# Latest

**URL:** https://discourse.vtk.org/latest.md?page=100

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

**Page:** 101

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## [Configure VTK project stuck at \[100%\] Linking cxx executable](https://discourse.vtk.org/t/configure-vtk-project-stuck-at-100-linking-cxx-executable/10542)

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**Author:** [@Sterben\_01](https://discourse.vtk.org/u/Sterben_01)\
**Replies:** 2\
**Last updated:** [January 26, 2023, 6:40am UTC](https://discourse.vtk.org/t/configure-vtk-project-stuck-at-100-linking-cxx-executable/10542 "2023-01-26T06:40:50Z")

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Hi! I’m just compiled and installed the VTK 9.2. I have a simple project and this is my CMakeList.txt cmake\_minimum\_required(VERSION 3.16) project (Helloworld) find\_package (VTK REQUIRED) include\_directories(${VTK\_INC…

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## [Using a C# VTK for Windows application through a browser](https://discourse.vtk.org/t/using-a-c-vtk-for-windows-application-through-a-browser/10510)

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**Author:** [@JimCR1966](https://discourse.vtk.org/u/JimCR1966)\
**Replies:** 4\
**Last updated:** [January 25, 2023, 9:27pm UTC](https://discourse.vtk.org/t/using-a-c-vtk-for-windows-application-through-a-browser/10510 "2023-01-25T21:27:11Z")

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I am trying to build a version of my C# (VS 2022) that can run through a browser using Cybelesoft’s Thinfinity Virtual UI. The vtkrendered windows do not work (simply not rendered). Has anybody else tried this? Is there …

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## [Masking structured data](https://discourse.vtk.org/t/masking-structured-data/10538)

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**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 2\
**Last updated:** [January 25, 2023, 9:06pm UTC](https://discourse.vtk.org/t/masking-structured-data/10538 "2023-01-25T21:06:36Z")

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Hi Developers I am in a situation where I am working on structured data, which needs to be filtered using a bit-mask, e.g. at least one of the first 3 bits must be set and always bit 7. I looked into vtkImageMaskBits, w…

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## [Making a Hello World VTK.js Proxy (help!)](https://discourse.vtk.org/t/making-a-hello-world-vtk-js-proxy-help/10537)

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**Author:** [@davidshq](https://discourse.vtk.org/u/davidshq)\
**Replies:** 7\
**Last updated:** [January 25, 2023, 5:29pm UTC](https://discourse.vtk.org/t/making-a-hello-world-vtk-js-proxy-help/10537 "2023-01-25T17:29:02Z")

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I’ve been messing around with VTK.js proxies for quite some time and still don’t feel I have a great handle on them, so I decided to try making the world’s simplest proxy / proxymanager - unfortunately it doesn’t work. H…

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## [InteractorStyleImageSlicing for Touch Screen](https://discourse.vtk.org/t/interactorstyleimageslicing-for-touch-screen/10445)

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**Author:** [@jilei-hao](https://discourse.vtk.org/u/jilei-hao)\
**Replies:** 6\
**Last updated:** [January 25, 2023, 2:43pm UTC](https://discourse.vtk.org/t/interactorstyleimageslicing-for-touch-screen/10445 "2023-01-25T14:43:18Z")

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I’m writing a tablet app for displaying image slices and want to override the handleStartPan function to make double touch & drag to change slices of the image, and disable the panning. Following code does not seem to wo…

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## [Frame rate for multiple viewports drops when streaming](https://discourse.vtk.org/t/frame-rate-for-multiple-viewports-drops-when-streaming/10485)

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**Author:** [@joaomlap](https://discourse.vtk.org/u/joaomlap)\
**Replies:** 7\
**Last updated:** [January 24, 2023, 5:23pm UTC](https://discourse.vtk.org/t/frame-rate-for-multiple-viewports-drops-when-streaming/10485 "2023-01-24T17:23:11Z")

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Hi I have an application that allows the users to navigate through discrete slices of a 3D model. They can to customize what they want to see. Each row contains 2 different slices of results of a CFD solve and a delta b…

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## [Python pip install 9.0.1 not installing](https://discourse.vtk.org/t/python-pip-install-9-0-1-not-installing/3864)

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**Author:** [@Gresliebear](https://discourse.vtk.org/u/Gresliebear)\
**Replies:** 4\
**Last updated:** [January 24, 2023, 2:45pm UTC](https://discourse.vtk.org/t/python-pip-install-9-0-1-not-installing/3864 "2023-01-24T14:45:16Z")

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I am calling vtk from requirements.txt but it could not find the latest version Could not find a version that satisfies the requirement vtk==9.0.1 (from -r requirements.txt (line 87)) (from versions: 8.0.0.dev2017071…

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## [Help with Paraview Glance: Opening file by passing the fileURL as argument](https://discourse.vtk.org/t/help-with-paraview-glance-opening-file-by-passing-the-fileurl-as-argument/4014)

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**Author:** [@Ramu](https://discourse.vtk.org/u/Ramu)\
**Replies:** 7\
**Last updated:** [January 24, 2023, 1:30pm UTC](https://discourse.vtk.org/t/help-with-paraview-glance-opening-file-by-passing-the-fileurl-as-argument/4014 "2023-01-24T13:30:36Z")

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Hello, I am am running Paraview Glance app based on instruction from github. I am using it as a simple viewer in my project. I want to know if there is any way to pass file as argument to viewer instead of using open di…

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## [why are my negative contours not generating with vtk.vtkContourFilter?](https://discourse.vtk.org/t/why-are-my-negative-contours-not-generating-with-vtk-vtkcontourfilter/10525)

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**Author:** [@Derek\_Eden](https://discourse.vtk.org/u/Derek_Eden)\
**Replies:** 0\
**Last updated:** [January 23, 2023, 4:12pm UTC](https://discourse.vtk.org/t/why-are-my-negative-contours-not-generating-with-vtk-vtkcontourfilter/10525 "2023-01-23T16:12:31Z")

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I am using vtk.vtkContourFilter to create isolines from a dataset. Everything seems to work fine, but any contour values I specify \<= 0 don’t seem to generate, even though there is definitely data with those values. I …

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## [How to get separate boundary for a tube?](https://discourse.vtk.org/t/how-to-get-separate-boundary-for-a-tube/10521)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 3\
**Last updated:** [January 23, 2023, 11:00am UTC](https://discourse.vtk.org/t/how-to-get-separate-boundary-for-a-tube/10521 "2023-01-23T11:00:44Z")

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For a tube without cap, I want to obtain the two cap. The boundary is calculated as: fe = vtk.vtkFeatureEdges() fe.SetInputData(tubePoly) fe.BoundaryEdgesOn() fe.FeatureEdgesOff() fe.NonManifoldEdgesOff() fe.ManifoldEd…

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## [NativeVTK Android Black Screen](https://discourse.vtk.org/t/nativevtk-android-black-screen/10106)

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**Author:** [@perphy](https://discourse.vtk.org/u/perphy)\
**Replies:** 2\
**Last updated:** [January 23, 2023, 9:14am UTC](https://discourse.vtk.org/t/nativevtk-android-black-screen/10106 "2023-01-23T09:14:39Z")

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Hi, I want to run vtk on android. I build vtk9.2.2 with ndk 25 on ubuntu. I try to run the official example NativeVTK. But I get black screen. Similar with Is vtk9.2.2 to new and not compatible with the newest and…

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## [Extracting particle physics from streamlines](https://discourse.vtk.org/t/extracting-particle-physics-from-streamlines/10518)

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**Author:** [@alanpatterson](https://discourse.vtk.org/u/alanpatterson)\
**Replies:** 1\
**Last updated:** [January 23, 2023, 7:31am UTC](https://discourse.vtk.org/t/extracting-particle-physics-from-streamlines/10518 "2023-01-23T07:31:50Z")

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I am trying to work out the correct method for recovering a particle’s movement in a vector field, from using the streamline integration of the vector field. Let’s say I have a vector velocity field. I generate streamli…

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## [vtkGradientFilter segmentation fault](https://discourse.vtk.org/t/vtkgradientfilter-segmentation-fault/10516)

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**Author:** [@FanWang10](https://discourse.vtk.org/u/FanWang10)\
**Replies:** 1\
**Last updated:** [January 22, 2023, 9:44pm UTC](https://discourse.vtk.org/t/vtkgradientfilter-segmentation-fault/10516 "2023-01-22T21:44:12Z")

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Hello, I am using to calculate the gradient of each vertex in an unstructured grid. I followed this example and made some changes: https://gitlab.kitware.com/vtk/vtk/-/blob/v9.2.0/Accelerators/Vtkm/Filters/Testing/Cxx/…

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## [vtkPolyData parallel processing](https://discourse.vtk.org/t/vtkpolydata-parallel-processing/10457)

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**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 4\
**Last updated:** [January 22, 2023, 6:59pm UTC](https://discourse.vtk.org/t/vtkpolydata-parallel-processing/10457 "2023-01-22T18:59:18Z")

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I am currently in a situation where I have vtkPolyData containing many points, but only a subset of these points are vertices in a mesh and have normals associated. I would like to like to perform some heavy operations …

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## [Fill / Color area of closed polyline](https://discourse.vtk.org/t/fill-color-area-of-closed-polyline/10497)

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**Author:** [@SebastianWilke](https://discourse.vtk.org/u/SebastianWilke)\
**Replies:** 4\
**Last updated:** [January 22, 2023, 6:47pm UTC](https://discourse.vtk.org/t/fill-color-area-of-closed-polyline/10497 "2023-01-22T18:47:43Z")

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Hello! I am rendering DICOM contours (Yes, against advice to use existing implementations). At the moment, I am creating vtkPolyData using vtkPoints and vtkCellArray from the 3D-point data extracted from DICOM. Then, I …

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## [How to label vtkPolyData?](https://discourse.vtk.org/t/how-to-label-vtkpolydata/10513)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 5\
**Last updated:** [January 21, 2023, 10:28am UTC](https://discourse.vtk.org/t/how-to-label-vtkpolydata/10513 "2023-01-21T10:28:48Z")

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For example, I have two poly data: poly1 & poly2. I want to use vtkAppendPolyData to merge the two polydata and get polyFinal. Is it possible to label poly1 and poly2 before vtkAppendPolyData so that I can know the cell…

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## [Extracting isosurface from a vtkImageData](https://discourse.vtk.org/t/extracting-isosurface-from-a-vtkimagedata/10502)

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**Author:** [@Jishnu](https://discourse.vtk.org/u/Jishnu)\
**Replies:** 9\
**Last updated:** [January 21, 2023, 10:27am UTC](https://discourse.vtk.org/t/extracting-isosurface-from-a-vtkimagedata/10502 "2023-01-21T10:27:28Z")

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I am trying to create an isosurface plot from a vtkImageData. I have a numpy array which has the scalar fields. I kept the scalar field as 0 and 1 for testing. Given below is my pipeline: import vtk from vtk.util import…

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## [some questions about volume rendering](https://discourse.vtk.org/t/some-questions-about-volume-rendering/10458)

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**Author:** [@HWsir](https://discourse.vtk.org/u/HWsir)\
**Replies:** 8\
**Last updated:** [January 21, 2023, 5:47am UTC](https://discourse.vtk.org/t/some-questions-about-volume-rendering/10458 "2023-01-21T05:47:41Z")

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I am using wslink and remote rendering to display the results of 3D reconstruction of medical images and cut through boxwidget on the web page, but the web page only displays images. After that, I displayed an official c…

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## [Adding a link library to a module](https://discourse.vtk.org/t/adding-a-link-library-to-a-module/10480)

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**Author:** [@djduke](https://discourse.vtk.org/u/djduke)\
**Replies:** 3\
**Last updated:** [January 21, 2023, 3:02am UTC](https://discourse.vtk.org/t/adding-a-link-library-to-a-module/10480 "2023-01-21T03:02:53Z")

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If I want to link an external library to a module I believe I need to use target\_link\_library(…). However when I try this with the Wrapping example module from the distribution I getan error when configuring cmake: t…

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## [Experiencing ImportErrror when loading vtk constants](https://discourse.vtk.org/t/experiencing-importerrror-when-loading-vtk-constants/10448)

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**Author:** [@Maximilian\_Nentwich](https://discourse.vtk.org/u/Maximilian_Nentwich)\
**Replies:** 1\
**Last updated:** [January 21, 2023, 2:57am UTC](https://discourse.vtk.org/t/experiencing-importerrror-when-loading-vtk-constants/10448 "2023-01-21T02:57:26Z")

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Hi VTK forum, I am getting an error when importing vtk (as part of brainspace) ImportError: cannot import name 'VTK\_UNICODE\_STRING' from 'vtk.util.vtkConstants' from the following command: from brainspace.null\_models…

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## [VTK module import error](https://discourse.vtk.org/t/vtk-module-import-error/10274)

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**Author:** [@Deepa](https://discourse.vtk.org/u/Deepa)\
**Replies:** 9\
**Last updated:** [January 21, 2023, 2:52am UTC](https://discourse.vtk.org/t/vtk-module-import-error/10274 "2023-01-21T02:52:20Z")

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Hi All, I am trying to run the following example (K3D-jupyter/volume\_renderer.ipynb at 3fef1ea419a84a51c8aed56cb285b9fcf0a18c9a · K3D-tools/K3D-jupyter · GitHub) in jupyter notebook. import k3d import math import numpy…

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## [How can I cut (clip) PolyData without closing the surface using vtk.js ?](https://discourse.vtk.org/t/how-can-i-cut-clip-polydata-without-closing-the-surface-using-vtk-js/10512)

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**Author:** [@Javi-r](https://discourse.vtk.org/u/Javi-r)\
**Replies:** 3\
**Last updated:** [January 21, 2023, 1:28am UTC](https://discourse.vtk.org/t/how-can-i-cut-clip-polydata-without-closing-the-surface-using-vtk-js/10512 "2023-01-21T01:28:22Z")

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How can I cut PolyData without closing the surface using vtk.js ? I would need something like vtkClipPolyData. I have seen that there is vtkClipClosedSurface but it closes the surface. I want something like this:

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## [volume not rendering using react](https://discourse.vtk.org/t/volume-not-rendering-using-react/10291)

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**Author:** [@jilei-hao](https://discourse.vtk.org/u/jilei-hao)\
**Replies:** 16\
**Last updated:** [January 20, 2023, 10:57pm UTC](https://discourse.vtk.org/t/volume-not-rendering-using-react/10291 "2023-01-20T22:57:24Z")

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I’m trying to combine the time series example with volume rendering in react. But following code renders nothing on the screen. The code downloads one frame of volume, and uses the vtkImageData-vtkVolumeMapper-vtkVolume…

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## [how to use vtkGradientFilter to get the gradient of each point in an unstructured grid in codes](https://discourse.vtk.org/t/how-to-use-vtkgradientfilter-to-get-the-gradient-of-each-point-in-an-unstructured-grid-in-codes/10514)

<div class="topic-metadata">

**Author:** [@FanWang10](https://discourse.vtk.org/u/FanWang10)\
**Replies:** 0\
**Last updated:** [January 20, 2023, 9:40pm UTC](https://discourse.vtk.org/t/how-to-use-vtkgradientfilter-to-get-the-gradient-of-each-point-in-an-unstructured-grid-in-codes/10514 "2023-01-20T21:40:22Z")

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Hello, I am trying to use vtkGradientFilter to calculate the gradient at each point. However I didn’t find an example that fits my need. What I have is a .vtu file. It is an unstructured grid with 5 triangle cells. Wha…

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## [Recolour outerline/border](https://discourse.vtk.org/t/recolour-outerline-border/10479)

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**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 2\
**Last updated:** [January 20, 2023, 8:30pm UTC](https://discourse.vtk.org/t/recolour-outerline-border/10479 "2023-01-20T20:30:10Z")

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Using vtk, I overlaid a mesh on a CT slice, as shown in the image below. However, I noticed a red edge appear in the vtkImagePlaneWidget’s outer line. I tried to fix it by changing the colour to white, but it didn’t work…

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## [From vtkRenderWindow to OpenCV Mat using python](https://discourse.vtk.org/t/from-vtkrenderwindow-to-opencv-mat-using-python/10508)

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**Author:** [@TartaPise](https://discourse.vtk.org/u/TartaPise)\
**Replies:** 1\
**Last updated:** [January 20, 2023, 2:37pm UTC](https://discourse.vtk.org/t/from-vtkrenderwindow-to-opencv-mat-using-python/10508 "2023-01-20T14:37:12Z")

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Hi guys, I’ve tried many different ways to transform a vtkRenderWindow into an OpenCV Mat but I could get it and the python wrap documentation is not very solid (or am I missing some websites?). Do you know how could I …

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## [Checking for contours of zero size](https://discourse.vtk.org/t/checking-for-contours-of-zero-size/10491)

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**Author:** [@BlueKnight7](https://discourse.vtk.org/u/BlueKnight7)\
**Replies:** 2\
**Last updated:** [January 19, 2023, 9:41pm UTC](https://discourse.vtk.org/t/checking-for-contours-of-zero-size/10491 "2023-01-19T21:41:47Z")

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This is a follow on off vtkContourGrid example - #7 by BlueKnight7 and requires a little background detail first. I’ve setup my code to have multiple mesh objects using vtkUnstructuredGrid’s. I want to be able to crea…

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## [Minimal VTK build with new module system](https://discourse.vtk.org/t/minimal-vtk-build-with-new-module-system/2813)

<div class="topic-metadata">

**Author:** [@biagas](https://discourse.vtk.org/u/biagas)\
**Replies:** 29\
**Last updated:** [January 19, 2023, 8:45pm UTC](https://discourse.vtk.org/t/minimal-vtk-build-with-new-module-system/2813 "2023-01-19T20:45:02Z")

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With vtk-8.1, Disabling groups and enabling only those modules needed was pretty straightforward to get only the desired pieces of vtk. Dependent modules of those requested were automagically also enabled. I downloaded …

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## [DLL load failed while importing vtkRenderingOpenVR](https://discourse.vtk.org/t/dll-load-failed-while-importing-vtkrenderingopenvr/10449)

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**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 3\
**Last updated:** [January 19, 2023, 7:11pm UTC](https://discourse.vtk.org/t/dll-load-failed-while-importing-vtkrenderingopenvr/10449 "2023-01-19T19:11:37Z")

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After building VTK (latest release branch) on Windows succussfully and generating a wheel, when I try to import vtk in Python, I get an error loading the DLL for vtkRenderingOpenVR: \>\>\> import vtk Traceback (most recent…

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## [vtk-9.2.5 python wrapper vtkProp3DCollection.GetNextProp3D() return null](https://discourse.vtk.org/t/vtk-9-2-5-python-wrapper-vtkprop3dcollection-getnextprop3d-return-null/10504)

<div class="topic-metadata">

**Author:** [@TartaPise](https://discourse.vtk.org/u/TartaPise)\
**Replies:** 5\
**Last updated:** [January 19, 2023, 4:52pm UTC](https://discourse.vtk.org/t/vtk-9-2-5-python-wrapper-vtkprop3dcollection-getnextprop3d-return-null/10504 "2023-01-19T16:52:57Z")

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Hello everyone, I’m new to the Forum, please treat me well and let me know if I do something wrong. I’m having issues writing a simple python function to save the centers of the actors in a vtkassembly. Here is the fun…

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