# Latest

**URL:** https://discourse.vtk.org/latest.md?page=192

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

**Page:** 193

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## [UString In VTK](https://discourse.vtk.org/t/ustring-in-vtk/4696)

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**Author:** [@Thomas\_Caissard](https://discourse.vtk.org/u/Thomas_Caissard)\
**Replies:** 6\
**Last updated:** [November 20, 2020, 11:33pm UTC](https://discourse.vtk.org/t/ustring-in-vtk/4696 "2020-11-20T23:33:49Z")

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Good morning everyone, whilst implementing a new feature in VTK, one of my colleague had performance issues w.r.t. to array type conversion. More precisely, he was casting something to a vtkFloatArray using the vtkArray…

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## [More complete EGL support](https://discourse.vtk.org/t/more-complete-egl-support/4708)

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**Author:** [@clintonstimpson](https://discourse.vtk.org/u/clintonstimpson)\
**Replies:** 1\
**Last updated:** [November 20, 2020, 5:26pm UTC](https://discourse.vtk.org/t/more-complete-egl-support/4708 "2020-11-20T17:26:46Z")

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Have there been any thoughts into having more complete support for EGL as a replacement for GLX? I’m interested in having EGL offscreen plus EGL onscreen (xcb/X11) in a single build of VTK.

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## [How to plot a smooth curve and attached to a surface?](https://discourse.vtk.org/t/how-to-plot-a-smooth-curve-and-attached-to-a-surface/4706)

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**Author:** [@Beheshtian](https://discourse.vtk.org/u/Beheshtian)\
**Replies:** 0\
**Last updated:** [November 20, 2020, 3:38pm UTC](https://discourse.vtk.org/t/how-to-plot-a-smooth-curve-and-attached-to-a-surface/4706 "2020-11-20T15:38:25Z")

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Hi all, I’m going to plot a curve that attached to a surface ( polydata) and be smooth. how can I do that? thank you all.

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## [how to joint twe actor via vtk(python ),](https://discourse.vtk.org/t/how-to-joint-twe-actor-via-vtk-python/4704)

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**Author:** [@wanglongday](https://discourse.vtk.org/u/wanglongday)\
**Replies:** 0\
**Last updated:** [November 20, 2020, 1:41pm UTC](https://discourse.vtk.org/t/how-to-joint-twe-actor-via-vtk-python/4704 "2020-11-20T13:41:24Z")

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how to joint twe actor via vtk(python ),for example ,how to joint picture frame and temple,them(twe actor) is made from section.,please,think you!

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## [Error: ModuleNotFoundError: No module named 'vtkmodules'](https://discourse.vtk.org/t/error-modulenotfounderror-no-module-named-vtkmodules/4515)

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**Author:** [@gautam\_kumar\_singh](https://discourse.vtk.org/u/gautam_kumar_singh)\
**Replies:** 3\
**Last updated:** [November 20, 2020, 11:49am UTC](https://discourse.vtk.org/t/error-modulenotfounderror-no-module-named-vtkmodules/4515 "2020-11-20T11:49:01Z")

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Hi @danlipsa My script is working fine from Mac/Windows Terminal. I am able to make exe file using pyinstaller but when i try to run exe file i am getting errors: emphasized text (py37) C:\\Users\\User\\Desktop\\Project\\…

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## [Wrong MPR image orientation when using vtkResliceImageViewer](https://discourse.vtk.org/t/wrong-mpr-image-orientation-when-using-vtkresliceimageviewer/4158)

<div class="topic-metadata">

**Author:** [@sherinnovation](https://discourse.vtk.org/u/sherinnovation)\
**Replies:** 6\
**Last updated:** [November 19, 2020, 4:45pm UTC](https://discourse.vtk.org/t/wrong-mpr-image-orientation-when-using-vtkresliceimageviewer/4158 "2020-11-19T16:45:01Z")

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I am using vtkResliceImageViewer for displaying MPRs. Depending on the dataset I load, I am facing problems related to orientation. In the below example image, first row shows the image orientations displayed in Slicer3D…

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## [How to fill the cylinder](https://discourse.vtk.org/t/how-to-fill-the-cylinder/4669)

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**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 1\
**Last updated:** [November 19, 2020, 10:45am UTC](https://discourse.vtk.org/t/how-to-fill-the-cylinder/4669 "2020-11-19T10:45:57Z")

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This is a hollow cylinder, How to fill it to be a solid cylinder?

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## [vtkImageReslice and vtkImageExtractComponents](https://discourse.vtk.org/t/vtkimagereslice-and-vtkimageextractcomponents/4679)

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**Author:** [@mogonen](https://discourse.vtk.org/u/mogonen)\
**Replies:** 3\
**Last updated:** [November 19, 2020, 1:01am UTC](https://discourse.vtk.org/t/vtkimagereslice-and-vtkimageextractcomponents/4679 "2020-11-19T01:01:41Z")

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Hi All, I have a method in application that uses ImageReslice and ExtractComponents together to etract the slice z from the 3d image m\_imageSrc and fill an imagebuffer using the transform xform as follows: m\_slicer-\>…

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## [9.0.0.rc1 ContextOpenGL2 not built](https://discourse.vtk.org/t/9-0-0-rc1-contextopengl2-not-built/2933)

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**Author:** [@Yue\_JIN](https://discourse.vtk.org/u/Yue_JIN)\
**Replies:** 10\
**Last updated:** [November 18, 2020, 6:14pm UTC](https://discourse.vtk.org/t/9-0-0-rc1-contextopengl2-not-built/2933 "2020-11-18T18:14:56Z")

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I’ve built 9.0rc1 and use 9.0rc1 to reconfigure my project. But it exists an error: “Could not find the VTK package with the following required components: RenderingContextOpenGL2.” I find that there is no cmake files in…

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## [Warp exodusII by vector](https://discourse.vtk.org/t/warp-exodusii-by-vector/4617)

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**Author:** [@trinitytest](https://discourse.vtk.org/u/trinitytest)\
**Replies:** 1\
**Last updated:** [November 18, 2020, 3:43pm UTC](https://discourse.vtk.org/t/warp-exodusii-by-vector/4617 "2020-11-18T15:43:50Z")

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I am trying to show a deformed mesh that is read in from an exodusII file. The display of the mesh should update the nodal positions by a vector called “DM”. I have been successful showing the undeformed mesh and displ…

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## [Can the pixel format be changed when renderinig a BGRA bitmap?](https://discourse.vtk.org/t/can-the-pixel-format-be-changed-when-renderinig-a-bgra-bitmap/4682)

<div class="topic-metadata">

**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 0\
**Last updated:** [November 18, 2020, 10:14am UTC](https://discourse.vtk.org/t/can-the-pixel-format-be-changed-when-renderinig-a-bgra-bitmap/4682 "2020-11-18T10:14:56Z")

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Hi, I worked on the .NET platform and had a bitmap in memory with BGRA channel in bitmap pixels. In this case, the bitmap will be wrongly rendered inside VTK. So I need to find a way to convert the bitmap pixels from BG…

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## [How to make a point cloud?](https://discourse.vtk.org/t/how-to-make-a-point-cloud/4578)

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**Author:** [@inhahe](https://discourse.vtk.org/u/inhahe)\
**Replies:** 11\
**Last updated:** [November 18, 2020, 4:45am UTC](https://discourse.vtk.org/t/how-to-make-a-point-cloud/4578 "2020-11-18T04:45:02Z")

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I suck at figuring out large projects; I can’t make heads or tails of the documentation. I don’t understand how people do it. :stuck\_out\_tongue: Basically, I want to know how to make a point cloud in C++. Well, more basi…

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## [Adding Multiple Views To vtkRenderWindow in vtk.js](https://discourse.vtk.org/t/adding-multiple-views-to-vtkrenderwindow-in-vtk-js/2070)

<div class="topic-metadata">

**Author:** [@Donny\_Zimmerman](https://discourse.vtk.org/u/Donny_Zimmerman)\
**Replies:** 4\
**Last updated:** [November 16, 2020, 2:45pm UTC](https://discourse.vtk.org/t/adding-multiple-views-to-vtkrenderwindow-in-vtk-js/2070 "2020-11-16T14:45:33Z")

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Can I add multiple views (vtkOpenGLRenderWindow) to vtkRenderWindow? If so how do I get certain vtkRenderer’s to only show in any particular view, since we add renderer’s to the vtkRenderWindow and not to the views?

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## [How to anti-alias in vtkRenderWindow](https://discourse.vtk.org/t/how-to-anti-alias-in-vtkrenderwindow/4556)

<div class="topic-metadata">

**Author:** [@carlusst](https://discourse.vtk.org/u/carlusst)\
**Replies:** 15\
**Last updated:** [November 17, 2020, 1:30pm UTC](https://discourse.vtk.org/t/how-to-anti-alias-in-vtkrenderwindow/4556 "2020-11-17T13:30:37Z")

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The vtkRenderWindow contains a collection of vtkRenderers, and parameters that control rendering features such as stereo, anti-aliasing, motion blur and focal depth. I have an image followed. . How could I do it w…

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## [How to import an PNG file with vtkImageImport?](https://discourse.vtk.org/t/how-to-import-an-png-file-with-vtkimageimport/4667)

<div class="topic-metadata">

**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 2\
**Last updated:** [November 17, 2020, 5:58am UTC](https://discourse.vtk.org/t/how-to-import-an-png-file-with-vtkimageimport/4667 "2020-11-17T05:58:22Z")

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Hi, I tried with following code snippet but got a wrong image rendered. MemoryStream ms1 = new MemoryStream(); Image image = Image.FromFile(@"D:\\visual studio 2015\\Projects\\VTKImageBufferRender\\VTKImage…

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## [Layered rendering with multiple renderers](https://discourse.vtk.org/t/layered-rendering-with-multiple-renderers/4670)

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**Author:** [@Faizan](https://discourse.vtk.org/u/Faizan)\
**Replies:** 1\
**Last updated:** [November 17, 2020, 2:04am UTC](https://discourse.vtk.org/t/layered-rendering-with-multiple-renderers/4670 "2020-11-17T02:04:02Z")

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Hello developers, I am stuck in a problem that seems a bit basic but still could not solve it yet. I am using multiple rendering layers to render different kinds of Fiber tracts (Red and orange) overlaid each other. As…

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## [How to use Press Key events with screenshot](https://discourse.vtk.org/t/how-to-use-press-key-events-with-screenshot/4656)

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**Author:** [@Alaa\_Eddine\_MAZOUZ](https://discourse.vtk.org/u/Alaa_Eddine_MAZOUZ)\
**Replies:** 2\
**Last updated:** [November 16, 2020, 5:42pm UTC](https://discourse.vtk.org/t/how-to-use-press-key-events-with-screenshot/4656 "2020-11-16T17:42:29Z")

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Hello, I’m new to VTK and have been trying to work on a small project in c++ to familiarize my self. I create an actor in a scene and I want to take a screenshot of the window when I want using a press key event, I foll…

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## [Insert Vector Data into vtkPolyData Object?](https://discourse.vtk.org/t/insert-vector-data-into-vtkpolydata-object/4671)

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**Author:** [@ksh\_co](https://discourse.vtk.org/u/ksh_co)\
**Replies:** 0\
**Last updated:** [November 16, 2020, 5:35pm UTC](https://discourse.vtk.org/t/insert-vector-data-into-vtkpolydata-object/4671 "2020-11-16T17:35:00Z")

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Hey Simplifying my last post and deleting it I’m using vtk python(8.1.0) in Anaconda. I’ve read polygon data in from .vtp files using vtkXMLPolyDataReader() and have a vtkPolyData object. I would like to update its Cel…

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## [I want to change the origin of the coordinates](https://discourse.vtk.org/t/i-want-to-change-the-origin-of-the-coordinates/4661)

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**Author:** [@Seram](https://discourse.vtk.org/u/Seram)\
**Replies:** 1\
**Last updated:** [November 16, 2020, 7:29am UTC](https://discourse.vtk.org/t/i-want-to-change-the-origin-of-the-coordinates/4661 "2020-11-16T07:29:40Z")

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Hello I want to change the origin of the coordinates, not change the viewing direction. 1 Attachments (28.49 MB) Expiration: 2020-12-15 Target.zip 28.49 MB I want to switch from left to right. What should I do? I…

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## [Any way to apply sparse matrix in vtkImageData?](https://discourse.vtk.org/t/any-way-to-apply-sparse-matrix-in-vtkimagedata/4654)

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**Author:** [@guojunjie4SD](https://discourse.vtk.org/u/guojunjie4SD)\
**Replies:** 5\
**Last updated:** [November 16, 2020, 3:05am UTC](https://discourse.vtk.org/t/any-way-to-apply-sparse-matrix-in-vtkimagedata/4654 "2020-11-16T03:05:46Z")

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I have skull CT images (about 500 images) and detect the skull data to do some test. The CT data is so large, example: 1024 \* 1024 \* 500, about 500 million points. After detecting the skull data, we found the skull data…

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## [vtkResliceImageViewer lookup table](https://discourse.vtk.org/t/vtkresliceimageviewer-lookup-table/4394)

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**Author:** [@ppiorun](https://discourse.vtk.org/u/ppiorun)\
**Replies:** 1\
**Last updated:** [November 15, 2020, 9:53pm UTC](https://discourse.vtk.org/t/vtkresliceimageviewer-lookup-table/4394 "2020-11-15T21:53:37Z")

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Hello, I have a DICOM visualization using my kind of four pane view. Initially I used vtkImageViewer2, but wanted to show reslice cursor, so moved to vtkResliceImageViewer. After processing I want to select certain voxe…

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## [How to construct subgrids of a set of tetrahedron](https://discourse.vtk.org/t/how-to-construct-subgrids-of-a-set-of-tetrahedron/4658)

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**Author:** [@wanyzh](https://discourse.vtk.org/u/wanyzh)\
**Replies:** 0\
**Last updated:** [November 14, 2020, 1:53am UTC](https://discourse.vtk.org/t/how-to-construct-subgrids-of-a-set-of-tetrahedron/4658 "2020-11-14T01:53:43Z")

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Hi, I have a set of tetrahedron elements and based on these host elements, I want to construct dual-elements around the node with hexahedron sectors. Each sector has eight vertices. The vertices are located at the node,…

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## [vtkDebugLeaks detects leaks without pattern](https://discourse.vtk.org/t/vtkdebugleaks-detects-leaks-without-pattern/4648)

<div class="topic-metadata">

**Author:** [@Keyn](https://discourse.vtk.org/u/Keyn)\
**Replies:** 2\
**Last updated:** [November 13, 2020, 6:55pm UTC](https://discourse.vtk.org/t/vtkdebugleaks-detects-leaks-without-pattern/4648 "2020-11-13T18:55:48Z")

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Hello everyone, I have a rather generic question about vtkDebugLeaks. I build vtk 8.2 successfully with it on and was using it for quite some time now. The only report i ever got form vtkDebugLeaks is the following on ex…

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## [Tips and tricks category](https://discourse.vtk.org/t/tips-and-tricks-category/4644)

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**Author:** [@jaswantp](https://discourse.vtk.org/u/jaswantp)\
**Replies:** 2\
**Last updated:** [November 13, 2020, 2:40pm UTC](https://discourse.vtk.org/t/tips-and-tricks-category/4644 "2020-11-13T14:40:57Z")

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It would be nice to have a place to host all tricks, hacks, best practices and maybe even dark arts type shenanigans possible in VTK C++. Very much like the one at discourse.paraview.org I’d envision it to contain code …

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## [Direction? Coordinate? How to change](https://discourse.vtk.org/t/direction-coordinate-how-to-change/4641)

<div class="topic-metadata">

**Author:** [@Seram](https://discourse.vtk.org/u/Seram)\
**Replies:** 3\
**Last updated:** [November 13, 2020, 2:55am UTC](https://discourse.vtk.org/t/direction-coordinate-how-to-change/4641 "2020-11-13T02:55:05Z")

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Hello I want to change the direction as shown on the right. What should I do…? I am getting a lot of help every time. Thank you. BR

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## [Change coordinate system from right to left-handed (change direction of Z axis)](https://discourse.vtk.org/t/change-coordinate-system-from-right-to-left-handed-change-direction-of-z-axis/4635)

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**Author:** [@kerim](https://discourse.vtk.org/u/kerim)\
**Replies:** 2\
**Last updated:** [November 13, 2020, 12:58am UTC](https://discourse.vtk.org/t/change-coordinate-system-from-right-to-left-handed-change-direction-of-z-axis/4635 "2020-11-13T00:58:13Z")

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Hi, VTK standard coordinate system is right-handed wich means that cross product X \* Y gives Z (like in the picture). I’m wondering is there is a way to change the native right-handed VTK coordinate system to left-ha…

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## [Performance of 2d Plotting](https://discourse.vtk.org/t/performance-of-2d-plotting/4633)

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**Author:** [@jhuels](https://discourse.vtk.org/u/jhuels)\
**Replies:** 12\
**Last updated:** [November 12, 2020, 8:42pm UTC](https://discourse.vtk.org/t/performance-of-2d-plotting/4633 "2020-11-12T20:42:38Z")

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Hello all, Does anyone have experience with performant real time 2d plotting? Current application: I have a simple test application that I’ve been tinkering with trying to evaluate the performance of 2d plotting. T…

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## [GLEW could not be initialized: Missing GL version - VTK under Python Windows](https://discourse.vtk.org/t/glew-could-not-be-initialized-missing-gl-version-vtk-under-python-windows/4598)

<div class="topic-metadata">

**Author:** [@silverthorn](https://discourse.vtk.org/u/silverthorn)\
**Replies:** 12\
**Last updated:** [November 12, 2020, 5:42pm UTC](https://discourse.vtk.org/t/glew-could-not-be-initialized-missing-gl-version-vtk-under-python-windows/4598 "2020-11-12T17:42:50Z")

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This is an issue that I have been having for some days and have not found a solution under various Python, VTK and OpenGl versions . I have tried many things - too many to list. I saw this under anaconda but have now giv…

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## [ospray cinematic rendering](https://discourse.vtk.org/t/ospray-cinematic-rendering/2455)

<div class="topic-metadata">

**Author:** [@svabhishek29](https://discourse.vtk.org/u/svabhishek29)\
**Replies:** 8\
**Last updated:** [November 12, 2020, 4:23pm UTC](https://discourse.vtk.org/t/ospray-cinematic-rendering/2455 "2020-11-12T16:23:50Z")

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Hi, i was trying to render a MRI volume using OSPRay, rw = vtk.vtkRenderWindow() r = vtk.vtkRenderer() rw.AddRenderer(r) rtp = vtk.vtkOSPRayPass() r.SetPass(rtp) the code i used is as shown above, when i try to run the…

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## [\[vtkjs\] Split view with linked camera - am I doing it right?](https://discourse.vtk.org/t/vtkjs-split-view-with-linked-camera-am-i-doing-it-right/4642)

<div class="topic-metadata">

**Author:** [@nicoco](https://discourse.vtk.org/u/nicoco)\
**Replies:** 2\
**Last updated:** [November 12, 2020, 3:14pm UTC](https://discourse.vtk.org/t/vtkjs-split-view-with-linked-camera-am-i-doing-it-right/4642 "2020-11-12T15:14:30Z")

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Hello all, I implemented a split view with linked cameras, similar to what paraview offers, using vtkjs. For this, I instantiated 2 vtkFullScreenRenderWindow with divs that span half the screen. left = vtkFullScreenRen…

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