# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=120

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

**Page:** 121

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## [Deprecated vtkUnstructuredGrid::SetCells](https://discourse.vtk.org/t/deprecated-vtkunstructuredgrid-setcells/4277)

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**Author:** [@RonRahaman](https://discourse.vtk.org/u/RonRahaman)\
**Replies:** 2\
**Last updated:** [September 30, 2020, 2:25pm UTC](https://discourse.vtk.org/t/deprecated-vtkunstructuredgrid-setcells/4277 "2020-09-30T14:25:07Z")

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One of our existing apps uses a deprecated form of vtkUnstructuredGrid::SetCells. Here it is in an older Doxygen: void vtkUnstructuredGrid::SetCells ( vtkUnsignedCharArray \*cellTypes, vtkIdTypeArray \*cellLocations,…

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## [Convert VTK-m-Contour output to vtkPolyData](https://discourse.vtk.org/t/convert-vtk-m-contour-output-to-vtkpolydata/4315)

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**Author:** [@McDave17](https://discourse.vtk.org/u/McDave17)\
**Replies:** 1\
**Last updated:** [September 29, 2020, 1:31pm UTC](https://discourse.vtk.org/t/convert-vtk-m-contour-output-to-vtkpolydata/4315 "2020-09-29T13:31:58Z")

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Im trying to convert my contour output back to a vtkPolyData object and I’m having trouble to figure out the correct parameters for the fromvtkm::Convert method. Here’s my code: #include \<vtkmlib/ImageDataConverter.h\> …

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## [VTK Polydata dataset with points only?](https://discourse.vtk.org/t/vtk-polydata-dataset-with-points-only/4293)

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**Author:** [@pjdf](https://discourse.vtk.org/u/pjdf)\
**Replies:** 5\
**Last updated:** [September 29, 2020, 12:55pm UTC](https://discourse.vtk.org/t/vtk-polydata-dataset-with-points-only/4293 "2020-09-29T12:55:59Z")

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I have a legacy POLYDATA dataset with only points and associated SCALARS (no CELLS) from some hydrologic simulation code. The only important piece of information is the location of the points themselves. I have two ques…

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## [How to use polydata and imagedata same time](https://discourse.vtk.org/t/how-to-use-polydata-and-imagedata-same-time/4308)

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**Author:** [@11112](https://discourse.vtk.org/u/11112)\
**Replies:** 2\
**Last updated:** [September 29, 2020, 1:36am UTC](https://discourse.vtk.org/t/how-to-use-polydata-and-imagedata-same-time/4308 "2020-09-29T01:36:13Z")

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Hey guys, I am now building a medical project and need some tips. This project is for surgeon. A doctor need to implant bone nail and interactive with nails. I have bone image data from CT, and STL file of nails. I ca…

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## [git lfs problem](https://discourse.vtk.org/t/git-lfs-problem/4303)

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**Author:** [@amaclean](https://discourse.vtk.org/u/amaclean)\
**Replies:** 4\
**Last updated:** [September 28, 2020, 10:29pm UTC](https://discourse.vtk.org/t/git-lfs-problem/4303 "2020-09-28T22:29:49Z")

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Until 24 Sept I have been able to upload images to vtk-examples with no problems. Now I am getting this message: Uploading LFS objects: 100% (6/6), 678 KB | 0 B/s, done. Enumerating objects: 27, done. Counting objects:…

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## [How to generate vtkImageData from mathematical function](https://discourse.vtk.org/t/how-to-generate-vtkimagedata-from-mathematical-function/4305)

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**Author:** [@McDave17](https://discourse.vtk.org/u/McDave17)\
**Replies:** 10\
**Last updated:** [September 28, 2020, 3:17pm UTC](https://discourse.vtk.org/t/how-to-generate-vtkimagedata-from-mathematical-function/4305 "2020-09-28T15:17:17Z")

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Hello. I’m trying to generate multiple DataSets containing Cayley surfaces in different levels of detail. The cayley surface is described by following function: f(x, y, z) = 1 - 16xyz - 4x^2 - 4y^2 - 4z^2 No I don’t…

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## [Topological problems](https://discourse.vtk.org/t/topological-problems/4299)

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**Author:** [@cobo](https://discourse.vtk.org/u/cobo)\
**Replies:** 1\
**Last updated:** [September 26, 2020, 2:42am UTC](https://discourse.vtk.org/t/topological-problems/4299 "2020-09-26T02:42:10Z")

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Starting point is a PolyData object that is supposed to be the watertight surface of one or several “bodies” that also does not include any non-manifold edges, but input may not always be like that! I realize that tes…

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## [Compiling VTK in virtual environment](https://discourse.vtk.org/t/compiling-vtk-in-virtual-environment/4302)

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**Author:** [@daluke](https://discourse.vtk.org/u/daluke)\
**Replies:** 0\
**Last updated:** [September 25, 2020, 6:23pm UTC](https://discourse.vtk.org/t/compiling-vtk-in-virtual-environment/4302 "2020-09-25T18:23:56Z")

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I have some trouble compiling VTK (8.9) using a conda virtual environment. While trying to run make, ld cannot find some important shared libraries /usr/bin/ld: cannot find /lib/libc.so.6 /usr/bin/ld: cannot find /usr/…

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## [Some problems about how to update the image when data is changing continuously](https://discourse.vtk.org/t/some-problems-about-how-to-update-the-image-when-data-is-changing-continuously/4257)

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**Author:** [@wudiii](https://discourse.vtk.org/u/wudiii)\
**Replies:** 7\
**Last updated:** [September 25, 2020, 2:29pm UTC](https://discourse.vtk.org/t/some-problems-about-how-to-update-the-image-when-data-is-changing-continuously/4257 "2020-09-25T14:29:02Z")

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I’m a beginner of VTK. I want to display the volume data of a lung which will be changed using some volume deformation algorithm. Frist, I use one thread to open the vtk context, and another thread to perform deformatio…

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## [Black image when using offscreen rendering inside Qt application](https://discourse.vtk.org/t/black-image-when-using-offscreen-rendering-inside-qt-application/3935)

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**Author:** [@hkroeger](https://discourse.vtk.org/u/hkroeger)\
**Replies:** 7\
**Last updated:** [September 25, 2020, 1:36pm UTC](https://discourse.vtk.org/t/black-image-when-using-offscreen-rendering-inside-qt-application/3935 "2020-09-25T13:36:33Z")

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I have written a library, which shall produce some rendering of scenes into images using VTK (no actual interactive 3D windows). I have two executables from which the library is used: one command line tool and a Qt base…

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## [how to 3d volume render numpy array](https://discourse.vtk.org/t/how-to-3d-volume-render-numpy-array/4261)

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**Author:** [@YolkandWhite](https://discourse.vtk.org/u/YolkandWhite)\
**Replies:** 5\
**Last updated:** [September 25, 2020, 5:21am UTC](https://discourse.vtk.org/t/how-to-3d-volume-render-numpy-array/4261 "2020-09-25T05:21:09Z")

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I’m trying to volume render an 3d numpy array with vtk python. I used to render it by getting the stack of images, but I’m trying to volume render with an 3d numpy array instead of stack of images. this picture below …

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## [VTK](https://discourse.vtk.org/t/vtk/4276)

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**Author:** [@cyAAA111](https://discourse.vtk.org/u/cyAAA111)\
**Replies:** 4\
**Last updated:** [September 24, 2020, 6:30am UTC](https://discourse.vtk.org/t/vtk/4276 "2020-09-24T06:30:57Z")

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Excuse me, how to use volume data to achieve 10000X10000X1000 resolution drawing, thank you very much.

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## [VTK-based annotation tool](https://discourse.vtk.org/t/vtk-based-annotation-tool/4273)

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**Author:** [@JDo8](https://discourse.vtk.org/u/JDo8)\
**Replies:** 1\
**Last updated:** [September 23, 2020, 4:04pm UTC](https://discourse.vtk.org/t/vtk-based-annotation-tool/4273 "2020-09-23T16:04:51Z")

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I’m evaluating VTK as a framework for a python-based annotation tool. My goal is to use e.g. cubes to annotate 3D data. Is this a viable option, do you have a better suggestion? Is it possible to “drag” a corner or sid…

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## [Allocate vs. SetNumberOfPoints](https://discourse.vtk.org/t/allocate-vs-setnumberofpoints/4278)

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**Author:** [@RonRahaman](https://discourse.vtk.org/u/RonRahaman)\
**Replies:** 4\
**Last updated:** [September 22, 2020, 10:39pm UTC](https://discourse.vtk.org/t/allocate-vs-setnumberofpoints/4278 "2020-09-22T22:39:13Z")

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For vtkPoints and other similar objects, when should I use Allocate and when should I use SetNumberOfPoints?

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## [VTKPython for 9.0](https://discourse.vtk.org/t/vtkpython-for-9-0/4260)

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**Author:** [@Francesc](https://discourse.vtk.org/u/Francesc)\
**Replies:** 4\
**Last updated:** [September 22, 2020, 9:08am UTC](https://discourse.vtk.org/t/vtkpython-for-9-0/4260 "2020-09-22T09:08:10Z")

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Hello, I am a new VTK user. So far I have downloaded VTK9.0 and build it with no issues. Now I am looking for VTKPython for Windows. How should I get it for 9.0? The python wheels have not worked for me. What is the m…

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## [The vtk VoxelContoursToSurfaceFilter output is not closed surface](https://discourse.vtk.org/t/the-vtk-voxelcontourstosurfacefilter-output-is-not-closed-surface/4258)

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**Author:** [@guojunjie4SD](https://discourse.vtk.org/u/guojunjie4SD)\
**Replies:** 7\
**Last updated:** [September 21, 2020, 7:12pm UTC](https://discourse.vtk.org/t/the-vtk-voxelcontourstosurfacefilter-output-is-not-closed-surface/4258 "2020-09-21T19:12:34Z")

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I used closed polygons as input polydata， but the result is not closed。 Anyone can give me some advice？ How to make the output closed? Mesh reconstruction(const Ring3dList &ring\_list, double slice\_spacing) { // ring3…

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## [VTK for begineer user.](https://discourse.vtk.org/t/vtk-for-begineer-user/4264)

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**Author:** [@semmana26](https://discourse.vtk.org/u/semmana26)\
**Replies:** 9\
**Last updated:** [September 21, 2020, 6:43pm UTC](https://discourse.vtk.org/t/vtk-for-begineer-user/4264 "2020-09-21T18:43:13Z")

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Hello everyone, I am a new user. I am asking the way to install VTK and tutorials and courses related with structural mechanic using VTK?

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## [How to catch window close events?](https://discourse.vtk.org/t/how-to-catch-window-close-events/4246)

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**Author:** [@Leo843](https://discourse.vtk.org/u/Leo843)\
**Replies:** 1\
**Last updated:** [September 21, 2020, 4:31am UTC](https://discourse.vtk.org/t/how-to-catch-window-close-events/4246 "2020-09-21T04:31:53Z")

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Hi all, I discovered VTK recently and I am trying to get used to it for now. Currently I am trying to plot some 2D curves that represents the evolution of the sin and cos functions through time at a given rate. To updat…

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## [vtkImageReslice origin/direction calculation problem](https://discourse.vtk.org/t/vtkimagereslice-origin-direction-calculation-problem/4248)

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**Author:** [@guojunjie4SD](https://discourse.vtk.org/u/guojunjie4SD)\
**Replies:** 1\
**Last updated:** [September 18, 2020, 10:19pm UTC](https://discourse.vtk.org/t/vtkimagereslice-origin-direction-calculation-problem/4248 "2020-09-18T22:19:43Z")

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Sorry to bother you. I really need some help in vtkImageReslice class!!! The Problem is : I get the vtkImageData from MR dicom images. I want to get the oblique image form it by given origin and direction; Here is …

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## [vtkDistanceWidget Individual Colors for Each End](https://discourse.vtk.org/t/vtkdistancewidget-individual-colors-for-each-end/4239)

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**Author:** [@raungst](https://discourse.vtk.org/u/raungst)\
**Replies:** 1\
**Last updated:** [September 18, 2020, 9:12pm UTC](https://discourse.vtk.org/t/vtkdistancewidget-individual-colors-for-each-end/4239 "2020-09-18T21:12:01Z")

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I’m trying to use the vtkDistanceWidget as more of a vector widget to signify direction. To show the user which direction is from and to, I’m trying to set the color of each cross hair to something different. However, th…

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## [Point ordering for vtkLagrangeHexahedron?](https://discourse.vtk.org/t/point-ordering-for-vtklagrangehexahedron/4253)

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**Author:** [@RonRahaman](https://discourse.vtk.org/u/RonRahaman)\
**Replies:** 2\
**Last updated:** [September 18, 2020, 7:50pm UTC](https://discourse.vtk.org/t/point-ordering-for-vtklagrangehexahedron/4253 "2020-09-18T19:50:22Z")

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I’m interested in using vtkLagrangeHexahedrons for my app (a spectral element simulation). I’ve written a simple example, but the surfaces look funky. This is a 3rd order hex, and it’s labeled with the vertex IDs. I’v…

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## [The vtkResliceImageViewer and the vtkResliceCursorRepresentation reslicer has different output](https://discourse.vtk.org/t/the-vtkresliceimageviewer-and-the-vtkreslicecursorrepresentation-reslicer-has-different-output/1774)

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**Author:** [@kohit](https://discourse.vtk.org/u/kohit)\
**Replies:** 5\
**Last updated:** [September 18, 2020, 12:47pm UTC](https://discourse.vtk.org/t/the-vtkresliceimageviewer-and-the-vtkreslicecursorrepresentation-reslicer-has-different-output/1774 "2020-09-18T12:47:00Z")

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Hi, I am using vtkResliceImageViewer follow the FourPaneViewer example, However, when I am using GetRepresentation()-\>GetReslice()-\>GetOutput(), sometimes the output image is different from the viewer output (mainly the…

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## [Volume cannot display in in iOS](https://discourse.vtk.org/t/volume-cannot-display-in-in-ios/2807)

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**Author:** [@cocacc](https://discourse.vtk.org/u/cocacc)\
**Replies:** 1\
**Last updated:** [September 18, 2020, 2:44am UTC](https://discourse.vtk.org/t/volume-cannot-display-in-in-ios/2807 "2020-09-18T02:44:31Z")

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I want to display Volume in iPhone (iPhone xR os 13.4 Xcode 11.3.1 VTK 8.2.0） I use Examples /VTK-8.2.0/Examples/iOS/VolumeRender but I got the error message： Generic Warning: In /VTK-8.2.0/Rendering/OpenGL2/vtkOpen…

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## [vtkTriangleFilter - Generate more triangles?](https://discourse.vtk.org/t/vtktrianglefilter-generate-more-triangles/4169)

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**Author:** [@MMoussa](https://discourse.vtk.org/u/MMoussa)\
**Replies:** 4\
**Last updated:** [September 17, 2020, 11:35pm UTC](https://discourse.vtk.org/t/vtktrianglefilter-generate-more-triangles/4169 "2020-09-17T23:35:58Z")

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I am using vtkTraingleFilter to triangulate a vtkUnstructuredGrid. My goal is to generate a smooth color map. My understanding is that I need more triangles to do this. For example a linear quadrilateral is rendered wi…

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## [VTU and VTK extension files](https://discourse.vtk.org/t/vtu-and-vtk-extension-files/4240)

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**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 1\
**Last updated:** [September 17, 2020, 11:31pm UTC](https://discourse.vtk.org/t/vtu-and-vtk-extension-files/4240 "2020-09-17T23:31:00Z")

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Dear All, Does .vtk extension files support volumetric (Tetrahedral) meshes? If so, where it can be found the specifications. Where it can be found the specifications of .vtu files? Thanks in Advance, Luis Gonçalves …

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## [Transform matrix of vtkboxwidget2 is different calculated](https://discourse.vtk.org/t/transform-matrix-of-vtkboxwidget2-is-different-calculated/4235)

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**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 0\
**Last updated:** [September 17, 2020, 7:54am UTC](https://discourse.vtk.org/t/transform-matrix-of-vtkboxwidget2-is-different-calculated/4235 "2020-09-17T07:54:35Z")

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Hello, I amb trying to understand the transformation matrix of the vtkboxwidget2. I want to have a bounding box widget with only translations. In some transformations the matrix gives the initial position and updates it…

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## [add observer on cell and point array](https://discourse.vtk.org/t/add-observer-on-cell-and-point-array/4202)

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**Author:** [@bistek](https://discourse.vtk.org/u/bistek)\
**Replies:** 3\
**Last updated:** [September 17, 2020, 11:56am UTC](https://discourse.vtk.org/t/add-observer-on-cell-and-point-array/4202 "2020-09-17T11:56:43Z")

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Hello, I have a polydata and I would like to run some callback function when the polydata in general, its cells or its points are modified. I attach the following test code as an example. # define points x = \[0.0, 0.0, …

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## [How write a own template class which inherits from an existing vtk class](https://discourse.vtk.org/t/how-write-a-own-template-class-which-inherits-from-an-existing-vtk-class/4195)

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**Author:** [@Amnesie](https://discourse.vtk.org/u/Amnesie)\
**Replies:** 5\
**Last updated:** [September 16, 2020, 2:36pm UTC](https://discourse.vtk.org/t/how-write-a-own-template-class-which-inherits-from-an-existing-vtk-class/4195 "2020-09-16T14:36:18Z")

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Hi everyone, I want to write a template class in vtk ,which inherits from an existing vtk class. I use this ReadDICOMSeries as example. Assuming I’m not sure the data type of \_ImageViewer,maybe vtkResliceImageViewer…

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## [ProbeFilter not producing the correct result](https://discourse.vtk.org/t/probefilter-not-producing-the-correct-result/4151)

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**Author:** [@isuruwi](https://discourse.vtk.org/u/isuruwi)\
**Replies:** 2\
**Last updated:** [September 15, 2020, 2:03pm UTC](https://discourse.vtk.org/t/probefilter-not-producing-the-correct-result/4151 "2020-09-15T14:03:00Z")

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I have created a 3D volumetric mesh and saved it as a vtkUnstrcturedGrid (i.e. as a .vtk file). This mesh consists of a box with an ellipsoid where the ellipsoid is inside of this box. This mesh has two scalars where the…

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## ["Unable to eglMakeCurrent" when using vtkEGLRenderWindow](https://discourse.vtk.org/t/unable-to-eglmakecurrent-when-using-vtkeglrenderwindow/4211)

<div class="topic-metadata">

**Author:** [@jonoweideman](https://discourse.vtk.org/u/jonoweideman)\
**Replies:** 4\
**Last updated:** [September 14, 2020, 2:47pm UTC](https://discourse.vtk.org/t/unable-to-eglmakecurrent-when-using-vtkeglrenderwindow/4211 "2020-09-14T14:47:39Z")

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Hi there. I’m attempting to build a client server application where a user can request high resolution renders of a data cube from various camera positions. The request contain information about the camera such as Positi…

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