# Latest

**URL:** https://discourse.vtk.org/latest.md?page=211

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

**Page:** 212

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## [vtkOBBTree with Multiple Lines](https://discourse.vtk.org/t/vtkobbtree-with-multiple-lines/3459)

<div class="topic-metadata">

**Author:** [@akaszynski](https://discourse.vtk.org/u/akaszynski)\
**Replies:** 2\
**Last updated:** [June 4, 2020, 2:56pm UTC](https://discourse.vtk.org/t/vtkobbtree-with-multiple-lines/3459 "2020-06-04T14:56:01Z")

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Hello, Is there any way to support multiple line segments via vtk via python? points = vtk.vtkPoints() cell\_ids = vtk.vtkIdList() poly\_data.obbTree.IntersectWithLine(np.array(origin), …

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## [Filter documentation](https://discourse.vtk.org/t/filter-documentation/3457)

<div class="topic-metadata">

**Author:** [@SimonFuet](https://discourse.vtk.org/u/SimonFuet)\
**Replies:** 3\
**Last updated:** [June 4, 2020, 7:35am UTC](https://discourse.vtk.org/t/filter-documentation/3457 "2020-06-04T07:35:50Z")

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Hi all, Is there an up-to-date documentation about VTK filters? i.e. a description of everything we must, should and can do when implementing a new filter… More precisely, the ProcessRequest method needs to be reimplem…

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## [Repeating Timer does not fire events if no other event occurs](https://discourse.vtk.org/t/repeating-timer-does-not-fire-events-if-no-other-event-occurs/2873)

<div class="topic-metadata">

**Author:** [@TomLKoller](https://discourse.vtk.org/u/TomLKoller)\
**Replies:** 2\
**Last updated:** [June 4, 2020, 2:08am UTC](https://discourse.vtk.org/t/repeating-timer-does-not-fire-events-if-no-other-event-occurs/2873 "2020-06-04T02:08:55Z")

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I was trying the Animation example https://lorensen.github.io/VTKExamples/site/Cxx/Utilities/Animation/ and it seems as the RepeatingTimer does only fire events when i hover the mouse over the window. When i stop the mo…

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## [Color](https://discourse.vtk.org/t/color/3439)

<div class="topic-metadata">

**Author:** [@Lokeshwar\_Obuli](https://discourse.vtk.org/u/Lokeshwar_Obuli)\
**Replies:** 2\
**Last updated:** [June 3, 2020, 4:46pm UTC](https://discourse.vtk.org/t/color/3439 "2020-06-03T16:46:34Z")

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What is the exact code to set the color and opacity of the actor. I am trying to render a .vtp file.

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## [Point Data as Input to vtkOrderStatistics/vtkDescriptiveStatistics](https://discourse.vtk.org/t/point-data-as-input-to-vtkorderstatistics-vtkdescriptivestatistics/3454)

<div class="topic-metadata">

**Author:** [@Resa](https://discourse.vtk.org/u/Resa)\
**Replies:** 3\
**Last updated:** [June 3, 2020, 1:58pm UTC](https://discourse.vtk.org/t/point-data-as-input-to-vtkorderstatistics-vtkdescriptivestatistics/3454 "2020-06-03T13:58:55Z")

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I am trying to use the function vtkOrderStatistics in order to compute the 20% quantiles of the point-data in Sphere-Clips. for example of this array: paraview.servermanager.Fetch(clip1).GetPointData().GetArray('activat…

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## [Calling Render method on vtkRenderWindow produces an error. (Vtk 9.0 - Python wrapper)](https://discourse.vtk.org/t/calling-render-method-on-vtkrenderwindow-produces-an-error-vtk-9-0-python-wrapper/3451)

<div class="topic-metadata">

**Author:** [@efdiloreto](https://discourse.vtk.org/u/efdiloreto)\
**Replies:** 4\
**Last updated:** [June 3, 2020, 12:16pm UTC](https://discourse.vtk.org/t/calling-render-method-on-vtkrenderwindow-produces-an-error-vtk-9-0-python-wrapper/3451 "2020-06-03T12:16:40Z")

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I’m trying to change the color of one of the actors. After change the color in the actor, I call the Render method and produces this error. 2020-06-01 12:45:40.413 ( 5.598s) \[ \] vtkOpenGLState.cxx:…

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## [Interaction problem while multi-object rendered in one actor](https://discourse.vtk.org/t/interaction-problem-while-multi-object-rendered-in-one-actor/3428)

<div class="topic-metadata">

**Author:** [@Cheng1087](https://discourse.vtk.org/u/Cheng1087)\
**Replies:** 1\
**Last updated:** [June 2, 2020, 9:18pm UTC](https://discourse.vtk.org/t/interaction-problem-while-multi-object-rendered-in-one-actor/3428 "2020-06-02T21:18:43Z")

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If there are many objects rendered in one actor, and I want to highlight one of the objects I clicked. there is a example: there are thousands sphere rendered in one actor, I used vtkCellPicker to select a cell, and I…

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## [question about draw region of interest](https://discourse.vtk.org/t/question-about-draw-region-of-interest/3429)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 1\
**Last updated:** [June 2, 2020, 9:06pm UTC](https://discourse.vtk.org/t/question-about-draw-region-of-interest/3429 "2020-06-02T21:06:01Z")

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The DICOM image can be read and rendered by using vtkResliceImageViewer. I want to draw region of interest(ROI) with the shapes like rectangle, circle(as the following picture show). After that, I want to modify the pix…

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## [How to create a vtkImageData with a three-channel matrix?](https://discourse.vtk.org/t/how-to-create-a-vtkimagedata-with-a-three-channel-matrix/3431)

<div class="topic-metadata">

**Author:** [@xun\_zhou](https://discourse.vtk.org/u/xun_zhou)\
**Replies:** 1\
**Last updated:** [June 2, 2020, 9:05pm UTC](https://discourse.vtk.org/t/how-to-create-a-vtkimagedata-with-a-three-channel-matrix/3431 "2020-06-02T21:05:09Z")

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Now i have a three-channel matrix, which represents an RGB image. I want to create a vtkImageData to store it.How can i set the properties of the vtkImageData?

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## [How to extract the points from vtkPoints with vtkLineWidget2?](https://discourse.vtk.org/t/how-to-extract-the-points-from-vtkpoints-with-vtklinewidget2/3449)

<div class="topic-metadata">

**Author:** [@Kim\_William](https://discourse.vtk.org/u/Kim_William)\
**Replies:** 1\
**Last updated:** [June 2, 2020, 7:36pm UTC](https://discourse.vtk.org/t/how-to-extract-the-points-from-vtkpoints-with-vtklinewidget2/3449 "2020-06-02T19:36:49Z")

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Hi all :slight\_smile: I am using vtkLineWidget2 attached to vtkRenderWindow. Is it possible to extract the points near(or along the vtkLineWidget2) the vtkLineWidget2? I would like to render the profile to the vtkCh…

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## [Is there a way not to use large contiguous memory?](https://discourse.vtk.org/t/is-there-a-way-not-to-use-large-contiguous-memory/3443)

<div class="topic-metadata">

**Author:** [@Yongun\_Lee](https://discourse.vtk.org/u/Yongun_Lee)\
**Replies:** 4\
**Last updated:** [June 2, 2020, 7:24pm UTC](https://discourse.vtk.org/t/is-there-a-way-not-to-use-large-contiguous-memory/3443 "2020-06-02T19:24:10Z")

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Is there a way not to use large contiguous memory? Hi. I am having a problem with memory fragmentation on 32bit operating system. https://vtk.org/pipermail/vtkusers/2010-July/061439.html https://vtk.org/pipermail/vtk…

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## [Texture mapping from 3 view based images](https://discourse.vtk.org/t/texture-mapping-from-3-view-based-images/3446)

<div class="topic-metadata">

**Author:** [@millerBrown](https://discourse.vtk.org/u/millerBrown)\
**Replies:** 0\
**Last updated:** [June 2, 2020, 7:41am UTC](https://discourse.vtk.org/t/texture-mapping-from-3-view-based-images/3446 "2020-06-02T07:41:26Z")

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i am a student in medical device engineering and i’m interested in the use of VTK I have 3d model with unwrapped UV and I have 3 images taken from 3 different angles in an equal light source. I only want to stitch im…

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## [Extract Point Data included in Line](https://discourse.vtk.org/t/extract-point-data-included-in-line/3434)

<div class="topic-metadata">

**Author:** [@Seram](https://discourse.vtk.org/u/Seram)\
**Replies:** 1\
**Last updated:** [June 1, 2020, 4:12pm UTC](https://discourse.vtk.org/t/extract-point-data-included-in-line/3434 "2020-06-01T16:12:29Z")

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Hello I want to extract the point data included in the line. I would be grateful if you could give me any hints or methods. My purpose is to compare the height (= Z) by outputting the Point Data in Profile form. T…

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## [Change actor color after window is rendered](https://discourse.vtk.org/t/change-actor-color-after-window-is-rendered/3437)

<div class="topic-metadata">

**Author:** [@efdiloreto](https://discourse.vtk.org/u/efdiloreto)\
**Replies:** 1\
**Last updated:** [June 1, 2020, 3:48pm UTC](https://discourse.vtk.org/t/change-actor-color-after-window-is-rendered/3437 "2020-06-01T15:48:00Z")

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Hi everybody, I am starting with VTK and I encounter this issue. I searched for this problem but I didn’t find anything. I hope somebody can help me. I’m trying to change the color of one of the actors. Seems like the m…

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## [About LineWidget2 Display](https://discourse.vtk.org/t/about-linewidget2-display/3433)

<div class="topic-metadata">

**Author:** [@Seram](https://discourse.vtk.org/u/Seram)\
**Replies:** 0\
**Last updated:** [June 1, 2020, 9:17am UTC](https://discourse.vtk.org/t/about-linewidget2-display/3433 "2020-06-01T09:17:18Z")

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Hello I have a question LineWidget2 (https://vtk.org/Wiki/VTK/Examples/Cxx/Widgets/LineWidget2) The line is not displayed until the mouse is over it. I want to know how to display lines before posting. \< Visualizati…

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## [Customizing dashboards](https://discourse.vtk.org/t/customizing-dashboards/3422)

<div class="topic-metadata">

**Author:** [@miro](https://discourse.vtk.org/u/miro)\
**Replies:** 1\
**Last updated:** [June 1, 2020, 1:34am UTC](https://discourse.vtk.org/t/customizing-dashboards/3422 "2020-06-01T01:34:24Z")

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Hi all, I’m trying to configure dashboard for our company project, and I can’t figure out how to set custom dashboards, e.g. master or merge-requests that I see on VTK’s dashboard. I only get the default Experimental, C…

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## [Building fails generating wrap hierarchy for VTK::CommonCore unable to open libvtkWrappingTools.so.1](https://discourse.vtk.org/t/building-fails-generating-wrap-hierarchy-for-vtk-commoncore-unable-to-open-libvtkwrappingtools-so-1/3427)

<div class="topic-metadata">

**Author:** [@badshah400](https://discourse.vtk.org/u/badshah400)\
**Replies:** 2\
**Last updated:** [May 31, 2020, 11:18pm UTC](https://discourse.vtk.org/t/building-fails-generating-wrap-hierarchy-for-vtk-commoncore-unable-to-open-libvtkwrappingtools-so-1/3427 "2020-05-31T23:18:42Z")

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When building VTK 9.0.0 on openSUSE Leap systems, I encounter the following issue \[ 172s\] make\[2\]: Entering directory '/home/abuild/rpmbuild/BUILD/VTK-9.0.0/build' \[ 172s\] \[ 2%\] Building C object Wrapping/Tools/CMake…

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## [How to deploy vtkNIFTIImagePrivate.h to the install path by cmake](https://discourse.vtk.org/t/how-to-deploy-vtkniftiimageprivate-h-to-the-install-path-by-cmake/3416)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 4\
**Last updated:** [May 30, 2020, 4:45pm UTC](https://discourse.vtk.org/t/how-to-deploy-vtkniftiimageprivate-h-to-the-install-path-by-cmake/3416 "2020-05-30T16:45:32Z")

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I want to use nifti\_1\_header struct in vtkNIFTIImagePrivate.h. I find the header file does not exsit in my vtk install path. I guess that I have missed some option in cmake. So, I want to know how to make correct setting…

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## [Vtk.js: Display vtkImageData with cellData](https://discourse.vtk.org/t/vtk-js-display-vtkimagedata-with-celldata/3417)

<div class="topic-metadata">

**Author:** [@emmanuel\_madarassou](https://discourse.vtk.org/u/emmanuel_madarassou)\
**Replies:** 1\
**Last updated:** [May 29, 2020, 1:01pm UTC](https://discourse.vtk.org/t/vtk-js-display-vtkimagedata-with-celldata/3417 "2020-05-29T13:01:34Z")

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Hi everyone, I’m trying to render cell data with vtkImageData to do something like a powermap. In my code I’m setting my cell data and when I add actor to the renderer, I have an error related to the pointData of my imag…

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## [How to transform coordinate between world coordinate system and volume(data) coordinate system](https://discourse.vtk.org/t/how-to-transform-coordinate-between-world-coordinate-system-and-volume-data-coordinate-system/3419)

<div class="topic-metadata">

**Author:** [@jiangyuanzhu](https://discourse.vtk.org/u/jiangyuanzhu)\
**Replies:** 0\
**Last updated:** [May 29, 2020, 12:43pm UTC](https://discourse.vtk.org/t/how-to-transform-coordinate-between-world-coordinate-system-and-volume-data-coordinate-system/3419 "2020-05-29T12:43:41Z")

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ear VTK, Could you please share more information about how to transform coordinate between world coordinate system and volume(data) coordinate system? In my project, a NIFTI volume data is loaded.And I displayed this v…

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## [How to manage vtkActor.](https://discourse.vtk.org/t/how-to-manage-vtkactor/3368)

<div class="topic-metadata">

**Author:** [@Yongun\_Lee](https://discourse.vtk.org/u/Yongun_Lee)\
**Replies:** 1\
**Last updated:** [May 28, 2020, 8:55pm UTC](https://discourse.vtk.org/t/how-to-manage-vtkactor/3368 "2020-05-28T20:55:16Z")

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Hello, I would like some advice on how to manage vtkActor. For example, is there a recommended way to remove only certain vtkActors added to the renderer? My program holds a pointer to a specific vtkActor, then there i…

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## [how to use "vtkStreamTracer"](https://discourse.vtk.org/t/how-to-use-vtkstreamtracer/3389)

<div class="topic-metadata">

**Author:** [@xuexl](https://discourse.vtk.org/u/xuexl)\
**Replies:** 3\
**Last updated:** [May 28, 2020, 8:28pm UTC](https://discourse.vtk.org/t/how-to-use-vtkstreamtracer/3389 "2020-05-28T20:28:45Z")

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I have two questions about “vtkStreamTracer”. One is the data setting by “SetInputConnection”, what is the format of data ? can i create by myself ? The other is the source setting by “SetSourceConnection”, why need t…

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## [Is it possible to run a VTK based application on a Windows server that does not have OpenGL support?](https://discourse.vtk.org/t/is-it-possible-to-run-a-vtk-based-application-on-a-windows-server-that-does-not-have-opengl-support/3414)

<div class="topic-metadata">

**Author:** [@rsahu](https://discourse.vtk.org/u/rsahu)\
**Replies:** 3\
**Last updated:** [May 28, 2020, 5:41pm UTC](https://discourse.vtk.org/t/is-it-possible-to-run-a-vtk-based-application-on-a-windows-server-that-does-not-have-opengl-support/3414 "2020-05-28T17:41:14Z")

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I tried using a VTK based application on a Windows server machine that does not have OpenGL support. The program crashes immediately for lack of OpenGL support. Is it possible to run a VTK based application on such a pl…

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## [VTK in Kivy app](https://discourse.vtk.org/t/vtk-in-kivy-app/3407)

<div class="topic-metadata">

**Author:** [@Hamburgerfinger](https://discourse.vtk.org/u/Hamburgerfinger)\
**Replies:** 0\
**Last updated:** [May 28, 2020, 5:42am UTC](https://discourse.vtk.org/t/vtk-in-kivy-app/3407 "2020-05-28T05:42:19Z")

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Has anyone tried to use VTK with the Kivy UI library? I’d like to add a vtk render window to a Kivy app, but have mostly no idea where to start.

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## [Can't change axis labels in vtkChartXYZ?](https://discourse.vtk.org/t/cant-change-axis-labels-in-vtkchartxyz/3394)

<div class="topic-metadata">

**Author:** [@mdaley](https://discourse.vtk.org/u/mdaley)\
**Replies:** 7\
**Last updated:** [May 28, 2020, 2:55am UTC](https://discourse.vtk.org/t/cant-change-axis-labels-in-vtkchartxyz/3394 "2020-05-28T02:55:43Z")

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Hello, in a vtkChartXY, I can just do this to change the title of an axis: chart-\>GetAxis(0)-\>SetTitle("My excellent axis title"); However, in a vtkChartXYZ the equiavalent code doesn’t work and I always get the same t…

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## [How to disable dragging for spline widget?](https://discourse.vtk.org/t/how-to-disable-dragging-for-spline-widget/3402)

<div class="topic-metadata">

**Author:** [@jaswantp](https://discourse.vtk.org/u/jaswantp)\
**Replies:** 0\
**Last updated:** [May 27, 2020, 10:13pm UTC](https://discourse.vtk.org/t/how-to-disable-dragging-for-spline-widget/3402 "2020-05-27T22:13:12Z")

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I want to limit the spline widget to a certain bounding box. In python, SetDragable is unavailable. I cannot even access the LineActor attribute and set it’s dragable property either! How to do it?

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## [Missing files or paths](https://discourse.vtk.org/t/missing-files-or-paths/3397)

<div class="topic-metadata">

**Author:** [@Quinn\_B](https://discourse.vtk.org/u/Quinn_B)\
**Replies:** 2\
**Last updated:** [May 27, 2020, 4:49pm UTC](https://discourse.vtk.org/t/missing-files-or-paths/3397 "2020-05-27T16:49:12Z")

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Hello again while trying to configure the build and generate the files I ran into these errors and was wondering if I needed to install another package or modify some files

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## [fill closed contours](https://discourse.vtk.org/t/fill-closed-contours/3343)

<div class="topic-metadata">

**Author:** [@Nina](https://discourse.vtk.org/u/Nina)\
**Replies:** 5\
**Last updated:** [May 21, 2020, 12:43am UTC](https://discourse.vtk.org/t/fill-closed-contours/3343 "2020-05-21T00:43:37Z")

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Hi, I want assing a 255 value for pixels inside a contour and 0 for outside pixels. the contour is composed of a set of 3D points that have same z-value. are there a vtk filters that allow to do that? vtkPolygon::Pointi…

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## [Smoothing Surface crashing](https://discourse.vtk.org/t/smoothing-surface-crashing/3384)

<div class="topic-metadata">

**Author:** [@ilandaniele](https://discourse.vtk.org/u/ilandaniele)\
**Replies:** 5\
**Last updated:** [May 26, 2020, 7:05pm UTC](https://discourse.vtk.org/t/smoothing-surface-crashing/3384 "2020-05-26T19:05:46Z")

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Good afternoon. In my project i convert a vtkVolume by some given DICOM files. Then i convert my vtkVolume on to a Surface by using vtkMarchingCubes and 6 steps more. Code is the following (myVolume is a class that in…

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## [Downgrade from OpenGL ES 4.6 Mesa 20.0.4 to OpenGL ES 3.0 Mesa 19.2.8 in ubuntu 20](https://discourse.vtk.org/t/downgrade-from-opengl-es-4-6-mesa-20-0-4-to-opengl-es-3-0-mesa-19-2-8-in-ubuntu-20/3395)

<div class="topic-metadata">

**Author:** [@vacingforo](https://discourse.vtk.org/u/vacingforo)\
**Replies:** 0\
**Last updated:** [May 26, 2020, 8:38am UTC](https://discourse.vtk.org/t/downgrade-from-opengl-es-4-6-mesa-20-0-4-to-opengl-es-3-0-mesa-19-2-8-in-ubuntu-20/3395 "2020-05-26T08:38:52Z")

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I have an application based on VTK 8.1.0 which only runs with OpenGL ES 3.0 Mesa 19.2.8 (Ubuntu 18). I want to run it in ubuntu 20 but the problem is that the version of opengl library is OpenGL ES 4.6 Mesa 20.0.4. Is t…

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