# Development **URL:** https://discourse.vtk.org/c/development/7.md?page=5 [Latest](https://discourse.vtk.org/latest.md) · [Categories](https://discourse.vtk.org/categories.md) · [Tags](https://discourse.vtk.org/tags.md) **Page:** 6 --- ## [How to convert a .vtk mesh from LPS to RAS coordinates for proper alignment with NIfTI volumes in NiiVue?](https://discourse.vtk.org/t/how-to-convert-a-vtk-mesh-from-lps-to-ras-coordinates-for-proper-alignment-with-nifti-volumes-in-niivue/15859)
**Author:** [@Natalia\_Fabiano](https://discourse.vtk.org/u/Natalia_Fabiano)\ **Replies:** 1\ **Last updated:** [July 24, 2025, 1:11pm UTC](https://discourse.vtk.org/t/how-to-convert-a-vtk-mesh-from-lps-to-ras-coordinates-for-proper-alignment-with-nifti-volumes-in-niivue/15859 "2025-07-24T13:11:11Z")
Question: I’m working with a .vtk surface mesh that was saved in LPS (Left-Posterior-Superior) coordinate space, and I want to overlay it correctly on a .nii.gz volume image in NiiVue, which uses RAS (Right-Anterior-… --- ## [VTK Array doesn't work correctly if it's used under Unreal Engine](https://discourse.vtk.org/t/vtk-array-doesnt-work-correctly-if-its-used-under-unreal-engine/15812)
**Author:** [@dragontesa](https://discourse.vtk.org/u/dragontesa)\ **Replies:** 13\ **Last updated:** [July 22, 2025, 7:31pm UTC](https://discourse.vtk.org/t/vtk-array-doesnt-work-correctly-if-its-used-under-unreal-engine/15812 "2025-07-22T19:31:09Z")
Hello Everyone. I’ve been trying to integrate VTK into Unreal Engine for months. I wrote a plugin to wrap VTK using as a thirdparty library. The plugin module built with RTTI enabled due to compiling VTK on Linux. Bu… --- ## [VTKSMP stdthread performance](https://discourse.vtk.org/t/vtksmp-stdthread-performance/15835)
**Author:** [@jakimmel](https://discourse.vtk.org/u/jakimmel)\ **Replies:** 6\ **Last updated:** [July 21, 2025, 10:48pm UTC](https://discourse.vtk.org/t/vtksmp-stdthread-performance/15835 "2025-07-21T22:48:02Z")
I’m attempting to generate a bunch of slices from a single polydata using vtkcutter, but while it does parallelize the operation using the vtkSMP API, it doesn’t produce a significant difference vs. single-threaded perfo… --- ## [Adding new partially quadratic element (Hexahedron with 10 nodes) to VTK](https://discourse.vtk.org/t/adding-new-partially-quadratic-element-hexahedron-with-10-nodes-to-vtk/15846)
**Author:** [@jayeshsingh1110](https://discourse.vtk.org/u/jayeshsingh1110)\ **Replies:** 0\ **Last updated:** [July 21, 2025, 6:14am UTC](https://discourse.vtk.org/t/adding-new-partially-quadratic-element-hexahedron-with-10-nodes-to-vtk/15846 "2025-07-21T06:14:34Z")
I am trying to add a new type of cell to VTK to handle partially quadratic elements. Using below image for reference: One of the case : I would like in addition to linear nodes of this element (which are from 0 to … --- ## [Changing AnimationScene Playmode from a reader plugin?](https://discourse.vtk.org/t/changing-animationscene-playmode-from-a-reader-plugin/15806)
**Author:** [@Manupio](https://discourse.vtk.org/u/Manupio)\ **Replies:** 4\ **Last updated:** [July 11, 2025, 2:53pm UTC](https://discourse.vtk.org/t/changing-animationscene-playmode-from-a-reader-plugin/15806 "2025-07-11T14:53:23Z")
I need to change the time step mode from within the C++ plugin of a reader. I can achieve the functionality I need with python, using this python code: GetAnimationScene().PlayMode = ‘Snap To TimeSteps’ but I want it … --- ## [Using @TrameApp, how do I simply create an endpoint that returns a string?](https://discourse.vtk.org/t/using-trameapp-how-do-i-simply-create-an-endpoint-that-returns-a-string/15763)
**Author:** [@uv382](https://discourse.vtk.org/u/uv382)\ **Replies:** 2\ **Last updated:** [June 26, 2025, 7:12pm UTC](https://discourse.vtk.org/t/using-trameapp-how-do-i-simply-create-an-endpoint-that-returns-a-string/15763 "2025-06-26T19:12:37Z")
Let’s say I have this simple @TrameApp: @TrameApp() class MyTrameApp: def \_\_init\_\_(self, server: Server = None): self.server = get\_server(server) def main(): app = MyTrameApp() app.server.start() i… --- ## [Hide vtkCaptionWidget anchor representation](https://discourse.vtk.org/t/hide-vtkcaptionwidget-anchor-representation/15748)
**Author:** [@Jessica\_Marquis](https://discourse.vtk.org/u/Jessica_Marquis)\ **Replies:** 0\ **Last updated:** [June 19, 2025, 6:28pm UTC](https://discourse.vtk.org/t/hide-vtkcaptionwidget-anchor-representation/15748 "2025-06-19T18:28:17Z")
I am trying to use the vtkCaptionWidget and would like to be able to show or hide the anchor representation point at will. Any time I use the vtkPointHandleRepresentation3D::SetVisibility function accessed from the vtkCa… --- ## [Viskores to replace VTK-m](https://discourse.vtk.org/t/viskores-to-replace-vtk-m/15579)
**Author:** [@Dave-Allured](https://discourse.vtk.org/u/Dave-Allured)\ **Replies:** 4\ **Last updated:** [June 17, 2025, 7:47pm UTC](https://discourse.vtk.org/t/viskores-to-replace-vtk-m/15579 "2025-06-17T19:47:33Z")
Viskores is the open source successor for VTK-m, which is being discontinued. What is the VTK support plan for the Viskores transition? https://gitlab.kitware.com/vtk/vtk-m/-/blob/master/README.md --- ## [vtkPythonAlgorithm : long running tasks and multiple computers ?](https://discourse.vtk.org/t/vtkpythonalgorithm-long-running-tasks-and-multiple-computers/15516)
**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\ **Replies:** 2\ **Last updated:** [June 14, 2025, 7:00pm UTC](https://discourse.vtk.org/t/vtkpythonalgorithm-long-running-tasks-and-multiple-computers/15516 "2025-06-14T19:00:53Z")
I am revisiting the following vtkPythonAlgorithm aricle from a HPC/cluster/multiple-computer perspective. I am unsure of the design scope of vtkAlgorithm hence the following question. I have long-running or compute int… --- ## [Updates to the coding conventions for C++17](https://discourse.vtk.org/t/updates-to-the-coding-conventions-for-c-17/15717)
**Author:** [@lgivord](https://discourse.vtk.org/u/lgivord)\ **Replies:** 2\ **Last updated:** [June 10, 2025, 10:52am UTC](https://discourse.vtk.org/t/updates-to-the-coding-conventions-for-c-17/15717 "2025-06-10T10:52:01Z")
Hello everyone, As we recently bump the CXX version from C++11 to C++17, I just updated the coding convention for C++17. Please take the time to read this document before your next contribution :slightly\_smiling\_face: … --- ## [VTK 9.4 debug build fails with MSVC due to "image size ... exceeds maximum allowable size"](https://discourse.vtk.org/t/vtk-9-4-debug-build-fails-with-msvc-due-to-image-size-exceeds-maximum-allowable-size/15520)
**Author:** [@lassoan](https://discourse.vtk.org/u/lassoan)\ **Replies:** 9\ **Last updated:** [June 7, 2025, 2:14pm UTC](https://discourse.vtk.org/t/vtk-9-4-debug-build-fails-with-msvc-due-to-image-size-exceeds-maximum-allowable-size/15520 "2025-06-07T14:14:10Z")
Debug build of VTK-9.4 fail on Windows if VTK\_ENABLE\_KITS is enabled, with this error: CommonCore-objects.dir\\Debug\\CommonCore-objects.lib : fatal error LNK1248: image size (10098384C) exceeds maximum allowable size (F… --- ## [pimpl management good practice](https://discourse.vtk.org/t/pimpl-management-good-practice/7582)
**Author:** [@mwestphal](https://discourse.vtk.org/u/mwestphal)\ **Replies:** 21\ **Last updated:** [June 5, 2025, 1:55pm UTC](https://discourse.vtk.org/t/pimpl-management-good-practice/7582 "2025-06-05T13:55:56Z")
Hi VTK devs. With the prevalence of pimpl in VTK I wonder what would be the best practice for it: EDIT: Use the solution: 4th : std::unique\_ptr SummaryClassic class vtkInternals; class vtkFilter public vtkObject { v… --- ## [HyperTreeGrid support in VTKHDF](https://discourse.vtk.org/t/hypertreegrid-support-in-vtkhdf/15150)
**Author:** [@Louis\_Gombert](https://discourse.vtk.org/u/Louis_Gombert)\ **Replies:** 26\ **Last updated:** [June 5, 2025, 1:20pm UTC](https://discourse.vtk.org/t/hypertreegrid-support-in-vtkhdf/15150 "2025-06-05T13:20:29Z")
The overlappingAMR data structure has been recently added to the VTKHDF specification, now is time for its cousin, the Hyper Tree Grid (HTG for short) to be specified as well. HTG is a compact and memory-efficient tree-… --- ## [Controlling Contour Widget interaction using points](https://discourse.vtk.org/t/controlling-contour-widget-interaction-using-points/15676)
**Author:** [@Aleena](https://discourse.vtk.org/u/Aleena)\ **Replies:** 1\ **Last updated:** [May 29, 2025, 10:32am UTC](https://discourse.vtk.org/t/controlling-contour-widget-interaction-using-points/15676 "2025-05-29T10:32:33Z")
I am a beginner working with VTK (version 8.2) and C++ as my programming language. I have implemented a vtkContourWidget on a vtkResliceImageViewer and would like to control its interaction using a predefined set of poin… --- ## [Question about ImageReslice Class in WebGPU](https://discourse.vtk.org/t/question-about-imagereslice-class-in-webgpu/15660)
**Author:** [@jeje](https://discourse.vtk.org/u/jeje)\ **Replies:** 3\ **Last updated:** [May 27, 2025, 1:00pm UTC](https://discourse.vtk.org/t/question-about-imagereslice-class-in-webgpu/15660 "2025-05-27T13:00:12Z")
Hello everyone, I have a question regarding the use of VTK with WebGPU. I’d like to know why the ImageReslice class isn’t imported into WebGPU. Could someone help shed some light on this? Additionally, I’m encountering… --- ## [Problems when compilate VTK build for wasm](https://discourse.vtk.org/t/problems-when-compilate-vtk-build-for-wasm/15648)
**Author:** [@jeje](https://discourse.vtk.org/u/jeje)\ **Replies:** 10\ **Last updated:** [May 20, 2025, 2:08pm UTC](https://discourse.vtk.org/t/problems-when-compilate-vtk-build-for-wasm/15648 "2025-05-20T14:08:58Z")
Hi, I’m currently doing an internship, and I have a problem. When I try to compile VTK in wasm, I get this error, and I don’t understand why CMake is used and not Emcmake when configuring VTK compilation for wasm. Also, … --- ## [Addition of polyline decimation implementations](https://discourse.vtk.org/t/addition-of-polyline-decimation-implementations/15643)
**Author:** [@Chayce\_Ross](https://discourse.vtk.org/u/Chayce_Ross)\ **Replies:** 1\ **Last updated:** [May 18, 2025, 9:20pm UTC](https://discourse.vtk.org/t/addition-of-polyline-decimation-implementations/15643 "2025-05-18T21:20:47Z")
I have been doing some (not very extensive) research on line decimation (polyline simplification or curve approximation in some literature). My understanding of the current algorithm for vtkDecimatePolylineFilter is as f… --- ## [Python-friendly return of 3-element vector from VTK class](https://discourse.vtk.org/t/python-friendly-return-of-3-element-vector-from-vtk-class/15583)
**Author:** [@lassoan](https://discourse.vtk.org/u/lassoan)\ **Replies:** 11\ **Last updated:** [May 9, 2025, 6:27pm UTC](https://discourse.vtk.org/t/python-friendly-return-of-3-element-vector-from-vtk-class/15583 "2025-05-09T18:27:09Z")
I’m looking for advice on how to implement returning of 3-element vector from a VTK method in the simplest and most Python-friendly way. The vector value is not stored in a class member variable (it is computed dynamica… --- ## [access all three scalar data arrays in the shader?](https://discourse.vtk.org/t/access-all-three-scalar-data-arrays-in-the-shader/15596)
**Author:** [@llibetter](https://discourse.vtk.org/u/llibetter)\ **Replies:** 1\ **Last updated:** [May 9, 2025, 10:26am UTC](https://discourse.vtk.org/t/access-all-three-scalar-data-arrays-in-the-shader/15596 "2025-05-09T10:26:49Z")
I have three scalar data arrays attached to the CellData of a vtkPolyData. Can I access all three scalar data arrays simultaneously in the shader? --- ## [problems about FourPaneViewer](https://discourse.vtk.org/t/problems-about-fourpaneviewer/15585)
**Author:** [@zhuofalin](https://discourse.vtk.org/u/zhuofalin)\ **Replies:** 0\ **Last updated:** [May 8, 2025, 1:26am UTC](https://discourse.vtk.org/t/problems-about-fourpaneviewer/15585 "2025-05-08T01:26:36Z")
Hello，There are the following questions that need to be asked In the FourPaneViewer example: Why does the crosshair disappear when the user changes the blend mode? What is the reason? Under normal circumstances, whet… --- ## [vtkGLTFImporter does not load textures](https://discourse.vtk.org/t/vtkgltfimporter-does-not-load-textures/14815)
**Author:** [@gongwaner](https://discourse.vtk.org/u/gongwaner)\ **Replies:** 10\ **Last updated:** [April 29, 2025, 6:08am UTC](https://discourse.vtk.org/t/vtkgltfimporter-does-not-load-textures/14815 "2025-04-29T06:08:14Z")
Hi, I’m trying to render GLTF models using VTK, and I followed this example. I first tried with the flight helmet model downloaded from sketchfab, and everything worked fine. Then I downloaded another model and read i… --- ## [Possible bug with multiple components in vtkImageAccumulate](https://discourse.vtk.org/t/possible-bug-with-multiple-components-in-vtkimageaccumulate/15509)
**Author:** [@IanL2](https://discourse.vtk.org/u/IanL2)\ **Replies:** 2\ **Last updated:** [April 23, 2025, 8:23am UTC](https://discourse.vtk.org/t/possible-bug-with-multiple-components-in-vtkimageaccumulate/15509 "2025-04-23T08:23:30Z")
Hi all, while investigating an unrelated issue while using vtkImageAccumulate (now solved), I noticed a bit of odd code in vtkImageAccumulateExecute. The part that increments the bin for the component seems to be outside… --- ## [conflict with vtknlohmann and nlohmann](https://discourse.vtk.org/t/conflict-with-vtknlohmann-and-nlohmann/14977)
**Author:** [@YeHuanjie](https://discourse.vtk.org/u/YeHuanjie)\ **Replies:** 5\ **Last updated:** [April 22, 2025, 4:16pm UTC](https://discourse.vtk.org/t/conflict-with-vtknlohmann-and-nlohmann/14977 "2025-04-22T16:16:33Z")
when i use pcl(1.14.0) and nlohmann(3.10.0) in my project, vtk(9.4.0) reports make error. it seems that there is a conflict with vtknlohmann and nlohmann. How can i use nlohmann in my project In file included from /usr/… --- ## [SMPTools to support Async execution](https://discourse.vtk.org/t/smptools-to-support-async-execution/15519)
**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\ **Replies:** 0\ **Last updated:** [April 19, 2025, 7:58pm UTC](https://discourse.vtk.org/t/smptools-to-support-async-execution/15519 "2025-04-19T19:58:16Z")
I know this is an unusual request, since when integrating VTK in native applications, you have a main thread and asynchronous execution belongs to the application. None the less. It is quite simple to extend the SMPToo… --- ## [vtkCaptionWidget bug?](https://discourse.vtk.org/t/vtkcaptionwidget-bug/15502)
**Author:** [@SeanHan](https://discourse.vtk.org/u/SeanHan)\ **Replies:** 0\ **Last updated:** [April 16, 2025, 3:13am UTC](https://discourse.vtk.org/t/vtkcaptionwidget-bug/15502 "2025-04-16T03:13:45Z")
I am currently facing a problem: when using both the ‘vtkResliceCursorWidget’ and the ‘vtkCaptionWidget’ simultaneously, neither of these components can respond to left mouse button press messages, but when used alone, t… --- ## [Activiz's OpenGL crash in Activiz](https://discourse.vtk.org/t/activizs-opengl-crash-in-activiz/15489)
**Author:** [@INCREADIBLE](https://discourse.vtk.org/u/INCREADIBLE)\ **Replies:** 3\ **Last updated:** [April 11, 2025, 11:32am UTC](https://discourse.vtk.org/t/activizs-opengl-crash-in-activiz/15489 "2025-04-11T11:32:32Z")
I am using Activiz9.4 and meet a OpenGL crash in demo HelloVTKAvalonia.it will throw a error \[OpenGL\]Unable to configure OpenGL FBO: '0'(String #988796281) And my pc use U9 285h with newest driver 32.0.101.6734 --- ## [Question about clipping algorithm in vtkClipClosedSurface](https://discourse.vtk.org/t/question-about-clipping-algorithm-in-vtkclipclosedsurface/15482)
**Author:** [@eagerbeaver04](https://discourse.vtk.org/u/eagerbeaver04)\ **Replies:** 2\ **Last updated:** [April 10, 2025, 3:45pm UTC](https://discourse.vtk.org/t/question-about-clipping-algorithm-in-vtkclipclosedsurface/15482 "2025-04-10T15:45:39Z")
I’m investigating the algorithm used in vtkClipClosedSurface and would appreciate some clarification about its implementation. Key questions: What specific clipping algorithm is implemented? (e.g., Sutherland-Hodgman,… --- ## [Parallel Problem in Activiz](https://discourse.vtk.org/t/parallel-problem-in-activiz/15478)
**Author:** [@INCREADIBLE](https://discourse.vtk.org/u/INCREADIBLE)\ **Replies:** 2\ **Last updated:** [April 7, 2025, 7:11am UTC](https://discourse.vtk.org/t/parallel-problem-in-activiz/15478 "2025-04-07T07:11:05Z")
i am using the activiz 9.4, and i want to use a Parallel.For to create multi vtkCell in the same time,the code like this : Parallel.For(0, input.GetNumberOfCells(), i =\> { var temp = vtkCell.… --- ## [Displaying multiple arrays into one plot using trame and jupyter notebook](https://discourse.vtk.org/t/displaying-multiple-arrays-into-one-plot-using-trame-and-jupyter-notebook/15472)
**Author:** [@zetwal](https://discourse.vtk.org/u/zetwal)\ **Replies:** 2\ **Last updated:** [April 3, 2025, 8:24pm UTC](https://discourse.vtk.org/t/displaying-multiple-arrays-into-one-plot-using-trame-and-jupyter-notebook/15472 "2025-04-03T20:24:41Z")
Hello I’m trying to display several datasets into one plot/window using jupyter notebook and trame but it’s instead displaying 3 separate windows. This is the code: plot\_1 = pv.PolyData(plot\_1\_points) plot\_1.plot(point… --- ## [vtkSplineRepresentation and/or vtkSplineWidget control visibility and other properties of control handles](https://discourse.vtk.org/t/vtksplinerepresentation-and-or-vtksplinewidget-control-visibility-and-other-properties-of-control-handles/15452)
**Author:** [@vipulraikar](https://discourse.vtk.org/u/vipulraikar)\ **Replies:** 3\ **Last updated:** [April 3, 2025, 6:15pm UTC](https://discourse.vtk.org/t/vtksplinerepresentation-and-or-vtksplinewidget-control-visibility-and-other-properties-of-control-handles/15452 "2025-04-03T18:15:03Z")
Hi All, I was wondering if there was a way in Python interface of VTK for individually control the properties of the props/actors (handles, line) that vtkSplineRepresentation or vtkSplineWidget produce? I see methods th… [Previous page](https://discourse.vtk.org/c/development/7.md?page=4) [Next page](https://discourse.vtk.org/c/development/7.md?page=6)