# Latest

**URL:** https://discourse.vtk.org/latest.md?page=164

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

**Page:** 165

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## [vtkImageViewer2's renderer has no actor](https://discourse.vtk.org/t/vtkimageviewer2s-renderer-has-no-actor/6540)

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**Author:** [@jjjkk](https://discourse.vtk.org/u/jjjkk)\
**Replies:** 2\
**Last updated:** [September 3, 2021, 8:56am UTC](https://discourse.vtk.org/t/vtkimageviewer2s-renderer-has-no-actor/6540 "2021-09-03T08:56:11Z")

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I use qt and vtk to visualize dicom file. And it works well. But when I want to add picker to my program I found imageViewer-\>GetRenderer()-\>GetActors() is empty, so I can’t pick anything. But the dicom picture can be …

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## [Finding Transformation Angle according to a custom axis](https://discourse.vtk.org/t/finding-transformation-angle-according-to-a-custom-axis/6533)

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**Author:** [@smoothumut](https://discourse.vtk.org/u/smoothumut)\
**Replies:** 2\
**Last updated:** [September 3, 2021, 5:45am UTC](https://discourse.vtk.org/t/finding-transformation-angle-according-to-a-custom-axis/6533 "2021-09-03T05:45:31Z")

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It is hard for me to explain my problem. I have a rectangular prism and it is placed in coordinate system with a random orientation the rectangular prism has its own normal vector, short plane vector(short edge axis) an…

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## [Using vtkMultiProcessController.Allreduce() in Python to ignore null search results](https://discourse.vtk.org/t/using-vtkmultiprocesscontroller-allreduce-in-python-to-ignore-null-search-results/6536)

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**Author:** [@csniker](https://discourse.vtk.org/u/csniker)\
**Replies:** 1\
**Last updated:** [September 2, 2021, 8:44pm UTC](https://discourse.vtk.org/t/using-vtkmultiprocesscontroller-allreduce-in-python-to-ignore-null-search-results/6536 "2021-09-02T20:44:29Z")

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I am trying to wrangle a parallelized computation using VTK methods (it is in Paraview if that helps anyone, but I believe the core question is purely VTK). I have been able to use the example here https://blog.kitware.c…

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

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**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")

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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…

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

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**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")

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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!

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## [QVTKWidget.h after VTK 7.1.1 install](https://discourse.vtk.org/t/qvtkwidget-h-after-vtk-7-1-1-install/6507)

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**Author:** [@Daniel\_Schimpf](https://discourse.vtk.org/u/Daniel_Schimpf)\
**Replies:** 2\
**Last updated:** [September 1, 2021, 6:03pm UTC](https://discourse.vtk.org/t/qvtkwidget-h-after-vtk-7-1-1-install/6507 "2021-09-01T18:03:40Z")

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Hello, I installed VTK 7.1.1 on two systems (raspberry pi os and ubuntu 16). On the first system (raspberry pi os) everything works fine and my project builds in qt with cmake. Now I want to move the project to another …

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## [vtkPolyDataToImageStencil wrong output almost random](https://discourse.vtk.org/t/vtkpolydatatoimagestencil-wrong-output-almost-random/6521)

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**Author:** [@Ervis](https://discourse.vtk.org/u/Ervis)\
**Replies:** 6\
**Last updated:** [September 1, 2021, 1:19pm UTC](https://discourse.vtk.org/t/vtkpolydatatoimagestencil-wrong-output-almost-random/6521 "2021-09-01T13:19:27Z")

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Hi I am using ActiViz.Net 64 v5.8.0 I am having an issue with vtkPolyDataToImageStencil where the output seems to have either extra lines or holes. I have attempted to combine vtkPolyDataToImageStencil with vtkImageSten…

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## [Python binaries with support for CameraOrientationWidget](https://discourse.vtk.org/t/python-binaries-with-support-for-cameraorientationwidget/6527)

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**Author:** [@rdbrn](https://discourse.vtk.org/u/rdbrn)\
**Replies:** 1\
**Last updated:** [September 1, 2021, 12:12pm UTC](https://discourse.vtk.org/t/python-binaries-with-support-for-cameraorientationwidget/6527 "2021-09-01T12:12:05Z")

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I’m trying to run the https://kitware.github.io/vtk-examples/site/Python/Widgets/CameraOrientationWidget/ example with vtk 9.0.3 installed from conda-forge on windows. This results in an AttributeError: module ‘vtkmod…

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## [convert python mesh object to vtkPolyData](https://discourse.vtk.org/t/convert-python-mesh-object-to-vtkpolydata/6512)

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**Author:** [@ferdymercury](https://discourse.vtk.org/u/ferdymercury)\
**Replies:** 4\
**Last updated:** [September 1, 2021, 10:05am UTC](https://discourse.vtk.org/t/convert-python-mesh-object-to-vtkpolydata/6512 "2021-09-01T10:05:55Z")

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Hello, In Python, I have an object of the following type: your\_mesh \<stl.mesh.Mesh object at 0x7fb108f06160\> \>\>\> your\_mesh.points array(\[\[ 250., -475., -100., -250., -475., -100., -250., -475., 1900.\], \[ 250., -…

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

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**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")

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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 …

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## [pvtu : number of pieces and relationship to parallel visualisation in Paraview](https://discourse.vtk.org/t/pvtu-number-of-pieces-and-relationship-to-parallel-visualisation-in-paraview/6522)

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**Author:** [@Nicholas\_Yue](https://discourse.vtk.org/u/Nicholas_Yue)\
**Replies:** 0\
**Last updated:** [August 31, 2021, 9:51pm UTC](https://discourse.vtk.org/t/pvtu-number-of-pieces-and-relationship-to-parallel-visualisation-in-paraview/6522 "2021-08-31T21:51:11Z")

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I am learning about vtu/pvtu I am testing out deal.ii which save data as vtu/pvtu, only one piece is being written out per snapshot. I plan to test out visualizing the data set on a 4 node cluster (each with GPU) and w…

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## [Python 3D volume rendering problem which I pass series of LSM Dicom image.](https://discourse.vtk.org/t/python-3d-volume-rendering-problem-which-i-pass-series-of-lsm-dicom-image/6503)

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**Author:** [@Yuvi-416](https://discourse.vtk.org/u/Yuvi-416)\
**Replies:** 3\
**Last updated:** [August 31, 2021, 9:01pm UTC](https://discourse.vtk.org/t/python-3d-volume-rendering-problem-which-i-pass-series-of-lsm-dicom-image/6503 "2021-08-31T21:01:12Z")

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Hello guys, I am trying to visualize series of dicomized microscope LSM into 3D visualization using the VTK python package. I wrote the below code which works perfectly for the CT Dicom image but not for the LSM image. …

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## [vtkCellPicker::GetCellId() always returns -1?](https://discourse.vtk.org/t/vtkcellpicker-getcellid-always-returns-1/6478)

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**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 1\
**Last updated:** [August 31, 2021, 5:20pm UTC](https://discourse.vtk.org/t/vtkcellpicker-getcellid-always-returns-1/6478 "2021-08-31T17:20:32Z")

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I’m using vtkCellPicker (vtk-8.2.0, ubuntu-18.04.5) to select points in vtkPolyData, by incorporating vtkCellPicker in my class that extends vtkInteractorStyleTrackballCamera. When I create the vtk pipeline in main() fol…

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## [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)

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**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")

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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 …

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

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**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")

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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…

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## [Timeseries many Files Data](https://discourse.vtk.org/t/timeseries-many-files-data/6516)

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**Author:** [@Tees](https://discourse.vtk.org/u/Tees)\
**Replies:** 0\
**Last updated:** [August 31, 2021, 1:57pm UTC](https://discourse.vtk.org/t/timeseries-many-files-data/6516 "2021-08-31T13:57:12Z")

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I have many vti time files which I load with the help of XMLImageDataReader and then I use the ImageDataGeometryFilter to get Polydata Output. My Idea was that I store the different files as Polydata like that: polyData…

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## [build latest vtk in wsl2(ubuntu2004) failed](https://discourse.vtk.org/t/build-latest-vtk-in-wsl2-ubuntu2004-failed/6501)

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**Author:** [@eton](https://discourse.vtk.org/u/eton)\
**Replies:** 5\
**Last updated:** [August 31, 2021, 2:39am UTC](https://discourse.vtk.org/t/build-latest-vtk-in-wsl2-ubuntu2004-failed/6501 "2021-08-31T02:39:21Z")

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Hi, everyone. I build vtk in windows’ wsl2 which is a ubuntu2004, always failed. use same way succeed in real ubuntu2004. Anyone can tell me why it failed or is it possible to solve the issue? Thanks. \[ 1%\] Built tar…

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## [\`vtkCubeAxesActor2D\` show Y and X axes at both sides](https://discourse.vtk.org/t/vtkcubeaxesactor2d-show-y-and-x-axes-at-both-sides/6505)

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**Author:** [@kerim](https://discourse.vtk.org/u/kerim)\
**Replies:** 0\
**Last updated:** [August 30, 2021, 6:23pm UTC](https://discourse.vtk.org/t/vtkcubeaxesactor2d-show-y-and-x-axes-at-both-sides/6505 "2021-08-30T18:23:08Z")

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Hi, I can’t find a way to display X-axis at both sides: bottom and top. The same I need to do with Y-axis. // Cube axes vtkNew\<vtkCubeAxesActor2D\> cubeAxesActor; cubeAxesActor-\>SetCamera(renderer-\>GetActiveCamera…

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## [Migration of machines to gitlab-ci](https://discourse.vtk.org/t/migration-of-machines-to-gitlab-ci/5170)

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**Author:** [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)\
**Replies:** 3\
**Last updated:** [August 30, 2021, 2:50pm UTC](https://discourse.vtk.org/t/migration-of-machines-to-gitlab-ci/5170 "2021-08-30T14:50:26Z")

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Now that VTK has some jobs on CI, I’m going to schedule some of the buildbots to be migrated over to the new CI setup. This will require reimaging the machines and bringing them up using our new setup procedures. The job…

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

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**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")

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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 …

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## [vtkImageReslice: how to make point in the center of output image](https://discourse.vtk.org/t/vtkimagereslice-how-to-make-point-in-the-center-of-output-image/486)

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**Author:** [@richardander](https://discourse.vtk.org/u/richardander)\
**Replies:** 3\
**Last updated:** [August 30, 2021, 10:05am UTC](https://discourse.vtk.org/t/vtkimagereslice-how-to-make-point-in-the-center-of-output-image/486 "2021-08-30T10:05:30Z")

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Hello, I am using vtkImageReslice to generate an image by resliceAxes which is created by a normal direction and passing a point . In the output image, I can define its size by SetOutputExtent. my question is how to ma…

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## [Which pick function should i used in DICOMImageSeries?](https://discourse.vtk.org/t/which-pick-function-should-i-used-in-dicomimageseries/6497)

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**Author:** [@jjjkk](https://discourse.vtk.org/u/jjjkk)\
**Replies:** 0\
**Last updated:** [August 30, 2021, 2:53am UTC](https://discourse.vtk.org/t/which-pick-function-should-i-used-in-dicomimageseries/6497 "2021-08-30T02:53:13Z")

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I try to use picker in ImageViewer2 which reade seriesof DICOMImage. But It seems picker-\>pick not work as the return value by pick is always zeor. The example I follow is using a 2d Image, while DICOMImage is a Series…

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

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**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")

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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…

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## [OSPRay 1.8 and TBB tbb2018\_20170919oss\_win Required](https://discourse.vtk.org/t/ospray-1-8-and-tbb-tbb2018-20170919oss-win-required/6493)

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**Author:** [@Adam\_Hendry](https://discourse.vtk.org/u/Adam_Hendry)\
**Replies:** 5\
**Last updated:** [August 29, 2021, 1:44am UTC](https://discourse.vtk.org/t/ospray-1-8-and-tbb-tbb2018-20170919oss-win-required/6493 "2021-08-29T01:44:59Z")

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Is there a reason why OSPRay 1.8, and TBB 2018 Update 1 (tbb2018\_20170919oss\_win) are required in VTK-9.0.3 and newer versions aren’t supported? Is this intentional?

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## [support for Sigmoid VOI-LUT Function](https://discourse.vtk.org/t/support-for-sigmoid-voi-lut-function/6456)

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**Author:** [@Taiji\_Zhao](https://discourse.vtk.org/u/Taiji_Zhao)\
**Replies:** 3\
**Last updated:** [August 27, 2021, 7:38pm UTC](https://discourse.vtk.org/t/support-for-sigmoid-voi-lut-function/6456 "2021-08-27T19:38:44Z")

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Hi every one, I am quite new to VTK and the forum. I am working on building a dicom viewer UI for mammograms (2D xray image of breast) based on VTK and got stucked on a problem of displaying a image with sigmoid voi-lut…

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## [vtkvolumemapper help](https://discourse.vtk.org/t/vtkvolumemapper-help/6486)

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**Author:** [@Hanxin\_Hua](https://discourse.vtk.org/u/Hanxin_Hua)\
**Replies:** 0\
**Last updated:** [August 27, 2021, 6:20pm UTC](https://discourse.vtk.org/t/vtkvolumemapper-help/6486 "2021-08-27T18:20:07Z")

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Hi there, I have an issue with vtkvolumemapper. void updateImage() { vtkSmartVolumeMapper\* mapper = nullptr; int sampleRate = 1; if (m\_Volume) { mapper = vtkSmartVolumeMapper::SafeDownCast(m\_Volume-\>GetMapper()); } i…

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## [Availability of testing data associated with VTK and ParaView](https://discourse.vtk.org/t/availability-of-testing-data-associated-with-vtk-and-paraview/6481)

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**Author:** [@MatthewFlamm](https://discourse.vtk.org/u/MatthewFlamm)\
**Replies:** 5\
**Last updated:** [August 27, 2021, 1:11pm UTC](https://discourse.vtk.org/t/availability-of-testing-data-associated-with-vtk-and-paraview/6481 "2021-08-27T13:11:08Z")

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I see that there is data used for testing VTK and ParaView or at data.kitware.com, but there is no explicit license associated with those datasets that I can find. I was looking into using a few of the datasets for inte…

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## [vtkCurvatures yields unreasonably large values along borders](https://discourse.vtk.org/t/vtkcurvatures-yields-unreasonably-large-values-along-borders/2527)

<div class="topic-metadata">

**Author:** [@normanius](https://discourse.vtk.org/u/normanius)\
**Replies:** 15\
**Last updated:** [August 27, 2021, 1:21am UTC](https://discourse.vtk.org/t/vtkcurvatures-yields-unreasonably-large-values-along-borders/2527 "2021-08-27T01:21:44Z")

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Hi Does anyone know why vtkCurvatures yields unreasonably high values close to the object’s border? See screenshot below. I expect the (Gaussian) curvature for my shapes to be in the range \[-0.5,1\]. However, I observe v…

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## [vtkPolyDataToImageStencil issue](https://discourse.vtk.org/t/vtkpolydatatoimagestencil-issue/6475)

<div class="topic-metadata">

**Author:** [@Hanxin\_Hua](https://discourse.vtk.org/u/Hanxin_Hua)\
**Replies:** 4\
**Last updated:** [August 26, 2021, 3:27pm UTC](https://discourse.vtk.org/t/vtkpolydatatoimagestencil-issue/6475 "2021-08-26T15:27:06Z")

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Hi everyone, I have a question about the usage of vtkPolyDataToImageStencil. vtkSmartPointer\<vtkCylinderSource\> cy = vtkSmartPointer\<vtkCylinderSource\>::New(); cy-\>SetHeight(20); cy-\>SetRadius(40); cy-\>SetResolution(20)…

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## ["vtkLineIntegralConvolution2D.h": No such file or directory](https://discourse.vtk.org/t/vtklineintegralconvolution2d-h-no-such-file-or-directory/6451)

<div class="topic-metadata">

**Author:** [@Tees](https://discourse.vtk.org/u/Tees)\
**Replies:** 10\
**Last updated:** [August 26, 2021, 12:50pm UTC](https://discourse.vtk.org/t/vtklineintegralconvolution2d-h-no-such-file-or-directory/6451 "2021-08-26T12:50:35Z")

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I get the following error message if I try to include any of the \<vtkLineIntegralConvolution2D.h \<vtkImageDataLIC2D.h\>\<vtkSurfaceLICMapper.h\>\<vtkSurfaceLICInterface.h\> libraries: Data (Include) cannot be opened: “vtkLin…

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