# Latest

**URL:** https://discourse.vtk.org/latest.md?page=227

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

**Page:** 228

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## [About AdjustRange of volume rendering](https://discourse.vtk.org/t/about-adjustrange-of-volume-rendering/2453)

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**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 0\
**Last updated:** [January 19, 2020, 8:45am UTC](https://discourse.vtk.org/t/about-adjustrange-of-volume-rendering/2453 "2020-01-19T08:45:00Z")

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I’m using vtkPiecewiseFunction to set opacity function of volume rendering. I can get correct rendering effect after using “AddPoint()”. Then I use “AdjustRange()” in line 109 for testing. But the effect of rendering on …

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## [vtkXdmfReader not working in Python on Ubuntu](https://discourse.vtk.org/t/vtkxdmfreader-not-working-in-python-on-ubuntu/2450)

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**Author:** [@Patrick\_Mineault](https://discourse.vtk.org/u/Patrick_Mineault)\
**Replies:** 1\
**Last updated:** [January 19, 2020, 1:16am UTC](https://discourse.vtk.org/t/vtkxdmfreader-not-working-in-python-on-ubuntu/2450 "2020-01-19T01:16:27Z")

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I am trying to use the vtkXdmfReader in Python to read a file. I was able to make this work on Windows with a pre-built Windows version of vtk without a hitch. Now I am trying this on Ubuntu and although vtk and its pyt…

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## [compatibility between vtk8.1 and Ubuntu14](https://discourse.vtk.org/t/compatibility-between-vtk8-1-and-ubuntu14/2445)

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**Author:** [@Charles\_Chen](https://discourse.vtk.org/u/Charles_Chen)\
**Replies:** 2\
**Last updated:** [January 17, 2020, 9:32am UTC](https://discourse.vtk.org/t/compatibility-between-vtk8-1-and-ubuntu14/2445 "2020-01-17T09:32:12Z")

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Hi all, I’d like to know if VTK-8.1 can work on Ubuntu 14, or where can I find the compatibility matrix between VTK and Ubuntu? Thanks in advance~

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## [vtk-commit list broken?](https://discourse.vtk.org/t/vtk-commit-list-broken/2433)

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**Author:** [@seanm](https://discourse.vtk.org/u/seanm)\
**Replies:** 7\
**Last updated:** [January 17, 2020, 2:46am UTC](https://discourse.vtk.org/t/vtk-commit-list-broken/2433 "2020-01-17T02:46:44Z")

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Hi all, Is it me or did messages to the vtk-commit list stop? I filter those mails and don’t always check that folder, but it seems there have been none for a few weeks: https://public.kitware.com/mailman/private/vtk-…

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## [Fastest picking of closest actor?](https://discourse.vtk.org/t/fastest-picking-of-closest-actor/2408)

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**Author:** [@mhalle](https://discourse.vtk.org/u/mhalle)\
**Replies:** 5\
**Last updated:** [January 16, 2020, 10:26pm UTC](https://discourse.vtk.org/t/fastest-picking-of-closest-actor/2408 "2020-01-16T22:26:58Z")

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I’ve been looking over the different picking methods in vtk.js, but I haven’t been able to figure the best way to do fast actor-level picking. I don’t need point or cell picking, but I need more accurate picking than bou…

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## [vtkStripper not joining contiguous lines to form a single vtkPolyLine.](https://discourse.vtk.org/t/vtkstripper-not-joining-contiguous-lines-to-form-a-single-vtkpolyline/2402)

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**Author:** [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)\
**Replies:** 3\
**Last updated:** [January 16, 2020, 5:11pm UTC](https://discourse.vtk.org/t/vtkstripper-not-joining-contiguous-lines-to-form-a-single-vtkpolyline/2402 "2020-01-16T17:11:46Z")

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Here is the rendering of three vtkLines: Now I use vtkStripper in the hopes of getting a single vtkPolyLine: vtkSmartPointer\<vtkPolyData\> poly = vtkSmartPointer\<vtkPolyData\>::New(); poly-\>SetPoints( points );…

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## [VTK with PySide2 is not working](https://discourse.vtk.org/t/vtk-with-pyside2-is-not-working/2439)

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**Author:** [@ian.liu88](https://discourse.vtk.org/u/ian.liu88)\
**Replies:** 1\
**Last updated:** [January 16, 2020, 3:03pm UTC](https://discourse.vtk.org/t/vtk-with-pyside2-is-not-working/2439 "2020-01-16T15:03:10Z")

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The following example is not working properly: import sys import PySide2 from PySide2.QtWidgets import QApplication from vtkmodules.qt.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor from vtkmodules.vtkFilt…

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## [How to change the colors of objects in VTK when using vtkAppendPolyData?](https://discourse.vtk.org/t/how-to-change-the-colors-of-objects-in-vtk-when-using-vtkappendpolydata/2431)

<div class="topic-metadata">

**Author:** [@ymmx](https://discourse.vtk.org/u/ymmx)\
**Replies:** 3\
**Last updated:** [January 16, 2020, 10:29am UTC](https://discourse.vtk.org/t/how-to-change-the-colors-of-objects-in-vtk-when-using-vtkappendpolydata/2431 "2020-01-16T10:29:53Z")

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I’m trying to modify the color of each object that I’ve placed in a vtkAppendPolyData but I get weird colors. I mean the object is not in one color but each face of it has a different color. I would like to have one c…

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## [centos7 vtkOpenGLRenderWindow cmake error](https://discourse.vtk.org/t/centos7-vtkopenglrenderwindow-cmake-error/2280)

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**Author:** [@yan](https://discourse.vtk.org/u/yan)\
**Replies:** 1\
**Last updated:** [January 16, 2020, 6:46am UTC](https://discourse.vtk.org/t/centos7-vtkopenglrenderwindow-cmake-error/2280 "2020-01-16T06:46:21Z")

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hello, when i ccmake 8.2.0 with offscreen window in centos7. i install freeglut and osmesa, ccmake some configure: VTK\_HAS\_OSMESA=ON VTK\_OPENGL\_HAS\_EGL = ON VTK\_OPENGL\_USE\_GLES = ON VTK\_PYTHON\_VERSION =3.6 VTK\_MODUL…

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## [Moment Invariants failing tests](https://discourse.vtk.org/t/moment-invariants-failing-tests/2432)

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**Author:** [@ken-martin](https://discourse.vtk.org/u/ken-martin)\
**Replies:** 0\
**Last updated:** [January 15, 2020, 3:04pm UTC](https://discourse.vtk.org/t/moment-invariants-failing-tests/2432 "2020-01-15T15:04:50Z")

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Four tests have been failing in this remote module for about 20 days. Here is an example https://open.cdash.org/viewTest.php?onlyfailed&buildid=6299699 Can someone fix these please? Failing that I will suppress them. T…

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## [Recent VTK HDF5 changes regressed library file names...](https://discourse.vtk.org/t/recent-vtk-hdf5-changes-regressed-library-file-names/2425)

<div class="topic-metadata">

**Author:** [@seanm](https://discourse.vtk.org/u/seanm)\
**Replies:** 1\
**Last updated:** [January 15, 2020, 2:23pm UTC](https://discourse.vtk.org/t/recent-vtk-hdf5-changes-regressed-library-file-names/2425 "2020-01-15T14:23:29Z")

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Ben, I see from git log you made some recent updates to HDF5 in VTK… Do you think those changes could have regressed the library file naming when installing VTK? Previously (to what change I’m not exactly sure) the fi…

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## [vtkCornerAnnotation and tabulation](https://discourse.vtk.org/t/vtkcornerannotation-and-tabulation/2428)

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**Author:** [@Romain](https://discourse.vtk.org/u/Romain)\
**Replies:** 0\
**Last updated:** [January 15, 2020, 10:48am UTC](https://discourse.vtk.org/t/vtkcornerannotation-and-tabulation/2428 "2020-01-15T10:48:13Z")

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Hi, I create a vtkCornerAnnotation with some text including tabulation but the tabulation are not shown. This an example how I use vtkCornerAnnoation: std::stringstring ss; ss \<\< u8"My perfect text with some \\t tabula…

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## [VTK is slow when I have a lot of actors (\>10000)](https://discourse.vtk.org/t/vtk-is-slow-when-i-have-a-lot-of-actors-10000/2421)

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**Author:** [@ymmx](https://discourse.vtk.org/u/ymmx)\
**Replies:** 3\
**Last updated:** [January 15, 2020, 9:11am UTC](https://discourse.vtk.org/t/vtk-is-slow-when-i-have-a-lot-of-actors-10000/2421 "2020-01-15T09:11:33Z")

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I’m trying to display a lot of actors in VTK but the rendering is very slow. I’m wondering if I used VTK correctly to display that much actors. In the code I have a mouse interactor which change the color of the selec…

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## [Tick lines with vtkScalarBarActor](https://discourse.vtk.org/t/tick-lines-with-vtkscalarbaractor/2268)

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**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 6\
**Last updated:** [January 15, 2020, 3:27am UTC](https://discourse.vtk.org/t/tick-lines-with-vtkscalarbaractor/2268 "2020-01-15T03:27:36Z")

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Is it possible to draw tick lines with the vtkScalarBarActor? Every example I’ve seen with VTK does not have tick lines. It’s odd to me that the method vtkScalarBarActor.SetDrawTickLabels exists to draw the labels but no…

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## [How to remove artifact patches from a surface mesh?](https://discourse.vtk.org/t/how-to-remove-artifact-patches-from-a-surface-mesh/2376)

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**Author:** [@normanius](https://discourse.vtk.org/u/normanius)\
**Replies:** 3\
**Last updated:** [January 15, 2020, 12:06am UTC](https://discourse.vtk.org/t/how-to-remove-artifact-patches-from-a-surface-mesh/2376 "2020-01-15T00:06:03Z")

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Happy New Year, to whom it applies! :champagne: I occasionally come across artifacts as indicated by the yellow ellipse below: Small surface patches that are connected with the main surface body by a single point only. …

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## [Error using VTK with PyInstaller](https://discourse.vtk.org/t/error-using-vtk-with-pyinstaller/1625)

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**Author:** [@Antoine](https://discourse.vtk.org/u/Antoine)\
**Replies:** 5\
**Last updated:** [January 14, 2020, 1:54pm UTC](https://discourse.vtk.org/t/error-using-vtk-with-pyinstaller/1625 "2020-01-14T13:54:02Z")

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Hello, I have an application in Python 3.7, with PyQt 5.13.0 and VTK 8.1.2. I use PyInstaller 3.5 to create an executable. The application works with my computer but not with the others on which I tested. I have these e…

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## [Is it possible to get the ZMap from the Point cloud data?](https://discourse.vtk.org/t/is-it-possible-to-get-the-zmap-from-the-point-cloud-data/2418)

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**Author:** [@Kim\_William](https://discourse.vtk.org/u/Kim_William)\
**Replies:** 0\
**Last updated:** [January 14, 2020, 12:00pm UTC](https://discourse.vtk.org/t/is-it-possible-to-get-the-zmap-from-the-point-cloud-data/2418 "2020-01-14T12:00:35Z")

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Hi all. I have a question about the ZMap and the Point cloud data. Because the Point cloud is in mm, there is no distortion in the image, even if the X and Y resolution are different. However, the ZMap in pixels has a…

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## [Rendering custom C++ objects](https://discourse.vtk.org/t/rendering-custom-c-objects/2378)

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**Author:** [@BotellaA](https://discourse.vtk.org/u/BotellaA)\
**Replies:** 10\
**Last updated:** [January 13, 2020, 8:53pm UTC](https://discourse.vtk.org/t/rendering-custom-c-objects/2378 "2020-01-13T20:53:02Z")

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I am looking for recommandations about your several web technologies. I have C++ objets with their own data structures (polygonal surfaces and unstructured grids) that I would like to display in a web or electron applic…

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## [Representing 4D image data with VTK](https://discourse.vtk.org/t/representing-4d-image-data-with-vtk/2401)

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**Author:** [@Seun](https://discourse.vtk.org/u/Seun)\
**Replies:** 6\
**Last updated:** [January 13, 2020, 7:04pm UTC](https://discourse.vtk.org/t/representing-4d-image-data-with-vtk/2401 "2020-01-13T19:04:53Z")

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Hi everyone, I would like to know if it’s possible to represent 4D data as a vtkImageData. As far as I understand, vtkImageData can only be used to encode 3D (i.e: voxel information) but I was wondering if there’s a way…

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## [Visualize Very large number of Lines, Points/Spheres with High Performance](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353)

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**Author:** [@sharon](https://discourse.vtk.org/u/sharon)\
**Replies:** 4\
**Last updated:** [January 12, 2020, 2:55am UTC](https://discourse.vtk.org/t/visualize-very-large-number-of-lines-points-spheres-with-high-performance/2353 "2020-01-12T02:55:44Z")

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Dear Experts, In my situation, i need visualize very large number of Lines, Points/Spheres, with high performance, Do you have any suggestions? My current implementation is put group of lines into polyData, then put p…

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## [Overlay two images](https://discourse.vtk.org/t/overlay-two-images/2412)

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**Author:** [@Hello\_World](https://discourse.vtk.org/u/Hello_World)\
**Replies:** 0\
**Last updated:** [January 11, 2020, 3:32pm UTC](https://discourse.vtk.org/t/overlay-two-images/2412 "2020-01-11T15:32:05Z")

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Hello, I have two medical scans in the .nrrd (and optional .nii) format and open them with simpleITK and vtkReader as vtkImageData. The first one is an MRI of the brain and the other is a segmented tumor. They both have…

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## [Application data bound to vtkActor](https://discourse.vtk.org/t/application-data-bound-to-vtkactor/2405)

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**Author:** [@mhalle](https://discourse.vtk.org/u/mhalle)\
**Replies:** 2\
**Last updated:** [January 11, 2020, 1:46pm UTC](https://discourse.vtk.org/t/application-data-bound-to-vtkactor/2405 "2020-01-11T13:46:34Z")

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Is there a way to associate private data with an actor in vtkjs? I want to be able to get back a handle to some application state when picking. Is using a JS Map my best option? Thanks.

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## [Is it possible to turn off the plane rotation function of vtkPlaneWidget during interaction？](https://discourse.vtk.org/t/is-it-possible-to-turn-off-the-plane-rotation-function-of-vtkplanewidget-during-interaction/2410)

<div class="topic-metadata">

**Author:** [@kknnnyy](https://discourse.vtk.org/u/kknnnyy)\
**Replies:** 0\
**Last updated:** [January 11, 2020, 12:42pm UTC](https://discourse.vtk.org/t/is-it-possible-to-turn-off-the-plane-rotation-function-of-vtkplanewidget-during-interaction/2410 "2020-01-11T12:42:44Z")

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In my project, I don’t need vtkPlaneWidget to rotate during interaction, how can I achieve it?

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## [Volume rendering with vtkVolumeRayCastMapper but need help extracting the rendered grayscale image.](https://discourse.vtk.org/t/volume-rendering-with-vtkvolumeraycastmapper-but-need-help-extracting-the-rendered-grayscale-image/2404)

<div class="topic-metadata">

**Author:** [@spencermanwell](https://discourse.vtk.org/u/spencermanwell)\
**Replies:** 0\
**Last updated:** [January 11, 2020, 3:13am UTC](https://discourse.vtk.org/t/volume-rendering-with-vtkvolumeraycastmapper-but-need-help-extracting-the-rendered-grayscale-image/2404 "2020-01-11T03:13:33Z")

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Hello VTK, I have been rendering volumes using vtkVolumeRayCastMapper with a modified vtkVolumeRayCastMIPFunction as grayscale images and I am interested in extracting the pixel values of these and writing the images to…

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## [Access violation when deleting actor made from GLTF importer](https://discourse.vtk.org/t/access-violation-when-deleting-actor-made-from-gltf-importer/2400)

<div class="topic-metadata">

**Author:** [@pbrousson](https://discourse.vtk.org/u/pbrousson)\
**Replies:** 3\
**Last updated:** [January 10, 2020, 5:32pm UTC](https://discourse.vtk.org/t/access-violation-when-deleting-actor-made-from-gltf-importer/2400 "2020-01-10T17:32:02Z")

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Hello, My application have to load different scenes repeatedly (synoptic views for SCADA application). I need to clean-up properly the renderer between to scenes to avoid increasing memory usage. I use a loop to clean…

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## [AMD GPU can't display the examples of vtk](https://discourse.vtk.org/t/amd-gpu-cant-display-the-examples-of-vtk/2399)

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**Author:** [@laomen](https://discourse.vtk.org/u/laomen)\
**Replies:** 0\
**Last updated:** [January 10, 2020, 9:59am UTC](https://discourse.vtk.org/t/amd-gpu-cant-display-the-examples-of-vtk/2399 "2020-01-10T09:59:33Z")

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Hi,guys: i built vtk examples of qt GUI,but i get some error when i run it. When i use Nvidia GPU,it can display.But when i change my GPU to AMD,it can’t work.it display the black.

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## [Python 3.8.1 deprecation warning](https://discourse.vtk.org/t/python-3-8-1-deprecation-warning/2394)

<div class="topic-metadata">

**Author:** [@amaclean](https://discourse.vtk.org/u/amaclean)\
**Replies:** 5\
**Last updated:** [January 9, 2020, 9:26pm UTC](https://discourse.vtk.org/t/python-3-8-1-deprecation-warning/2394 "2020-01-09T21:26:03Z")

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If you look at the following code, there is a deprecation warning for: colors.SetColor("BkgColor", \[0.3, 0.6, 0.3, 1.0\]) As you can see from the code, I tried several alternatives including vtk.vtkColor4ub and vtk.vtkC…

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## [Extracting data from the unstructured grid using vtkplane cutter](https://discourse.vtk.org/t/extracting-data-from-the-unstructured-grid-using-vtkplane-cutter/2362)

<div class="topic-metadata">

**Author:** [@venkatesh](https://discourse.vtk.org/u/venkatesh)\
**Replies:** 1\
**Last updated:** [January 9, 2020, 4:54pm UTC](https://discourse.vtk.org/t/extracting-data-from-the-unstructured-grid-using-vtkplane-cutter/2362 "2020-01-09T16:54:04Z")

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Hi, I am trying to using vtkPlane() and vtkCutter in python to read the unstructured data. I have the volume data and wanted to extract data over a plane. So, I pass the plane location and normal to extract the data. Th…

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## ['-Wl,-rpath' not executed when building version 8.2.0](https://discourse.vtk.org/t/wl-rpath-not-executed-when-building-version-8-2-0/2383)

<div class="topic-metadata">

**Author:** [@Rigel](https://discourse.vtk.org/u/Rigel)\
**Replies:** 5\
**Last updated:** [January 9, 2020, 9:30am UTC](https://discourse.vtk.org/t/wl-rpath-not-executed-when-building-version-8-2-0/2383 "2020-01-09T09:30:40Z")

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Hi, I downloaded version 8.2.0 of VTK from the website and CMaked it with default settings (the only flag being CMAKE\_INSTALL\_PREFIX; CMake version 3.10.2 on Ubuntu 18.04.3 LTS). Now, running e.g.: ldd -r ${HOME}/VTK/8…

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## [Selectively disable and enable default mouse interactions in vtk](https://discourse.vtk.org/t/selectively-disable-and-enable-default-mouse-interactions-in-vtk/2338)

<div class="topic-metadata">

**Author:** [@Sathiya\_Moorthy](https://discourse.vtk.org/u/Sathiya_Moorthy)\
**Replies:** 2\
**Last updated:** [January 9, 2020, 5:42am UTC](https://discourse.vtk.org/t/selectively-disable-and-enable-default-mouse-interactions-in-vtk/2338 "2020-01-09T05:42:44Z")

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hi all, i want to selectively disable and enable default mouse interactions in vtk. does anyone know how to selectively disable/enable the interactions using vtkInteractorStyle or any of its subclasses.

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