# Latest

**URL:** https://discourse.vtk.org/latest.md?page=139

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

**Page:** 140

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## [Visualize Field data python](https://discourse.vtk.org/t/visualize-field-data-python/8066)

<div class="topic-metadata">

**Author:** [@imomnipresent](https://discourse.vtk.org/u/imomnipresent)\
**Replies:** 0\
**Last updated:** [March 16, 2022, 8:24am UTC](https://discourse.vtk.org/t/visualize-field-data-python/8066 "2022-03-16T08:24:41Z")

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I would like to visualize the displacement field data on my unstructured grid created using vtkPoints() in python. I have the displacement field data at each point. How can i create a vtu file with all these data (point …

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## [How to sharpe the rendered volume?](https://discourse.vtk.org/t/how-to-sharpe-the-rendered-volume/8019)

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**Author:** [@Yuvi-416](https://discourse.vtk.org/u/Yuvi-416)\
**Replies:** 5\
**Last updated:** [March 15, 2022, 5:41pm UTC](https://discourse.vtk.org/t/how-to-sharpe-the-rendered-volume/8019 "2022-03-15T17:41:40Z")

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Hi there, I tried to render the DICOM image using both VTK Python and VTK.js. The VTK Python output is more sharp and very good, whereas the output that I receive from VTK.js is not very good as I am using the same para…

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## [How to save the graphics file created by the widget](https://discourse.vtk.org/t/how-to-save-the-graphics-file-created-by-the-widget/8053)

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**Author:** [@3xxx](https://discourse.vtk.org/u/3xxx)\
**Replies:** 2\
**Last updated:** [March 15, 2022, 3:56pm UTC](https://discourse.vtk.org/t/how-to-save-the-graphics-file-created-by-the-widget/8053 "2022-03-15T15:56:44Z")

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Dear VTK team, I draw the lines with the mouse and want to save then like .vtk file, see the example LineWidget I’m looking for a way to save all the lines data to an file in VTK.js. Could you please advice me somethi…

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## [Get closest line segment](https://discourse.vtk.org/t/get-closest-line-segment/8050)

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**Author:** [@rvilums](https://discourse.vtk.org/u/rvilums)\
**Replies:** 1\
**Last updated:** [March 15, 2022, 2:16pm UTC](https://discourse.vtk.org/t/get-closest-line-segment/8050 "2022-03-15T14:16:53Z")

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Hi! I have a polyData consisting of lines. When I click on the screen, how to get the closest line/cell. My idea is the following. Get line or two points of the ray representing downwards line from camera (how? where …

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## [Extract specified contour from vtkImageData](https://discourse.vtk.org/t/extract-specified-contour-from-vtkimagedata/8055)

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**Author:** [@xianger.qi](https://discourse.vtk.org/u/xianger.qi)\
**Replies:** 0\
**Last updated:** [March 15, 2022, 7:24am UTC](https://discourse.vtk.org/t/extract-specified-contour-from-vtkimagedata/8055 "2022-03-15T07:24:37Z")

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i have a vtkImageData, and a contour polydata. please refer to below picture. the white contour, which is refered by red arrow represent clipping contour clips the volume data. i want to get the target vtkimagedata …

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## [How to get the pixel data of the current view after adjusting the camera？](https://discourse.vtk.org/t/how-to-get-the-pixel-data-of-the-current-view-after-adjusting-the-camera/8047)

<div class="topic-metadata">

**Author:** [@whxxyhf](https://discourse.vtk.org/u/whxxyhf)\
**Replies:** 1\
**Last updated:** [March 14, 2022, 1:30pm UTC](https://discourse.vtk.org/t/how-to-get-the-pixel-data-of-the-current-view-after-adjusting-the-camera/8047 "2022-03-14T13:30:25Z")

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I use volume actor to create MPR view. When I adjust the camera, I want to get the pixel data of the new view before rendering. Can you help me?

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## [VTK in a c# application](https://discourse.vtk.org/t/vtk-in-a-c-application/8043)

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**Author:** [@Fred](https://discourse.vtk.org/u/Fred)\
**Replies:** 2\
**Last updated:** [March 14, 2022, 1:05pm UTC](https://discourse.vtk.org/t/vtk-in-a-c-application/8043 "2022-03-14T13:05:31Z")

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Hi, I am building an application in C# and I would like to know if it si possible to use VTK in such application. If so is it possible to render 3D volumes, and if so what data structure should I use. Frederic.

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## [9 node quadrilateral file format](https://discourse.vtk.org/t/9-node-quadrilateral-file-format/8036)

<div class="topic-metadata">

**Author:** [@jman87](https://discourse.vtk.org/u/jman87)\
**Replies:** 1\
**Last updated:** [March 14, 2022, 7:42am UTC](https://discourse.vtk.org/t/9-node-quadrilateral-file-format/8036 "2022-03-14T07:42:19Z")

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Hi all, Can anyone tell me if there is a 9-node quad element supported in vtk? And if so, what the node numbering and element type is? I know there’s a 27-node hex supported that is not yet documented in the User’s Gui…

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## [Where to find treemesh.vtk](https://discourse.vtk.org/t/where-to-find-treemesh-vtk/8037)

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**Author:** [@BlueKnight7](https://discourse.vtk.org/u/BlueKnight7)\
**Replies:** 2\
**Last updated:** [March 13, 2022, 7:35pm UTC](https://discourse.vtk.org/t/where-to-find-treemesh-vtk/8037 "2022-03-13T19:35:20Z")

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I can’t seem to find where I can download files like treemesh.vtk as discussed in the ClipUnstructuredGridWithPlane example. Can someone point me to the location?

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## [Whenerever i pass getGaussianBlurPass output to mapper to render, the canvas shows nothing](https://discourse.vtk.org/t/whenerever-i-pass-getgaussianblurpass-output-to-mapper-to-render-the-canvas-shows-nothing/8045)

<div class="topic-metadata">

**Author:** [@Yuvi-416](https://discourse.vtk.org/u/Yuvi-416)\
**Replies:** 0\
**Last updated:** [March 13, 2022, 4:22pm UTC](https://discourse.vtk.org/t/whenerever-i-pass-getgaussianblurpass-output-to-mapper-to-render-the-canvas-shows-nothing/8045 "2022-03-13T16:22:57Z")

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I am trying to apply getGaussianBlurPass filter to decrease the noise from the image and then pass that image to mapper for rendering. But whenever i try that canvas shows empty image. And in console: I receive No input…

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## [How to define different unstructured grids that share the same points (also for different time steps)](https://discourse.vtk.org/t/how-to-define-different-unstructured-grids-that-share-the-same-points-also-for-different-time-steps/8041)

<div class="topic-metadata">

**Author:** [@bva99](https://discourse.vtk.org/u/bva99)\
**Replies:** 0\
**Last updated:** [March 12, 2022, 4:02pm UTC](https://discourse.vtk.org/t/how-to-define-different-unstructured-grids-that-share-the-same-points-also-for-different-time-steps/8041 "2022-03-12T16:02:44Z")

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Is it possible to define different unstructured grids that share the same Points, without having to write the points in each file? This is supposing only one time-step. I imagine that vtkMultiPieceDataSet should do so, …

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## [How to generate Vascular stent?](https://discourse.vtk.org/t/how-to-generate-vascular-stent/8032)

<div class="topic-metadata">

**Author:** [@junqiangchen](https://discourse.vtk.org/u/junqiangchen)\
**Replies:** 1\
**Last updated:** [March 12, 2022, 5:45am UTC](https://discourse.vtk.org/t/how-to-generate-vascular-stent/8032 "2022-03-12T05:45:30Z")

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hi,i want generate Virtual Vascular Stent in VTK，i can generate simple Vascular Stent,like this and i want make simple Vascular Stent more truely，like this result： can anyone know how to do it? thank you!!

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## [Can't change color of vtkParametricFunction generated object](https://discourse.vtk.org/t/cant-change-color-of-vtkparametricfunction-generated-object/8034)

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**Author:** [@niebrueg](https://discourse.vtk.org/u/niebrueg)\
**Replies:** 1\
**Last updated:** [March 12, 2022, 4:47am UTC](https://discourse.vtk.org/t/cant-change-color-of-vtkparametricfunction-generated-object/8034 "2022-03-12T04:47:33Z")

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I’m generating a custom parametric object and it always draws as black regardless of what I try. I want to color it based on the distance from the origin. I’ve tried SetScalarModeToDistance on the Parametric Function S…

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## [Two renderer on same layer](https://discourse.vtk.org/t/two-renderer-on-same-layer/8030)

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**Author:** [@DLevy](https://discourse.vtk.org/u/DLevy)\
**Replies:** 2\
**Last updated:** [March 11, 2022, 9:24pm UTC](https://discourse.vtk.org/t/two-renderer-on-same-layer/8030 "2022-03-11T21:24:21Z")

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Hello, im trying to display a point cloud and the axis/ground/various static data. I can create my points and axis without any issue. My problem is that the lines that represent the axis are always in front, even if th…

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## [vtkImageResliceMapper and ResampleToScreenPixels on HiDPI display](https://discourse.vtk.org/t/vtkimagereslicemapper-and-resampletoscreenpixels-on-hidpi-display/8018)

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**Author:** [@simonesneault](https://discourse.vtk.org/u/simonesneault)\
**Replies:** 6\
**Last updated:** [March 11, 2022, 3:07pm UTC](https://discourse.vtk.org/t/vtkimagereslicemapper-and-resampletoscreenpixels-on-hidpi-display/8018 "2022-03-11T15:07:00Z")

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Hello community, We have done the migration from the old vtkImagePlaneWidget to the less old vtkImageResliceMapper in our software. This greatly improve the quality of the rendering when we are zooming, but on some setu…

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## [Produce VTK unstuctured grid output without copying data into VTK](https://discourse.vtk.org/t/produce-vtk-unstuctured-grid-output-without-copying-data-into-vtk/7980)

<div class="topic-metadata">

**Author:** [@Luke\_Dalessandro](https://discourse.vtk.org/u/Luke_Dalessandro)\
**Replies:** 3\
**Last updated:** [March 11, 2022, 3:05pm UTC](https://discourse.vtk.org/t/produce-vtk-unstuctured-grid-output-without-copying-data-into-vtk/7980 "2022-03-11T15:05:52Z")

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We’ve been using VTK/ParaView for a couple of years now as an output format for our simulations for a-posteriori visualization an analysis. The current solution is to copy all of the relevant simulation data out of our s…

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## [Python wrappers for Qt model adapters](https://discourse.vtk.org/t/python-wrappers-for-qt-model-adapters/8022)

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**Author:** [@manatee](https://discourse.vtk.org/u/manatee)\
**Replies:** 0\
**Last updated:** [March 10, 2022, 4:34pm UTC](https://discourse.vtk.org/t/python-wrappers-for-qt-model-adapters/8022 "2022-03-10T16:34:49Z")

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Hi all, are there any plans to provide wrappers for Qt model adapters anytime soon? The one I’m most interested in is QVTKTableModelAdapter. I tried building from source with Qt, but haven’t found them. Should that hav…

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## [How to add color to vtkUnstructuredGrid vtkTetra data not add color to its point](https://discourse.vtk.org/t/how-to-add-color-to-vtkunstructuredgrid-vtktetra-data-not-add-color-to-its-point/8024)

<div class="topic-metadata">

**Author:** [@xiaoerlaigeid](https://discourse.vtk.org/u/xiaoerlaigeid)\
**Replies:** 2\
**Last updated:** [March 11, 2022, 3:49am UTC](https://discourse.vtk.org/t/how-to-add-color-to-vtkunstructuredgrid-vtktetra-data-not-add-color-to-its-point/8024 "2022-03-11T03:49:54Z")

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I want to add colour to the vtkTetra itself, not its points. Could anyone give me a example? This example is add color to the points vtk-examples/Cube.py at aa1716a165150f338f6182ce1ac174334f3b9003 · Kitware/vtk-example…

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## [Does it have to keep two 3d images has the same spacing and origin when using vtkImageBlend to blend them?](https://discourse.vtk.org/t/does-it-have-to-keep-two-3d-images-has-the-same-spacing-and-origin-when-using-vtkimageblend-to-blend-them/8017)

<div class="topic-metadata">

**Author:** [@snow](https://discourse.vtk.org/u/snow)\
**Replies:** 2\
**Last updated:** [March 11, 2022, 1:40am UTC](https://discourse.vtk.org/t/does-it-have-to-keep-two-3d-images-has-the-same-spacing-and-origin-when-using-vtkimageblend-to-blend-them/8017 "2022-03-11T01:40:31Z")

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I have 2 3d images ,which have different dimension, origin and spacing ,they both are Grayscale image . When i use volume rendering or put them in 3dSclicer , Their spatial positions match well. but when i use vtkim…

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## [CellData removed after FlyingEdges3d](https://discourse.vtk.org/t/celldata-removed-after-flyingedges3d/8015)

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**Author:** [@sassafrass](https://discourse.vtk.org/u/sassafrass)\
**Replies:** 7\
**Last updated:** [March 10, 2022, 8:49pm UTC](https://discourse.vtk.org/t/celldata-removed-after-flyingedges3d/8015 "2022-03-10T20:49:12Z")

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I am relatively new user of VTK. I’m rendering an isosurface with the following procedure: 1 Create vtkUnisgnedCharArray with the scalars on a 3D grid. 2 Create an vtkImageData and set the PointData to the scalars arr…

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## [jupyterview - A VTK Data visualization extension for JupyterLab](https://discourse.vtk.org/t/jupyterview-a-vtk-data-visualization-extension-for-jupyterlab/8012)

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**Author:** [@trungleduc](https://discourse.vtk.org/u/trungleduc)\
**Replies:** 4\
**Last updated:** [March 10, 2022, 5:47pm UTC](https://discourse.vtk.org/t/jupyterview-a-vtk-data-visualization-extension-for-jupyterlab/8012 "2022-03-10T17:47:55Z")

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Hello, First of all, I would like to thank all people working on vtk.js, it is a great library! I created jupyterview, an extension that integrates vtk.js with jupyterlab. It can read vtu, vtp, vtk , pvd file and it su…

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## [apply undo/redo on a vtkActor](https://discourse.vtk.org/t/apply-undo-redo-on-a-vtkactor/8020)

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**Author:** [@willk](https://discourse.vtk.org/u/willk)\
**Replies:** 0\
**Last updated:** [March 10, 2022, 3:45pm UTC](https://discourse.vtk.org/t/apply-undo-redo-on-a-vtkactor/8020 "2022-03-10T15:45:00Z")

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How can i apply a undo/redo action on a Actor so that I can comeback to the previous movement of the actor?

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## [Fixed VTK Java Wrappers on macOS](https://discourse.vtk.org/t/fixed-vtk-java-wrappers-on-macos/7467)

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**Author:** [@Martin3d](https://discourse.vtk.org/u/Martin3d)\
**Replies:** 2\
**Last updated:** [March 10, 2022, 3:08pm UTC](https://discourse.vtk.org/t/fixed-vtk-java-wrappers-on-macos/7467 "2022-03-10T15:08:22Z")

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Hi, I just would like to report that running VTK Java wrappers on macOS no longer crashes as long as one use JOGL 2.4. I have patched JOGL 2.4 so that it can run on Apple M1 and deployed the whole as maven artifacts on…

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## [How to merge two resliceActors one on top of other?](https://discourse.vtk.org/t/how-to-merge-two-resliceactors-one-on-top-of-other/8005)

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**Author:** [@stoune](https://discourse.vtk.org/u/stoune)\
**Replies:** 3\
**Last updated:** [March 10, 2022, 12:17pm UTC](https://discourse.vtk.org/t/how-to-merge-two-resliceactors-one-on-top-of-other/8005 "2022-03-10T12:17:24Z")

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Hey, in a ResliceCursorWidget, I’m trying to display the brain volume, in addition to a fMRI mask on the top of it, so on each widget interaction we could see the changes in the brain slices and in fMRI slices, I used a…

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## [a question about vtkImplicitFunction::EvaluateGradient](https://discourse.vtk.org/t/a-question-about-vtkimplicitfunction-evaluategradient/7999)

<div class="topic-metadata">

**Author:** [@KeyboardMan](https://discourse.vtk.org/u/KeyboardMan)\
**Replies:** 10\
**Last updated:** [March 10, 2022, 6:02am UTC](https://discourse.vtk.org/t/a-question-about-vtkimplicitfunction-evaluategradient/7999 "2022-03-10T06:02:15Z")

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The description on the documentation is "Evaluate function gradient at position x-y-z and pass back vector.But I don’t understand what it does. I created a new class，inherited from vtkImplicitFunction,i overrid EvaluateG…

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## [model on top issue in WASM](https://discourse.vtk.org/t/model-on-top-issue-in-wasm/8016)

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**Author:** [@reichtiger](https://discourse.vtk.org/u/reichtiger)\
**Replies:** 0\
**Last updated:** [March 10, 2022, 2:28am UTC](https://discourse.vtk.org/t/model-on-top-issue-in-wasm/8016 "2022-03-10T02:28:58Z")

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Hello, everyone. I have successfully compile VTK-9.1.0 to webassembly and it runs in docker fine. Here is the issue when I need to show model on top of others. On win11 local C++, it runs OK : =======================…

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## [Lesson 17.1: Point Membership Classification with OpenCascade + VTK](https://discourse.vtk.org/t/lesson-17-1-point-membership-classification-with-opencascade-vtk/8009)

<div class="topic-metadata">

**Author:** [@anon41080341](https://discourse.vtk.org/u/anon41080341)\
**Replies:** 0\
**Last updated:** [March 9, 2022, 11:12am UTC](https://discourse.vtk.org/t/lesson-17-1-point-membership-classification-with-opencascade-vtk/8009 "2022-03-09T11:12:20Z")

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//Dear OCC VTK enthusiasts //A simple example that is the same as shown in Lesson 17, but in VTK. \[Lesson 17.1: Point Membership Classification with OpenCascade - YouTube\] //You will see A Cone from AIS-BRepPrimAPI\_Ma…

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## [How to use vtkPlaneSource to control width and height rather than actor.SetScale(..)?](https://discourse.vtk.org/t/how-to-use-vtkplanesource-to-control-width-and-height-rather-than-actor-setscale/8008)

<div class="topic-metadata">

**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 0\
**Last updated:** [March 9, 2022, 8:52am UTC](https://discourse.vtk.org/t/how-to-use-vtkplanesource-to-control-width-and-height-rather-than-actor-setscale/8008 "2022-03-09T08:52:18Z")

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All example is using SetScale to do it,how to use vtkPlaneSource itself to set width and height,is it possible?

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## [How to set the camera's orientation back to (0,0,0)?](https://discourse.vtk.org/t/how-to-set-the-cameras-orientation-back-to-0-0-0/7984)

<div class="topic-metadata">

**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 3\
**Last updated:** [March 9, 2022, 8:49am UTC](https://discourse.vtk.org/t/how-to-set-the-cameras-orientation-back-to-0-0-0/7984 "2022-03-09T08:49:14Z")

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Hello,I have tried like this: print("Before ", renderer.GetActiveCamera().GetOrientation()) ori = renderer.GetActiveCamera().GetOrientation() renderer.GetActiveCamera().Elevation(0 - ori\[0\]) renderer.GetActiveCamera…

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## [vtkRedistributeDataSetFilter - cuts to MPI ranks](https://discourse.vtk.org/t/vtkredistributedatasetfilter-cuts-to-mpi-ranks/7927)

<div class="topic-metadata">

**Author:** [@klevtsov](https://discourse.vtk.org/u/klevtsov)\
**Replies:** 4\
**Last updated:** [March 9, 2022, 3:18am UTC](https://discourse.vtk.org/t/vtkredistributedatasetfilter-cuts-to-mpi-ranks/7927 "2022-03-09T03:18:00Z")

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Hi, I’m using vtkRedistributeDataSetFilter to partition an input mesh across N MPI ranks. I then need to establish for each rank a set of candidate “neighbor” ranks that might contain shared vertices. When N is a power …

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