# Development

**URL:** https://discourse.vtk.org/c/development/7.md?page=34

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

**Page:** 35

---

## [Extract opacity value at 3d point (in a form of world coordinate) on vtkImageData?](https://discourse.vtk.org/t/extract-opacity-value-at-3d-point-in-a-form-of-world-coordinate-on-vtkimagedata/6687)

<div class="topic-metadata">

**Author:** [@YuezhenQin](https://discourse.vtk.org/u/YuezhenQin)\
**Replies:** 0\
**Last updated:** [September 24, 2021, 8:50am UTC](https://discourse.vtk.org/t/extract-opacity-value-at-3d-point-in-a-form-of-world-coordinate-on-vtkimagedata/6687 "2021-09-24T08:50:35Z")

</div>

Given that ijk\[3\] is the world coordinate of a point and xyz\[3\] is transformed by (connector-\>GetOutput()-\>TransformPhysicalPointToContinuousIndex(ijk\[0\], ijk\[1\], ijk\[2\], xyz); I have tried the following ways: volume-\>…

---

## [Point data in some few points in an unstructured grid](https://discourse.vtk.org/t/point-data-in-some-few-points-in-an-unstructured-grid/6655)

<div class="topic-metadata">

**Author:** [@Sagues](https://discourse.vtk.org/u/Sagues)\
**Replies:** 0\
**Last updated:** [September 17, 2021, 6:46pm UTC](https://discourse.vtk.org/t/point-data-in-some-few-points-in-an-unstructured-grid/6655 "2021-09-17T18:46:20Z")

</div>

I have an unstructured grid with 100 points and I have to add data in few points, for instance 10 points. If I create an abstract array with this data and only add data in 10 points, then I have a lot of points with NAN …

---

## [Write several unstructured grids](https://discourse.vtk.org/t/write-several-unstructured-grids/6623)

<div class="topic-metadata">

**Author:** [@Sagues](https://discourse.vtk.org/u/Sagues)\
**Replies:** 8\
**Last updated:** [September 17, 2021, 6:42pm UTC](https://discourse.vtk.org/t/write-several-unstructured-grids/6623 "2021-09-17T18:42:49Z")

</div>

Is it possible to write several unstructured grids in one file without use MultiblockDataSet?

---

## [Feasibility of breaking change to vtkWindow interface](https://discourse.vtk.org/t/feasibility-of-breaking-change-to-vtkwindow-interface/6619)

<div class="topic-metadata">

**Author:** [@Connor.Bowley](https://discourse.vtk.org/u/Connor.Bowley)\
**Replies:** 2\
**Last updated:** [September 14, 2021, 2:21pm UTC](https://discourse.vtk.org/t/feasibility-of-breaking-change-to-vtkwindow-interface/6619 "2021-09-14T14:21:35Z")

</div>

Hello. While working to increase rendering efficiency of I noticed via valgrind’s callgrind tool that vtkWindow::GetSize() was taking up more time than expected. Caching the TileSize on change of Size/TileScale improved …

---

## [\`vtkAxisActor2D\` setting label font size doesn't work](https://discourse.vtk.org/t/vtkaxisactor2d-setting-label-font-size-doesnt-work/6613)

<div class="topic-metadata">

**Author:** [@kerim](https://discourse.vtk.org/u/kerim)\
**Replies:** 0\
**Last updated:** [September 11, 2021, 10:10pm UTC](https://discourse.vtk.org/t/vtkaxisactor2d-setting-label-font-size-doesnt-work/6613 "2021-09-11T22:10:40Z")

</div>

Hi, I’m trying to set constant font size for vtkAxisActor2D labels. Acoordint to the documentation there is a method UseFontSizeFromPropertyOn() wich should be used if we want to manually set font size via text propert…

---

## [VTK class for pvd files](https://discourse.vtk.org/t/vtk-class-for-pvd-files/6589)

<div class="topic-metadata">

**Author:** [@Sagues](https://discourse.vtk.org/u/Sagues)\
**Replies:** 3\
**Last updated:** [September 9, 2021, 12:27pm UTC](https://discourse.vtk.org/t/vtk-class-for-pvd-files/6589 "2021-09-09T12:27:15Z")

</div>

Is there any c++ class in vtk to write .pvd files?

---

## [vtk BoxWidget coordinates](https://discourse.vtk.org/t/vtk-boxwidget-coordinates/6572)

<div class="topic-metadata">

**Author:** [@Ana\_Margarida\_Mota](https://discourse.vtk.org/u/Ana_Margarida_Mota)\
**Replies:** 0\
**Last updated:** [September 7, 2021, 6:05pm UTC](https://discourse.vtk.org/t/vtk-boxwidget-coordinates/6572 "2021-09-07T18:05:06Z")

</div>

Hello! I define boxWidget-\>PlaceWidget(xmin, xmax, ymin, ymax, zmin, zmax). Than, When I try to “read” again the same coordinates, the values are completely different and I can’t understand why…? I am sending here part…

---

## [SimpleVTK Java example crashing on MacOS](https://discourse.vtk.org/t/simplevtk-java-example-crashing-on-macos/6472)

<div class="topic-metadata">

**Author:** [@Martin3d](https://discourse.vtk.org/u/Martin3d)\
**Replies:** 5\
**Last updated:** [September 7, 2021, 3:06pm UTC](https://discourse.vtk.org/t/simplevtk-java-example-crashing-on-macos/6472 "2021-09-07T15:06:42Z")

</div>

Hi, I ran the SimpleVTK example and encountered either crashes or warnings depending on the Java version. Are there existing workarounds to let VTK display java panels on MacOS + Java 14? Not sure this may help, but I …

---

## ["Display data histogram" Breaks on Windows](https://discourse.vtk.org/t/display-data-histogram-breaks-on-windows/6554)

<div class="topic-metadata">

**Author:** [@adamgranthendry](https://discourse.vtk.org/u/adamgranthendry)\
**Replies:** 4\
**Last updated:** [September 6, 2021, 5:56am UTC](https://discourse.vtk.org/t/display-data-histogram-breaks-on-windows/6554 "2021-09-06T05:56:44Z")

</div>

Opening a DICOM stack, visualizing as a Volume, and then opening the Color Map Editor and choosing Dislay data histogram causes ParaView to crash (program hangs and then shuts down unexpectedly). System Hardware OS: …

---

## [Groups of cells in unstructured grid](https://discourse.vtk.org/t/groups-of-cells-in-unstructured-grid/6532)

<div class="topic-metadata">

**Author:** [@Sagues](https://discourse.vtk.org/u/Sagues)\
**Replies:** 0\
**Last updated:** [September 2, 2021, 3:15pm UTC](https://discourse.vtk.org/t/groups-of-cells-in-unstructured-grid/6532 "2021-09-02T15:15:59Z")

</div>

I have to write vtk files using vtk library to write unstructured grids. And I need to create groups of cells according to type of cells (triangles, linees, etc) or materials (beams, shells, iron, etc…). Moreover, I woul…

---

## [Chinese characters rendering issue.](https://discourse.vtk.org/t/chinese-characters-rendering-issue/4457)

<div class="topic-metadata">

**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 8\
**Last updated:** [September 2, 2021, 4:03am UTC](https://discourse.vtk.org/t/chinese-characters-rendering-issue/4457 "2021-09-02T04:03:18Z")

</div>

I want to add a vtkTextActor with Chinese character inputs, but got a warning vtkUnicodeString::from\_utf8(): not a valid UTF-8 string. Can any exprets give me some hints on how to solve this problem? Thanks a lot!

---

## [\`Do: test\` is now gitlab-ci based](https://discourse.vtk.org/t/do-test-is-now-gitlab-ci-based/6508)

<div class="topic-metadata">

**Author:** [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)\
**Replies:** 2\
**Last updated:** [August 31, 2021, 10:06pm UTC](https://discourse.vtk.org/t/do-test-is-now-gitlab-ci-based/6508 "2021-08-31T22:06:21Z")

</div>

Hi all, The robot’s Do: test command now talks to gitlab-ci and the buildbot setups have been removed for VTK. Tracking the addition of those configuration (which were busted on buildbot anyways) has been added to this …

---

## [Python wrapping of \`std::vector\<std::string\>\` does not work when there are multiple overloads](https://discourse.vtk.org/t/python-wrapping-of-std-vector-std-string-does-not-work-when-there-are-multiple-overloads/6517)

<div class="topic-metadata">

**Author:** [@lassoan](https://discourse.vtk.org/u/lassoan)\
**Replies:** 2\
**Last updated:** [August 31, 2021, 4:41pm UTC](https://discourse.vtk.org/t/python-wrapping-of-std-vector-std-string-does-not-work-when-there-are-multiple-overloads/6517 "2021-08-31T16:41:53Z")

</div>

According to the Python wrapper documentation, I can pass Python string list to methods that take std::vector\<std::string\> (or as reference/const reference) as input. This works very nicely, except when we have multiple …

---

## [Computation of tangent vectors on polyData](https://discourse.vtk.org/t/computation-of-tangent-vectors-on-polydata/6502)

<div class="topic-metadata">

**Author:** [@omarElsayed](https://discourse.vtk.org/u/omarElsayed)\
**Replies:** 1\
**Last updated:** [August 31, 2021, 4:34pm UTC](https://discourse.vtk.org/t/computation-of-tangent-vectors-on-polydata/6502 "2021-08-31T16:34:43Z")

</div>

Hello, I am trying to compute the tangent vectors at each vertex of an STL file. Using proper macros as declared in vtkPolyDataTangents “https://vtk.org/doc/nightly/html/vtkPolyDataTangents\_8h\_source.html”. The output d…

---

## [vtkDataSetSurfaceFilter: triangle strips support](https://discourse.vtk.org/t/vtkdatasetsurfacefilter-triangle-strips-support/6492)

<div class="topic-metadata">

**Author:** [@utkarshayachit](https://discourse.vtk.org/u/utkarshayachit)\
**Replies:** 3\
**Last updated:** [August 30, 2021, 11:22am UTC](https://discourse.vtk.org/t/vtkdatasetsurfacefilter-triangle-strips-support/6492 "2021-08-30T11:22:22Z")

</div>

I was wondering if any one cares about triangle strip support in filters like vtkDataSetSurfaceFilter ? To keep the implementation simple, I am tempted to say we should remove such special cases and simply let users use …

---

## [Compilation error: #include \<limits\> required in several files](https://discourse.vtk.org/t/compilation-error-include-limits-required-in-several-files/6496)

<div class="topic-metadata">

**Author:** [@dariop](https://discourse.vtk.org/u/dariop)\
**Replies:** 1\
**Last updated:** [August 29, 2021, 6:27pm UTC](https://discourse.vtk.org/t/compilation-error-include-limits-required-in-several-files/6496 "2021-08-29T18:27:07Z")

</div>

Hi, in order to compile v9.0.3 on ArchLinux with GCC 11.1.0 I had to add #include \<limits\> in the following files: Common/Core/vtkGenericDataArray.h Common/Core/vtkGenericDataArrayLookupHelper.h Common/DataModel/vtkPiec…

---

## [Segmentation fault with vtkGeometryFilter on 4 threads](https://discourse.vtk.org/t/segmentation-fault-with-vtkgeometryfilter-on-4-threads/5735)

<div class="topic-metadata">

**Author:** [@mohd-afeef-badri](https://discourse.vtk.org/u/mohd-afeef-badri)\
**Replies:** 4\
**Last updated:** [May 20, 2021, 1:48pm UTC](https://discourse.vtk.org/t/segmentation-fault-with-vtkgeometryfilter-on-4-threads/5735 "2021-05-20T13:48:08Z")

</div>

Dear Experts, I have a vtu file containing a mesh composed of hexahedrons and polyhedrons. When I try to use vtkGeometryFilter() on this data it results in segmentation fault. I have included a MWE via python that can …

---

## [VTK membership sweep performed](https://discourse.vtk.org/t/vtk-membership-sweep-performed/6453)

<div class="topic-metadata">

**Author:** [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)\
**Replies:** 0\
**Last updated:** [August 24, 2021, 1:23pm UTC](https://discourse.vtk.org/t/vtk-membership-sweep-performed/6453 "2021-08-24T13:23:31Z")

</div>

Hi all, We recently went through the VTK member’s list on GitLab and removed or downgraded permissions for those that are either no longer at Kitware or haven’t been active. If any permissions were downgraded/removed in…

---

## [How can i integrate the QWidget and the vtkContextView?](https://discourse.vtk.org/t/how-can-i-integrate-the-qwidget-and-the-vtkcontextview/2895)

<div class="topic-metadata">

**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 4\
**Last updated:** [August 21, 2021, 10:34am UTC](https://discourse.vtk.org/t/how-can-i-integrate-the-qwidget-and-the-vtkcontextview/2895 "2021-08-21T10:34:36Z")

</div>

How can i integrate the vtkContextView withe the Qt’widget like QVTKＷＩｇｅｔ?

---

## [Vulkan Development](https://discourse.vtk.org/t/vulkan-development/3307)

<div class="topic-metadata">

**Author:** [@ken-martin](https://discourse.vtk.org/u/ken-martin)\
**Replies:** 26\
**Last updated:** [August 17, 2021, 9:20pm UTC](https://discourse.vtk.org/t/vulkan-development/3307 "2021-08-17T21:20:55Z")

</div>

For those who are interested here is a branch that includes basic Vulkan support missing many features and clearly a WIP. But feel free to play, extend, submit, etc. https://gitlab.kitware.com/ken-martin/vtk/-/tree/vulk…

---

## [Bug: vtkMetaImageWriter not writing vtkMetaImage Direction Matrix to the TransformMatrix line](https://discourse.vtk.org/t/bug-vtkmetaimagewriter-not-writing-vtkmetaimage-direction-matrix-to-the-transformmatrix-line/6405)

<div class="topic-metadata">

**Author:** [@MJJ](https://discourse.vtk.org/u/MJJ)\
**Replies:** 0\
**Last updated:** [August 17, 2021, 6:43pm UTC](https://discourse.vtk.org/t/bug-vtkmetaimagewriter-not-writing-vtkmetaimage-direction-matrix-to-the-transformmatrix-line/6405 "2021-08-17T18:43:39Z")

</div>

Also, a related bug: the vtkMetaImageReader does not read the TransformMatrix line. For example, see the sample .mhd file attached. It has a non identity TransformMatrix. (well… nvm as a new user i cant upload attache…

---

## [vtk.js data structure please explain please help](https://discourse.vtk.org/t/vtk-js-data-structure-please-explain-please-help/6376)

<div class="topic-metadata">

**Author:** [@gzt036](https://discourse.vtk.org/u/gzt036)\
**Replies:** 4\
**Last updated:** [August 16, 2021, 4:10pm UTC](https://discourse.vtk.org/t/vtk-js-data-structure-please-explain-please-help/6376 "2021-08-16T16:10:34Z")

</div>

Please explain the vtk.js data structure, expecially how ‘model’ is used. For example, const range = imageData.getPointData().getScalars().getRange(); if you go through debugger, you can see imageData is a bunch of usel…

---

## [vtkImageData 3D cropping](https://discourse.vtk.org/t/vtkimagedata-3d-cropping/6361)

<div class="topic-metadata">

**Author:** [@Hanxin\_Hua](https://discourse.vtk.org/u/Hanxin_Hua)\
**Replies:** 6\
**Last updated:** [August 13, 2021, 1:32pm UTC](https://discourse.vtk.org/t/vtkimagedata-3d-cropping/6361 "2021-08-13T13:32:40Z")

</div>

Hi, I’m having a trouble of vtkImageData. Basically, I used vtkImageData to read and store the DICOM. And use vtkVolume to display this image. See the pic below. And now I want to define a 3D polygon (say Three-dime…

---

## [vtkWindowedSincPolyDataFilter Smoothing - Processing Script](https://discourse.vtk.org/t/vtkwindowedsincpolydatafilter-smoothing-processing-script/6346)

<div class="topic-metadata">

**Author:** [@Kyle](https://discourse.vtk.org/u/Kyle)\
**Replies:** 7\
**Last updated:** [August 11, 2021, 6:25pm UTC](https://discourse.vtk.org/t/vtkwindowedsincpolydatafilter-smoothing-processing-script/6346 "2021-08-11T18:25:08Z")

</div>

Hello, I understand that vtkWindowedSincPolyDataFilter implements Taubin smoothing on closed surfaces. I am attempting to implement a script which achieves the following: input: .nii file containing 3D segmentation lab…

---

## [How to make empty space in vtkPolyData?](https://discourse.vtk.org/t/how-to-make-empty-space-in-vtkpolydata/6344)

<div class="topic-metadata">

**Author:** [@11119](https://discourse.vtk.org/u/11119)\
**Replies:** 2\
**Last updated:** [August 11, 2021, 2:58am UTC](https://discourse.vtk.org/t/how-to-make-empty-space-in-vtkpolydata/6344 "2021-08-11T02:58:38Z")

</div>

I want to create an empty space in one plane. Each plane is made up of hexagons, and one plane contains the other and has a larger shape. I tried to find the difference using vtkBooleanOperationPolyData, but I couldn’t…

---

## [gitlab.kitware.com expected downtime August 10, 5:30PM ET](https://discourse.vtk.org/t/gitlab-kitware-com-expected-downtime-august-10-5-30pm-et/6349)

<div class="topic-metadata">

**Author:** [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)\
**Replies:** 1\
**Last updated:** [August 10, 2021, 11:00pm UTC](https://discourse.vtk.org/t/gitlab-kitware-com-expected-downtime-august-10-5-30pm-et/6349 "2021-08-10T23:00:23Z")

</div>

gitlab.kitware.com will be offline for maintenance starting at 5:30pm ET today, August 10, 2021. A process that takes an unknown amount of time (at least a few hours) needs to complete before it will be back online.

---

## [Python 2 deprecation?](https://discourse.vtk.org/t/python-2-deprecation/5833)

<div class="topic-metadata">

**Author:** [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)\
**Replies:** 3\
**Last updated:** [August 9, 2021, 4:36pm UTC](https://discourse.vtk.org/t/python-2-deprecation/5833 "2021-08-09T16:36:13Z")

</div>

I’ve opened an MR to deprecate Python2 support. Any objections? We can remove it in the VTK release after the next one.

---

## [Curious about VTK CI hardware configuration](https://discourse.vtk.org/t/curious-about-vtk-ci-hardware-configuration/6338)

<div class="topic-metadata">

**Author:** [@jaswantp](https://discourse.vtk.org/u/jaswantp)\
**Replies:** 1\
**Last updated:** [August 9, 2021, 2:15pm UTC](https://discourse.vtk.org/t/curious-about-vtk-ci-hardware-configuration/6338 "2021-08-09T14:15:48Z")

</div>

I’ve been looking at this https://gitlab.kitware.com/vtk/vtk/-/ci/editor I’m curious to know some configuration details of the machines that aren’t “renderless”. The renderless ones are likely configured to build VTK a…

---

## [vtkStructuredGrid() and vtkStructuredGrid.FindCell()](https://discourse.vtk.org/t/vtkstructuredgrid-and-vtkstructuredgrid-findcell/6306)

<div class="topic-metadata">

**Author:** [@joag](https://discourse.vtk.org/u/joag)\
**Replies:** 2\
**Last updated:** [August 9, 2021, 6:54am UTC](https://discourse.vtk.org/t/vtkstructuredgrid-and-vtkstructuredgrid-findcell/6306 "2021-08-09T06:54:22Z")

</div>

Dear vtk-users, During an internship at the Max Planck Institute for Plasma physics I have used your library a lot for interpolating from a structured grid of the fusion device we have here which has a very complicated …

---

## [Building VTK with Qt support - VTK looks in the wrong place for qmlplugindump](https://discourse.vtk.org/t/building-vtk-with-qt-support-vtk-looks-in-the-wrong-place-for-qmlplugindump/6325)

<div class="topic-metadata">

**Author:** [@rbaleksandar](https://discourse.vtk.org/u/rbaleksandar)\
**Replies:** 3\
**Last updated:** [August 8, 2021, 7:37pm UTC](https://discourse.vtk.org/t/building-vtk-with-qt-support-vtk-looks-in-the-wrong-place-for-qmlplugindump/6325 "2021-08-08T19:37:09Z")

</div>

I have installed Qt 5.15 via the official installer and not the package manager of my Xubuntu 20.04. According to cmake all the required cmake variables are set (Qt5\_DIR, Qt5Core\_DIR etc.). The build goes without any is…

[Previous page](https://discourse.vtk.org/c/development/7.md?page=33)

[Next page](https://discourse.vtk.org/c/development/7.md?page=35)