# Latest

**URL:** https://discourse.vtk.org/latest.md?page=171

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

**Page:** 172

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## [Failed to use Vue + vtk.js](https://discourse.vtk.org/t/failed-to-use-vue-vtk-js/6094)

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**Author:** [@agiles](https://discourse.vtk.org/u/agiles)\
**Replies:** 1\
**Last updated:** [June 28, 2021, 3:37pm UTC](https://discourse.vtk.org/t/failed-to-use-vue-vtk-js/6094 "2021-06-28T15:37:35Z")

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Hello Sebastien, I used “Vue create…” and “NPM install – save VTK. JS” to create a very simple project, the purpose is to verify the correctness of a piece of code, but I found that the canvas of the web page has appe…

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## [Compare a pixel value between a VTK volume and ITK image](https://discourse.vtk.org/t/compare-a-pixel-value-between-a-vtk-volume-and-itk-image/6092)

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**Author:** [@Hector\_Martinez](https://discourse.vtk.org/u/Hector_Martinez)\
**Replies:** 0\
**Last updated:** [June 28, 2021, 12:38pm UTC](https://discourse.vtk.org/t/compare-a-pixel-value-between-a-vtk-volume-and-itk-image/6092 "2021-06-28T12:38:02Z")

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I have two vtkPolyData, one is a liver and the other a tumor. First of all, I select n points from the liver and then, I calculate the Hausdorff distance “” between this points and the tumor. (These vtkPolyDatas, “.vtp” …

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## [Paraview with MESA](https://discourse.vtk.org/t/paraview-with-mesa/6090)

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**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 1\
**Last updated:** [June 28, 2021, 10:55am UTC](https://discourse.vtk.org/t/paraview-with-mesa/6090 "2021-06-28T10:55:08Z")

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Dear All, Kitware has Paraview compiled with MESA for Linux. My question is: Has datacenters (Azure) some OpenGL simulator like MESA for Windows that works with normal Paraview? Thanks, Luís Gonçalves

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## [How to convert from RGB byte array to vtkImageData?](https://discourse.vtk.org/t/how-to-convert-from-rgb-byte-array-to-vtkimagedata/6088)

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**Author:** [@Kim\_William](https://discourse.vtk.org/u/Kim_William)\
**Replies:** 1\
**Last updated:** [June 28, 2021, 12:23am UTC](https://discourse.vtk.org/t/how-to-convert-from-rgb-byte-array-to-vtkimagedata/6088 "2021-06-28T00:23:42Z")

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Hi all. I’m using vtkImageViewer2 with vtkImageData to draw the mono8 image. My code is as below: vtkNew\<vtkImageData\> imageData; vtkSmartPointer\<vtkAbstractArray\> arr; arr = vtkUnsignedCharArray::New(); vtkSmartPoin…

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## [Setting values of CMAKE\_XYZ\_OUTPUT\_DIRECTORY](https://discourse.vtk.org/t/setting-values-of-cmake-xyz-output-directory/6051)

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**Author:** [@adamrankin](https://discourse.vtk.org/u/adamrankin)\
**Replies:** 5\
**Last updated:** [June 27, 2021, 9:04pm UTC](https://discourse.vtk.org/t/setting-values-of-cmake-xyz-output-directory/6051 "2021-06-27T21:04:53Z")

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@ben.boeckel @lassoan In previous versions of VTK, we were able to set the build output directories for the various files, which we rely on in order to be able to launch our project from within the development environme…

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## [Is there a way to get access to ImageSlice data as they are rendered?](https://discourse.vtk.org/t/is-there-a-way-to-get-access-to-imageslice-data-as-they-are-rendered/5980)

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**Author:** [@Andrzej\_Marciniak](https://discourse.vtk.org/u/Andrzej_Marciniak)\
**Replies:** 1\
**Last updated:** [June 27, 2021, 4:16am UTC](https://discourse.vtk.org/t/is-there-a-way-to-get-access-to-imageslice-data-as-they-are-rendered/5980 "2021-06-27T04:16:17Z")

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I have built a widget to create a histogram for selected area. It works similar to 3D Slicer Segment Editor Effect - Local Threshold, except for the fact that when the interpolation is on - the shape of “my version” of …

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## [Nearest neighbour interpolation](https://discourse.vtk.org/t/nearest-neighbour-interpolation/6081)

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**Author:** [@nfisdnf986](https://discourse.vtk.org/u/nfisdnf986)\
**Replies:** 1\
**Last updated:** [June 25, 2021, 8:10pm UTC](https://discourse.vtk.org/t/nearest-neighbour-interpolation/6081 "2021-06-25T20:10:16Z")

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I seem to be getting a linear interpolation output even when trying to use Nearest neighbour. Code: #!/usr/bin/env python3 import vtk from vtk.util.numpy\_support import vtk\_to\_numpy, numpy\_to\_vtk import numpy as np …

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## [VTK Python 3.9 Wheels](https://discourse.vtk.org/t/vtk-python-3-9-wheels/5049)

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**Author:** [@akaszynski](https://discourse.vtk.org/u/akaszynski)\
**Replies:** 6\
**Last updated:** [June 25, 2021, 5:51pm UTC](https://discourse.vtk.org/t/vtk-python-3-9-wheels/5049 "2021-06-25T17:51:15Z")

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Hello, Would it be possible for VTK/Kitware to publish Python 3.9 wheels for 9.0.1? I can even build wheels if you’d like. I ask this because we have a few projects that rely on VTK and we’d really like to support Pyt…

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## [Read STL Binary](https://discourse.vtk.org/t/read-stl-binary/6075)

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**Author:** [@bot](https://discourse.vtk.org/u/bot)\
**Replies:** 0\
**Last updated:** [June 25, 2021, 10:55am UTC](https://discourse.vtk.org/t/read-stl-binary/6075 "2021-06-25T10:55:08Z")

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I have an stl binary in an XML file like this. Can you share with me how to read the data? \<strRawSTLData encoding="base64" datatype="STL"\> RXhwb3J0ZWQgZnJvbSBCbGVuZGVyLTIuOTIuMAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAA…

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## [How to display point cloud in gray value](https://discourse.vtk.org/t/how-to-display-point-cloud-in-gray-value/6073)

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**Author:** [@Wei\_Sam](https://discourse.vtk.org/u/Wei_Sam)\
**Replies:** 0\
**Last updated:** [June 25, 2021, 8:51am UTC](https://discourse.vtk.org/t/how-to-display-point-cloud-in-gray-value/6073 "2021-06-25T08:51:45Z")

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Hi Everyone i would like to display the point cloud data in grayscale value, does anyone know how to do? Thanks very much!

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## [Load JPEG from URL into a texture in vtk.js](https://discourse.vtk.org/t/load-jpeg-from-url-into-a-texture-in-vtk-js/824)

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**Author:** [@Donny\_Zimmerman](https://discourse.vtk.org/u/Donny_Zimmerman)\
**Replies:** 7\
**Last updated:** [June 25, 2021, 1:25am UTC](https://discourse.vtk.org/t/load-jpeg-from-url-into-a-texture-in-vtk-js/824 "2021-06-25T01:25:32Z")

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I have searched the vtk.js API and examples and I am unable to find out how to load a vtkTexture from a JPEG image retrieved from a URL. Similar to vtkJPEGReader in standard VTK. Any help would be appreciated.

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## [Two renderers](https://discourse.vtk.org/t/two-renderers/6050)

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**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 8\
**Last updated:** [June 24, 2021, 3:13pm UTC](https://discourse.vtk.org/t/two-renderers/6050 "2021-06-24T15:13:27Z")

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Dear All, If in example “web-project-templates-master” in @exportRpc("vtk.initialize") def createVisualization(self): it is created two renderers is the example ready to deal with the two? And renderer2 = renderWind…

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## [VTKGeometry.fromPolygons throws ArrayIndexOutOfBoundsException on Linux with Java wrappers.](https://discourse.vtk.org/t/vtkgeometry-frompolygons-throws-arrayindexoutofboundsexception-on-linux-with-java-wrappers/6063)

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**Author:** [@rprib](https://discourse.vtk.org/u/rprib)\
**Replies:** 0\
**Last updated:** [June 24, 2021, 1:39pm UTC](https://discourse.vtk.org/t/vtkgeometry-frompolygons-throws-arrayindexoutofboundsexception-on-linux-with-java-wrappers/6063 "2021-06-24T13:39:43Z")

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VTK 9.0.1 with Java wrapper built in Fedora 34 using OpenJDK 11(LTS) ArrayIndexOutOfBoundsException: Array region 0…8 out of bounds for length -356509659 {AnalysisController} \[2021-06-22 11:37:02\] INFO: at vtk.vt…

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## [Keep the scene horizontal](https://discourse.vtk.org/t/keep-the-scene-horizontal/6060)

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**Author:** [@ali-zakaria](https://discourse.vtk.org/u/ali-zakaria)\
**Replies:** 0\
**Last updated:** [June 24, 2021, 9:08am UTC](https://discourse.vtk.org/t/keep-the-scene-horizontal/6060 "2021-06-24T09:08:09Z")

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Hello, I am using vtkInteractorStyleTrackballCamera, and I want to always keep the scene horizontal and avoid situations where the scene tilts: Is there a simple way to achieve that please ?

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## [How to set the rotation center of an actor in VTK](https://discourse.vtk.org/t/how-to-set-the-rotation-center-of-an-actor-in-vtk/6056)

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**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 0\
**Last updated:** [June 24, 2021, 3:30am UTC](https://discourse.vtk.org/t/how-to-set-the-rotation-center-of-an-actor-in-vtk/6056 "2021-06-24T03:30:22Z")

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## [About MPR CPR SSD VE按代VRT](https://discourse.vtk.org/t/about-mpr-cpr-ssd-ve-vrt/6044)

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**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 5\
**Last updated:** [June 24, 2021, 1:28am UTC](https://discourse.vtk.org/t/about-mpr-cpr-ssd-ve-vrt/6044 "2021-06-24T01:28:18Z")

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There are only MC and VR technologies in VTK, where are the codes or algorithm principles of MPR, CPR, SSD, VRT, VE and VRT reconstruction technologies？

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## [How to achieve the following objectives, can someone give some suggestions](https://discourse.vtk.org/t/how-to-achieve-the-following-objectives-can-someone-give-some-suggestions/6048)

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**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 2\
**Last updated:** [June 24, 2021, 1:14am UTC](https://discourse.vtk.org/t/how-to-achieve-the-following-objectives-can-someone-give-some-suggestions/6048 "2021-06-24T01:14:16Z")

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## [How to add texture coordinates to an XML VTK File?](https://discourse.vtk.org/t/how-to-add-texture-coordinates-to-an-xml-vtk-file/5999)

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**Author:** [@datathing](https://discourse.vtk.org/u/datathing)\
**Replies:** 2\
**Last updated:** [June 23, 2021, 8:27pm UTC](https://discourse.vtk.org/t/how-to-add-texture-coordinates-to-an-xml-vtk-file/5999 "2021-06-23T20:27:53Z")

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Hi, I haven’t been able to find any information on how to do this. I want to be able to add texture coordinates to .vtu file. A simple example being the following shape: …which is defined by the following .vtu in XML…

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## [How to add border to ViewPort?](https://discourse.vtk.org/t/how-to-add-border-to-viewport/6049)

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**Author:** [@shrikant](https://discourse.vtk.org/u/shrikant)\
**Replies:** 1\
**Last updated:** [June 23, 2021, 5:10pm UTC](https://discourse.vtk.org/t/how-to-add-border-to-viewport/6049 "2021-06-23T17:10:54Z")

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Hi, I have added two new view port to render window. I would like to add borders to new view port. Can someone help me? I was thinking to lines and make border but if there is any straight forward method?

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## [How to use vtkImageSliceMapper-\>SetSliceNumber?](https://discourse.vtk.org/t/how-to-use-vtkimageslicemapper-setslicenumber/6038)

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**Author:** [@kretep](https://discourse.vtk.org/u/kretep)\
**Replies:** 3\
**Last updated:** [June 23, 2021, 1:24pm UTC](https://discourse.vtk.org/t/how-to-use-vtkimageslicemapper-setslicenumber/6038 "2021-06-23T13:24:06Z")

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Hi, I’m visualizing a sliced image volume using a vtkImageSliceMapper and vtkImageSlice. Slicing through it with the vtkInteractorStyleImage works fine, but when I want to set the slice index through code (I want to sync…

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## [How can I export Tubes to .obj](https://discourse.vtk.org/t/how-can-i-export-tubes-to-obj/6015)

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**Author:** [@Matt](https://discourse.vtk.org/u/Matt)\
**Replies:** 11\
**Last updated:** [June 23, 2021, 7:59am UTC](https://discourse.vtk.org/t/how-can-i-export-tubes-to-obj/6015 "2021-06-23T07:59:13Z")

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Hi, I am wondering how to export tubes to a .obj file. I am trying to visualize Networkx graphs with vtk and create a model, but the vtkOBJExporter() will not export the tubes. I have tried turning capping on but that d…

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## [Python VTK Windows OpenGL error](https://discourse.vtk.org/t/python-vtk-windows-opengl-error/6040)

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**Author:** [@GuillaumeJacquenot](https://discourse.vtk.org/u/GuillaumeJacquenot)\
**Replies:** 2\
**Last updated:** [June 23, 2021, 7:10am UTC](https://discourse.vtk.org/t/python-vtk-windows-opengl-error/6040 "2021-06-23T07:10:22Z")

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Hello dear VTK developers / users I am trying to use vtk 9.0.1 from python 3.8.1 on a Windows 10 machine with Intel Graphics UHD 620. Unfortunately, when I try to open a window, I have a nasty OpenGL error. Does anyon…

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## [error with a same vtkactor add in different vtkrender](https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045)

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**Author:** [@Hurmean](https://discourse.vtk.org/u/Hurmean)\
**Replies:** 3\
**Last updated:** [June 23, 2021, 5:42am UTC](https://discourse.vtk.org/t/error-with-a-same-vtkactor-add-in-different-vtkrender/6045 "2021-06-23T05:42:32Z")

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when a vtkactor add in differert vtkrender with different vtkrenderwindow, this doesn’t work.

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## [load obj file with Vtkobjreader giving relative path](https://discourse.vtk.org/t/load-obj-file-with-vtkobjreader-giving-relative-path/6032)

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**Author:** [@Raj\_Kumar\_Ranabhat](https://discourse.vtk.org/u/Raj_Kumar_Ranabhat)\
**Replies:** 1\
**Last updated:** [June 23, 2021, 5:29am UTC](https://discourse.vtk.org/t/load-obj-file-with-vtkobjreader-giving-relative-path/6032 "2021-06-23T05:29:20Z")

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Hi , I was trying to load obj file using VtkobjectReader in C++ While loading a obj with SetFileName if I give a full path of the obj, it works. However, I would like to load that file with relative path because I am i…

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## [Position plane in 3D picture](https://discourse.vtk.org/t/position-plane-in-3d-picture/6025)

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**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 2\
**Last updated:** [June 23, 2021, 5:12am UTC](https://discourse.vtk.org/t/position-plane-in-3d-picture/6025 "2021-06-23T05:12:19Z")

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Dear All, I want to position a plane in an 3D picture (Skull). How I navigate in a 3D perspective? The mouse has 2D coordinates. If I use pickpoint I will be limited to the bone (skull) points to position the plane. A…

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## [DebugTools for MSVC](https://discourse.vtk.org/t/debugtools-for-msvc/6043)

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**Author:** [@shogarth](https://discourse.vtk.org/u/shogarth)\
**Replies:** 0\
**Last updated:** [June 22, 2021, 10:44pm UTC](https://discourse.vtk.org/t/debugtools-for-msvc/6043 "2021-06-22T22:44:45Z")

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If you are debugging VTK on Windows with Visual Studio, there are some natvis files to configure your debugger available to as part of DebugTools. They configure the debugger to show a synthesized, easier to debug with, …

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## [Where to look for difference image on gitlab ci?](https://discourse.vtk.org/t/where-to-look-for-difference-image-on-gitlab-ci/6042)

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**Author:** [@jaswantp](https://discourse.vtk.org/u/jaswantp)\
**Replies:** 2\
**Last updated:** [June 22, 2021, 6:09pm UTC](https://discourse.vtk.org/t/where-to-look-for-difference-image-on-gitlab-ci/6042 "2021-06-22T18:09:23Z")

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A test failed on GitLab ci. The logs indicate that a difference png file is in build/Testing/Temporary . I downloaded artifacts and I can’t find them, maybe I’m looking in the wrong place? \<DartMeasurementFile name="Dif…

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## [What's the relationship between Dolly and Zoom?](https://discourse.vtk.org/t/whats-the-relationship-between-dolly-and-zoom/6026)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 3\
**Last updated:** [June 22, 2021, 12:09pm UTC](https://discourse.vtk.org/t/whats-the-relationship-between-dolly-and-zoom/6026 "2021-06-22T12:09:29Z")

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vtkCamera has two methods for zoom in/out: Dolly and Zoom. What’s relationship between Dolly and Zoom? Moreover, for vtkCamera::Dolly(dolly) and vtkCamera::Zoom(zoomfactor), how to convert the dolly to zoomfactor?

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## [How to get the opengl symbolic constants using vtk?](https://discourse.vtk.org/t/how-to-get-the-opengl-symbolic-constants-using-vtk/6028)

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**Author:** [@devmessias](https://discourse.vtk.org/u/devmessias)\
**Replies:** 2\
**Last updated:** [June 22, 2021, 1:21pm UTC](https://discourse.vtk.org/t/how-to-get-the-opengl-symbolic-constants-using-vtk/6028 "2021-06-22T13:21:43Z")

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Hi, using the vtkOpenGLState it’s possible to set specific states for a given opengl instance using for example vtkglBlendFuncSeparate. My question it’s how I get the unsigned values from symbolic constants like GL\_ZER…

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## [CUDA and OpenCL](https://discourse.vtk.org/t/cuda-and-opencl/5609)

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**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 3\
**Last updated:** [June 22, 2021, 4:03am UTC](https://discourse.vtk.org/t/cuda-and-opencl/5609 "2021-06-22T04:03:15Z")

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Dear All, Does VTK uses CUDA or OpenCL (with CPU or GPU) for processing? Or can be enabled? Thanks, Luís Gonçalves

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