# Latest

**URL:** https://discourse.vtk.org/latest.md?page=119

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

**Page:** 120

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## [std::bad\_alloc exception when building example](https://discourse.vtk.org/t/std-bad-alloc-exception-when-building-example/9261)

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**Author:** [@louisld](https://discourse.vtk.org/u/louisld)\
**Replies:** 4\
**Last updated:** [September 1, 2022, 10:05am UTC](https://discourse.vtk.org/t/std-bad-alloc-exception-when-building-example/9261 "2022-09-01T10:05:15Z")

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I am trying to build the cylinder example from the doc. I use cmake then open the project in Visual Studio. I am able to build the project but when I run it in debug mode I get the following error : Exception thrown at …

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## [Cost of creating vtkMapper / vtkActor instances](https://discourse.vtk.org/t/cost-of-creating-vtkmapper-vtkactor-instances/9254)

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**Author:** [@DStranz](https://discourse.vtk.org/u/DStranz)\
**Replies:** 9\
**Last updated:** [September 1, 2022, 3:42am UTC](https://discourse.vtk.org/t/cost-of-creating-vtkmapper-vtkactor-instances/9254 "2022-09-01T03:42:53Z")

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I am continuing the implementation of my 3D scatterplot, consisting of spheres, each of which can have a different size and color. My current implementation uses a vtkMultiBlockDataSet to hold all of the spheres as bloc…

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## [Building VTK in Ubuntu 21.04. OpenGL missing.](https://discourse.vtk.org/t/building-vtk-in-ubuntu-21-04-opengl-missing/9256)

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**Author:** [@Jatin\_Chaudhary](https://discourse.vtk.org/u/Jatin_Chaudhary)\
**Replies:** 1\
**Last updated:** [August 31, 2022, 7:13pm UTC](https://discourse.vtk.org/t/building-vtk-in-ubuntu-21-04-opengl-missing/9256 "2022-08-31T19:13:21Z")

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Hello, I tried to build VTK using the instructions on the GitHub page of VTK. I got the following error: CMake Error at CMake/vtkModule.cmake:4579 (message): Could not find the OpenGL external dependency. Call Stack …

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## [VTK and WebAssembly](https://discourse.vtk.org/t/vtk-and-webassembly/4021)

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**Author:** [@Donny\_Zimmerman](https://discourse.vtk.org/u/Donny_Zimmerman)\
**Replies:** 4\
**Last updated:** [August 31, 2022, 5:20pm UTC](https://discourse.vtk.org/t/vtk-and-webassembly/4021 "2022-08-31T17:20:47Z")

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I am excited about the possibility of using VTK on the client browser via WebAssembly. I know there has been some work done to get the non-rendering part of VTK to compile to WebAssembly. I am a little confused why ITK i…

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## [Vtk9.1 for Qml with QQuickvtkrenderItem have some issues.](https://discourse.vtk.org/t/vtk9-1-for-qml-with-qquickvtkrenderitem-have-some-issues/7601)

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**Author:** [@edwardAllen](https://discourse.vtk.org/u/edwardAllen)\
**Replies:** 6\
**Last updated:** [August 31, 2022, 2:53am UTC](https://discourse.vtk.org/t/vtk9-1-for-qml-with-qquickvtkrenderitem-have-some-issues/7601 "2022-08-31T02:53:20Z")

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Hi every developer , hope you can see this: I found some issues when I use vtk9.1 and qml .Below is the one description ： When I add a cameraorientationwidget with QQuickVTKInteractiveWidget by use QQuickVTKRenderIte…

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## [Multiple coloring for one volume](https://discourse.vtk.org/t/multiple-coloring-for-one-volume/9238)

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**Author:** [@Kalsyc](https://discourse.vtk.org/u/Kalsyc)\
**Replies:** 3\
**Last updated:** [August 30, 2022, 2:01pm UTC](https://discourse.vtk.org/t/multiple-coloring-for-one-volume/9238 "2022-08-30T14:01:44Z")

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Hi all, (using vtkjs) As stated in the title, I need to implement a feature where the user is able to render a single Volume with different colors (color mapping) for different sections. The sections are to be defined a…

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## [vcpkg support for vtk 9.1?](https://discourse.vtk.org/t/vcpkg-support-for-vtk-9-1/7804)

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**Author:** [@Markus\_Heller](https://discourse.vtk.org/u/Markus_Heller)\
**Replies:** 4\
**Last updated:** [August 30, 2022, 1:20pm UTC](https://discourse.vtk.org/t/vcpkg-support-for-vtk-9-1/7804 "2022-08-30T13:20:26Z")

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I was just wondering whether anyone here would know when/if vtk 9.1 might become available via vcpkg?

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## [Colored coincident surface display problem](https://discourse.vtk.org/t/colored-coincident-surface-display-problem/3924)

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**Author:** [@Cheng1087](https://discourse.vtk.org/u/Cheng1087)\
**Replies:** 5\
**Last updated:** [August 30, 2022, 11:37am UTC](https://discourse.vtk.org/t/colored-coincident-surface-display-problem/3924 "2022-08-30T11:37:51Z")

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As shown in the figure, the three colored surfaces partially overlap. It appears weird. How can i avoid this?

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## [VTK cannot open file OpenGL::GL.lib](https://discourse.vtk.org/t/vtk-cannot-open-file-opengl-gl-lib/9060)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 6\
**Last updated:** [August 30, 2022, 6:26am UTC](https://discourse.vtk.org/t/vtk-cannot-open-file-opengl-gl-lib/9060 "2022-08-30T06:26:18Z")

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I want to link RenderingOpenGL2 in my project: find\_package(VTK COMPONENTS ... RenderingOpenGL2 ) But the cmake reports a bug: Target "Pro" links to target "OpenGL::GL" but the target was not found. Perhaps a fi…

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## [How can I load a DICOM image from a VTK.js not using itk-wasm?](https://discourse.vtk.org/t/how-can-i-load-a-dicom-image-from-a-vtk-js-not-using-itk-wasm/9136)

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**Author:** [@YHJ](https://discourse.vtk.org/u/YHJ)\
**Replies:** 8\
**Last updated:** [August 29, 2022, 11:59pm UTC](https://discourse.vtk.org/t/how-can-i-load-a-dicom-image-from-a-vtk-js-not-using-itk-wasm/9136 "2022-08-29T23:59:13Z")

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Hi, all In the back-end environment, the DICOM file was entered via ITK python and a 3D image (.nrrd, .mha…) was created. Assuming using the REST API, is there a way to read the ITK generated Image Binary Data without …

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## [How can I show the past orbital trajectory of two orbiting bodies?](https://discourse.vtk.org/t/how-can-i-show-the-past-orbital-trajectory-of-two-orbiting-bodies/9223)

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**Author:** [@leon1122](https://discourse.vtk.org/u/leon1122)\
**Replies:** 2\
**Last updated:** [August 29, 2022, 9:18pm UTC](https://discourse.vtk.org/t/how-can-i-show-the-past-orbital-trajectory-of-two-orbiting-bodies/9223 "2022-08-29T21:18:17Z")

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I am currently modelling an ellipsoid and a sphere orbiting one another using vtkParametricEllipsoid and vtkSphereSource respectively. At each timestep, they read coordinates from a data file and update their positions u…

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## [Update multiple algorithms concurrently](https://discourse.vtk.org/t/update-multiple-algorithms-concurrently/9228)

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**Author:** [@Olivier](https://discourse.vtk.org/u/Olivier)\
**Replies:** 5\
**Last updated:** [August 29, 2022, 1:36pm UTC](https://discourse.vtk.org/t/update-multiple-algorithms-concurrently/9228 "2022-08-29T13:36:40Z")

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Hi Friends, My use case involves a unique AppendPolyData, which input is many PolyDataAlgorithm (connected with SetInputConnectionByNumber). Inputs PolyDataAlgorithm are totally independent each-others, and can be quit…

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## [Activiz - implementing custom interactor style](https://discourse.vtk.org/t/activiz-implementing-custom-interactor-style/8946)

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**Author:** [@mortifiedpenguin](https://discourse.vtk.org/u/mortifiedpenguin)\
**Replies:** 4\
**Last updated:** [August 29, 2022, 8:54am UTC](https://discourse.vtk.org/t/activiz-implementing-custom-interactor-style/8946 "2022-08-29T08:54:25Z")

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Hi, I’m using Activiz with C# and want to use a custom interactor style. To this end I subclassed vtkInteractorStyleTrackballCamera and overriden the OnLeftButtonDown function. However, the overriden method is never cal…

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## [How to draw lines in VTK so they can be displayed in paraview](https://discourse.vtk.org/t/how-to-draw-lines-in-vtk-so-they-can-be-displayed-in-paraview/9200)

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**Author:** [@anirudh\_puligandla](https://discourse.vtk.org/u/anirudh_puligandla)\
**Replies:** 4\
**Last updated:** [August 29, 2022, 8:14am UTC](https://discourse.vtk.org/t/how-to-draw-lines-in-vtk-so-they-can-be-displayed-in-paraview/9200 "2022-08-29T08:14:27Z")

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I am trying draw a primitive scene with multiple polyData objects, write them into .ply file and view it using paraview. So far I am able to display an ellipsoid source, two sets of arrow sources showing axes of cameras …

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## [Fixing the unstable camera up vector when rotating horizontally](https://discourse.vtk.org/t/fixing-the-unstable-camera-up-vector-when-rotating-horizontally/9177)

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**Author:** [@Martin3d](https://discourse.vtk.org/u/Martin3d)\
**Replies:** 8\
**Last updated:** [August 29, 2022, 6:51am UTC](https://discourse.vtk.org/t/fixing-the-unstable-camera-up-vector-when-rotating-horizontally/9177 "2022-08-29T06:51:29Z")

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When rotating the camera around a scene with vtkInteractorStyleTrackballCamera, there is a unsatisfying swinging effect that I would like to avoid. I mainly want to know if you agree with the solution before starting to …

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## [How to update 2D Slicing Data and 3D graphics syschronously in FourPaneViewer (VTK9.2 Examples)](https://discourse.vtk.org/t/how-to-update-2d-slicing-data-and-3d-graphics-syschronously-in-fourpaneviewer-vtk9-2-examples/9234)

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**Author:** [@kuangliu774392519](https://discourse.vtk.org/u/kuangliu774392519)\
**Replies:** 0\
**Last updated:** [August 29, 2022, 1:47am UTC](https://discourse.vtk.org/t/how-to-update-2d-slicing-data-and-3d-graphics-syschronously-in-fourpaneviewer-vtk9-2-examples/9234 "2022-08-29T01:47:39Z")

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Lately I encountered some difficulties. I need to implement a function in FourPaneViewer(VTK9.2 Example).When I roll the mouse wheel,2D Slicing Data and 3D graphics will update at the same time.What should i do to acco…

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## [Possible improvement for MultiBlock deep copies](https://discourse.vtk.org/t/possible-improvement-for-multiblock-deep-copies/9152)

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**Author:** [@patrick-laurin](https://discourse.vtk.org/u/patrick-laurin)\
**Replies:** 1\
**Last updated:** [August 29, 2022, 4:56am UTC](https://discourse.vtk.org/t/possible-improvement-for-multiblock-deep-copies/9152 "2022-08-29T04:56:19Z")

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Hi all, Today, I was questioning myself on the deep copy mechanism of the vtkMultiBlockDataSet vs. the shallow copy one. In the Shallow Copy, there is preservation of the metadata even if the child block’s data object …

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## [ActiViz and WPF Slider](https://discourse.vtk.org/t/activiz-and-wpf-slider/9160)

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**Author:** [@a772485252](https://discourse.vtk.org/u/a772485252)\
**Replies:** 1\
**Last updated:** [August 29, 2022, 4:39am UTC](https://discourse.vtk.org/t/activiz-and-wpf-slider/9160 "2022-08-29T04:39:02Z")

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When I drag the slider to render, the value of the slider will jump to the maximum or minimum value and then come back. Annotate render, and the slider will be normal. private void slider\_ValueChanged(object sender,Rout…

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## [MPR how to adjusts window width and window level synchronously?](https://discourse.vtk.org/t/mpr-how-to-adjusts-window-width-and-window-level-synchronously/9205)

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**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 1\
**Last updated:** [August 29, 2022, 1:42am UTC](https://discourse.vtk.org/t/mpr-how-to-adjusts-window-width-and-window-level-synchronously/9205 "2022-08-29T01:42:52Z")

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for MPR model how to adjusts window width and window level synchronously?

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## [Distance scalar computation between surface and polyline](https://discourse.vtk.org/t/distance-scalar-computation-between-surface-and-polyline/9225)

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**Author:** [@DFlyer](https://discourse.vtk.org/u/DFlyer)\
**Replies:** 1\
**Last updated:** [August 28, 2022, 1:49pm UTC](https://discourse.vtk.org/t/distance-scalar-computation-between-surface-and-polyline/9225 "2022-08-28T13:49:23Z")

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Hello all! I have a polydata with triangle cells (surface) and another polydata with polyline cells. I need scalar distance values on surface computed from polyline. I tried these, vtkDistancePolyDataFilter - Works o…

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## [Zoom without scaling](https://discourse.vtk.org/t/zoom-without-scaling/9224)

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**Author:** [@DStranz](https://discourse.vtk.org/u/DStranz)\
**Replies:** 3\
**Last updated:** [August 28, 2022, 12:37pm UTC](https://discourse.vtk.org/t/zoom-without-scaling/9224 "2022-08-28T12:37:51Z")

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I am creating a 3D scatterplot of spheres where each sphere might have a different size and spheres could overlap. I have a 2D implementation of this in Qt using circles where as I zoom in, the circles remain a constant…

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## [ColorTransferFunction - set alpha for a single point](https://discourse.vtk.org/t/colortransferfunction-set-alpha-for-a-single-point/9156)

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**Author:** [@zaidb](https://discourse.vtk.org/u/zaidb)\
**Replies:** 6\
**Last updated:** [August 27, 2022, 1:14am UTC](https://discourse.vtk.org/t/colortransferfunction-set-alpha-for-a-single-point/9156 "2022-08-27T01:14:50Z")

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Hello, I am currently using vtkColorTransferFunction together with a preset colormap to color points, which very convenient when processing all points as a whole. However, I’m trying to implement a “focus” feature, whi…

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## [Build with qt6 qmlplugindump executable not found.](https://discourse.vtk.org/t/build-with-qt6-qmlplugindump-executable-not-found/8971)

<div class="topic-metadata">

**Author:** [@edwardAllen](https://discourse.vtk.org/u/edwardAllen)\
**Replies:** 3\
**Last updated:** [August 26, 2022, 2:43pm UTC](https://discourse.vtk.org/t/build-with-qt6-qmlplugindump-executable-not-found/8971 "2022-08-26T14:43:23Z")

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Bug report : qmlplugindump executable not found. Goto cmake file : VTK/GUISupport/QtQuick/qml/CMakeLists.txt Line : 68 get\_target\_property(qt\_qmake\_location "Qt${vtk\_qt\_major\_version}::qmake" LOCATION) get\_filename\_…

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## [Occasional access violation exception from during vtkRendering](https://discourse.vtk.org/t/occasional-access-violation-exception-from-during-vtkrendering/9140)

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**Author:** [@jj\_seaspn](https://discourse.vtk.org/u/jj_seaspn)\
**Replies:** 2\
**Last updated:** [August 26, 2022, 2:40pm UTC](https://discourse.vtk.org/t/occasional-access-violation-exception-from-during-vtkrendering/9140 "2022-08-26T14:40:43Z")

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We are facing occasional runtime crashes from NVIDIA and VTK due to the Access Violation exception. We are using vtk 8.1.0. Please suggest if this is any known problem and any solution or workaround exists. Exception me…

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## [vtkOBBTree not giving full coverage even for the sample solid](https://discourse.vtk.org/t/vtkobbtree-not-giving-full-coverage-even-for-the-sample-solid/9219)

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**Author:** [@marcocecchiscmgroup](https://discourse.vtk.org/u/marcocecchiscmgroup)\
**Replies:** 4\
**Last updated:** [August 26, 2022, 12:21pm UTC](https://discourse.vtk.org/t/vtkobbtree-not-giving-full-coverage-even-for-the-sample-solid/9219 "2022-08-26T12:21:02Z")

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The example VisualizeOBBTree, when run with NumberOfCellsPerNode = 5 and MaxLevel = 10 gives what follows for the sample solid, a simple convex sphere-like solid. Why is that? The header comments in the source code …

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## [Question about vtkImageStencil](https://discourse.vtk.org/t/question-about-vtkimagestencil/9217)

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**Author:** [@Hanxin\_Hua](https://discourse.vtk.org/u/Hanxin_Hua)\
**Replies:** 2\
**Last updated:** [August 25, 2022, 8:11pm UTC](https://discourse.vtk.org/t/question-about-vtkimagestencil/9217 "2022-08-25T20:11:32Z")

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Hi, do the stencil and the input need to be the same size while using vtkImageStencil? vtkSmartPointer\<vtkImageData\> RemoveOsteotomyFromImage(vtkImageData\* imageWithOsteotomy, vtkImageData\* imageToRemoveOsteotomy) { vt…

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## [VTK Trame Docker Issue](https://discourse.vtk.org/t/vtk-trame-docker-issue/9112)

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**Author:** [@kypss50102](https://discourse.vtk.org/u/kypss50102)\
**Replies:** 23\
**Last updated:** [August 25, 2022, 4:06pm UTC](https://discourse.vtk.org/t/vtk-trame-docker-issue/9112 "2022-08-25T16:06:54Z")

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Hi, I’m working on a web application using VTK trame. Currently there are two things on which I’m a bit stuck. I have finish the trame app using the python examples of the VTK and the vuetify UI. However when I want to …

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## [Would compressed VTK arrays be a good idea?](https://discourse.vtk.org/t/would-compressed-vtk-arrays-be-a-good-idea/9178)

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**Author:** [@jfausty](https://discourse.vtk.org/u/jfausty)\
**Replies:** 13\
**Last updated:** [August 25, 2022, 10:35am UTC](https://discourse.vtk.org/t/would-compressed-vtk-arrays-be-a-good-idea/9178 "2022-08-25T10:35:03Z")

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Hi all, I am currently studying the feasibility of including implicit arrays (i.e. arrays that do not have allocated data in memory but that are instead implicit mappings/functions behind the scenes) into VTK. These new…

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## [specularPower = 0 yields black surfaces](https://discourse.vtk.org/t/specularpower-0-yields-black-surfaces/9215)

<div class="topic-metadata">

**Author:** [@andreasbuykx](https://discourse.vtk.org/u/andreasbuykx)\
**Replies:** 0\
**Last updated:** [August 25, 2022, 7:40am UTC](https://discourse.vtk.org/t/specularpower-0-yields-black-surfaces/9215 "2022-08-25T07:40:25Z")

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With gouraud or flat shading, setting specular power to 0 causes the surface to be rendered all black. I ran into this strange issue in our Qt 5.15 and VTK 9.1 based FEA application on Intel UHD 770 graphics (and other …

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## [Labels not appearing flush on the face on vtkhexahedron](https://discourse.vtk.org/t/labels-not-appearing-flush-on-the-face-on-vtkhexahedron/9210)

<div class="topic-metadata">

**Author:** [@ujjwala](https://discourse.vtk.org/u/ujjwala)\
**Replies:** 0\
**Last updated:** [August 25, 2022, 3:10am UTC](https://discourse.vtk.org/t/labels-not-appearing-flush-on-the-face-on-vtkhexahedron/9210 "2022-08-25T03:10:18Z")

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Hi VTK experts, I’m displaying a bunch of vtkHexahedrons in an vtkUnstructuredGrid and trying to display custom labels on each face/side of each hexahedron. I’m currently using one actor for the vtkUnstructuredGrid and …

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