# Latest

**URL:** https://discourse.vtk.org/latest.md?page=186

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

**Page:** 187

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## [VTK.js Courses?](https://discourse.vtk.org/t/vtk-js-courses/214)

<div class="topic-metadata">

**Author:** [@dannyrb](https://discourse.vtk.org/u/dannyrb)\
**Replies:** 5\
**Last updated:** [February 2, 2021, 6:24am UTC](https://discourse.vtk.org/t/vtk-js-courses/214 "2021-02-02T06:24:55Z")

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:wave: Hello, I am a maintainer over at cornerstone-tools, and we get a large number of requests for 2D/3D MPR functionality. Often times, we point our users toward: VTK.js’s documentation site OHIF’s VTK.js plugin H…

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## [Array resizing](https://discourse.vtk.org/t/array-resizing/5115)

<div class="topic-metadata">

**Author:** [@olesenm](https://discourse.vtk.org/u/olesenm)\
**Replies:** 0\
**Last updated:** [February 1, 2021, 4:54pm UTC](https://discourse.vtk.org/t/array-resizing/5115 "2021-02-01T16:54:10Z")

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I was sifting through the openfoam reader and stumbled across something that looks to me like legacy code: // this is necessary due to the strange vtkDataArrayTemplate::Resize() // implementation when the array size is …

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## [Debug looking for DLLs with -gd suffix](https://discourse.vtk.org/t/debug-looking-for-dlls-with-gd-suffix/3300)

<div class="topic-metadata">

**Author:** [@khlitoshi](https://discourse.vtk.org/u/khlitoshi)\
**Replies:** 2\
**Last updated:** [February 1, 2021, 11:06am UTC](https://discourse.vtk.org/t/debug-looking-for-dlls-with-gd-suffix/3300 "2021-02-01T11:06:34Z")

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I developed an application based on VTK 8.2. I compiled vtk from source in Debug and Release mode. When I run my application in debug mode it complains about not finding VTK Dll vtkChartsCore-8.2-gd.dll I compiled VTK …

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## [Assigning a particular vector array result to VTKStreamTracer](https://discourse.vtk.org/t/assigning-a-particular-vector-array-result-to-vtkstreamtracer/5110)

<div class="topic-metadata">

**Author:** [@Swarna\_Ravali](https://discourse.vtk.org/u/Swarna_Ravali)\
**Replies:** 0\
**Last updated:** [February 1, 2021, 10:46am UTC](https://discourse.vtk.org/t/assigning-a-particular-vector-array-result-to-vtkstreamtracer/5110 "2021-02-01T10:46:11Z")

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Hi, Mainly VTKStreamTracer takes InputData and SourceConnection to plot the flowlines. In my scenario, I have vtkUnstructuredgrid with various vector array results. My query is that, how can we assign a particular vecto…

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## [Unknown CMake command "vtk\_module\_config"](https://discourse.vtk.org/t/unknown-cmake-command-vtk-module-config/1295)

<div class="topic-metadata">

**Author:** [@Rogermc](https://discourse.vtk.org/u/Rogermc)\
**Replies:** 3\
**Last updated:** [February 1, 2021, 7:09am UTC](https://discourse.vtk.org/t/unknown-cmake-command-vtk-module-config/1295 "2021-02-01T07:09:45Z")

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Mac-Mini 2018 OSX 10.14.15 XCode 10.2.1 VTK Latest git pull origin master I tried to build Examples/Tutorial/Step1/Cxx but Cmake Configure fails with: CMake Error at CMakeLists.txt:7 (vtk\_module\_config): Unknown C…

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## [get centroids in python script](https://discourse.vtk.org/t/get-centroids-in-python-script/5073)

<div class="topic-metadata">

**Author:** [@Marco\_De\_Pietri](https://discourse.vtk.org/u/Marco_De_Pietri)\
**Replies:** 10\
**Last updated:** [January 30, 2021, 3:35pm UTC](https://discourse.vtk.org/t/get-centroids-in-python-script/5073 "2021-01-30T15:35:18Z")

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Hi I am trying to extract the centroids of an unstructured mesh in a python script. Sorry if it is a noob question, as I am an not an expert with the vtk module. My understanding is that the vtk classes and its public me…

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## [Looking for a Python VTK equivalent to Matlab's Isosurface function](https://discourse.vtk.org/t/looking-for-a-python-vtk-equivalent-to-matlabs-isosurface-function/5087)

<div class="topic-metadata">

**Author:** [@Vardonir](https://discourse.vtk.org/u/Vardonir)\
**Replies:** 6\
**Last updated:** [January 30, 2021, 12:33pm UTC](https://discourse.vtk.org/t/looking-for-a-python-vtk-equivalent-to-matlabs-isosurface-function/5087 "2021-01-30T12:33:54Z")

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I have the data as a (n\_x\*n\_y\*n\_z) array in Matlab, which I can easily transfer over to numpy using scipy.io. My code so far looks like this: frommat = loadmat("thefile.mat") the3d = frommat\["appropriate heade…

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## [vtkStaticCellLocator throws error on IntersectWithLine](https://discourse.vtk.org/t/vtkstaticcelllocator-throws-error-on-intersectwithline/5095)

<div class="topic-metadata">

**Author:** [@DFlyer](https://discourse.vtk.org/u/DFlyer)\
**Replies:** 1\
**Last updated:** [January 29, 2021, 7:37pm UTC](https://discourse.vtk.org/t/vtkstaticcelllocator-throws-error-on-intersectwithline/5095 "2021-01-29T19:37:16Z")

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I am trying to intersect a polydata ( tri mesh) with a line, I am using vtkStaticCellLocator filter as follows vtkSmartPointer\< vtkStaticCellLocator\> pCellLocator = vtkSmartPointer\<vtkStaticCellLocator\>::New(); pCellLoc…

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## [how can I show molecular orbital with vtk](https://discourse.vtk.org/t/how-can-i-show-molecular-orbital-with-vtk/5093)

<div class="topic-metadata">

**Author:** [@mjavan](https://discourse.vtk.org/u/mjavan)\
**Replies:** 1\
**Last updated:** [January 29, 2021, 3:32pm UTC](https://discourse.vtk.org/t/how-can-i-show-molecular-orbital-with-vtk/5093 "2021-01-29T15:32:46Z")

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I want read a gaussian cube file with vtkGaussianCubeReader and show isosurface of the Molecular orbitals similar as I found some class such as vtkProgrammableElectronicData and vtkMolecule but I dont know how can I se…

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## [Thickness or Depth of a polydata along a direction](https://discourse.vtk.org/t/thickness-or-depth-of-a-polydata-along-a-direction/5076)

<div class="topic-metadata">

**Author:** [@DFlyer](https://discourse.vtk.org/u/DFlyer)\
**Replies:** 6\
**Last updated:** [January 29, 2021, 6:53am UTC](https://discourse.vtk.org/t/thickness-or-depth-of-a-polydata-along-a-direction/5076 "2021-01-29T06:53:36Z")

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Hello, I am trying to scalar plot thickness ( or depth ) of a water tight polydata along a direction. Currently I create a line from a point on polydata and perform vtkOBBTree -\> IntersectWithLine, get the distance bet…

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## [Help!I need compiled qt5.15+VTK8.2+DEBUG (means the compiled version is VTK8.2 +DEBUG and support QT5.15 development, )](https://discourse.vtk.org/t/help-i-need-compiled-qt5-15-vtk8-2-debug-means-the-compiled-version-is-vtk8-2-debug-and-support-qt5-15-development/4965)

<div class="topic-metadata">

**Author:** [@Riton](https://discourse.vtk.org/u/Riton)\
**Replies:** 13\
**Last updated:** [January 29, 2021, 6:26am UTC](https://discourse.vtk.org/t/help-i-need-compiled-qt5-15-vtk8-2-debug-means-the-compiled-version-is-vtk8-2-debug-and-support-qt5-15-development/4965 "2021-01-29T06:26:06Z")

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I have qt5.15+VTK9.0+DEBUG,but the functions do not work right.And I also have qt5.15+VTK8.2+RELEASE,then the functions work right.But when I compiled qt5.15+VTK8.2+DEBUG by myself,it always failed.So who can give me th…

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## [Comparing DRR with x-ray image](https://discourse.vtk.org/t/comparing-drr-with-x-ray-image/5075)

<div class="topic-metadata">

**Author:** [@tzodge](https://discourse.vtk.org/u/tzodge)\
**Replies:** 1\
**Last updated:** [January 28, 2021, 3:28am UTC](https://discourse.vtk.org/t/comparing-drr-with-x-ray-image/5075 "2021-01-28T03:28:56Z")

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I want to compare a DRR of a CT scan with an Xray. Is there any way that I can find an optimal transfer function using VTK ? Thanks

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## [How to blend a gray and rgb image?](https://discourse.vtk.org/t/how-to-blend-a-gray-and-rgb-image/5072)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 2\
**Last updated:** [January 28, 2021, 12:23am UTC](https://discourse.vtk.org/t/how-to-blend-a-gray-and-rgb-image/5072 "2021-01-28T00:23:55Z")

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I need to blend a gray and rgb image, and my code is: import vtk import numpy as np from vtk.util.numpy\_support import vtk\_to\_numpy, numpy\_to\_vtk def numpyToVTK(data, multi\_component=False): if multi\_component == …

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## [How to avoid the sawtooth from vtkImageReslice?](https://discourse.vtk.org/t/how-to-avoid-the-sawtooth-from-vtkimagereslice/5023)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 3\
**Last updated:** [January 27, 2021, 2:54pm UTC](https://discourse.vtk.org/t/how-to-avoid-the-sawtooth-from-vtkimagereslice/5023 "2021-01-27T14:54:53Z")

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I find there is sawtooth for the output of vtkImageReslice, how can I avoid this sawtooth? Any suggestion is appreciated!

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## [vtkImageTracerWidget not receiving events on Mac (pyQt5). bug?](https://discourse.vtk.org/t/vtkimagetracerwidget-not-receiving-events-on-mac-pyqt5-bug/5052)

<div class="topic-metadata">

**Author:** [@soren](https://discourse.vtk.org/u/soren)\
**Replies:** 5\
**Last updated:** [January 27, 2021, 9:45am UTC](https://discourse.vtk.org/t/vtkimagetracerwidget-not-receiving-events-on-mac-pyqt5-bug/5052 "2021-01-27T09:45:31Z")

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Hi, I posted this in support last week but with no luck. I am re-posting here as this is a potential bug based on differing results on Linux/Mac and with and without PyQt rendering. I have trouble with vtkImageTracerWi…

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## [Cannot use QVTKRenderWindowInteractor and QWebEngineView together in one application.](https://discourse.vtk.org/t/cannot-use-qvtkrenderwindowinteractor-and-qwebengineview-together-in-one-application/5059)

<div class="topic-metadata">

**Author:** [@sherinnovation](https://discourse.vtk.org/u/sherinnovation)\
**Replies:** 3\
**Last updated:** [January 26, 2021, 9:06pm UTC](https://discourse.vtk.org/t/cannot-use-qvtkrenderwindowinteractor-and-qwebengineview-together-in-one-application/5059 "2021-01-26T21:06:12Z")

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When I use QVTKRenderWindowInteractor and QWebEngineView together in my PyQt source running under Windows 10, I get the following error whenever I close the application window. vtkWin32OpenGLRenderWin:217 ERR| vtkWi…

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## [Is there a way to get the raw data array in vtkDataArray by zero-copy ?](https://discourse.vtk.org/t/is-there-a-way-to-get-the-raw-data-array-in-vtkdataarray-by-zero-copy/5061)

<div class="topic-metadata">

**Author:** [@1116](https://discourse.vtk.org/u/1116)\
**Replies:** 4\
**Last updated:** [January 27, 2021, 2:12am UTC](https://discourse.vtk.org/t/is-there-a-way-to-get-the-raw-data-array-in-vtkdataarray-by-zero-copy/5061 "2021-01-27T02:12:36Z")

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Hello, I try to get the offsetArray and the connectivityArray from the cellArray, and then transfer them to other program for further processing. I noticed that the return value of GetConnectivityArray() function is vtk…

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## [Splitting cells on a PolyData](https://discourse.vtk.org/t/splitting-cells-on-a-polydata/5021)

<div class="topic-metadata">

**Author:** [@whophil](https://discourse.vtk.org/u/whophil)\
**Replies:** 8\
**Last updated:** [January 26, 2021, 4:07pm UTC](https://discourse.vtk.org/t/splitting-cells-on-a-polydata/5021 "2021-01-26T16:07:57Z")

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I’d like to “split” cells on a PolyData surface, adding vertices and cells. For example, in the screenshot below, I am starting with the black mesh, and I’d like to add all the points where the pink lines intersect the m…

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## [vtkMultiVolume - Clipping plane implemented?](https://discourse.vtk.org/t/vtkmultivolume-clipping-plane-implemented/5056)

<div class="topic-metadata">

**Author:** [@tchen87](https://discourse.vtk.org/u/tchen87)\
**Replies:** 2\
**Last updated:** [January 26, 2021, 4:08pm UTC](https://discourse.vtk.org/t/vtkmultivolume-clipping-plane-implemented/5056 "2021-01-26T16:08:16Z")

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I have been playing around with vtkMultiVolume, and I have not been able to apply clipping planes successfully to the actor. Am I missing something or have clipping planes not been implemented for this feature yet?

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## [Using QVTKOpenGLNativeWidget in PyQt](https://discourse.vtk.org/t/using-qvtkopenglnativewidget-in-pyqt/5058)

<div class="topic-metadata">

**Author:** [@sherinnovation](https://discourse.vtk.org/u/sherinnovation)\
**Replies:** 0\
**Last updated:** [January 26, 2021, 11:33am UTC](https://discourse.vtk.org/t/using-qvtkopenglnativewidget-in-pyqt/5058 "2021-01-26T11:33:39Z")

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I would like to use the class QVTKOpenGLNativeWidget in my PyQt application as I am facing problems with my existing QVTKRenderWindowInteractor class when used along with QWebEngineView Does anyone know how to import th…

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## [Read sequence picture with different position](https://discourse.vtk.org/t/read-sequence-picture-with-different-position/5015)

<div class="topic-metadata">

**Author:** [@shan\_tong](https://discourse.vtk.org/u/shan_tong)\
**Replies:** 1\
**Last updated:** [January 26, 2021, 1:41am UTC](https://discourse.vtk.org/t/read-sequence-picture-with-different-position/5015 "2021-01-26T01:41:46Z")

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Hi when I read sequence picture with different position I have a problem. My sequence images are randomly collected images, so the coordinates are not continuous in one direction like CT images. How should I read my im…

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## [Unhandled Rejection (TypeError): Cannot read property 'pixelRepresentation' of undefined](https://discourse.vtk.org/t/unhandled-rejection-typeerror-cannot-read-property-pixelrepresentation-of-undefined/5055)

<div class="topic-metadata">

**Author:** [@MarkoNikovic](https://discourse.vtk.org/u/MarkoNikovic)\
**Replies:** 0\
**Last updated:** [January 25, 2021, 7:28pm UTC](https://discourse.vtk.org/t/unhandled-rejection-typeerror-cannot-read-property-pixelrepresentation-of-undefined/5055 "2021-01-25T19:28:01Z")

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Hello Everyone, How are you? I am using react-vtkjs-viewport module in our project (React Rescripts) I set initialize setting vtkRules in rescript.js for VTK. Now I have node mudule representation error I wish any…

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## [QT Signals and slots](https://discourse.vtk.org/t/qt-signals-and-slots/5053)

<div class="topic-metadata">

**Author:** [@dporter](https://discourse.vtk.org/u/dporter)\
**Replies:** 1\
**Last updated:** [January 25, 2021, 6:06pm UTC](https://discourse.vtk.org/t/qt-signals-and-slots/5053 "2021-01-25T18:06:42Z")

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I’ve spent a couple of days trying to get a my QPushButton to fire and signal and recognizing a slot. The strange thing is I’ve gotten gotten other button to work perfectly, and I set up this button the same exact way as…

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## [how does vtkIdType work?](https://discourse.vtk.org/t/how-does-vtkidtype-work/5024)

<div class="topic-metadata">

**Author:** [@1116](https://discourse.vtk.org/u/1116)\
**Replies:** 4\
**Last updated:** [January 23, 2021, 11:05am UTC](https://discourse.vtk.org/t/how-does-vtkidtype-work/5024 "2021-01-23T11:05:54Z")

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It looks that vtkIdType can be an integer type with the 32bit or 64bit based on runtime information (https://vtk.org/doc/release/4.2/html/classvtkIdType.html), I’m curious how it works, where it is defined, and what are …

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## [ParaView, VTK and CMake training course in Lyon, France in march 2021](https://discourse.vtk.org/t/paraview-vtk-and-cmake-training-course-in-lyon-france-in-march-2021/4987)

<div class="topic-metadata">

**Author:** [@mwestphal](https://discourse.vtk.org/u/mwestphal)\
**Replies:** 3\
**Last updated:** [January 21, 2021, 5:23pm UTC](https://discourse.vtk.org/t/paraview-vtk-and-cmake-training-course-in-lyon-france-in-march-2021/4987 "2021-01-21T17:23:52Z")

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Kitware SAS is organizing online VTK and ParaView training course (basic and advanced) in march 2020. Always wanted to use VTK to create visualization of your data but did not know how to start? Already have some C++ o…

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## [Why the vtkSelectPolyData returns wrong area?](https://discourse.vtk.org/t/why-the-vtkselectpolydata-returns-wrong-area/5041)

<div class="topic-metadata">

**Author:** [@Jaafar\_Nasrabadi](https://discourse.vtk.org/u/Jaafar_Nasrabadi)\
**Replies:** 0\
**Last updated:** [January 21, 2021, 10:26am UTC](https://discourse.vtk.org/t/why-the-vtkselectpolydata-returns-wrong-area/5041 "2021-01-21T10:26:03Z")

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Hi. I selected a region of a polydata by a loop of points and extract selected region inside the loop with vtkSelectPolyData and vtkClipPolyData but it contains extra points. sometimes vtkSelectPolyData can’t select a…

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## [running and functional examples available?](https://discourse.vtk.org/t/running-and-functional-examples-available/4865)

<div class="topic-metadata">

**Author:** [@Jens](https://discourse.vtk.org/u/Jens)\
**Replies:** 8\
**Last updated:** [January 21, 2021, 3:38pm UTC](https://discourse.vtk.org/t/running-and-functional-examples-available/4865 "2021-01-21T15:38:37Z")

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Good day, OS: Windows 10 using VS2019 (C++) after changing from VTK 8.2 to 9.0.1 none of the examples run anymore. I compiled the cone6 example but it immediately returns from the vtkRenderWindowInteractor::Start() fu…

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## [vtkFPSMonitor](https://discourse.vtk.org/t/vtkfpsmonitor/5031)

<div class="topic-metadata">

**Author:** [@liyunfei18](https://discourse.vtk.org/u/liyunfei18)\
**Replies:** 4\
**Last updated:** [January 20, 2021, 9:08am UTC](https://discourse.vtk.org/t/vtkfpsmonitor/5031 "2021-01-20T09:08:29Z")

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I want to use vtkFPSMonitor to display fps and I use setRenderWindow to pass my renderWindow to vtkFPSMonitor. The canvas in vtkFPSMonitor works well, but the info cannot be displayed. This is function renderInfo(): fu…

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## [Scalar range widget](https://discourse.vtk.org/t/scalar-range-widget/637)

<div class="topic-metadata">

**Author:** [@lgeoffroy](https://discourse.vtk.org/u/lgeoffroy)\
**Replies:** 14\
**Last updated:** [January 19, 2021, 7:24pm UTC](https://discourse.vtk.org/t/scalar-range-widget/637 "2021-01-19T19:24:55Z")

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Hello, I am building a React app and I need to visualize some vtkjs scenes, and I want to add a scalar range widget like the one you can find on the Calculator example (https://kitware.github.io/vtk-js/examples/Calculat…

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## [vtkImageTracerWidget not receiving events on Mac (pyQt5)](https://discourse.vtk.org/t/vtkimagetracerwidget-not-receiving-events-on-mac-pyqt5/5034)

<div class="topic-metadata">

**Author:** [@soren](https://discourse.vtk.org/u/soren)\
**Replies:** 0\
**Last updated:** [January 19, 2021, 2:08pm UTC](https://discourse.vtk.org/t/vtkimagetracerwidget-not-receiving-events-on-mac-pyqt5/5034 "2021-01-19T14:08:36Z")

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Hi, I have trouble with vtkImageTracerWidget on Mac. The code below shows an image (zeros) and a vtkImageTracerWidget is active on to (so you can draw an outline). This works on Linux, but on Mac the ImagetracerWidget a…

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