# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=45

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

**Page:** 46

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## [Alternative/Backport of vtkPVGridAxes3DActor in VTK](https://discourse.vtk.org/t/alternative-backport-of-vtkpvgridaxes3dactor-in-vtk/11873)

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**Author:** [@BotellaA](https://discourse.vtk.org/u/BotellaA)\
**Replies:** 1\
**Last updated:** [July 5, 2023, 12:37pm UTC](https://discourse.vtk.org/t/alternative-backport-of-vtkpvgridaxes3dactor-in-vtk/11873 "2023-07-05T12:37:01Z")

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I have a VTKWeb workflow and I found the vtkPVGridAxes3DActor that I would like to use. Is there a way to use it with only VTK without Paraview? Are there other ways to achieve the same feature as vtkPVGridAxes3DActor …

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## [2D Transferfunction - Shader failed to compile - ScatteringBlending](https://discourse.vtk.org/t/2d-transferfunction-shader-failed-to-compile-scatteringblending/11841)

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**Author:** [@DMelenberg](https://discourse.vtk.org/u/DMelenberg)\
**Replies:** 13\
**Last updated:** [July 5, 2023, 8:51am UTC](https://discourse.vtk.org/t/2d-transferfunction-shader-failed-to-compile-scatteringblending/11841 "2023-07-05T08:51:00Z")

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Hi all, I need assistance with implementing my vtkGPUVolumeRayCastMapper pipeline in python. I want to use a 2D transfer function and make the volume something as realistic as possible using the following parameters. G…

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## [React-vtk-js documentation](https://discourse.vtk.org/t/react-vtk-js-documentation/11871)

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**Author:** [@OlumideSamuel](https://discourse.vtk.org/u/OlumideSamuel)\
**Replies:** 1\
**Last updated:** [July 4, 2023, 5:32pm UTC](https://discourse.vtk.org/t/react-vtk-js-documentation/11871 "2023-07-04T17:32:25Z")

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Hello, Is there an official documentation for react-vtk-js APIs? I have checked the official github repo here, though there are examples, but there’s no explicit documentation that shows the props accepted by the core co…

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## [What is relationship between position and actor center?](https://discourse.vtk.org/t/what-is-relationship-between-position-and-actor-center/11875)

<div class="topic-metadata">

**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 0\
**Last updated:** [July 4, 2023, 3:38pm UTC](https://discourse.vtk.org/t/what-is-relationship-between-position-and-actor-center/11875 "2023-07-04T15:38:03Z")

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Hello, are these right? 1 - The DataSet.center is the geometric center of the object in model space; 2 - The Actor.center is the coordinates of DataSet.center in world space; 3 - Actor.SetPositon will move it to the s…

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## [How to mark some area of an object with specific color in vtkPolyData?](https://discourse.vtk.org/t/how-to-mark-some-area-of-an-object-with-specific-color-in-vtkpolydata/11868)

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**Author:** [@yen](https://discourse.vtk.org/u/yen)\
**Replies:** 3\
**Last updated:** [July 4, 2023, 1:36am UTC](https://discourse.vtk.org/t/how-to-mark-some-area-of-an-object-with-specific-color-in-vtkpolydata/11868 "2023-07-04T01:36:34Z")

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Hello, the picture above is an object that I display with vtkPolyData. I want to make the protrusion parts in this object become red to show the position of defects. However, I fail serveral times. The class I use is …

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## [VTK Training Courses coming up in August 2023](https://discourse.vtk.org/t/vtk-training-courses-coming-up-in-august-2023/11870)

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**Author:** [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)\
**Replies:** 0\
**Last updated:** [July 3, 2023, 4:05pm UTC](https://discourse.vtk.org/t/vtk-training-courses-coming-up-in-august-2023/11870 "2023-07-03T16:05:18Z")

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Learn from the developers behind VTK at Kitware’s live user training courses. We’re hosting a VTK Beginner Course August 21-22 and VTK Advanced Course August 23-24. Register before August 7th and receive a 20% discount! …

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## [QML - VTKRenderWindow inside a rectangle](https://discourse.vtk.org/t/qml-vtkrenderwindow-inside-a-rectangle/11850)

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**Author:** [@ZelieR](https://discourse.vtk.org/u/ZelieR)\
**Replies:** 4\
**Last updated:** [July 3, 2023, 12:55pm UTC](https://discourse.vtk.org/t/qml-vtkrenderwindow-inside-a-rectangle/11850 "2023-07-03T12:55:16Z")

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Hi everyone, I’am trying tu use vtk in a QML project. I’d like to display my vtk window in a ColumnLayout in my QML but I think I did something wrong because it doesn’t work. I use VTK 9.2.6 Here is my qml: import Q…

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## [Surface reconstruction by vtk delaunay 3d](https://discourse.vtk.org/t/surface-reconstruction-by-vtk-delaunay-3d/11866)

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**Author:** [@yen](https://discourse.vtk.org/u/yen)\
**Replies:** 0\
**Last updated:** [July 3, 2023, 1:12am UTC](https://discourse.vtk.org/t/surface-reconstruction-by-vtk-delaunay-3d/11866 "2023-07-03T01:12:05Z")

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Hello, I want to reconstruct the surface of a 3d object in vtk, which is a pcl point cloud type. However, when I use vtk delaunay to reconstruct the surface, I encountered the problem that vtk did not show anything and t…

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## [How to convert dicom sequences into the following directory structure](https://discourse.vtk.org/t/how-to-convert-dicom-sequences-into-the-following-directory-structure/11853)

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**Author:** [@865979216](https://discourse.vtk.org/u/865979216)\
**Replies:** 2\
**Last updated:** [July 1, 2023, 8:07am UTC](https://discourse.vtk.org/t/how-to-convert-dicom-sequences-into-the-following-directory-structure/11853 "2023-07-01T08:07:52Z")

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## [\[javascript\] Deform polydata using known segments for each cell](https://discourse.vtk.org/t/javascript-deform-polydata-using-known-segments-for-each-cell/11730)

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**Author:** [@Alex\_Vergara](https://discourse.vtk.org/u/Alex_Vergara)\
**Replies:** 2\
**Last updated:** [June 30, 2023, 2:41pm UTC](https://discourse.vtk.org/t/javascript-deform-polydata-using-known-segments-for-each-cell/11730 "2023-06-30T14:41:34Z")

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Basically, I need to replicate this BMI Visualizer - BMIWebgl | Perceiving Systems. They define a set of points and a function for each of them depending on height and weight. I have polydata models and I need to warp t…

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## [Intersect polydata and get interpolated normal](https://discourse.vtk.org/t/intersect-polydata-and-get-interpolated-normal/11851)

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**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 0\
**Last updated:** [June 29, 2023, 7:19pm UTC](https://discourse.vtk.org/t/intersect-polydata-and-get-interpolated-normal/11851 "2023-06-29T19:19:41Z")

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Hi Developers I am looking for the fastest possible way to intersect polydata with lines and at the same time get an interpolated normal. I looked into how this is done in vtkImplicitPolyDataDistance and I could potenti…

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## [What are exacted differences between Origin,Center and Position of an actor?](https://discourse.vtk.org/t/what-are-exacted-differences-between-origin-center-and-position-of-an-actor/11849)

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**Author:** [@AlexLuya](https://discourse.vtk.org/u/AlexLuya)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 4:22pm UTC](https://discourse.vtk.org/t/what-are-exacted-differences-between-origin-center-and-position-of-an-actor/11849 "2023-06-29T16:22:11Z")

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Hello,I got this image,but these 3 concepts are still quite confusing for me. Questions are: 1,Are all the these 3 values relative to world coordinate system(WCS)? 2,The Center is the geometric center of an actor,an…

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## [functional MRI couldn't display the texture](https://discourse.vtk.org/t/functional-mri-couldnt-display-the-texture/11838)

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**Author:** [@veltia](https://discourse.vtk.org/u/veltia)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 8:30am UTC](https://discourse.vtk.org/t/functional-mri-couldnt-display-the-texture/11838 "2023-06-29T08:30:23Z")

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Hello, I was trying to use the vtkImageViewer2 class to display the slice of functional MRI, but it doesn’t display the image texture same as in 3D Slicer. if (fileName.endsWith("nii")) { m\_pvtkNIIReader-\>SetFile…

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## [What's the difference between these OffScreen modes in VTK: SetOffScreenRendering; VTK\_USE\_OFFSCREEN\_EGL; GLEW\_OSMESA;](https://discourse.vtk.org/t/whats-the-difference-between-these-offscreen-modes-in-vtk-setoffscreenrendering-vtk-use-offscreen-egl-glew-osmesa/11807)

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**Author:** [@gpu](https://discourse.vtk.org/u/gpu)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 3:18am UTC](https://discourse.vtk.org/t/whats-the-difference-between-these-offscreen-modes-in-vtk-setoffscreenrendering-vtk-use-offscreen-egl-glew-osmesa/11807 "2023-06-29T03:18:28Z")

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What’s the difference between these OffScreen modes in VTK: SetOffScreenRendering; VTK\_USE\_OFFSCREEN\_EGL; GLEW\_OSMESA; What’s the advantage and disadvantage? What’s their usage scenario?

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## [what's the advantage of ShaderProgram::Substitute? why design the shader pipeline and architecture like this: substitue string to get the real final shader; find by name every frame then SetUniform?](https://discourse.vtk.org/t/whats-the-advantage-of-shaderprogram-substitute-why-design-the-shader-pipeline-and-architecture-like-this-substitue-string-to-get-the-real-final-shader-find-by-name-every-frame-then-setuniform/11830)

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**Author:** [@gpu](https://discourse.vtk.org/u/gpu)\
**Replies:** 1\
**Last updated:** [June 28, 2023, 7:59am UTC](https://discourse.vtk.org/t/whats-the-advantage-of-shaderprogram-substitute-why-design-the-shader-pipeline-and-architecture-like-this-substitue-string-to-get-the-real-final-shader-find-by-name-every-frame-then-setuniform/11830 "2023-06-28T07:59:24Z")

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the shader pipeline and architecture, why ? substitue string to get the real final shader; Why not write some real shader maby uber shader? and isn’t too hard to read the shader? i’m new to VTK, and very curious abo…

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## [How to use vtkStructuredGridClip to clip tkStructuredGrid data with a plane？](https://discourse.vtk.org/t/how-to-use-vtkstructuredgridclip-to-clip-tkstructuredgrid-data-with-a-plane/11829)

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**Author:** [@jlxy11](https://discourse.vtk.org/u/jlxy11)\
**Replies:** 1\
**Last updated:** [June 28, 2023, 1:53am UTC](https://discourse.vtk.org/t/how-to-use-vtkstructuredgridclip-to-clip-tkstructuredgrid-data-with-a-plane/11829 "2023-06-28T01:53:45Z")

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I hope to use vtkStructuredGridClip to achieve cutting vtkStructuredGrid data with a plane, but I can’t find the sample code in vtkStructuredGridClip Class Reference, which caused me a lot of difficulties, I hope to get …

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## [vtk axis](https://discourse.vtk.org/t/vtk-axis/11831)

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**Author:** [@842034272](https://discourse.vtk.org/u/842034272)\
**Replies:** 0\
**Last updated:** [June 27, 2023, 11:32am UTC](https://discourse.vtk.org/t/vtk-axis/11831 "2023-06-27T11:32:52Z")

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I want to use vtk to implement a coordinate axis about a two-dimensional image，keeping axes tick on left/bottom screen when I scale/translate image,and limit the image translate range within the axes range,anyone can hel…

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## [Building VTK with NVIDIA EGL for headless server](https://discourse.vtk.org/t/building-vtk-with-nvidia-egl-for-headless-server/11825)

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**Author:** [@RonRahaman](https://discourse.vtk.org/u/RonRahaman)\
**Replies:** 0\
**Last updated:** [June 26, 2023, 8:34pm UTC](https://discourse.vtk.org/t/building-vtk-with-nvidia-egl-for-headless-server/11825 "2023-06-26T20:34:21Z")

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Hi all, I’d like to build VTK on our headless server with the NVIDIA EGL libraries. However, I’m having trouble finding the right libraries and headers to link to. Any advice? Were running RHEL 7.9 with the NVIDIA 51…

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## [Issues in configuring software with VTK Dependency - Fails in VTK cmake files](https://discourse.vtk.org/t/issues-in-configuring-software-with-vtk-dependency-fails-in-vtk-cmake-files/11805)

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**Author:** [@EnderWiggin14](https://discourse.vtk.org/u/EnderWiggin14)\
**Replies:** 4\
**Last updated:** [June 26, 2023, 6:08pm UTC](https://discourse.vtk.org/t/issues-in-configuring-software-with-vtk-dependency-fails-in-vtk-cmake-files/11805 "2023-06-26T18:08:45Z")

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I’ve been trying to configure and build ElmerFemGUI with VTK support, but it is failing when the VTK cmake files start looking for libGLEW.so. More specifically it actually has found the file, but it breaks in vtkDetectL…

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## [Framebuffer Object creation not working in Python](https://discourse.vtk.org/t/framebuffer-object-creation-not-working-in-python/11791)

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**Author:** [@joaodellagli](https://discourse.vtk.org/u/joaodellagli)\
**Replies:** 1\
**Last updated:** [June 25, 2023, 11:36pm UTC](https://discourse.vtk.org/t/framebuffer-object-creation-not-working-in-python/11791 "2023-06-25T23:36:05Z")

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I am developing a feature for FURY, a python graphics library I am working on (that is entirely built with vtk), and this feature has FBOs as core for its functionality, as they will be used for multiple drawings. Well, …

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## [how to output a vtkTextureObject as jpg, png, bmp, etc?](https://discourse.vtk.org/t/how-to-output-a-vtktextureobject-as-jpg-png-bmp-etc/11806)

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**Author:** [@gpu](https://discourse.vtk.org/u/gpu)\
**Replies:** 3\
**Last updated:** [June 25, 2023, 12:33pm UTC](https://discourse.vtk.org/t/how-to-output-a-vtktextureobject-as-jpg-png-bmp-etc/11806 "2023-06-25T12:33:25Z")

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how to output a vtkTextureObject as jpg, png, bmp, etc? there is not api in vtkTextureObject can do this. thanks!

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## [How to append overlapping polyDatas?](https://discourse.vtk.org/t/how-to-append-overlapping-polydatas/11799)

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**Author:** [@somso2e](https://discourse.vtk.org/u/somso2e)\
**Replies:** 1\
**Last updated:** [June 25, 2023, 8:53am UTC](https://discourse.vtk.org/t/how-to-append-overlapping-polydatas/11799 "2023-06-25T08:53:46Z")

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I have multiple polygons defined by a set of point coordinates. These polygons could be on each three axes and might overlap each other. I want to create a binary mask from these polygons and extract all the voxels that …

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## [must call manually call Render() every frame after SetOffScreenRendering(1)?](https://discourse.vtk.org/t/must-call-manually-call-render-every-frame-after-setoffscreenrendering-1/11808)

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**Author:** [@gpu](https://discourse.vtk.org/u/gpu)\
**Replies:** 0\
**Last updated:** [June 25, 2023, 2:43am UTC](https://discourse.vtk.org/t/must-call-manually-call-render-every-frame-after-setoffscreenrendering-1/11808 "2023-06-25T02:43:34Z")

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must call manually call Render() every frame after SetOffScreenRendering(1)? how to write this loop normally? found that after SetOffScreenRendering(1), Render() was not called after Start() as there is no Win32Window,…

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## [vtkScalarBarActor using trame's VtkLocalView](https://discourse.vtk.org/t/vtkscalarbaractor-using-trames-vtklocalview/11771)

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**Author:** [@raz](https://discourse.vtk.org/u/raz)\
**Replies:** 4\
**Last updated:** [June 23, 2023, 9:17pm UTC](https://discourse.vtk.org/t/vtkscalarbaractor-using-trames-vtklocalview/11771 "2023-06-23T21:17:56Z")

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Hello, I’m trying to display a vtkScalarBarActor using a trame app’s VtkLocalView. However, the trame app displays only the 2 extreme colors of the bar, without all the intermediate colors. Additionally, the trame app’s…

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## [how to correctly pass a custom polygon to vtkPolyDataToImageStencil?](https://discourse.vtk.org/t/how-to-correctly-pass-a-custom-polygon-to-vtkpolydatatoimagestencil/11785)

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**Author:** [@somso2e](https://discourse.vtk.org/u/somso2e)\
**Replies:** 3\
**Last updated:** [June 23, 2023, 7:59am UTC](https://discourse.vtk.org/t/how-to-correctly-pass-a-custom-polygon-to-vtkpolydatatoimagestencil/11785 "2023-06-23T07:59:38Z")

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I’m trying to extract ROIs from 3D medical images. This ROI consists of multiple 2D polygons which themselves are represented by a list of points. Each polygon is in a plane parallel to one of the coordinates axes; meani…

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## [vscode failed to build for one example but could build another one successfully](https://discourse.vtk.org/t/vscode-failed-to-build-for-one-example-but-could-build-another-one-successfully/11765)

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**Author:** [@lake\_lagunita](https://discourse.vtk.org/u/lake_lagunita)\
**Replies:** 4\
**Last updated:** [June 22, 2023, 8:46pm UTC](https://discourse.vtk.org/t/vscode-failed-to-build-for-one-example-but-could-build-another-one-successfully/11765 "2023-06-22T20:46:12Z")

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Hello, I am using MSVC as code generator and trying to build examples using vscode. I have chosen two official examples, one is DisplacementPlot and the other is Hello The DisplacementPlot example could be built and r…

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## [How to clip polydata along ribbon?](https://discourse.vtk.org/t/how-to-clip-polydata-along-ribbon/11539)

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**Author:** [@matthew.strugari](https://discourse.vtk.org/u/matthew.strugari)\
**Replies:** 12\
**Last updated:** [June 22, 2023, 5:35pm UTC](https://discourse.vtk.org/t/how-to-clip-polydata-along-ribbon/11539 "2023-06-22T17:35:20Z")

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Hi all, I am having difficulty clipping my polydata along a specific path and would be very grateful for some assistance. As shown in the image below, I am trying to clip my (green) polydata along a path corresponding …

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## [Can I handle reader errors myself without having the error window open?](https://discourse.vtk.org/t/can-i-handle-reader-errors-myself-without-having-the-error-window-open/11793)

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**Author:** [@Gub](https://discourse.vtk.org/u/Gub)\
**Replies:** 1\
**Last updated:** [June 22, 2023, 3:31pm UTC](https://discourse.vtk.org/t/can-i-handle-reader-errors-myself-without-having-the-error-window-open/11793 "2023-06-22T15:31:50Z")

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I am using the vtkFacetReader class (which I have recently discussed in another post) to read FACET files and load them into the renderer. Currently, when the reader encounters an error a new vtkOutputWindow is opened th…

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## [How to use tone mapping correctly when displaying transparent structures using depth peeling ?](https://discourse.vtk.org/t/how-to-use-tone-mapping-correctly-when-displaying-transparent-structures-using-depth-peeling/11794)

<div class="topic-metadata">

**Author:** [@ctroesch](https://discourse.vtk.org/u/ctroesch)\
**Replies:** 0\
**Last updated:** [June 22, 2023, 2:48pm UTC](https://discourse.vtk.org/t/how-to-use-tone-mapping-correctly-when-displaying-transparent-structures-using-depth-peeling/11794 "2023-06-22T14:48:24Z")

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Hi there, I am trying to render 3D models with transparent structures using Depth Peeling, PBR, SSAO and Tone Mapping. To do so, I use the vtkRenderStepsPass with the following configuration: // Create renderer const …

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## [multiple definition of \`exodus\_unused\_symbol\_dummy\_1' when building VTK 8.2.0](https://discourse.vtk.org/t/multiple-definition-of-exodus-unused-symbol-dummy-1-when-building-vtk-8-2-0/11744)

<div class="topic-metadata">

**Author:** [@RavenWorks](https://discourse.vtk.org/u/RavenWorks)\
**Replies:** 3\
**Last updated:** [June 22, 2023, 10:43am UTC](https://discourse.vtk.org/t/multiple-definition-of-exodus-unused-symbol-dummy-1-when-building-vtk-8-2-0/11744 "2023-06-22T10:43:52Z")

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I’m trying to build VTK 8.2.0 on Arch Linux on a Steam Deck, in hopes of using it with an Azure Kinect for photogrammetry… it’s been QUITE a journey getting all the right dependencies installed, but I’ve finally hit an …

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