# Development

**URL:** https://discourse.vtk.org/c/development/7.md?page=48

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

**Page:** 49

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## [calculate the center of mass incorrectly after clipping polydata](https://discourse.vtk.org/t/calculate-the-center-of-mass-incorrectly-after-clipping-polydata/1691)

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**Author:** [@Matthijs\_Hendriks](https://discourse.vtk.org/u/Matthijs_Hendriks)\
**Replies:** 2\
**Last updated:** [September 4, 2019, 2:09pm UTC](https://discourse.vtk.org/t/calculate-the-center-of-mass-incorrectly-after-clipping-polydata/1691 "2019-09-04T14:09:00Z")

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The center of mass is calculate not correctly after clipping a polydata. I get the center of mass of the original polydata

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## [Display slice plane](https://discourse.vtk.org/t/display-slice-plane/1546)

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**Author:** [@1111](https://discourse.vtk.org/u/1111)\
**Replies:** 14\
**Last updated:** [September 4, 2019, 2:31am UTC](https://discourse.vtk.org/t/display-slice-plane/1546 "2019-09-04T02:31:30Z")

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Hi, I want to display the slice plane selected by vtkImplicitPlaneWidget2 as a two-dimensional image while synchronizing in another window. Can you tell me how to display while synchronizing? The code to reslice was c…

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## [about moving camera without rotating the vtkVolume](https://discourse.vtk.org/t/about-moving-camera-without-rotating-the-vtkvolume/1680)

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**Author:** [@Moun](https://discourse.vtk.org/u/Moun)\
**Replies:** 0\
**Last updated:** [September 3, 2019, 10:01am UTC](https://discourse.vtk.org/t/about-moving-camera-without-rotating-the-vtkvolume/1680 "2019-09-03T10:01:53Z")

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Hello, I would like to know if it is possible to move the camera without rotating the actor? I used and it doesn’t work correctly? Also, I would like to range the position of vtkVolume. I fixed the position but when w…

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## [Switched from OpenGL to OpenGL2, rescaling of vtkTextActor stopped working](https://discourse.vtk.org/t/switched-from-opengl-to-opengl2-rescaling-of-vtktextactor-stopped-working/1678)

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**Author:** [@michael23](https://discourse.vtk.org/u/michael23)\
**Replies:** 0\
**Last updated:** [September 2, 2019, 2:54pm UTC](https://discourse.vtk.org/t/switched-from-opengl-to-opengl2-rescaling-of-vtktextactor-stopped-working/1678 "2019-09-02T14:54:42Z")

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Hi, after re-compiling VTK 7.1 from OpenGL to OpenGL2, the rescaling of vtkTextActor stopped working. The size of the text stays the same despite of the viewport/window size. vtkSmartPointer textActor = vtkSmartPointe…

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## [Rasterized output with vtkOpenGLGL2PSExporter](https://discourse.vtk.org/t/rasterized-output-with-vtkopenglgl2psexporter/1642)

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**Author:** [@Sowmiya](https://discourse.vtk.org/u/Sowmiya)\
**Replies:** 2\
**Last updated:** [August 27, 2019, 10:39am UTC](https://discourse.vtk.org/t/rasterized-output-with-vtkopenglgl2psexporter/1642 "2019-08-27T10:39:01Z")

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Dear all, I have recently upgraded to VTK 8.2 and using vtkOpenGLGL2PSExporter to export vector graphics formats such as PDF, EPS and SVG. I am facing the similar problem as discussed here -https://public.kitware.com/p…

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## [vtkGPUVolumeRayCastMapper and Qt (bug?)](https://discourse.vtk.org/t/vtkgpuvolumeraycastmapper-and-qt-bug/1640)

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**Author:** [@Romain](https://discourse.vtk.org/u/Romain)\
**Replies:** 0\
**Last updated:** [August 23, 2019, 10:16am UTC](https://discourse.vtk.org/t/vtkgpuvolumeraycastmapper-and-qt-bug/1640 "2019-08-23T10:16:55Z")

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Hello everyone, I’m working on Windows 10 1903, with Visual Studio 2017 (19.16.27031.1), VTK 8.2 and Qt 5.12.4. My graphic cards is a RTX 2080 Max-Q and the Nvidia driver version is 431.70. I try to use vtkGPUVolumeRa…

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## [vtkEventData.h is missing](https://discourse.vtk.org/t/vtkeventdata-h-is-missing/1634)

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**Author:** [@Alfonso\_ZR](https://discourse.vtk.org/u/Alfonso_ZR)\
**Replies:** 6\
**Last updated:** [August 22, 2019, 1:38pm UTC](https://discourse.vtk.org/t/vtkeventdata-h-is-missing/1634 "2019-08-22T13:38:07Z")

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Hey all, I’m working on a VR program, and when I try to compile it I get the following error: Cannot open include file: ‘vtkEventData.h’; no such file or directory. What could be issue here?

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## [vtk::MakeSmartPointer(T\*), vtk::TakeSmartPointer(T\*)](https://discourse.vtk.org/t/vtk-makesmartpointer-t-vtk-takesmartpointer-t/1287)

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**Author:** [@allison.vacanti](https://discourse.vtk.org/u/allison.vacanti)\
**Replies:** 1\
**Last updated:** [August 22, 2019, 12:47am UTC](https://discourse.vtk.org/t/vtk-makesmartpointer-t-vtk-takesmartpointer-t/1287 "2019-08-22T00:47:57Z")

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One of the remaining tedious parts of using vtkSmartPointer is their creation. For instance, consider creating a new vtkCompositeDataSetIterator from vtkCompositeDataSet::NewIterator() and putting it into a smart pointer…

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## [OpenVR modules with VTK and Python](https://discourse.vtk.org/t/openvr-modules-with-vtk-and-python/1592)

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**Author:** [@Alfonso\_ZR](https://discourse.vtk.org/u/Alfonso_ZR)\
**Replies:** 3\
**Last updated:** [August 17, 2019, 7:02pm UTC](https://discourse.vtk.org/t/openvr-modules-with-vtk-and-python/1592 "2019-08-17T19:02:59Z")

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Good day everyone, I’m having some issues when trying to use the Open VR modules to display something in my python program. My code looks as follows (all of this is done in the Spyder IDE): import vtk def main(): …

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## [Painting individual voxels of a Structured Grid (vtkPolyData) differently.](https://discourse.vtk.org/t/painting-individual-voxels-of-a-structured-grid-vtkpolydata-differently/1574)

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**Author:** [@Seun](https://discourse.vtk.org/u/Seun)\
**Replies:** 1\
**Last updated:** [August 16, 2019, 2:16pm UTC](https://discourse.vtk.org/t/painting-individual-voxels-of-a-structured-grid-vtkpolydata-differently/1574 "2019-08-16T14:16:31Z")

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Hello everyone, I have a situation where I have a vtkPolyData created from a structured grid and would like the voxels of this grid painted individually based on some criteria. That is for instance if a voxel is being e…

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## [Adding a YAML library in VTK](https://discourse.vtk.org/t/adding-a-yaml-library-in-vtk/1578)

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**Author:** [@williamfgc](https://discourse.vtk.org/u/williamfgc)\
**Replies:** 7\
**Last updated:** [August 15, 2019, 2:48pm UTC](https://discourse.vtk.org/t/adding-a-yaml-library-in-vtk/1578 "2019-08-15T14:48:16Z")

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Has the possibility of adding a YAML reader been considered in VTK thirdparty? I’d certainly use it due to the human-readable/editable aspects for formulating flexible visualization configuration inputs as a “recipe” (in…

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## [Lookiing for an x3d viewer](https://discourse.vtk.org/t/lookiing-for-an-x3d-viewer/1561)

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**Author:** [@lorensen](https://discourse.vtk.org/u/lorensen)\
**Replies:** 4\
**Last updated:** [August 14, 2019, 8:37pm UTC](https://discourse.vtk.org/t/lookiing-for-an-x3d-viewer/1561 "2019-08-14T20:37:21Z")

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Folks, I’m fixing a bug in vtkX3DExporter. I can’t find an x3d viewer for MAC OS or Ubuntu. Can someone point me to a viewer that they have used? I’ve tried the x3d viewer plugin for chrome on both systems, but neither …

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## [What is the purpose of this line?](https://discourse.vtk.org/t/what-is-the-purpose-of-this-line/1575)

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**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 5\
**Last updated:** [August 14, 2019, 3:37am UTC](https://discourse.vtk.org/t/what-is-the-purpose-of-this-line/1575 "2019-08-14T03:37:45Z")

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Hello, I am trying to understand vtkVoxelContourToSurface. I am looking at this example, https://www.paraview.org/Wiki/VTK/Examples/Cxx/PolyData/ContoursToSurface What is the purpose of these three lines? pt\[0\] = stat…

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## [vtkViewport's purpose](https://discourse.vtk.org/t/vtkviewports-purpose/1576)

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**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 1\
**Last updated:** [August 13, 2019, 9:24pm UTC](https://discourse.vtk.org/t/vtkviewports-purpose/1576 "2019-08-13T21:24:55Z")

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Hello, what is the purpose of using SetViewport on a vtkRenderer object. What does it do? Thank you.

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## [Import images progressive](https://discourse.vtk.org/t/import-images-progressive/1571)

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**Author:** [@yonvaida](https://discourse.vtk.org/u/yonvaida)\
**Replies:** 0\
**Last updated:** [August 13, 2019, 9:16am UTC](https://discourse.vtk.org/t/import-images-progressive/1571 "2019-08-13T09:16:05Z")

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Hello, I create a software that reads dicom images. Images is received from server and i wanted to load them progressive, when image comes i want to append it to vtkImageData. Can someone help me ? Thanks

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## [collision of two objects](https://discourse.vtk.org/t/collision-of-two-objects/1519)

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**Author:** [@Vahid](https://discourse.vtk.org/u/Vahid)\
**Replies:** 4\
**Last updated:** [August 11, 2019, 9:03pm UTC](https://discourse.vtk.org/t/collision-of-two-objects/1519 "2019-08-11T21:03:26Z")

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Dear All, I imported two objects and I would like to detect the collision of theses objects. After the contact, I want to stop the moving object. Could you please give me some advise on this question ? Thanks

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## [Signed vs. unsigned pixel data in DICOMAppHelper](https://discourse.vtk.org/t/signed-vs-unsigned-pixel-data-in-dicomapphelper/955)

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**Author:** [@jfollweiler](https://discourse.vtk.org/u/jfollweiler)\
**Replies:** 6\
**Last updated:** [August 11, 2019, 8:39pm UTC](https://discourse.vtk.org/t/signed-vs-unsigned-pixel-data-in-dicomapphelper/955 "2019-08-11T20:39:00Z")

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I’m attempting to use the vtkDICOMImageReader class to read in some DICOM files. The pixel data in the DICOM file headers is written as signed shorts and is to be rescaled as floats. In the DICOMAppHelper class with th…

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## [Passing data](https://discourse.vtk.org/t/passing-data/1497)

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**Author:** [@Richard\_Thompson](https://discourse.vtk.org/u/Richard_Thompson)\
**Replies:** 1\
**Last updated:** [August 11, 2019, 4:20am UTC](https://discourse.vtk.org/t/passing-data/1497 "2019-08-11T04:20:57Z")

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Hi, I have a 2 vtkDelaunay3D objects that I want to pass into vtkBooleanOPerationPolyDataFilter. What is the general syntax to accomplish this? Thanks.

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## [vtkMath, vtkPointLocator, vtkDistancePolyDataFilter issue](https://discourse.vtk.org/t/vtkmath-vtkpointlocator-vtkdistancepolydatafilter-issue/1487)

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**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 1\
**Last updated:** [August 11, 2019, 4:09am UTC](https://discourse.vtk.org/t/vtkmath-vtkpointlocator-vtkdistancepolydatafilter-issue/1487 "2019-08-11T04:09:36Z")

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Hello, I recieve these errors when I try to pass a vtkAppendPolyData to a vtkBooleanOperationPolyDataFilter. What do these errors mean? Any help would be appreciated. Thanks! Generic Warning: In /work/standalone-x64-bui…

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## [Segmentation Fault](https://discourse.vtk.org/t/segmentation-fault/1540)

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**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 2\
**Last updated:** [August 11, 2019, 4:02am UTC](https://discourse.vtk.org/t/segmentation-fault/1540 "2019-08-11T04:02:26Z")

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Hello, I get a segmentation fault (core dumped) error whenever I run my program. This happens when I draw non circular contours. Here is the code: def generateVolume(self): if len(self.reslicers\[self.contourOrient…

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## [Redefine Cells of simplex mesh](https://discourse.vtk.org/t/redefine-cells-of-simplex-mesh/1514)

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**Author:** [@srbn.ghosh99](https://discourse.vtk.org/u/srbn.ghosh99)\
**Replies:** 1\
**Last updated:** [August 9, 2019, 11:28am UTC](https://discourse.vtk.org/t/redefine-cells-of-simplex-mesh/1514 "2019-08-09T11:28:22Z")

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Hi, In my simplex mesh, I want to Redefine some cells with different points and save them. Lets say , one cell has 6 points,(1,2,3,4,5,6). I want to eliminate one point from the cell and redefine with (1,2,3,4,5). I am…

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## [vtkSmithPlot vtkChart](https://discourse.vtk.org/t/vtksmithplot-vtkchart/1510)

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**Author:** [@jal](https://discourse.vtk.org/u/jal)\
**Replies:** 0\
**Last updated:** [August 7, 2019, 7:52pm UTC](https://discourse.vtk.org/t/vtksmithplot-vtkchart/1510 "2019-08-07T19:52:06Z")

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Is anyone aware of an implementation of smith chart for vtkPlot/vtkChart? Didn’t want to go off on my own if something exists.

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## [Actor is oddly coloured](https://discourse.vtk.org/t/actor-is-oddly-coloured/1504)

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**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 6\
**Last updated:** [August 7, 2019, 6:43pm UTC](https://discourse.vtk.org/t/actor-is-oddly-coloured/1504 "2019-08-07T18:43:15Z")

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Hi, I declared a vtkActor and set it to one colour. I pass a vtkBooleanOperationPolyDataFilter to the vtkPolyDataMapper and then to the vtkActor. When the vtkActor is rendered, it is not the colour I specified. Instead,…

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## [What does this error mean?](https://discourse.vtk.org/t/what-does-this-error-mean/1509)

<div class="topic-metadata">

**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 1\
**Last updated:** [August 7, 2019, 6:34pm UTC](https://discourse.vtk.org/t/what-does-this-error-mean/1509 "2019-08-07T18:34:21Z")

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HI, I pass a vtkBooleanOperationPolyDataFilter to vtkDelaunay3D. I create a mapper and actor to display it. The actor renders successfully, but I get this error: vtkDelaunay3D (0x3280c00): 1 degenerate triangles encoun…

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## [Removing all inputs](https://discourse.vtk.org/t/removing-all-inputs/1505)

<div class="topic-metadata">

**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 4\
**Last updated:** [August 7, 2019, 3:36pm UTC](https://discourse.vtk.org/t/removing-all-inputs/1505 "2019-08-07T15:36:32Z")

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Hi, I have a vtkBooleanOperationPolyDataFilter, ports 0 and 1 have been set with information.When I call RemoveAllInputs(), port 0 has 0 input connections but port 1 still has an input connection. Can any suggest a solu…

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## [Offset value](https://discourse.vtk.org/t/offset-value/1499)

<div class="topic-metadata">

**Author:** [@Richard\_Thompson](https://discourse.vtk.org/u/Richard_Thompson)\
**Replies:** 0\
**Last updated:** [August 6, 2019, 4:02pm UTC](https://discourse.vtk.org/t/offset-value/1499 "2019-08-06T16:02:42Z")

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Hi, I know vtkDelaunay3D has an offset value. What does this offset value do and does it affect the creation of a convex hull? Thanks.

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## [vtkAppendPolyData](https://discourse.vtk.org/t/vtkappendpolydata/1495)

<div class="topic-metadata">

**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 1\
**Last updated:** [August 6, 2019, 12:51pm UTC](https://discourse.vtk.org/t/vtkappendpolydata/1495 "2019-08-06T12:51:39Z")

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Hi, I am inputting multiple contours into a vtkAppendPolyData object, does it matter what order I add these contours? I want to create a convex hull. Say from left to right, I create a large circle, small circle, and la…

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## [Problems using vtkContourWidget, vtkAppendPolyData, and vtkDelaunay3D](https://discourse.vtk.org/t/problems-using-vtkcontourwidget-vtkappendpolydata-and-vtkdelaunay3d/1480)

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**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 2\
**Last updated:** [August 5, 2019, 12:56pm UTC](https://discourse.vtk.org/t/problems-using-vtkcontourwidget-vtkappendpolydata-and-vtkdelaunay3d/1480 "2019-08-05T12:56:17Z")

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Hello, I have a ImageResliceVTKWidget. I can move across a series of medical images. Say I am moving from left to right between images. To create a contour on a certain image, I use the vtkContourWidget. I click multip…

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## [How do I write animation video files in VP9 (libvpx) codec format using vtk ?](https://discourse.vtk.org/t/how-do-i-write-animation-video-files-in-vp9-libvpx-codec-format-using-vtk/1478)

<div class="topic-metadata">

**Author:** [@aravind90](https://discourse.vtk.org/u/aravind90)\
**Replies:** 3\
**Last updated:** [August 3, 2019, 2:50am UTC](https://discourse.vtk.org/t/how-do-i-write-animation-video-files-in-vp9-libvpx-codec-format-using-vtk/1478 "2019-08-03T02:50:41Z")

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I was successful in saving animation video using classes vtkAVIWriter and vtkFFMPEGWriter with different codec formats, but I would prefer saving videos in VP9 codec format (libvpx) which is completely royalty free. Has …

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## [Smart PolyDataToImageData](https://discourse.vtk.org/t/smart-polydatatoimagedata/1442)

<div class="topic-metadata">

**Author:** [@Patrick\_Laurin](https://discourse.vtk.org/u/Patrick_Laurin)\
**Replies:** 4\
**Last updated:** [July 30, 2019, 2:43pm UTC](https://discourse.vtk.org/t/smart-polydatatoimagedata/1442 "2019-07-30T14:43:26Z")

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Greetings, I have been trying to create a simple PolyDataToImageData, but I’m unable to update the extent of the image properly! In fact, there’s only one thing that makes me unable to do it right. What blocks me is… I…

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