# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=15

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

**Page:** 16

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## [Display scalar value on points](https://discourse.vtk.org/t/display-scalar-value-on-points/15054)

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**Author:** [@Julien\_Champagnol](https://discourse.vtk.org/u/Julien_Champagnol)\
**Replies:** 6\
**Last updated:** [December 21, 2024, 8:54pm UTC](https://discourse.vtk.org/t/display-scalar-value-on-points/15054 "2024-12-21T20:54:58Z")

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I, I’d like to display scalar values on points but it gets displayed on cells Here is is my code : def setMeshVertexAttribute(self, id, name): reader = self.get\_object(id)\["reader"\] # reader is a vtkXMLGenericD…

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## [Building the RenderingTk Module on Windows](https://discourse.vtk.org/t/building-the-renderingtk-module-on-windows/15036)

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**Author:** [@SchnFlo](https://discourse.vtk.org/u/SchnFlo)\
**Replies:** 7\
**Last updated:** [December 18, 2024, 3:27pm UTC](https://discourse.vtk.org/t/building-the-renderingtk-module-on-windows/15036 "2024-12-18T15:27:04Z")

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Hi! I am currently using the classes implemented in the RenderingTk module in a python project. I managed to build the wrapped vtkRenderingTk-X.X.so on Linux, but I am struggling to get it to work on Windows. I followe…

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## [Row-major ordering in VTK-m](https://discourse.vtk.org/t/row-major-ordering-in-vtk-m/15045)

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**Author:** [@Francisco](https://discourse.vtk.org/u/Francisco)\
**Replies:** 0\
**Last updated:** [December 18, 2024, 11:45am UTC](https://discourse.vtk.org/t/row-major-ordering-in-vtk-m/15045 "2024-12-18T11:45:58Z")

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Is there a good way to use VTKm with external Uniform datasets (ie. “3D Images”) in row-major ordering? I have been able to successfully create some VTKm DataSets from existing structured data in my code with zero-copy,…

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## [out of core volume data binning](https://discourse.vtk.org/t/out-of-core-volume-data-binning/14280)

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**Author:** [@Limz90](https://discourse.vtk.org/u/Limz90)\
**Replies:** 12\
**Last updated:** [December 17, 2024, 6:30pm UTC](https://discourse.vtk.org/t/out-of-core-volume-data-binning/14280 "2024-12-17T18:30:16Z")

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Hi, I am using vtk for volume rendering and now i am having issue to renderer big volume. Is there any method in VTK to render out of core data? Thanks

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## [Weird memory consumption](https://discourse.vtk.org/t/weird-memory-consumption/15033)

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**Author:** [@Olivier](https://discourse.vtk.org/u/Olivier)\
**Replies:** 0\
**Last updated:** [December 17, 2024, 9:47am UTC](https://discourse.vtk.org/t/weird-memory-consumption/15033 "2024-12-17T09:47:02Z")

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Hi friends, I’m running a very simple Windows/OpenGL application, that creates 20 RenderWindow, with default properties / no Actor, and call Render() on each one. When creating RenderWindows, total application memory s…

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## [Selected edges disappear for certain viewing angles when using Parallel Projection](https://discourse.vtk.org/t/selected-edges-disappear-for-certain-viewing-angles-when-using-parallel-projection/14993)

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**Author:** [@whereismymoney](https://discourse.vtk.org/u/whereismymoney)\
**Replies:** 4\
**Last updated:** [December 17, 2024, 5:37am UTC](https://discourse.vtk.org/t/selected-edges-disappear-for-certain-viewing-angles-when-using-parallel-projection/14993 "2024-12-17T05:37:42Z")

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The issue can be illustrated with the VTK example HighlightSelection and the standard sample data file called cow.vtp (let me know if you would like me to attach copies here). As an alternative to the cow, you can use an…

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## [Documentation for QVTKOpenGLNativeWidget needs to be updated](https://discourse.vtk.org/t/documentation-for-qvtkopenglnativewidget-needs-to-be-updated/15013)

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**Author:** [@whereismymoney](https://discourse.vtk.org/u/whereismymoney)\
**Replies:** 3\
**Last updated:** [December 16, 2024, 8:45am UTC](https://discourse.vtk.org/t/documentation-for-qvtkopenglnativewidget-needs-to-be-updated/15013 "2024-12-16T08:45:16Z")

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Currently the documentation at https://vtk.org/doc/nightly/html/classQVTKOpenGLNativeWidget.html says “You can use QVTKOpenGLNativeWidget::copyToFormat …” In VTK 8.2.0, copyToFormat() is defined in QVTKOpenGLWindow.h. …

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## [I've encountered a program crash issue with a refresh image display program.](https://discourse.vtk.org/t/ive-encountered-a-program-crash-issue-with-a-refresh-image-display-program/15029)

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**Author:** [@marlon.ma](https://discourse.vtk.org/u/marlon.ma)\
**Replies:** 0\
**Last updated:** [December 16, 2024, 7:40am UTC](https://discourse.vtk.org/t/ive-encountered-a-program-crash-issue-with-a-refresh-image-display-program/15029 "2024-12-16T07:40:55Z")

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ShowImageDll.cpp (8.4 KB) ShowImageDll.h (1.2 KB) This is my code. I have completed a display control library that retrieves image blocks through shared memory using the transmitted smid, then copies them over, refresh…

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## [After testing, it was found that updating only the vtkMapper of vtkActor itself without replacing the new vtkPolyDataMapper object after editing vtkPoints has no effect](https://discourse.vtk.org/t/after-testing-it-was-found-that-updating-only-the-vtkmapper-of-vtkactor-itself-without-replacing-the-new-vtkpolydatamapper-object-after-editing-vtkpoints-has-no-effect/15014)

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**Author:** [@jiajiadelequ](https://discourse.vtk.org/u/jiajiadelequ)\
**Replies:** 9\
**Last updated:** [December 16, 2024, 2:22am UTC](https://discourse.vtk.org/t/after-testing-it-was-found-that-updating-only-the-vtkmapper-of-vtkactor-itself-without-replacing-the-new-vtkpolydatamapper-object-after-editing-vtkpoints-has-no-effect/15014 "2024-12-16T02:22:48Z")

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void CustomVtkInteractorStyleTapeMeasure::StartRotate() { Superclass::StartRotate(); vtkRenderer\* renderer = this-\>Interactor-\>GetRenderWindow()-\>GetRenderers()-\>GetFirstRenderer(); this-\>Interactor-\>GetRenderWindow()-\>…

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## [Creating 3D objects and slice them to obtain 2D numpy array](https://discourse.vtk.org/t/creating-3d-objects-and-slice-them-to-obtain-2d-numpy-array/14768)

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**Author:** [@Sah](https://discourse.vtk.org/u/Sah)\
**Replies:** 6\
**Last updated:** [December 13, 2024, 3:54pm UTC](https://discourse.vtk.org/t/creating-3d-objects-and-slice-them-to-obtain-2d-numpy-array/14768 "2024-12-13T15:54:37Z")

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Dear all, this might be a stupid question, but I am completely new in the topic and I need some help in understanding the best approach. I am creating an anatomical model, and the idea is that when I’m done with it, I n…

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## [vtkGLTFImporter Unable to start animation](https://discourse.vtk.org/t/vtkgltfimporter-unable-to-start-animation/15011)

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**Author:** [@Pancake\_Z](https://discourse.vtk.org/u/Pancake_Z)\
**Replies:** 1\
**Last updated:** [December 13, 2024, 9:14am UTC](https://discourse.vtk.org/t/vtkgltfimporter-unable-to-start-animation/15011 "2024-12-13T09:14:59Z")

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importer use UpdateTimeStep doesn’t work num\_animations = importer.GetNumberOfAnimations() print(f"Number of animations: {num\_animations}") if num\_animations \> 0: importer.EnableAnimation(0) …

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## [Custom Shader Implementation for Floor Plane Grid](https://discourse.vtk.org/t/custom-shader-implementation-for-floor-plane-grid/12685)

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**Author:** [@Ruben\_Moermans](https://discourse.vtk.org/u/Ruben_Moermans)\
**Replies:** 5\
**Last updated:** [December 13, 2024, 7:44am UTC](https://discourse.vtk.org/t/custom-shader-implementation-for-floor-plane-grid/12685 "2024-12-13T07:44:12Z")

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I’m currently working on a project where I’m trying to implement a floor plane grid using a custom vertex and fragment shader. I came across a helpful example and decided to adapt it for my use in VTK. A couple question…

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## [How to load texture with GLTFReader](https://discourse.vtk.org/t/how-to-load-texture-with-gltfreader/12515)

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**Author:** [@Theodliu](https://discourse.vtk.org/u/Theodliu)\
**Replies:** 4\
**Last updated:** [December 12, 2024, 3:14pm UTC](https://discourse.vtk.org/t/how-to-load-texture-with-gltfreader/12515 "2024-12-12T15:14:05Z")

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Hi I’m trying to load gltf model. But can I load animation and texture at the same time? I refer to GLTFReader + texture and VTK: vtkGLTFReader Class Reference. vtkGLTFReader can load animations but it can’t load texture…

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## [Issue with Empty vtkImageData and Rendering Updates](https://discourse.vtk.org/t/issue-with-empty-vtkimagedata-and-rendering-updates/14996)

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**Author:** [@WailmerPail](https://discourse.vtk.org/u/WailmerPail)\
**Replies:** 4\
**Last updated:** [December 12, 2024, 3:11pm UTC](https://discourse.vtk.org/t/issue-with-empty-vtkimagedata-and-rendering-updates/14996 "2024-12-12T15:11:36Z")

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Hi everyone, I’m encountering an issue that: a vtkVolume still will not being displayed after modifying the data of corresponding vtkImageData when it was initially empty (all values set to 0). However, if I create a …

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## [GLTFReader + texture](https://discourse.vtk.org/t/gltfreader-texture/4455)

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**Author:** [@skoudoro](https://discourse.vtk.org/u/skoudoro)\
**Replies:** 2\
**Last updated:** [December 12, 2024, 2:29pm UTC](https://discourse.vtk.org/t/gltfreader-texture/4455 "2024-12-12T14:29:50Z")

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Hi everyone, I am using the python binding of VTK 9.0.1. After loading a gltf model via vtkGLTFReader, I can see the model on my scene and start different animations. However, I can not see any texture on my model. I …

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## [Reading a vtp file give an error](https://discourse.vtk.org/t/reading-a-vtp-file-give-an-error/14998)

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**Author:** [@bardina](https://discourse.vtk.org/u/bardina)\
**Replies:** 7\
**Last updated:** [December 12, 2024, 8:58am UTC](https://discourse.vtk.org/t/reading-a-vtp-file-give-an-error/14998 "2024-12-12T08:58:06Z")

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Hi, I am new in this community. I try to read a vtp file, it is a DTC hull which can be read by Paraview. I write a python script to read this file :slight\_smile: import vtk filename = "hull.vtp" reader = vtk.vtkXM…

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## [Slow ec2 comparing to my mac m2 machine](https://discourse.vtk.org/t/slow-ec2-comparing-to-my-mac-m2-machine/14979)

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**Author:** [@DanielAmmar](https://discourse.vtk.org/u/DanielAmmar)\
**Replies:** 2\
**Last updated:** [December 10, 2024, 5:49am UTC](https://discourse.vtk.org/t/slow-ec2-comparing-to-my-mac-m2-machine/14979 "2024-12-10T05:49:25Z")

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Hello, I found that my mac m2 is much faster performing the following code, comparing to bigger machines in the cloud (c7i.8xlarge, g5.2xlarge), and I suspect this is something to do with connecting to the screen. Clas…

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## [vtkResliceCursorWidget: output images are cropped](https://discourse.vtk.org/t/vtkreslicecursorwidget-output-images-are-cropped/4244)

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**Author:** [@pasquamatt](https://discourse.vtk.org/u/pasquamatt)\
**Replies:** 18\
**Last updated:** [December 9, 2024, 12:39pm UTC](https://discourse.vtk.org/t/vtkreslicecursorwidget-output-images-are-cropped/4244 "2024-12-09T12:39:14Z")

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Hi to all, I am trying to set up a four pane medical image viewer in Python, but I notice that the displayed images seem to be cropped, especially when more than one cursor has been rotated. Here you can see a GIF showi…

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## [Mouse position qt vtk 9.3](https://discourse.vtk.org/t/mouse-position-qt-vtk-9-3/13260)

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**Author:** [@Tobias-Med](https://discourse.vtk.org/u/Tobias-Med)\
**Replies:** 2\
**Last updated:** [December 9, 2024, 12:21pm UTC](https://discourse.vtk.org/t/mouse-position-qt-vtk-9-3/13260 "2024-12-09T12:21:01Z")

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Hello together, I am using vtk (9.3) with qt (6.5.3) using the QQuickVTKItem class. The problem I am facing is that mouse positions do not seem to be translated from qml to vtk correctly. For testing purpose I used the …

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## [How can I copy camera transform to an actor ?](https://discourse.vtk.org/t/how-can-i-copy-camera-transform-to-an-actor/14987)

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**Author:** [@Seb-surgar](https://discourse.vtk.org/u/Seb-surgar)\
**Replies:** 0\
**Last updated:** [December 9, 2024, 11:10am UTC](https://discourse.vtk.org/t/how-can-i-copy-camera-transform-to-an-actor/14987 "2024-12-09T11:10:33Z")

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Hello, I want to have an actor thet represents the camera with the same orientation and position than the camera. I would like to attach objects to this “root camera” actor to simplify the positionning of different ele…

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## [vtkOpenGLState error](https://discourse.vtk.org/t/vtkopenglstate-error/14983)

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**Author:** [@inferna15](https://discourse.vtk.org/u/inferna15)\
**Replies:** 0\
**Last updated:** [December 9, 2024, 8:09am UTC](https://discourse.vtk.org/t/vtkopenglstate-error/14983 "2024-12-09T08:09:18Z")

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I’m writing a DLL to use in C# WPF, but when I run the DLL’s render function, I get the following error. 2024-12-09 10:50:49.643 ( 3.722s) \[ 7FC9116B0740\] vtkOpenGLState.cxx:57 WARN| Error in cache state for…

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## [the speed of vtk.vtkMarchingCubes is slow, how to speed it up?](https://discourse.vtk.org/t/the-speed-of-vtk-vtkmarchingcubes-is-slow-how-to-speed-it-up/2426)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 11\
**Last updated:** [December 9, 2024, 2:44am UTC](https://discourse.vtk.org/t/the-speed-of-vtk-vtkmarchingcubes-is-slow-how-to-speed-it-up/2426 "2024-12-09T02:44:57Z")

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Currently, I want to extract the isosurface from a volume image, and I use vtk.vtkMarchingCubes to implement it. Moreover, I want to change the iso-value by mouse. I have implement the code as following: import vtk, sys…

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## [How to render point as square in PCLVisualizer?](https://discourse.vtk.org/t/how-to-render-point-as-square-in-pclvisualizer/14966)

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**Author:** [@tomdong](https://discourse.vtk.org/u/tomdong)\
**Replies:** 4\
**Last updated:** [December 8, 2024, 4:24am UTC](https://discourse.vtk.org/t/how-to-render-point-as-square-in-pclvisualizer/14966 "2024-12-08T04:24:05Z")

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I’m using vtk9.3 from pcl1.14.1, the default rendering shape of point is sphere. My question is how to render them as square (which always face to user). Thanks a lot!

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## [WASM Threading memory out of bounds](https://discourse.vtk.org/t/wasm-threading-memory-out-of-bounds/14917)

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**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 6\
**Last updated:** [December 7, 2024, 5:33pm UTC](https://discourse.vtk.org/t/wasm-threading-memory-out-of-bounds/14917 "2024-12-07T17:33:06Z")

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Hi Developers I can get WebGPU to work fine with the release candidate 9.4.0. I am little puzzled, why you require “-sASYNCIFY” to be used. I would prefer the calls to be blocking, e.g. GetRenderWindow(). I am working …

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## [In VTK9.3.1 When I read data in the Exodus file format, how can I retrieve the time for each time step?](https://discourse.vtk.org/t/in-vtk9-3-1-when-i-read-data-in-the-exodus-file-format-how-can-i-retrieve-the-time-for-each-time-step/14973)

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**Author:** [@shils](https://discourse.vtk.org/u/shils)\
**Replies:** 0\
**Last updated:** [December 6, 2024, 6:37am UTC](https://discourse.vtk.org/t/in-vtk9-3-1-when-i-read-data-in-the-exodus-file-format-how-can-i-retrieve-the-time-for-each-time-step/14973 "2024-12-06T06:37:08Z")

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vtkSmartPointer\<vtkExodusIIReader\> reader = vtkSmartPointer\<vtkExodusIIReader\>::New(); reader-\>SetFileName(filePath.toStdString().c\_str()); reader-\>Update(); int cnt = reader-\>GetNumberOfTimeSteps();

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## [VTK with tkinter](https://discourse.vtk.org/t/vtk-with-tkinter/6738)

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**Author:** [@Kamil](https://discourse.vtk.org/u/Kamil)\
**Replies:** 8\
**Last updated:** [December 6, 2024, 1:30am UTC](https://discourse.vtk.org/t/vtk-with-tkinter/6738 "2024-12-06T01:30:41Z")

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I am trying to combine VTK with tkinter. However I am getting following error. \_tkinter.TclError: couldn’t load library “vtkRenderingTk-9.0.dll”: this library or a dependent library could not be found in library path I…

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## [extract surface face values with vtkGeometryFilter](https://discourse.vtk.org/t/extract-surface-face-values-with-vtkgeometryfilter/14971)

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**Author:** [@Mhs\_goud](https://discourse.vtk.org/u/Mhs_goud)\
**Replies:** 0\
**Last updated:** [December 5, 2024, 9:26pm UTC](https://discourse.vtk.org/t/extract-surface-face-values-with-vtkgeometryfilter/14971 "2024-12-05T21:26:50Z")

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Hi, I have my data in a vtkunstructuredgrid format. I want to assign a value to each grid cell, and then compute the corresponding surface values with vtkGeometryFilter. so in 3d, imagine a cube has a value assigned to i…

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## [VTK for QT](https://discourse.vtk.org/t/vtk-for-qt/14758)

<div class="topic-metadata">

**Author:** [@kkwang955](https://discourse.vtk.org/u/kkwang955)\
**Replies:** 3\
**Last updated:** [December 5, 2024, 5:26pm UTC](https://discourse.vtk.org/t/vtk-for-qt/14758 "2024-12-05T17:26:21Z")

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When I used vtk in qt, there was an error like this. Generic Warning: In vtkOpenGLState.cxx, line 57 Error in cache state for GL\_DEPTH\_WRITEMASK Generic Warning: In vtkOpenGLState.cxx, line 263 at stack loc at vtksys:…

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## [Activiz, replacing the underlying vtk binaries](https://discourse.vtk.org/t/activiz-replacing-the-underlying-vtk-binaries/14950)

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**Author:** [@mortifiedpenguin](https://discourse.vtk.org/u/mortifiedpenguin)\
**Replies:** 7\
**Last updated:** [December 5, 2024, 2:15pm UTC](https://discourse.vtk.org/t/activiz-replacing-the-underlying-vtk-binaries/14950 "2024-12-05T14:15:32Z")

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I am using Activiz and attempt to replace the underlying vtk binaries with ones I have compiled myself (using VS 2022), since I did some minor code changes. However when I start my project, I get a P/Invoke error that t…

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## [Issue in while compiling VTK6.3 version source code on Ubuntu 22.04 LTS](https://discourse.vtk.org/t/issue-in-while-compiling-vtk6-3-version-source-code-on-ubuntu-22-04-lts/14957)

<div class="topic-metadata">

**Author:** [@ASTAR](https://discourse.vtk.org/u/ASTAR)\
**Replies:** 23\
**Last updated:** [December 5, 2024, 1:02pm UTC](https://discourse.vtk.org/t/issue-in-while-compiling-vtk6-3-version-source-code-on-ubuntu-22-04-lts/14957 "2024-12-05T13:02:12Z")

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Hi, I am trying to compile the source code of VTK6.3 version from GITHUB on Ubuntu 22.04 LTS using gcc +14.04 version of the compiler in the machine, but I used get the following error message : CMake Error at CMake/vtk…

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