# Latest

**URL:** https://discourse.vtk.org/latest.md?page=148

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

**Page:** 149

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## [Generate array with partial pixel information from shapes](https://discourse.vtk.org/t/generate-array-with-partial-pixel-information-from-shapes/7459)

<div class="topic-metadata">

**Author:** [@daberle](https://discourse.vtk.org/u/daberle)\
**Replies:** 2\
**Last updated:** [January 3, 2022, 11:28pm UTC](https://discourse.vtk.org/t/generate-array-with-partial-pixel-information-from-shapes/7459 "2022-01-03T23:28:50Z")

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Can I create a polygon or shape of some sort in VTK and then get access to the raw data such that I can convert it to a 2D or 3D array of type float or double? When I do this I would like to also save partial pixel info…

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## [Adding renderer to renderer window](https://discourse.vtk.org/t/adding-renderer-to-renderer-window/7494)

<div class="topic-metadata">

**Author:** [@Taimour](https://discourse.vtk.org/u/Taimour)\
**Replies:** 1\
**Last updated:** [January 3, 2022, 4:52pm UTC](https://discourse.vtk.org/t/adding-renderer-to-renderer-window/7494 "2022-01-03T16:52:33Z")

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Can someone explain what is wrong with this code? It crashes on third line when ren is added to the renderer window. I am working MDI application. this-\>ren = vtkRenderer::New(); this-\>renWin = vtkWin32OpenGLRenderWin…

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## [I'm not able to change the default colormap in VTK (python)](https://discourse.vtk.org/t/im-not-able-to-change-the-default-colormap-in-vtk-python/7546)

<div class="topic-metadata">

**Author:** [@Altertango](https://discourse.vtk.org/u/Altertango)\
**Replies:** 0\
**Last updated:** [January 2, 2022, 9:39pm UTC](https://discourse.vtk.org/t/im-not-able-to-change-the-default-colormap-in-vtk-python/7546 "2022-01-02T21:39:16Z")

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Hello and happy new year to everyone, I’m trying to import some triangulated surfaces DEMs (digital elevation models) from a csv file to vtk. I have no problem importing the file and creating the triangles in VTK, I als…

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## [vtk\_modules warning in CMake Project](https://discourse.vtk.org/t/vtk-modules-warning-in-cmake-project/7530)

<div class="topic-metadata">

**Author:** [@Michael\_Jackson](https://discourse.vtk.org/u/Michael_Jackson)\
**Replies:** 1\
**Last updated:** [January 2, 2022, 9:27pm UTC](https://discourse.vtk.org/t/vtk-modules-warning-in-cmake-project/7530 "2022-01-02T21:27:08Z")

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When I configure my project that uses VTK I am consistently getting this error: No \`MODULES\` passed to \`vtk\_modules\_autoinit\`. Call Stack (most recent call first): common/CMakeLists.txt:42 (vtk\_module\_autoinit) This…

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## [paraview openfoam mesh Reader](https://discourse.vtk.org/t/paraview-openfoam-mesh-reader/7539)

<div class="topic-metadata">

**Author:** [@HorstvanGrass](https://discourse.vtk.org/u/HorstvanGrass)\
**Replies:** 1\
**Last updated:** [December 31, 2021, 9:19pm UTC](https://discourse.vtk.org/t/paraview-openfoam-mesh-reader/7539 "2021-12-31T21:19:01Z")

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Hi, I’m developping a custom openfoam reader using vtk.js. Therefore I need a tool analog to paraview to read the mesh. I’m interested about the techniques paraview is using for this. Is it simply read all the points a…

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## [Python example code for splineWidget.GetSummedLength](https://discourse.vtk.org/t/python-example-code-for-splinewidget-getsummedlength/7529)

<div class="topic-metadata">

**Author:** [@Dgg820502](https://discourse.vtk.org/u/Dgg820502)\
**Replies:** 5\
**Last updated:** [December 31, 2021, 11:54am UTC](https://discourse.vtk.org/t/python-example-code-for-splinewidget-getsummedlength/7529 "2021-12-31T11:54:03Z")

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I am trying use splineWidget.GetSummedLength() to get the length of spline, but I always get the same length data no matter how I moved spline around. Please let know if there is example code for splineWidget.GetSummedL…

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## [Extract volume from vtkImageData](https://discourse.vtk.org/t/extract-volume-from-vtkimagedata/7448)

<div class="topic-metadata">

**Author:** [@Valentin\_Regueiro](https://discourse.vtk.org/u/Valentin_Regueiro)\
**Replies:** 1\
**Last updated:** [December 31, 2021, 9:59am UTC](https://discourse.vtk.org/t/extract-volume-from-vtkimagedata/7448 "2021-12-31T09:59:22Z")

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Hi everyone, I’m running a segmentation which produces various separate volumes that are then added to a vtkRenderer as vtkActors. The problem is, that the bounds of this volumes (vtkImageData) correspond to the bounds…

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## [Creating actors after vtkImageBlend](https://discourse.vtk.org/t/creating-actors-after-vtkimageblend/7434)

<div class="topic-metadata">

**Author:** [@Valentin\_Regueiro](https://discourse.vtk.org/u/Valentin_Regueiro)\
**Replies:** 1\
**Last updated:** [December 31, 2021, 9:58am UTC](https://discourse.vtk.org/t/creating-actors-after-vtkimageblend/7434 "2021-12-31T09:58:43Z")

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Hello everyone, first of all I’m a noob trying to learn VTK so excuse me if the question seems unnecessary. I can not find an answer anywhere. Right now I am getting vtkImageData from nifti Images, which is passed thro…

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## [Annoying Dots in Snapshots on Volume Render](https://discourse.vtk.org/t/annoying-dots-in-snapshots-on-volume-render/7535)

<div class="topic-metadata">

**Author:** [@tigerhu7](https://discourse.vtk.org/u/tigerhu7)\
**Replies:** 1\
**Last updated:** [December 31, 2021, 1:58am UTC](https://discourse.vtk.org/t/annoying-dots-in-snapshots-on-volume-render/7535 "2021-12-31T01:58:55Z")

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I have an issue on taking snapshots on volume render visualization. The following is my procedure. \[1\] add renderer ren1 = vtk.vtkRenderer() ren1.AddVolume(volume) ren1.SetBackground(0,0,0) ren1.GetActiveCamera().…

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## [Obtaining graph relationships of filters and connections ?](https://discourse.vtk.org/t/obtaining-graph-relationships-of-filters-and-connections/7536)

<div class="topic-metadata">

**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 0\
**Last updated:** [December 31, 2021, 1:49am UTC](https://discourse.vtk.org/t/obtaining-graph-relationships-of-filters-and-connections/7536 "2021-12-31T01:49:03Z")

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In the C++ api, after creating various filters and connecting them is there some API or mechanism to find out the graph of the connections and hopefully find the leaf/sink nodes where calling Update() will exercise the g…

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## [Histogram from vtkTable](https://discourse.vtk.org/t/histogram-from-vtktable/7519)

<div class="topic-metadata">

**Author:** [@drpeterfranz](https://discourse.vtk.org/u/drpeterfranz)\
**Replies:** 4\
**Last updated:** [December 30, 2021, 8:34pm UTC](https://discourse.vtk.org/t/histogram-from-vtktable/7519 "2021-12-30T20:34:25Z")

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I can’t find an appropriate filter to generate a 1D histogram from a vtkTable. There are classes to generate 2D histograms from images etc. I also found vtkmHistogram but when I build against the required variables then …

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## [How to set the property for a 3D text?](https://discourse.vtk.org/t/how-to-set-the-property-for-a-3d-text/7528)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 0\
**Last updated:** [December 30, 2021, 9:30am UTC](https://discourse.vtk.org/t/how-to-set-the-property-for-a-3d-text/7528 "2021-12-30T09:30:10Z")

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I want to add 3D text in my application, and vtkVectorText may help: vtkSmartPointer\<vtkVectorText\> text = vtkSmartPointer\<vtkVectorText\>::New(); text-\>SetText("hello, world"); text-\>Update(); vtkSmartPointer\<vtkPolyDa…

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## [Support of new/additional image format ?](https://discourse.vtk.org/t/support-of-new-additional-image-format/7524)

<div class="topic-metadata">

**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 1\
**Last updated:** [December 30, 2021, 9:22am UTC](https://discourse.vtk.org/t/support-of-new-additional-image-format/7524 "2021-12-30T09:22:52Z")

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Hi, Where and which class should I study if I want to support additional image format in VTK ? Cheers

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## [Legacy PolyData File Compatibility](https://discourse.vtk.org/t/legacy-polydata-file-compatibility/5354)

<div class="topic-metadata">

**Author:** [@tbirdso](https://discourse.vtk.org/u/tbirdso)\
**Replies:** 10\
**Last updated:** [December 30, 2021, 2:44am UTC](https://discourse.vtk.org/t/legacy-polydata-file-compatibility/5354 "2021-12-30T02:44:17Z")

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Hi there! I’m trying to use VTK’s Python wrapping to resample an ITK mesh stored in a legacy .vtk file with VTK Data Format 2.0. It appears that vtkPolyDataReader is able to successfully import from this format, but wri…

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## [Can we write out the old VTK 4.2 file format with VTK 9?](https://discourse.vtk.org/t/can-we-write-out-the-old-vtk-4-2-file-format-with-vtk-9/5066)

<div class="topic-metadata">

**Author:** [@Alan\_Morris](https://discourse.vtk.org/u/Alan_Morris)\
**Replies:** 19\
**Last updated:** [December 30, 2021, 2:42am UTC](https://discourse.vtk.org/t/can-we-write-out-the-old-vtk-4-2-file-format-with-vtk-9/5066 "2021-12-30T02:42:50Z")

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We are running into an issue upgrading ShapeWorks to VTK 9. We have an export mesh capability that writes out a polydata to a .vtk file. Our users import this into other tools such as CloudCompare. When we upgrade to …

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## [Is there an easy vtkTexture shallow copy from vtkOBJImporter to a vtkClipClosedSurface or a vtkFrustumSource](https://discourse.vtk.org/t/is-there-an-easy-vtktexture-shallow-copy-from-vtkobjimporter-to-a-vtkclipclosedsurface-or-a-vtkfrustumsource/7518)

<div class="topic-metadata">

**Author:** [@Joel\_Mckay](https://discourse.vtk.org/u/Joel_Mckay)\
**Replies:** 0\
**Last updated:** [December 29, 2021, 3:45am UTC](https://discourse.vtk.org/t/is-there-an-easy-vtktexture-shallow-copy-from-vtkobjimporter-to-a-vtkclipclosedsurface-or-a-vtkfrustumsource/7518 "2021-12-29T03:45:19Z")

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This old site has described an import/export method, but I suspect there must be an easier generic way of handling this common task in libvtk. As the initial texture/map is not being modified, it makes sense someone li…

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## [QVTKOpenGLNativeWidget turn to be transparent when pick actor](https://discourse.vtk.org/t/qvtkopenglnativewidget-turn-to-be-transparent-when-pick-actor/7445)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 1\
**Last updated:** [December 29, 2021, 1:24am UTC](https://discourse.vtk.org/t/qvtkopenglnativewidget-turn-to-be-transparent-when-pick-actor/7445 "2021-12-29T01:24:28Z")

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I am implement the project with QVTKOpenGLNativeWidget, and it works fine. Then, I want to pick actor in the mouseMoveEvent, but the widget turn to be transparent when the cursor is move to the button (no click): …

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## [Recording or taking screenshots of Tait-Bryan Rotation on Object in VTK](https://discourse.vtk.org/t/recording-or-taking-screenshots-of-tait-bryan-rotation-on-object-in-vtk/7493)

<div class="topic-metadata">

**Author:** [@Charles\_Shin](https://discourse.vtk.org/u/Charles_Shin)\
**Replies:** 2\
**Last updated:** [December 28, 2021, 7:54pm UTC](https://discourse.vtk.org/t/recording-or-taking-screenshots-of-tait-bryan-rotation-on-object-in-vtk/7493 "2021-12-28T19:54:36Z")

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Hi, I am trying to record or take screenshot of rotating multiple objects (head, tumor, etc.) in tait-bryan/euler fashion with specific angles. However, I can only find camera rotation for VTK, which is not what I wanted…

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## [How to show an local axes in the center of actor?](https://discourse.vtk.org/t/how-to-show-an-local-axes-in-the-center-of-actor/7514)

<div class="topic-metadata">

**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 1\
**Last updated:** [December 28, 2021, 1:38pm UTC](https://discourse.vtk.org/t/how-to-show-an-local-axes-in-the-center-of-actor/7514 "2021-12-28T13:38:53Z")

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Something like this: As you can see,the left cube has a local axes in the center when clicking it,how to do same thing with VTK?

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## [How to prevent the ball to be streched to an ellipsoid when dragging the window.](https://discourse.vtk.org/t/how-to-prevent-the-ball-to-be-streched-to-an-ellipsoid-when-dragging-the-window/7515)

<div class="topic-metadata">

**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 1\
**Last updated:** [December 28, 2021, 1:18pm UTC](https://discourse.vtk.org/t/how-to-prevent-the-ball-to-be-streched-to-an-ellipsoid-when-dragging-the-window/7515 "2021-12-28T13:18:41Z")

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As you can,when dragging the bottom edge of window,the ball becomes an ellipsoid After clicking the windows,it is restored as ball. How to fix this issue?

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## [vtkMarchingSquares for DICOM \*.dcm/png/bmp stack](https://discourse.vtk.org/t/vtkmarchingsquares-for-dicom-dcm-png-bmp-stack/7510)

<div class="topic-metadata">

**Author:** [@cfd\_payne](https://discourse.vtk.org/u/cfd_payne)\
**Replies:** 2\
**Last updated:** [December 28, 2021, 11:24am UTC](https://discourse.vtk.org/t/vtkmarchingsquares-for-dicom-dcm-png-bmp-stack/7510 "2021-12-28T11:24:08Z")

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@lassoan @dgobbi Continuing the discussion from Stack of PNG files to be rendered as 3D: I have a similar situation where the data seems 2D+t \[typically coronary angiograms\], i’m trying to understand “qualitative” flow…

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## [vtkReader.parse is not a function](https://discourse.vtk.org/t/vtkreader-parse-is-not-a-function/7485)

<div class="topic-metadata">

**Author:** [@bernland](https://discourse.vtk.org/u/bernland)\
**Replies:** 2\
**Last updated:** [December 27, 2021, 8:41pm UTC](https://discourse.vtk.org/t/vtkreader-parse-is-not-a-function/7485 "2021-12-27T20:41:57Z")

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Running the below code const vtkReader = vtkXMLPolyDataReader.newInstance(); vtkReader.parse(xmlStr); results in TypeError: vtkReader.parse is not a function. What am I missing here?

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## [vtkExecutableRunner : ported to Windows ?](https://discourse.vtk.org/t/vtkexecutablerunner-ported-to-windows/7501)

<div class="topic-metadata">

**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 2\
**Last updated:** [December 27, 2021, 1:57pm UTC](https://discourse.vtk.org/t/vtkexecutablerunner-ported-to-windows/7501 "2021-12-27T13:57:45Z")

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I am able to run the command “echo HELLO WORLD” via vtkExecutableRunner on Linux but not on Windows. I get the following errors. Any suggestion as to how I might be able to fix it ? 2021-12-26 14:54:06.152 ( 0.012s) \[…

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## [how to use the vtk in VS2019](https://discourse.vtk.org/t/how-to-use-the-vtk-in-vs2019/7508)

<div class="topic-metadata">

**Author:** [@BKL](https://discourse.vtk.org/u/BKL)\
**Replies:** 0\
**Last updated:** [December 27, 2021, 1:29pm UTC](https://discourse.vtk.org/t/how-to-use-the-vtk-in-vs2019/7508 "2021-12-27T13:29:59Z")

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I am new to vtk. i have already installed vtk, but when i run the cxxexample i downloaded from the vtk website by Visual studio 2019, it says ALL\_BUILD access denied. How can I solve it?

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## [VTK-7.1.1 installation](https://discourse.vtk.org/t/vtk-7-1-1-installation/1057)

<div class="topic-metadata">

**Author:** [@sourav0921](https://discourse.vtk.org/u/sourav0921)\
**Replies:** 4\
**Last updated:** [December 27, 2021, 11:15am UTC](https://discourse.vtk.org/t/vtk-7-1-1-installation/1057 "2021-12-27T11:15:45Z")

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Hi, I was trying to install VTK-7.1.1 using cmake 3.14 in a CRAY-LINUX server. After configuration when I was trying to make it during the process it saying that, " 23%\] Building C object Utilities/KWIML/vtkkwiml/test/…

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## [Any example or tips to render sea surface(shader+FFT)?](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432)

<div class="topic-metadata">

**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 5\
**Last updated:** [December 27, 2021, 9:30am UTC](https://discourse.vtk.org/t/any-example-or-tips-to-render-sea-surface-shader-fft/7432 "2021-12-27T09:30:18Z")

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Any example or tips to do it? If can’t be done with VTK,any opengl integration mechanism suggestion is appreciated also.

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## [Tutorial\_Step1.cxx went wrong--help(vtk9)](https://discourse.vtk.org/t/tutorial-step1-cxx-went-wrong-help-vtk9/7455)

<div class="topic-metadata">

**Author:** [@juno](https://discourse.vtk.org/u/juno)\
**Replies:** 1\
**Last updated:** [December 27, 2021, 9:17am UTC](https://discourse.vtk.org/t/tutorial-step1-cxx-went-wrong-help-vtk9/7455 "2021-12-27T09:17:51Z")

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Tutorial\_Step1.cxx went wrong when it was run in VS2019. No windows appeared and the programme exited directely!Why?

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## [Any suggestions for beginners :) on improving color mappings](https://discourse.vtk.org/t/any-suggestions-for-beginners-on-improving-color-mappings/7495)

<div class="topic-metadata">

**Author:** [@Kostas\_Politis](https://discourse.vtk.org/u/Kostas_Politis)\
**Replies:** 1\
**Last updated:** [December 26, 2021, 10:33pm UTC](https://discourse.vtk.org/t/any-suggestions-for-beginners-on-improving-color-mappings/7495 "2021-12-26T22:33:34Z")

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Hello all, I’ve just started using VTK so I’m trying some mapper options for biquadratic quads in a relatively coarse mesh(1600 cells). Without and with interpolation (option aVtkMapper-\>InterpolateScalarsBeforeMappingO…

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## [How to listen zoom event to to keep a fixed ratio of axises\_length/window\_width?](https://discourse.vtk.org/t/how-to-listen-zoom-event-to-to-keep-a-fixed-ratio-of-axises-length-window-width/7486)

<div class="topic-metadata">

**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 1\
**Last updated:** [December 26, 2021, 2:48pm UTC](https://discourse.vtk.org/t/how-to-listen-zoom-event-to-to-keep-a-fixed-ratio-of-axises-length-window-width/7486 "2021-12-26T14:48:35Z")

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Hello, I have put an vtkAxesActor in the centor of window,if putting a big object or zoom out too much,this actor will become tiny.Any way to keep a fixed ratio of axis\_length/window\_width?I want to listen to zoom even…

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## [Error: no override found for 'vtkGPUVolumeRayCastMapper'](https://discourse.vtk.org/t/error-no-override-found-for-vtkgpuvolumeraycastmapper/7483)

<div class="topic-metadata">

**Author:** [@jjjkk](https://discourse.vtk.org/u/jjjkk)\
**Replies:** 1\
**Last updated:** [December 26, 2021, 2:31pm UTC](https://discourse.vtk.org/t/error-no-override-found-for-vtkgpuvolumeraycastmapper/7483 "2021-12-26T14:31:47Z")

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I use VTK for a lot. Most of class work well but now I got this error report after I want to use volume renderer. Generic Warning: In C:\\vcpkg\\buildtrees\\vtk\\src\\edd2e5233f-f32830fbf2.clean\\Rendering\\Volume\\vtkGPUVolume…

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