# Development

**URL:** https://discourse.vtk.org/c/development/7.md?page=14

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

**Page:** 15

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## [Request for input: VTK/Python API](https://discourse.vtk.org/t/request-for-input-vtk-python-api/13132)

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**Author:** [@berk.geveci](https://discourse.vtk.org/u/berk.geveci)\
**Replies:** 14\
**Last updated:** [February 29, 2024, 8:00pm UTC](https://discourse.vtk.org/t/request-for-input-vtk-python-api/13132 "2024-02-29T20:00:57Z")

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Hi all, In this post, I introduced some of the changes we are making to the VTK wrappers. One of these is the introduction of an operator to easily connect sources and filters. I initially proposed using \>\>. Later | was…

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## [Is it possible to Mantain the Scalar Data After Decimation?](https://discourse.vtk.org/t/is-it-possible-to-mantain-the-scalar-data-after-decimation/13409)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 0\
**Last updated:** [February 28, 2024, 10:35pm UTC](https://discourse.vtk.org/t/is-it-possible-to-mantain-the-scalar-data-after-decimation/13409 "2024-02-28T22:35:32Z")

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Hello, After the decimation process are all the scalar information of cells and points lost? Thank you, \`\`\` vtkSmartPointer\<vtkDecimatePro\> decimator = vtkSmartPointer\<vtkDecimatePro\>::New(); decimator-\>SetInputData(i…

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## [I created a set of tools for mining database visualisation and spatial analysis](https://discourse.vtk.org/t/i-created-a-set-of-tools-for-mining-database-visualisation-and-spatial-analysis/13126)

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**Author:** [@Altertango](https://discourse.vtk.org/u/Altertango)\
**Replies:** 10\
**Last updated:** [February 27, 2024, 7:08pm UTC](https://discourse.vtk.org/t/i-created-a-set-of-tools-for-mining-database-visualisation-and-spatial-analysis/13126 "2024-02-27T19:08:27Z")

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Hello everyone, I work in the mining industry. Im based in France, near Grenoble, but work mostly with environmental and geochemical data of mining projects from South America. At the start of each project, we have to i…

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## [Plotting y vapues on chartxy](https://discourse.vtk.org/t/plotting-y-vapues-on-chartxy/13328)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 7\
**Last updated:** [February 22, 2024, 6:10pm UTC](https://discourse.vtk.org/t/plotting-y-vapues-on-chartxy/13328 "2024-02-22T18:10:15Z")

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Hi, Is it possible to plot the y values of each point in chartxy? Thank you

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## [Wireframe Representation not Working](https://discourse.vtk.org/t/wireframe-representation-not-working/13353)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 0\
**Last updated:** [February 22, 2024, 12:16am UTC](https://discourse.vtk.org/t/wireframe-representation-not-working/13353 "2024-02-22T00:16:37Z")

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Hello, I transformed the visualize fill holes example into a function, but the wireframe representation isn’t working: void visualizeHoles(vtkSmartPointer\<vtkPolyData\> originalPolyData, vtkSmartPointer\<vtkPolyData\> …

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## [vtkStdString HighlightPickedActor](https://discourse.vtk.org/t/vtkstdstring-highlightpickedactor/13225)

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**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 2\
**Last updated:** [February 21, 2024, 11:13pm UTC](https://discourse.vtk.org/t/vtkstdstring-highlightpickedactor/13225 "2024-02-21T23:13:47Z")

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Hi Developers I am trying to promote VTK for some people and we have seen some weird issues. For vtkNamedColors, the strings, e.g. “White” gets interpreted as pure non-sense. We use the latest VIsual Studio 2022 and has…

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## [How to silently handle warnings and error messages from vtk functions / classes](https://discourse.vtk.org/t/how-to-silently-handle-warnings-and-error-messages-from-vtk-functions-classes/8670)

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**Author:** [@BlueKnight7](https://discourse.vtk.org/u/BlueKnight7)\
**Replies:** 25\
**Last updated:** [February 21, 2024, 5:44am UTC](https://discourse.vtk.org/t/how-to-silently-handle-warnings-and-error-messages-from-vtk-functions-classes/8670 "2024-02-21T05:44:38Z")

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First, a little background: I’m using (C++) vtkIntersectionPolyDataFilter to perfrom boolean operations (union, intersection, difference) on geometric bodies such as spheres and cylinders. For instance, if 2 bodies do …

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## [Can I generate a representation of the cell tree locator?](https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 3\
**Last updated:** [February 17, 2024, 3:09pm UTC](https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319 "2024-02-17T15:09:02Z")

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Hello, I don’t know the answer since the celltreelocator does not have levels but buckets. Also I am rendering offscreen but it is working. Thank you, NAMESPACE: namespace {class vtkSliderCallback : public vtkComman…

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## [Tree Timing Question](https://discourse.vtk.org/t/tree-timing-question/13327)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 0\
**Last updated:** [February 16, 2024, 9:51pm UTC](https://discourse.vtk.org/t/tree-timing-question/13327 "2024-02-16T21:51:01Z")

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Hello, I am having a little trouble to understant the timing test. Because when the function timme(insert tree)tree is called what is variable is the maxlevel, but in the output graph the x-axis is called max points per…

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## [How to make](https://discourse.vtk.org/t/how-to-make/10969)

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**Author:** [@enderby\_matherror](https://discourse.vtk.org/u/enderby_matherror)\
**Replies:** 3\
**Last updated:** [February 16, 2024, 12:44pm UTC](https://discourse.vtk.org/t/how-to-make/10969 "2024-02-16T12:44:54Z")

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How to create a meta-VTK for use with embedded Linux Yocto?

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## [Composite Data Sets for the VTKHDF format](https://discourse.vtk.org/t/composite-data-sets-for-the-vtkhdf-format/12190)

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**Author:** [@jfausty](https://discourse.vtk.org/u/jfausty)\
**Replies:** 22\
**Last updated:** [February 9, 2024, 7:54am UTC](https://discourse.vtk.org/t/composite-data-sets-for-the-vtkhdf-format/12190 "2024-02-09T07:54:41Z")

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This thread is dedicated to proposing a new design for the VTKHDF format that would describe vtkPartitionedDataSetCollections and vtkMultiBlockDataSets. The general idea is to have an Assembly group in the file that des…

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## [GetBuildTime of cell locators?](https://discourse.vtk.org/t/getbuildtime-of-cell-locators/13314)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 1\
**Last updated:** [February 14, 2024, 4:20pm UTC](https://discourse.vtk.org/t/getbuildtime-of-cell-locators/13314 "2024-02-14T16:20:55Z")

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Hello, What is the unit when you request the function getbuildtime of an locator? Thanks

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## [Mapping Scalars into colors](https://discourse.vtk.org/t/mapping-scalars-into-colors/13306)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 1\
**Last updated:** [February 13, 2024, 11:44pm UTC](https://discourse.vtk.org/t/mapping-scalars-into-colors/13306 "2024-02-13T23:44:50Z")

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Hello, I am trying to color the connected components in the image according to their cell scalar value array. The scalarbar renders ok, with the correct labels, but the image renders only with one color. Thank you s…

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## [Serialization of VTK objects](https://discourse.vtk.org/t/serialization-of-vtk-objects/13308)

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**Author:** [@LucasGandel](https://discourse.vtk.org/u/LucasGandel)\
**Replies:** 3\
**Last updated:** [February 13, 2024, 2:20pm UTC](https://discourse.vtk.org/t/serialization-of-vtk-objects/13308 "2024-02-13T14:20:30Z")

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The goal of this post is to inform others about the ongoing efforts regarding serialization/deserialization in VTK. @alexy.pellegrini and @jaswantp started separate efforts to address slightly different use cases \[1\], a…

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## [Best way to clip a volume with an arbitrarily shaped surface](https://discourse.vtk.org/t/best-way-to-clip-a-volume-with-an-arbitrarily-shaped-surface/13279)

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**Author:** [@mortifiedpenguin](https://discourse.vtk.org/u/mortifiedpenguin)\
**Replies:** 0\
**Last updated:** [February 7, 2024, 12:55pm UTC](https://discourse.vtk.org/t/best-way-to-clip-a-volume-with-an-arbitrarily-shaped-surface/13279 "2024-02-07T12:55:40Z")

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I have a case where I want to cut off a certain part of the volume with an arbitrary surface. This surface is not a plane and currently represented by a vtkPolyData in my case. What would be the best way of doing so? T…

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## [Back projecting images back to 3D](https://discourse.vtk.org/t/back-projecting-images-back-to-3d/13116)

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**Author:** [@NahomKidane](https://discourse.vtk.org/u/NahomKidane)\
**Replies:** 1\
**Last updated:** [February 6, 2024, 9:19pm UTC](https://discourse.vtk.org/t/back-projecting-images-back-to-3d/13116 "2024-02-06T21:19:54Z")

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Hello Everyone, I’m currently working on generating 2D projection images of a 3D surface mesh from various camera positions and need to project back the 2D image information after processing, such as labeling the correc…

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## [vtkPolygon concave rendering bug](https://discourse.vtk.org/t/vtkpolygon-concave-rendering-bug/13251)

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**Author:** [@PeterFranzSeequent](https://discourse.vtk.org/u/PeterFranzSeequent)\
**Replies:** 5\
**Last updated:** [February 6, 2024, 7:51pm UTC](https://discourse.vtk.org/t/vtkpolygon-concave-rendering-bug/13251 "2024-02-06T19:51:01Z")

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A concave vtkPolygon has rendering issues. I have tested this with multiple different shapes; the example I provide below is minimalistic. The bug propagates into other filters as well; for example a vtkGeometryFilter on…

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## [Can't Add scalar data array to polydata.](https://discourse.vtk.org/t/cant-add-scalar-data-array-to-polydata/13252)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 1\
**Last updated:** [February 5, 2024, 10:07pm UTC](https://discourse.vtk.org/t/cant-add-scalar-data-array-to-polydata/13252 "2024-02-05T22:07:46Z")

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Hello, I’ve been using a function to try to add a material scalar array to a mesh but have not been able to do it. Thank you, vtkSmartPointer\<vtkPolyData\> SegmentationIO::Add\_Material(vtkSmartPointer\<vtkPolyD…

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## [vtkFillHolesFilter algorithm's multiple edge neighbors case currently fails, suggestions for proper approach](https://discourse.vtk.org/t/vtkfillholesfilter-algorithms-multiple-edge-neighbors-case-currently-fails-suggestions-for-proper-approach/13013)

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**Author:** [@dsebald](https://discourse.vtk.org/u/dsebald)\
**Replies:** 2\
**Last updated:** [February 5, 2024, 9:04pm UTC](https://discourse.vtk.org/t/vtkfillholesfilter-algorithms-multiple-edge-neighbors-case-currently-fails-suggestions-for-proper-approach/13013 "2024-02-05T21:04:42Z")

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In the vtkFillHolesFilter algorithm is the following line of code for the case of multiple edge neighbors else if (neighbors-\>GetNumberOfIds() \> 1) { // have to logically split this verte…

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## [More modern C++ pipeline setup](https://discourse.vtk.org/t/more-modern-c-pipeline-setup/13244)

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**Author:** [@dcthomp](https://discourse.vtk.org/u/dcthomp)\
**Replies:** 1\
**Last updated:** [February 3, 2024, 1:33am UTC](https://discourse.vtk.org/t/more-modern-c-pipeline-setup/13244 "2024-02-03T01:33:48Z")

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As a parallel to @berk.geveci’s post on more pythonic wrappers (and particularly @jaswantp’s example, I’d like input on how we might use modern C++ and the nlohmann::json to achieve something similar in native C++. Here…

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## [vtkPropPicker in VTK 9.1 is now returning wrong world coordinates.](https://discourse.vtk.org/t/vtkproppicker-in-vtk-9-1-is-now-returning-wrong-world-coordinates/8061)

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**Author:** [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)\
**Replies:** 52\
**Last updated:** [February 2, 2024, 3:36am UTC](https://discourse.vtk.org/t/vtkproppicker-in-vtk-9-1-is-now-returning-wrong-world-coordinates/8061 "2024-02-02T03:36:43Z")

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Dear people, Recently I migrated code from VTK 8.1 to 9.1. Giving or taking minor changes (mostly related to deprecated API), most of VTK code stayed the same. However, the behavior of vtkPropPicker::GetPickPosition() …

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## [Introduce \`vtkForEach\` filter](https://discourse.vtk.org/t/introduce-vtkforeach-filter/12448)

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**Author:** [@Charles\_Gueunet](https://discourse.vtk.org/u/Charles_Gueunet)\
**Replies:** 6\
**Last updated:** [February 1, 2024, 4:01pm UTC](https://discourse.vtk.org/t/introduce-vtkforeach-filter/12448 "2024-02-01T16:01:34Z")

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This post presents a new vtkForEach filter. Included in Common/Execution model, this is a filter of a new kind, operating at the pipeline level. Its general purpose is to create a loop on a sub-pipeline part. It is heavi…

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## [Geting Scalars to DiscreteMarchingCubes](https://discourse.vtk.org/t/geting-scalars-to-discretemarchingcubes/13158)

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**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\
**Replies:** 5\
**Last updated:** [January 31, 2024, 9:56pm UTC](https://discourse.vtk.org/t/geting-scalars-to-discretemarchingcubes/13158 "2024-01-31T21:56:37Z")

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Hello, I am currently applying discretemarchingcubes to extract multiple valued segmentation label. The filter is working fine. However I am applying computescalarson() but I am getting in trouble trying to retrieve eac…

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## [vtkGLTFReader unable to read data from .glb files](https://discourse.vtk.org/t/vtkgltfreader-unable-to-read-data-from-glb-files/13187)

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**Author:** [@Sai\_Chaitanya\_Rodda](https://discourse.vtk.org/u/Sai_Chaitanya_Rodda)\
**Replies:** 7\
**Last updated:** [January 30, 2024, 10:29am UTC](https://discourse.vtk.org/t/vtkgltfreader-unable-to-read-data-from-glb-files/13187 "2024-01-30T10:29:19Z")

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Hello All, I am using VTK 9.3.0 and have seen that vtkGLTFReader is unable to read “.glb” files. Altough it is able to read “.gltf” perfectly and this problem doesn’t occur in VTK 9.1.0. Please check my below code for …

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## [VTK touch screen operation function development](https://discourse.vtk.org/t/vtk-touch-screen-operation-function-development/13185)

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**Author:** [@jing\_zhanglei](https://discourse.vtk.org/u/jing_zhanglei)\
**Replies:** 0\
**Last updated:** [January 30, 2024, 8:29am UTC](https://discourse.vtk.org/t/vtk-touch-screen-operation-function-development/13185 "2024-01-30T08:29:04Z")

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I currently use is ubuntu20.04 qt5.12.9, vtk8.2.0, I want to on a touch screen to operate single refers to dicom two-dimensional image scaling, translation, adjust a window wide function, but there are few this informati…

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## [How to only render one vtkRender in vtkRenderWindow with two vtkRenders](https://discourse.vtk.org/t/how-to-only-render-one-vtkrender-in-vtkrenderwindow-with-two-vtkrenders/11425)

<div class="topic-metadata">

**Author:** [@Pisces2018](https://discourse.vtk.org/u/Pisces2018)\
**Replies:** 11\
**Last updated:** [January 29, 2024, 3:04am UTC](https://discourse.vtk.org/t/how-to-only-render-one-vtkrender-in-vtkrenderwindow-with-two-vtkrenders/11425 "2024-01-29T03:04:33Z")

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Hello everyone, I want to draw a polygon on the volumn data in freehand drawing. When mouse move, the volumn data and the ploygon render together, so the screen will stutter. So I split the two data into two renders, w…

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## [Using std::vector\<\> (and other goodies) in the public API](https://discourse.vtk.org/t/using-std-vector-and-other-goodies-in-the-public-api/13142)

<div class="topic-metadata">

**Author:** [@berk.geveci](https://discourse.vtk.org/u/berk.geveci)\
**Replies:** 10\
**Last updated:** [January 26, 2024, 2:11pm UTC](https://discourse.vtk.org/t/using-std-vector-and-other-goodies-in-the-public-api/13142 "2024-01-26T14:11:57Z")

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Hi folks, This is a request for feedback. TLDR: I am proposing that we allow extending our API to support std::vector\<\> based convenience methods. This is to make the C++ and Python APIs easier to use. I am curious to …

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## [VTK 9.3.0 static library build error with VS2019 compiler](https://discourse.vtk.org/t/vtk-9-3-0-static-library-build-error-with-vs2019-compiler/13100)

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**Author:** [@dlrdave](https://discourse.vtk.org/u/dlrdave)\
**Replies:** 6\
**Last updated:** [January 25, 2024, 10:03pm UTC](https://discourse.vtk.org/t/vtk-9-3-0-static-library-build-error-with-vs2019-compiler/13100 "2024-01-25T22:03:01Z")

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I get the following, when attempting to build VTK 9.3.0 with BUILD\_SHARED\_LIBS=OFF and the VS2019 compiler: vtkCommonCore-9.3.lib(vtkSMPToolsAPI.cxx.obj) : error LNK2019: unresolved external symbol “public: bool \_\_cdecl…

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## [qml cannot receive messages sent by vtk&c++](https://discourse.vtk.org/t/qml-cannot-receive-messages-sent-by-vtk-c/13144)

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**Author:** [@chloe](https://discourse.vtk.org/u/chloe)\
**Replies:** 0\
**Last updated:** [January 25, 2024, 4:30am UTC](https://discourse.vtk.org/t/qml-cannot-receive-messages-sent-by-vtk-c/13144 "2024-01-25T04:30:49Z")

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qml does not receive the signal sent when the Qevent mouse event changes in vtk derived class MyObject, but if the emit function is called directly from the main function using the object of MyObject, qml can accept it. …

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## [VTKHDF: support transient data for OverlappingAMR](https://discourse.vtk.org/t/vtkhdf-support-transient-data-for-overlappingamr/13123)

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**Author:** [@lgivord](https://discourse.vtk.org/u/lgivord)\
**Replies:** 1\
**Last updated:** [January 24, 2024, 8:35am UTC](https://discourse.vtk.org/t/vtkhdf-support-transient-data-for-overlappingamr/13123 "2024-01-24T08:35:48Z")

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This thread is dedicated to proposing an improvement for the VTKHDF file format regarding OverlappingAMR in Transient context. The documentation for both can be found here: OverlappingAMR : VTK File Formats - VTK docu…

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