# \#rendering

**URL:** https://discourse.vtk.org/tag/rendering/17.md

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

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## [Enable hardware selection even with installed render pass](https://discourse.vtk.org/t/enable-hardware-selection-even-with-installed-render-pass/16494)

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**Author:** [@peter.thompson](https://discourse.vtk.org/u/peter.thompson)\
**Replies:** 0\
**Last updated:** [July 27, 2026, 9:40pm UTC](https://discourse.vtk.org/t/enable-hardware-selection-even-with-installed-render-pass/16494 "2026-07-27T21:40:54Z")

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I recently ran into something similar to this issue: vtkShadowMapPass causes actor picking doesn't work,and the actors with vtkUnstructuredGrid source don't show anymore. To summarize the issue: installing a render pass …

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## [Slow Rendering of large 2D Image on MacOS, but not Linux or Windows](https://discourse.vtk.org/t/slow-rendering-of-large-2d-image-on-macos-but-not-linux-or-windows/16277)

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**Author:** [@Michael\_Jackson](https://discourse.vtk.org/u/Michael_Jackson)\
**Replies:** 6\
**Last updated:** [February 9, 2026, 10:00pm UTC](https://discourse.vtk.org/t/slow-rendering-of-large-2d-image-on-macos-but-not-linux-or-windows/16277 "2026-02-09T22:00:08Z")

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Hello, We have an existing application that uses VTK 9.5.2 for our 3D visualization. We have noticed that when we load large 2D images (23,500 x 23,500 pixels) that the interaction rendering speed on MacOS is about 3~4 …

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## [\[Volume Rendering\] Incorrect Depth Occlusion Between Two Intersecting Spheres in VTK 9.1.0](https://discourse.vtk.org/t/volume-rendering-incorrect-depth-occlusion-between-two-intersecting-spheres-in-vtk-9-1-0/16177)

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**Author:** [@maomaolemon](https://discourse.vtk.org/u/maomaolemon)\
**Replies:** 1\
**Last updated:** [January 7, 2026, 4:22am UTC](https://discourse.vtk.org/t/volume-rendering-incorrect-depth-occlusion-between-two-intersecting-spheres-in-vtk-9-1-0/16177 "2026-01-07T04:22:36Z")

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\[Note: English is not my first language, so please let me know if anything is unclear.\] I’m working on a scientific visualization project using VTK 9.1.0 with C++, where I need to render two intersecting, completely opa…

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## [\[Volume Rendering\] Rendering artifacts after window refresh and model hide/show operations in VTK 9.1.0](https://discourse.vtk.org/t/volume-rendering-rendering-artifacts-after-window-refresh-and-model-hide-show-operations-in-vtk-9-1-0/16179)

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**Author:** [@maomaolemon](https://discourse.vtk.org/u/maomaolemon)\
**Replies:** 0\
**Last updated:** [December 10, 2025, 9:45am UTC](https://discourse.vtk.org/t/volume-rendering-rendering-artifacts-after-window-refresh-and-model-hide-show-operations-in-vtk-9-1-0/16179 "2025-12-10T09:45:45Z")

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Problem Description: I’m using vtkOpenGLGPUVolumeRayCastMapper to render volumetric data imported via vtkImageImport. The data source is a series of 128×128 CV\_8UC1 images, as implemented in my ShowImageData() function …

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## [\[Coincident Topology\] backside lines blink when "PolygonOffset" is set](https://discourse.vtk.org/t/coincident-topology-backside-lines-blink-when-polygonoffset-is-set/16158)

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**Author:** [@a-ciue](https://discourse.vtk.org/u/a-ciue)\
**Replies:** 0\
**Last updated:** [November 25, 2025, 10:50am UTC](https://discourse.vtk.org/t/coincident-topology-backside-lines-blink-when-polygonoffset-is-set/16158 "2025-11-25T10:50:57Z")

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Hi, I have a polydata with polys and lines. Some part of lines is behind the polys and they are covered by polys. I found and activated the “PolygonOffset” coincident topology. The “covered” issue is unsolved and I enco…

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## [Gamma Correction unavoidable](https://discourse.vtk.org/t/gamma-correction-unavoidable/16155)

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**Author:** [@killer3d](https://discourse.vtk.org/u/killer3d)\
**Replies:** 2\
**Last updated:** [November 25, 2025, 2:35am UTC](https://discourse.vtk.org/t/gamma-correction-unavoidable/16155 "2025-11-25T02:35:47Z")

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https://gitlab.kitware.com/vtk/vtk/-/issues/19849 In https://github.com/Kitware/VTK/blob/master/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx, void main() { float gamma = 2.2; // for each sample in the multi sample buff…

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## [vtkCubeSource / vtkBoxWidget coupling issue](https://discourse.vtk.org/t/vtkcubesource-vtkboxwidget-coupling-issue/15797)

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**Author:** [@madmoonman](https://discourse.vtk.org/u/madmoonman)\
**Replies:** 3\
**Last updated:** [July 9, 2025, 9:53am UTC](https://discourse.vtk.org/t/vtkcubesource-vtkboxwidget-coupling-issue/15797 "2025-07-09T09:53:25Z")

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Hello vtk-Experts, I’ve encountered yet another interesting problem. For a few years I have been developing an in-house tool using vtk and PyQt5. Currently I do not have a working minimal example, but I will build one i…

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## [Correct usage of SetPixelAspect() or possible workaround](https://discourse.vtk.org/t/correct-usage-of-setpixelaspect-or-possible-workaround/15602)

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**Author:** [@Sandor](https://discourse.vtk.org/u/Sandor)\
**Replies:** 2\
**Last updated:** [May 13, 2025, 8:14pm UTC](https://discourse.vtk.org/t/correct-usage-of-setpixelaspect-or-possible-workaround/15602 "2025-05-13T20:14:11Z")

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Hi, I would like to render my scene anisotropically , pixels stretched or compressed, the python vtk code below doesn’t seems to produce the expected behavior, no detectable distortion with any value specified. import …

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## [QVTKOpenGLNativeWidget in QGraphicsView Causing White Screen in Qt 6.5.6](https://discourse.vtk.org/t/qvtkopenglnativewidget-in-qgraphicsview-causing-white-screen-in-qt-6-5-6/14764)

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**Author:** [@Manjunath\_AV](https://discourse.vtk.org/u/Manjunath_AV)\
**Replies:** 1\
**Last updated:** [March 3, 2025, 9:26pm UTC](https://discourse.vtk.org/t/qvtkopenglnativewidget-in-qgraphicsview-causing-white-screen-in-qt-6-5-6/14764 "2025-03-03T21:26:50Z")

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We are currently in the process of porting our project from Qt 5.15 to Qt 6.5.6. In Qt 5.15, we were successfully using QGLWidget in conjunction with QGraphicsView. However, after the upgrade to Qt 6, we have replaced QG…

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## [Volume Rendering for Medical data](https://discourse.vtk.org/t/volume-rendering-for-medical-data/15027)

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**Author:** [@Emmynabs](https://discourse.vtk.org/u/Emmynabs)\
**Replies:** 7\
**Last updated:** [January 30, 2025, 6:05pm UTC](https://discourse.vtk.org/t/volume-rendering-for-medical-data/15027 "2025-01-30T18:05:59Z")

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i am new with using VTK so i need guidance on how to go about using it for Volume rendering using C++ or python as the programming language

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## [Interpolation in vtkPolyData](https://discourse.vtk.org/t/interpolation-in-vtkpolydata/15043)

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**Author:** [@A.M\_Shahpouri](https://discourse.vtk.org/u/A.M_Shahpouri)\
**Replies:** 0\
**Last updated:** [December 18, 2024, 7:51am UTC](https://discourse.vtk.org/t/interpolation-in-vtkpolydata/15043 "2024-12-18T07:51:27Z")

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Hi everyone . I want to create an polydata like this :slight\_smile: I created this Polydata by this code : auto appendPolyData = vtkSmartPointer\<vtkAppendPolyData\>::New(); for (const auto& slice : contour.Sli…

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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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## [edge rendering issue on mac m1](https://discourse.vtk.org/t/edge-rendering-issue-on-mac-m1/14638)

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**Author:** [@frankham](https://discourse.vtk.org/u/frankham)\
**Replies:** 5\
**Last updated:** [October 3, 2024, 2:03am UTC](https://discourse.vtk.org/t/edge-rendering-issue-on-mac-m1/14638 "2024-10-03T02:03:14Z")

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I am writing an application that renders edges using simple lines with coloring based on a scalar value and lookup table. On linux and my older intel-based mac the following simple example works as expected, with edge co…

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## [vtkImageResliceMapper DICOM image slice disappears when zoomed in enough](https://discourse.vtk.org/t/vtkimagereslicemapper-dicom-image-slice-disappears-when-zoomed-in-enough/14276)

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**Author:** [@jvokac](https://discourse.vtk.org/u/jvokac)\
**Replies:** 2\
**Last updated:** [July 23, 2024, 6:36am UTC](https://discourse.vtk.org/t/vtkimagereslicemapper-dicom-image-slice-disappears-when-zoomed-in-enough/14276 "2024-07-23T06:36:35Z")

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Hi! Our company has been making a piece of software with VTK for some time now and we’ve been using the vtkImageResliceMapper class to display DICOM CT images ( vtkImageData ). I came across an issue when zooming into t…

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## [volume rendering error on call GetDepthImage()](https://discourse.vtk.org/t/volume-rendering-error-on-call-getdepthimage/13900)

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**Author:** [@a74856h669](https://discourse.vtk.org/u/a74856h669)\
**Replies:** 0\
**Last updated:** [May 17, 2024, 3:51am UTC](https://discourse.vtk.org/t/volume-rendering-error-on-call-getdepthimage/13900 "2024-05-17T03:51:00Z")

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When I set the six clip planes during volume rendering, the depth image is correct when I don’t rotate the camera lens, but when I rotate the camera lens I get a problem where the depth image is partially missing T…

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## [volume rendering frequency is very slow](https://discourse.vtk.org/t/volume-rendering-frequency-is-very-slow/12941)

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**Author:** [@Hedwig\_Huang](https://discourse.vtk.org/u/Hedwig_Huang)\
**Replies:** 2\
**Last updated:** [December 26, 2023, 3:16pm UTC](https://discourse.vtk.org/t/volume-rendering-frequency-is-very-slow/12941 "2023-12-26T15:16:20Z")

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Hi there! I am working on volume rendering for MIP/MinIP, VR and VE for MRI. Now here I edited so many codes for renderer, renderwindow, actor and mapper, etc. But I found that it’s quite weried that when I tried to int…

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## [vtkAnnotatedCubeActor display with shadows](https://discourse.vtk.org/t/vtkannotatedcubeactor-display-with-shadows/12943)

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**Author:** [@a1401358759](https://discourse.vtk.org/u/a1401358759)\
**Replies:** 0\
**Last updated:** [December 20, 2023, 12:52pm UTC](https://discourse.vtk.org/t/vtkannotatedcubeactor-display-with-shadows/12943 "2023-12-20T12:52:52Z")

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use vtk==9.2.6,as you can see in the image above,if I set cube.GetCubeProperty().SetEdgeVisibility(1),the cube displayed as the following,why?

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## [QT integration with vtkImageViewer2 in QVTKOpenGLNativeWidget](https://discourse.vtk.org/t/qt-integration-with-vtkimageviewer2-in-qvtkopenglnativewidget/12824)

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**Author:** [@MagicLudo](https://discourse.vtk.org/u/MagicLudo)\
**Replies:** 1\
**Last updated:** [December 2, 2023, 7:03am UTC](https://discourse.vtk.org/t/qt-integration-with-vtkimageviewer2-in-qvtkopenglnativewidget/12824 "2023-12-02T07:03:40Z")

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Hello everyone ! I’m new to using QT and VTK and trying to get the two to work together. The actual project is very simple and it’s a test project (few lines of code) for a bigger one. I would like to be able to displa…

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## [rendering in vtk.js compared to python rendering](https://discourse.vtk.org/t/rendering-in-vtk-js-compared-to-python-rendering/12743)

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**Author:** [@cpe](https://discourse.vtk.org/u/cpe)\
**Replies:** 0\
**Last updated:** [November 17, 2023, 11:33pm UTC](https://discourse.vtk.org/t/rendering-in-vtk-js-compared-to-python-rendering/12743 "2023-11-17T23:33:52Z")

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Greetings, Basically, I do not have a mesh vtk file, I have a flattened array of data that I want to visualize using vtk.js. I have already made the render using VTK in Python, but there are some differences in the resu…

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## [vtk how to disable memory extra cost when call render()?](https://discourse.vtk.org/t/vtk-how-to-disable-memory-extra-cost-when-call-render/12439)

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**Author:** [@ch\_zeng](https://discourse.vtk.org/u/ch_zeng)\
**Replies:** 6\
**Last updated:** [October 18, 2023, 1:04pm UTC](https://discourse.vtk.org/t/vtk-how-to-disable-memory-extra-cost-when-call-render/12439 "2023-10-18T13:04:12Z")

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Hi All, after load a vtkdataset,should use the renderWindow-\>Render()。but i found it will have a extra memory cost when the data is more than 100mb。 for example:a vtkdataset size is 500mb ,it’ll cost from 500mb to 1.5G …

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## [Rendering tubes and spheres and QVTKOpenGLNativeWidget](https://discourse.vtk.org/t/rendering-tubes-and-spheres-and-qvtkopenglnativewidget/12168)

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**Author:** [@totte\_karlsson](https://discourse.vtk.org/u/totte_karlsson)\
**Replies:** 10\
**Last updated:** [October 12, 2023, 2:09pm UTC](https://discourse.vtk.org/t/rendering-tubes-and-spheres-and-qvtkopenglnativewidget/12168 "2023-10-12T14:09:38Z")

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Hello, We are rendering polylines and are using the technique described here to render points as spheres, pixels and wire vs tubes. I found that when using a console application, points are rendered as ‘pixels’ (square…

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## [Incorrect result of boolean difference](https://discourse.vtk.org/t/incorrect-result-of-boolean-difference/12422)

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**Author:** [@Arnav-2004](https://discourse.vtk.org/u/Arnav-2004)\
**Replies:** 3\
**Last updated:** [October 9, 2023, 7:44am UTC](https://discourse.vtk.org/t/incorrect-result-of-boolean-difference/12422 "2023-10-09T07:44:03Z")

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import vtk cube1 = vtk.vtkCubeSource() cube1.SetXLength(1.1) cube1.SetYLength(10) cube1.SetZLength(10) cube1.Update() tri\_filter1 = vtk.vtkTriangleFilter() tri\_filter1.SetInputData(cube1.GetOutput()) tri\_filter1.Update…

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## [How can I make my interactor stop queuing events while an event is being carried out?](https://discourse.vtk.org/t/how-can-i-make-my-interactor-stop-queuing-events-while-an-event-is-being-carried-out/12404)

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**Author:** [@user12345](https://discourse.vtk.org/u/user12345)\
**Replies:** 4\
**Last updated:** [October 5, 2023, 9:03am UTC](https://discourse.vtk.org/t/how-can-i-make-my-interactor-stop-queuing-events-while-an-event-is-being-carried-out/12404 "2023-10-05T09:03:34Z")

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In this minimal example that moves the camera aimed at the sphere when you right click, I want to have an interactor that moves the camera when I click. This takes some time, and during that time, I want the interactor t…

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## [Selecting Surface Cells](https://discourse.vtk.org/t/selecting-surface-cells/12256)

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**Author:** [@Mordrago](https://discourse.vtk.org/u/Mordrago)\
**Replies:** 2\
**Last updated:** [September 21, 2023, 1:50pm UTC](https://discourse.vtk.org/t/selecting-surface-cells/12256 "2023-09-21T13:50:48Z")

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Hello! While implementing the code using VTK, I encountered a problem with selecting a cell on the grid surface. I am only concerned with marking the visible cells from the user’s perspective(camera position). Selectin…

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## [How can I set up the scale range in vtkRenderingWindow?](https://discourse.vtk.org/t/how-can-i-set-up-the-scale-range-in-vtkrenderingwindow/11745)

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**Author:** [@yen](https://discourse.vtk.org/u/yen)\
**Replies:** 3\
**Last updated:** [June 19, 2023, 10:27pm UTC](https://discourse.vtk.org/t/how-can-i-set-up-the-scale-range-in-vtkrenderingwindow/11745 "2023-06-19T22:27:20Z")

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Hello, I am a new comer to vtk recently. I want to ask a question. Can I set up the scale in vtk windows? Here is my 3D object. However, since some value is up to 21000, which represent that the original laser sensor…

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## [VTK+WebGPU: native graphics APIs on the desktop](https://discourse.vtk.org/t/vtk-webgpu-native-graphics-apis-on-the-desktop/11550)

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**Author:** [@jaswantp](https://discourse.vtk.org/u/jaswantp)\
**Replies:** 1\
**Last updated:** [May 28, 2023, 1:09am UTC](https://discourse.vtk.org/t/vtk-webgpu-native-graphics-apis-on-the-desktop/11550 "2023-05-28T01:09:14Z")

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We are making efforts to implement VTK rendering with WebGPU on the desktop using native graphics APIs such as DirectX12, Metal and Vulkan. Read more on our blog! VTK-WebGPU on the desktop