:** [@samm-vs](https://discourse.vtk.org/u/samm-vs)\
**Replies:** 3\
**Last updated:** [August 13, 2020, 9:32pm UTC](https://discourse.vtk.org/t/formatting-own-data-into-vtk-supported-format/3928 "2020-08-13T21:32:59Z")

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Hi I am a student in college trying to do a project using vtk.js to visualize datasets. However, the polydata datasets that the prof provide me are not any commonly supported types. Moreover, I am not famility with 3D da…

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## [How to create a gradient color shift](https://discourse.vtk.org/t/how-to-create-a-gradient-color-shift/3973)

<div class="topic-metadata">

**Author:** [@samm-vs](https://discourse.vtk.org/u/samm-vs)\
**Replies:** 1\
**Last updated:** [August 13, 2020, 5:54pm UTC](https://discourse.vtk.org/t/how-to-create-a-gradient-color-shift/3973 "2020-08-13T17:54:09Z")

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I have scaler data for color ranging from -5.000 to 5.000 with -1000000000.0 as areas I would like to be transparent. how do I create a color transfer function or an opacity function where the flow of color from -5 to 5 …

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## [Write file in vtk format](https://discourse.vtk.org/t/write-file-in-vtk-format/3964)

<div class="topic-metadata">

**Author:** [@Yakov](https://discourse.vtk.org/u/Yakov)\
**Replies:** 0\
**Last updated:** [August 13, 2020, 10:21am UTC](https://discourse.vtk.org/t/write-file-in-vtk-format/3964 "2020-08-13T10:21:04Z")

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I want to create vtk file with mesh The vtk should have : vtk DataFile Version 3.0 POINTS POLYGONS NORMALS I create a 3d cube object cube1 = vtk.vtkCubeSource() cube1.SetXLength(6) cube1.SetYLength(10) cube1.SetZLe…

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## [Trouble between pointer of vtkObject and emscripten](https://discourse.vtk.org/t/trouble-between-pointer-of-vtkobject-and-emscripten/3971)

<div class="topic-metadata">

**Author:** [@Nicolas\_Lenoir](https://discourse.vtk.org/u/Nicolas_Lenoir)\
**Replies:** 0\
**Last updated:** [August 13, 2020, 1:52pm UTC](https://discourse.vtk.org/t/trouble-between-pointer-of-vtkobject-and-emscripten/3971 "2020-08-13T13:52:07Z")

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Hello I have a question about the using of vtk in the binding of a c++ class that use some vtkObject pointer, in fact I can compile my bind with emscripten and when I run the .js file in output I can execute my test code…

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## [QGraphicsitems in QGraphicsscene](https://discourse.vtk.org/t/qgraphicsitems-in-qgraphicsscene/3970)

<div class="topic-metadata">

**Author:** [@tommi](https://discourse.vtk.org/u/tommi)\
**Replies:** 0\
**Last updated:** [August 13, 2020, 1:02pm UTC](https://discourse.vtk.org/t/qgraphicsitems-in-qgraphicsscene/3970 "2020-08-13T13:02:01Z")

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Hello, i want to use Qt - QGraphicsitems in a QGraphicsscene with VTK-Support. But is seems, that QVTKGraphicsitem is no longer supportet. Is there an alternative?

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## [Visualization of 2D height point data.](https://discourse.vtk.org/t/visualization-of-2d-height-point-data/3951)

<div class="topic-metadata">

**Author:** [@NeoDreamer](https://discourse.vtk.org/u/NeoDreamer)\
**Replies:** 4\
**Last updated:** [August 13, 2020, 7:26am UTC](https://discourse.vtk.org/t/visualization-of-2d-height-point-data/3951 "2020-08-13T07:26:00Z")

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I have height point data that shape of 2D matrix. Which is best way to visualize that data.

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## [Ghost points and ExtractSurface](https://discourse.vtk.org/t/ghost-points-and-extractsurface/3901)

<div class="topic-metadata">

**Author:** [@cchan](https://discourse.vtk.org/u/cchan)\
**Replies:** 3\
**Last updated:** [August 11, 2020, 8:44pm UTC](https://discourse.vtk.org/t/ghost-points-and-extractsurface/3901 "2020-08-11T20:44:41Z")

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Hello! I’m writing a C++ VTK filter, and I’m trying to understand the idea of ghost points and how multiblock topology works. My understanding is that in MPI mode, ExtractSurface should be ignoring boundaries between M…

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## [Show specific tissue on vtkVolume](https://discourse.vtk.org/t/show-specific-tissue-on-vtkvolume/3916)

<div class="topic-metadata">

**Author:** [@flaviu2](https://discourse.vtk.org/u/flaviu2)\
**Replies:** 5\
**Last updated:** [August 11, 2020, 5:58pm UTC](https://discourse.vtk.org/t/show-specific-tissue-on-vtkvolume/3916 "2020-08-11T17:58:41Z")

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I have a vtkVolume on a vtkRenderer, with AddRGBPoint call and AddPoint call for vtkColorTransferFunction and vtkPiecewiseFunction used for vtkVolumeProperty. Is there any possibility to color in a solid color (red or s…

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## [Where to find old vtk for Python?](https://discourse.vtk.org/t/where-to-find-old-vtk-for-python/3937)

<div class="topic-metadata">

**Author:** [@tbillah](https://discourse.vtk.org/u/tbillah)\
**Replies:** 5\
**Last updated:** [August 11, 2020, 5:50pm UTC](https://discourse.vtk.org/t/where-to-find-old-vtk-for-python/3937 "2020-08-11T17:50:07Z")

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Hi all, vtk PyPI only has versions \>8.0.0. Is there a place where I can get vtk==7.1? I tried pip install vtk==7.1 only to run in to: Collecting vtk==7.1 ERROR: Could not find a version that satisfies the requirement…

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## [How can i use the vtkStreamtracer to generate a streamline with my unstructured grid data(vtu)](https://discourse.vtk.org/t/how-can-i-use-the-vtkstreamtracer-to-generate-a-streamline-with-my-unstructured-grid-data-vtu/790)

<div class="topic-metadata">

**Author:** [@stargazer](https://discourse.vtk.org/u/stargazer)\
**Replies:** 6\
**Last updated:** [August 11, 2020, 5:44pm UTC](https://discourse.vtk.org/t/how-can-i-use-the-vtkstreamtracer-to-generate-a-streamline-with-my-unstructured-grid-data-vtu/790 "2020-08-11T17:44:56Z")

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I\`m using VTK to visualize data coming from xflow in vtu. When I use the Paraview, it can generate the right streamline, but when I use the VTK to visualize my data, it only displays the outline and the airplane mode…

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## [Updating data input for VolumeMapper without copying data](https://discourse.vtk.org/t/updating-data-input-for-volumemapper-without-copying-data/3943)

<div class="topic-metadata">

**Author:** [@R.Engelken](https://discourse.vtk.org/u/R.Engelken)\
**Replies:** 2\
**Last updated:** [August 11, 2020, 3:29pm UTC](https://discourse.vtk.org/t/updating-data-input-for-volumemapper-without-copying-data/3943 "2020-08-11T15:29:01Z")

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Hello, I use the following pipeline: ImageData -\> SmartVolumeMapper -\> … with 1 scalar component To prevent copying data I want to retrieve a pointer to the image data array and give it to another interface If I use …

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## [Contour filter - add nodes programatically](https://discourse.vtk.org/t/contour-filter-add-nodes-programatically/1127)

<div class="topic-metadata">

**Author:** [@Andyjk1406](https://discourse.vtk.org/u/Andyjk1406)\
**Replies:** 7\
**Last updated:** [August 11, 2020, 1:48pm UTC](https://discourse.vtk.org/t/contour-filter-add-nodes-programatically/1127 "2020-08-11T13:48:49Z")

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I’m struggling to add nodes programatically. I can add one, but then things crash when I try to add a second or try to interact to add more nodes. I have modified this example with about 6 more lines near the end as sho…

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## [VTK 9 Python vtkContextView not working](https://discourse.vtk.org/t/vtk-9-python-vtkcontextview-not-working/3761)

<div class="topic-metadata">

**Author:** [@wfenz](https://discourse.vtk.org/u/wfenz)\
**Replies:** 8\
**Last updated:** [August 11, 2020, 12:24pm UTC](https://discourse.vtk.org/t/vtk-9-python-vtkcontextview-not-working/3761 "2020-08-11T12:24:05Z")

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Hello, I tried a simple example showing a 2D Graph in a Context View, which runs without problems in VTK 8.2, but leads to a segmentation fault when using VTK 9.01 (under Windows 10, Python 3.6.8). Is this a known issue,…

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## [Issue with VTK 9.0.2 - vtk DICOM reader and viewer2](https://discourse.vtk.org/t/issue-with-vtk-9-0-2-vtk-dicom-reader-and-viewer2/3946)

<div class="topic-metadata">

**Author:** [@Balaji](https://discourse.vtk.org/u/Balaji)\
**Replies:** 2\
**Last updated:** [August 11, 2020, 4:40am UTC](https://discourse.vtk.org/t/issue-with-vtk-9-0-2-vtk-dicom-reader-and-viewer2/3946 "2020-08-11T04:40:46Z")

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Hi, I’m newbie with Qt and VTK. Here my task is to display dicom image in Qt desktop GUI application. Qt version 5.12 Vtk version 9.0.2 Window 10, VS 16 2017 I have tried with VTK example of ReadDicomseriesQt, When…

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## [Create polyline using independent color from each point](https://discourse.vtk.org/t/create-polyline-using-independent-color-from-each-point/3949)

<div class="topic-metadata">

**Author:** [@lyz](https://discourse.vtk.org/u/lyz)\
**Replies:** 0\
**Last updated:** [August 11, 2020, 1:35am UTC](https://discourse.vtk.org/t/create-polyline-using-independent-color-from-each-point/3949 "2020-08-11T01:35:40Z")

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Is there some method to create polyline using independent color from each point? each point owns the unique color. and the color of the polyline is interpolated by each point.

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## [Crashes on mac OS](https://discourse.vtk.org/t/crashes-on-mac-os/3531)

<div class="topic-metadata">

**Author:** [@codeling](https://discourse.vtk.org/u/codeling)\
**Replies:** 6\
**Last updated:** [August 10, 2020, 10:29pm UTC](https://discourse.vtk.org/t/crashes-on-mac-os/3531 "2020-08-10T22:29:12Z")

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We have a program using Qt and VTK that runs on both Windows and Linux, and which I am now trying to get running on Mac OS. I have managed to get it to build and run there, but when loading a dataset (which triggers show…

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## [Catching opengl errors](https://discourse.vtk.org/t/catching-opengl-errors/3945)

<div class="topic-metadata">

**Author:** [@mykolav](https://discourse.vtk.org/u/mykolav)\
**Replies:** 1\
**Last updated:** [August 10, 2020, 7:54pm UTC](https://discourse.vtk.org/t/catching-opengl-errors/3945 "2020-08-10T19:54:21Z")

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Hi all, what would be the recommended way to handle errors that occur inside vtk, specifically connected with opengl errors? I’m creating a volume with dimensions that exceed my available VRAM, and I get the opengl and …

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## [How to render a GLTF model correctly](https://discourse.vtk.org/t/how-to-render-a-gltf-model-correctly/3938)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 1\
**Last updated:** [August 9, 2020, 8:40am UTC](https://discourse.vtk.org/t/how-to-render-a-gltf-model-correctly/3938 "2020-08-09T08:40:44Z")

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Hi everyone, I have compiled and built VTK 9.0.1 successfully. I want to load a gltf model. It’s a cube exported from blender2.8 and it can be render in other gltf viewer. I use vtkGLTFReader . I can get nbScenes and n…

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## [FourPaneViewer example gives error glBindFramebuffer1 OpenGL errors detected](https://discourse.vtk.org/t/fourpaneviewer-example-gives-error-glbindframebuffer1-opengl-errors-detected/3922)

<div class="topic-metadata">

**Author:** [@Enes\_Albay](https://discourse.vtk.org/u/Enes_Albay)\
**Replies:** 2\
**Last updated:** [August 7, 2020, 3:02pm UTC](https://discourse.vtk.org/t/fourpaneviewer-example-gives-error-glbindframebuffer1-opengl-errors-detected/3922 "2020-08-07T15:02:36Z")

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Hi, I am trying to run FourPaneViewer example which is provided by VTK. I have updated it to work with VTK 9.x. But the example gives errors at the following lines: for this line : riw\[i\]-\>SetInputData(reader-\>GetOutpu…

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## [vtkWrapHierarchy.cmake help/reminder](https://discourse.vtk.org/t/vtkwraphierarchy-cmake-help-reminder/3929)

<div class="topic-metadata">

**Author:** [@djduke](https://discourse.vtk.org/u/djduke)\
**Replies:** 1\
**Last updated:** [August 7, 2020, 12:08pm UTC](https://discourse.vtk.org/t/vtkwraphierarchy-cmake-help-reminder/3929 "2020-08-07T12:08:45Z")

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I’ve been trying to rebuild a local project after a significant break, and am running in o a problem. when I try to configure I get find: vtkWrapHierarchy.cmake: No such file or directory My VTK Users’s guides is stu…

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## [detect large curvature](https://discourse.vtk.org/t/detect-large-curvature/3933)

<div class="topic-metadata">

**Author:** [@Daniel](https://discourse.vtk.org/u/Daniel)\
**Replies:** 0\
**Last updated:** [August 7, 2020, 9:28am UTC](https://discourse.vtk.org/t/detect-large-curvature/3933 "2020-08-07T09:28:57Z")

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Hi there, I have a vtkPolyData on which I want to detect “strong” curvatures. At best the coordinates of these places should be stored. In the screenshot a possible situation is circled. Here the whole encircled are…

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## [Slow when using vtkRenderer, vtkRenderWindow](https://discourse.vtk.org/t/slow-when-using-vtkrenderer-vtkrenderwindow/3906)

<div class="topic-metadata">

**Author:** [@Seram](https://discourse.vtk.org/u/Seram)\
**Replies:** 6\
**Last updated:** [August 7, 2020, 6:20am UTC](https://discourse.vtk.org/t/slow-when-using-vtkrenderer-vtkrenderwindow/3906 "2020-08-07T06:20:26Z")

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Hello I received 3D Sensor data and developed 3D Viewer using VTK. The time to call both functions continues to increase. Global variable vtkNew m\_vtkRenderWindow; vtkNew m\_vtkRenderer; UpdatePointerToWindow() { …

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