# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=105

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

**Page:** 106

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## [Delaunay triangulation numerically sensitive vtk-9.0.1 vtkDelaunay2D handle large numbers of points System.StackOverflowException](https://discourse.vtk.org/t/delaunay-triangulation-numerically-sensitive-vtk-9-0-1-vtkdelaunay2d-handle-large-numbers-of-points-system-stackoverflowexception/5729)

<div class="topic-metadata">

**Author:** [@yaoganxingwei](https://discourse.vtk.org/u/yaoganxingwei)\
**Replies:** 2\
**Last updated:** [May 10, 2021, 9:22am UTC](https://discourse.vtk.org/t/delaunay-triangulation-numerically-sensitive-vtk-9-0-1-vtkdelaunay2d-handle-large-numbers-of-points-system-stackoverflowexception/5729 "2021-05-10T09:22:38Z")

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In VTK, Delaunay triangulation is numerically sensitive. The vtk-9.0.1 version of vtkDelaunay2D may not be robust enough to reliably handle large numbers of points(For example, 3 million points.). IDE pops up Exception…

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## [python bindings of vtk based tools](https://discourse.vtk.org/t/python-bindings-of-vtk-based-tools/3003)

<div class="topic-metadata">

**Author:** [@kayarre](https://discourse.vtk.org/u/kayarre)\
**Replies:** 14\
**Last updated:** [May 8, 2021, 10:01pm UTC](https://discourse.vtk.org/t/python-bindings-of-vtk-based-tools/3003 "2021-05-08T22:01:41Z")

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In reading through this discussion on Remote modules vs external modules I want to create python bindings for a c++ project that heavily depends on VTK, and possibly make a paraview plugin with it. What would be the bes…

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## [modify position of points on boundary of polydata surface](https://discourse.vtk.org/t/modify-position-of-points-on-boundary-of-polydata-surface/5716)

<div class="topic-metadata">

**Author:** [@bistek](https://discourse.vtk.org/u/bistek)\
**Replies:** 1\
**Last updated:** [May 7, 2021, 4:40pm UTC](https://discourse.vtk.org/t/modify-position-of-points-on-boundary-of-polydata-surface/5716 "2021-05-07T16:40:33Z")

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Hello, I am trying to modify the coordinates of points on the boundary of a triangulated surface (polydata made of triangle cells), in order to slightly expand some sections of the boundary in a direction that is perpend…

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## [Passing python vtk\_ptr to C++ Failed](https://discourse.vtk.org/t/passing-python-vtk-ptr-to-c-failed/5713)

<div class="topic-metadata">

**Author:** [@WailmerPail](https://discourse.vtk.org/u/WailmerPail)\
**Replies:** 6\
**Last updated:** [May 7, 2021, 3:39pm UTC](https://discourse.vtk.org/t/passing-python-vtk-ptr-to-c-failed/5713 "2021-05-07T15:39:10Z")

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Hello Team, I tried to pass the py\_vtk\_ptr to cpp\_vtk for modifiying the value rapidly. I used the method from pletzer/vtkpythoncpp, like ///==== addr = int(pdata.GetAddressAsString(‘vtkPolyData’)\[5:\], 16) lib.foo(c…

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## [VTK 6.3.0](https://discourse.vtk.org/t/vtk-6-3-0/5734)

<div class="topic-metadata">

**Author:** [@colinbannister](https://discourse.vtk.org/u/colinbannister)\
**Replies:** 2\
**Last updated:** [May 7, 2021, 1:52pm UTC](https://discourse.vtk.org/t/vtk-6-3-0/5734 "2021-05-07T13:52:11Z")

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I am trying to build ITK-snap which has VTK as a pre-requisite.BuildingITK-SNAP. The version recommended is 6.3.0, but I can’t find a download. Can anyone help ? Thanks in advance Colin

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## [When I use QVTKOpenGLStereoWidget](https://discourse.vtk.org/t/when-i-use-qvtkopenglstereowidget/5723)

<div class="topic-metadata">

**Author:** [@loufear](https://discourse.vtk.org/u/loufear)\
**Replies:** 1\
**Last updated:** [May 7, 2021, 8:18am UTC](https://discourse.vtk.org/t/when-i-use-qvtkopenglstereowidget/5723 "2021-05-07T08:18:14Z")

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QVTKOpenGLStereoWidget actor ghosting \* When mouse events are triggered

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## [Streamtracer with CSV data](https://discourse.vtk.org/t/streamtracer-with-csv-data/5720)

<div class="topic-metadata">

**Author:** [@Ondrej\_Tkadlec](https://discourse.vtk.org/u/Ondrej_Tkadlec)\
**Replies:** 0\
**Last updated:** [May 6, 2021, 8:00pm UTC](https://discourse.vtk.org/t/streamtracer-with-csv-data/5720 "2021-05-06T20:00:31Z")

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Hi, I’m trying to make 3D streamtracer with data from CSV file. It has 3 columns x,y,z for points in 3D space and 3 columns vx,vy,vz for the 3D vector that belongs to that point. I’m able to plot glyph plot but I’m unab…

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## [Darker version of lookup table for backfaces of vtkPolyData?](https://discourse.vtk.org/t/darker-version-of-lookup-table-for-backfaces-of-vtkpolydata/2108)

<div class="topic-metadata">

**Author:** [@maleike](https://discourse.vtk.org/u/maleike)\
**Replies:** 8\
**Last updated:** [May 6, 2021, 6:24pm UTC](https://discourse.vtk.org/t/darker-version-of-lookup-table-for-backfaces-of-vtkpolydata/2108 "2021-05-06T18:24:20Z")

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I am using vtkPolyData for visualization of surfaces in my application. By default I derive a backface color for the object as a ‘darker’ version of the frontface color so that users can easily tell apart inside and outs…

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## [Animation & actor-\>SetMapper](https://discourse.vtk.org/t/animation-actor-setmapper/5704)

<div class="topic-metadata">

**Author:** [@nparent](https://discourse.vtk.org/u/nparent)\
**Replies:** 1\
**Last updated:** [May 6, 2021, 3:07pm UTC](https://discourse.vtk.org/t/animation-actor-setmapper/5704 "2021-05-06T15:07:08Z")

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Hi, I would like to create animations in which I change the vtkMapper of the actor. Basically, I have a curve (rod) that I want to animate. It is named yarn and it evolves in time by calling yarn-\>step() and then I ca…

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## [Forcing rendering](https://discourse.vtk.org/t/forcing-rendering/5692)

<div class="topic-metadata">

**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 1\
**Last updated:** [May 4, 2021, 4:04pm UTC](https://discourse.vtk.org/t/forcing-rendering/5692 "2021-05-04T16:04:56Z")

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Dear All, I do the rendering of several volumes in same 3D image. Some of them are over the others and shadow the previous rendered ones. How I force re-render the previous ones (volumes) to appear the shadowed areas?…

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## [Performance degrade for more than 10000 actor](https://discourse.vtk.org/t/performance-degrade-for-more-than-10000-actor/5683)

<div class="topic-metadata">

**Author:** [@Anil\_Singh](https://discourse.vtk.org/u/Anil_Singh)\
**Replies:** 7\
**Last updated:** [May 4, 2021, 3:00pm UTC](https://discourse.vtk.org/t/performance-degrade-for-more-than-10000-actor/5683 "2021-05-04T15:00:09Z")

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Hello Team, I tried to support large actor count with individual interaction. Performance degrade when actor count goes beyond 1000 actor. Please support me on this. I need to move individual sphere with mouse as same t…

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## [Co-planar surfaces rendered differently depending on depth peeling activation](https://discourse.vtk.org/t/co-planar-surfaces-rendered-differently-depending-on-depth-peeling-activation/5616)

<div class="topic-metadata">

**Author:** [@afa](https://discourse.vtk.org/u/afa)\
**Replies:** 5\
**Last updated:** [May 4, 2021, 2:38pm UTC](https://discourse.vtk.org/t/co-planar-surfaces-rendered-differently-depending-on-depth-peeling-activation/5616 "2021-05-04T14:38:53Z")

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Hello, I often find myself in a situation where I have to deal with co-planar surfaces. The render differs depending whether or not I am using depth peeling. Occlussion or composite change nothing in the result. I am …

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## [To render the real size of actor without zooming](https://discourse.vtk.org/t/to-render-the-real-size-of-actor-without-zooming/5385)

<div class="topic-metadata">

**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 3\
**Last updated:** [May 4, 2021, 1:39pm UTC](https://discourse.vtk.org/t/to-render-the-real-size-of-actor-without-zooming/5385 "2021-05-04T13:39:57Z")

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I am rendering circles in the position of the mouse. My surprise is if I zoom in the scene and I add a circle they become larger than the original one. If it has a radius of three I would like to see the circle of radius…

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## [add label to clicked 3D position](https://discourse.vtk.org/t/add-label-to-clicked-3d-position/3828)

<div class="topic-metadata">

**Author:** [@mohammad\_jalili](https://discourse.vtk.org/u/mohammad_jalili)\
**Replies:** 1\
**Last updated:** [May 4, 2021, 1:37pm UTC](https://discourse.vtk.org/t/add-label-to-clicked-3d-position/3828 "2021-05-04T13:37:33Z")

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Hello everyone. I have rendered a 3D DICOM and now I want to add vtkTextActor3D in some 3D position when user clicks. How to do that?

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## [Render window stuck after setting interpolation type to linear](https://discourse.vtk.org/t/render-window-stuck-after-setting-interpolation-type-to-linear/5702)

<div class="topic-metadata">

**Author:** [@xxyyy159](https://discourse.vtk.org/u/xxyyy159)\
**Replies:** 0\
**Last updated:** [May 4, 2021, 1:32pm UTC](https://discourse.vtk.org/t/render-window-stuck-after-setting-interpolation-type-to-linear/5702 "2021-05-04T13:32:57Z")

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Hi all, I’m using vtkCameraInterpolator for some program and I find an example here(link below). https://kitware.github.io/vtk-examples/site/Cxx/Rendering/InterpolateCamera/ After setting the interpolation type to lin…

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## [How can I obtain the intersection line from a isosurface which is cut by other surface?](https://discourse.vtk.org/t/how-can-i-obtain-the-intersection-line-from-a-isosurface-which-is-cut-by-other-surface/5691)

<div class="topic-metadata">

**Author:** [@DavidMiraut](https://discourse.vtk.org/u/DavidMiraut)\
**Replies:** 5\
**Last updated:** [May 4, 2021, 1:05pm UTC](https://discourse.vtk.org/t/how-can-i-obtain-the-intersection-line-from-a-isosurface-which-is-cut-by-other-surface/5691 "2021-05-04T13:05:09Z")

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Hello, I would like to obtain the representation of the intersection of an isosurface with other surface (in this example code, it is just a plane). The isosurface is extrated from a volume image via vtkMarchingCubes, v…

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## [pypi vtk on macOS 11 Big Sur](https://discourse.vtk.org/t/pypi-vtk-on-macos-11-big-sur/5647)

<div class="topic-metadata">

**Author:** [@noamb](https://discourse.vtk.org/u/noamb)\
**Replies:** 2\
**Last updated:** [May 4, 2021, 12:54pm UTC](https://discourse.vtk.org/t/pypi-vtk-on-macos-11-big-sur/5647 "2021-05-04T12:54:47Z")

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What’s the current status of python vtk installation via pip on the latest macOS (11)? I’m reluctant to upgrade because I’ve heard rumors that it’s not working, and the binary files on pypi do seem a bit old to support …

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## [get intersection between 2 obj](https://discourse.vtk.org/t/get-intersection-between-2-obj/5699)

<div class="topic-metadata">

**Author:** [@RAUMIK\_RANA](https://discourse.vtk.org/u/RAUMIK_RANA)\
**Replies:** 0\
**Last updated:** [May 4, 2021, 11:57am UTC](https://discourse.vtk.org/t/get-intersection-between-2-obj/5699 "2021-05-04T11:57:35Z")

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I am trying to get intersection between 2 obj files. first one is sphere and second one is cylinder. I am using ‘vtkCollisionDetectionFilter’ for that. but I did not get it. I got 0 points in polyData. here is my co…

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## [Encrypt stl](https://discourse.vtk.org/t/encrypt-stl/5672)

<div class="topic-metadata">

**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 2\
**Last updated:** [May 4, 2021, 8:48am UTC](https://discourse.vtk.org/t/encrypt-stl/5672 "2021-05-04T08:48:56Z")

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Hello, I have a doubt, I have a database with stls you can use in the software and select them and the vtk reads the stl. But everybody that has the software, can copy the stls. Is there something in vtk, to encrypt it …

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## [Error while Running CMAKE configure on VTK9.0 in Ubuntu](https://discourse.vtk.org/t/error-while-running-cmake-configure-on-vtk9-0-in-ubuntu/5688)

<div class="topic-metadata">

**Author:** [@Homersbm](https://discourse.vtk.org/u/Homersbm)\
**Replies:** 2\
**Last updated:** [May 4, 2021, 5:32am UTC](https://discourse.vtk.org/t/error-while-running-cmake-configure-on-vtk9-0-in-ubuntu/5688 "2021-05-04T05:32:59Z")

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Environment: Ubuntu:20.04.2 LST Compiler: G++ 9.3.0 CMAKE Version: 3.20.2 - Generator - Unix MakeFIles vtk version: 9 I get the following error: Could NOT find X11 (missing: Xt) CMake Error at CMake/vtkModule.cmake:4…

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## [Segfault while finding intersection of vtkPolyData with python](https://discourse.vtk.org/t/segfault-while-finding-intersection-of-vtkpolydata-with-python/317)

<div class="topic-metadata">

**Author:** [@dimkal](https://discourse.vtk.org/u/dimkal)\
**Replies:** 5\
**Last updated:** [May 4, 2021, 1:54am UTC](https://discourse.vtk.org/t/segfault-while-finding-intersection-of-vtkpolydata-with-python/317 "2021-05-04T01:54:33Z")

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Visualizing two polyData objects, I see that they overlap, however, I cannot calculate their intersection with VTK in python. What am I doing wrong??? I get the following error: $ python test.py VOLUME of probe1: 8.3…

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## [VTK find\_package fails with includes](https://discourse.vtk.org/t/vtk-find-package-fails-with-includes/5671)

<div class="topic-metadata">

**Author:** [@nparent](https://discourse.vtk.org/u/nparent)\
**Replies:** 12\
**Last updated:** [May 3, 2021, 10:55am UTC](https://discourse.vtk.org/t/vtk-find-package-fails-with-includes/5671 "2021-05-03T10:55:35Z")

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Hi, I am facing an issue with the includes in my code. In my CMakeLists.txt I first create a library, then an executable which include vtk headers. If I remove the add\_library (so far my executable does not depend on i…

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## [VTK 9 and Java- vtk.jar not automatically generated. Also location of wrapper dlls](https://discourse.vtk.org/t/vtk-9-and-java-vtk-jar-not-automatically-generated-also-location-of-wrapper-dlls/3354)

<div class="topic-metadata">

**Author:** [@eclrgp](https://discourse.vtk.org/u/eclrgp)\
**Replies:** 17\
**Last updated:** [May 2, 2021, 5:46am UTC](https://discourse.vtk.org/t/vtk-9-and-java-vtk-jar-not-automatically-generated-also-location-of-wrapper-dlls/3354 "2021-05-02T05:46:41Z")

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Using Visual Studio ( actually 2019 but I also have 2017) and using cmake 3.17.2 on Windows 10 1909 The step to compile the java wrappers and build vtk.jar seems not to be run although the rest of the build happens. Th…

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## [vtkAssembly and vtkExporter](https://discourse.vtk.org/t/vtkassembly-and-vtkexporter/5679)

<div class="topic-metadata">

**Author:** [@a-u](https://discourse.vtk.org/u/a-u)\
**Replies:** 0\
**Last updated:** [May 1, 2021, 11:13pm UTC](https://discourse.vtk.org/t/vtkassembly-and-vtkexporter/5679 "2021-05-01T23:13:45Z")

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I’m trying to export an assembly to e.g. gltf but all the positions and colors are lost. It does render correctly before exporting. Is this to be expected? import vtk renderer = vtk.vtkRenderer() renderWindow = vtk.vtk…

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## [Problems aligning oblique slice with objects in scene](https://discourse.vtk.org/t/problems-aligning-oblique-slice-with-objects-in-scene/5668)

<div class="topic-metadata">

**Author:** [@Egredior](https://discourse.vtk.org/u/Egredior)\
**Replies:** 1\
**Last updated:** [May 1, 2021, 8:56pm UTC](https://discourse.vtk.org/t/problems-aligning-oblique-slice-with-objects-in-scene/5668 "2021-05-01T20:56:20Z")

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Hello, I am trying to render oblique slices from a DICOM with an object in the scene in the right spot and orientation. I know where the object is in DICOM space, and have a 4x4 matrix for it. I have calculated axial, s…

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## [vtkObject and C++ const-ness - not possible?](https://discourse.vtk.org/t/vtkobject-and-c-const-ness-not-possible/4942)

<div class="topic-metadata">

**Author:** [@dsemikin](https://discourse.vtk.org/u/dsemikin)\
**Replies:** 6\
**Last updated:** [May 1, 2021, 8:48am UTC](https://discourse.vtk.org/t/vtkobject-and-c-const-ness-not-possible/4942 "2021-05-01T08:48:18Z")

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Hello, I just wanted to be sure on this topic: is it correct, that VTK basically gives up on using const-ness in C++ sense? For example, it is not meaningful to e.g. implement an algorithm, which would expost its resul…

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## [Re-divide surface to get similar-sized cell](https://discourse.vtk.org/t/re-divide-surface-to-get-similar-sized-cell/5621)

<div class="topic-metadata">

**Author:** [@cbhushan](https://discourse.vtk.org/u/cbhushan)\
**Replies:** 5\
**Last updated:** [April 30, 2021, 4:36pm UTC](https://discourse.vtk.org/t/re-divide-surface-to-get-similar-sized-cell/5621 "2021-04-30T16:36:04Z")

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I am looking for some suggestions of how to achieve this: Re-divide a surface (polydata with only triangles) to get similar-sized cells with minimal change from the original surface. May be I am overlooking something, bu…

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## [Python 3.9](https://discourse.vtk.org/t/python-3-9/4369)

<div class="topic-metadata">

**Author:** [@axh](https://discourse.vtk.org/u/axh)\
**Replies:** 3\
**Last updated:** [April 30, 2021, 10:44am UTC](https://discourse.vtk.org/t/python-3-9/4369 "2021-04-30T10:44:42Z")

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Will there be Python 3.9 pre-built binary wheels as you have for Python 3.8?

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## [TimeSteps on vtkMultiBlockDataSet](https://discourse.vtk.org/t/timesteps-on-vtkmultiblockdataset/5670)

<div class="topic-metadata">

**Author:** [@j-miguel](https://discourse.vtk.org/u/j-miguel)\
**Replies:** 0\
**Last updated:** [April 30, 2021, 4:52am UTC](https://discourse.vtk.org/t/timesteps-on-vtkmultiblockdataset/5670 "2021-04-30T04:52:21Z")

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Hi there, I’m currently trying to implement some animations on top of our current Vtk system. So far, I’ve been using the Interactor Timer Event and updating my data manually but now I need to interpolate my Series. I…

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## [How to calculate the surface area generated from vtkCutter?](https://discourse.vtk.org/t/how-to-calculate-the-surface-area-generated-from-vtkcutter/5662)

<div class="topic-metadata">

**Author:** [@x2778768](https://discourse.vtk.org/u/x2778768)\
**Replies:** 0\
**Last updated:** [April 29, 2021, 9:54am UTC](https://discourse.vtk.org/t/how-to-calculate-the-surface-area-generated-from-vtkcutter/5662 "2021-04-29T09:54:13Z")

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Hi, I’m using vtkCutter to cut my 3d model(vtkPolydata). Through this I get a cutter surface. Now I want to calculate the area of the surface. Here is a part of my code: vtkSmartPointer\<vtkCutter\> Cutter = vtkS…

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