# Latest

**URL:** https://discourse.vtk.org/latest.md?page=99

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

**Page:** 100

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## [Get single contour from vtkPolyData](https://discourse.vtk.org/t/get-single-contour-from-vtkpolydata/10536)

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**Author:** [@SebastianWilke](https://discourse.vtk.org/u/SebastianWilke)\
**Replies:** 10\
**Last updated:** [February 5, 2023, 1:30pm UTC](https://discourse.vtk.org/t/get-single-contour-from-vtkpolydata/10536 "2023-02-05T13:30:02Z")

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Hi! I have vtkPolyData containing contour data for multiple slices created using vtkPolyData::SetPoints() and vtkPolyData::SetLines(): Is there a convenient way to extract a single of these contour lines (possibly w…

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## [SetOrigin do not work for actor with trackball interactor style](https://discourse.vtk.org/t/setorigin-do-not-work-for-actor-with-trackball-interactor-style/10476)

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**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 7\
**Last updated:** [February 3, 2023, 9:21pm UTC](https://discourse.vtk.org/t/setorigin-do-not-work-for-actor-with-trackball-interactor-style/10476 "2023-02-03T21:21:51Z")

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I am using vtkInteractorStyleTrackballActor with Spin method. For Spin method, the actor would rotate along the actor center. How can I change the rotation center? Does actor.SetOrigin work? The explanation of SetOrigi…

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## [changing the PointSource model](https://discourse.vtk.org/t/changing-the-pointsource-model/10586)

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**Author:** [@sandy](https://discourse.vtk.org/u/sandy)\
**Replies:** 10\
**Last updated:** [February 3, 2023, 8:44pm UTC](https://discourse.vtk.org/t/changing-the-pointsource-model/10586 "2023-02-03T20:44:26Z")

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Hi, this is my first day with vtk-js-master. The random spherical point cloud demo works fine for me with 10000 points, it looks like a snowball. As a first step I have modified the index.js in the vtk-js-master/Sources/…

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## [How to use vtkResliceCursorWidget ??](https://discourse.vtk.org/t/how-to-use-vtkreslicecursorwidget/10604)

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**Author:** [@kookoo9999](https://discourse.vtk.org/u/kookoo9999)\
**Replies:** 1\
**Last updated:** [February 3, 2023, 3:38pm UTC](https://discourse.vtk.org/t/how-to-use-vtkreslicecursorwidget/10604 "2023-02-03T15:38:13Z")

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Hello I’m tryna use vtkReslicecursor to update the Reslice Image when I control the widget on 3D View or MPR like this and I’m looking for example of using vtkResliceCursor but I could’nt find… Is there some example u…

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## [Combined raster/vector plots using Tikz for scientific publications](https://discourse.vtk.org/t/combined-raster-vector-plots-using-tikz-for-scientific-publications/10607)

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**Author:** [@fraseyboo](https://discourse.vtk.org/u/fraseyboo)\
**Replies:** 0\
**Last updated:** [February 3, 2023, 11:31am UTC](https://discourse.vtk.org/t/combined-raster-vector-plots-using-tikz-for-scientific-publications/10607 "2023-02-03T11:31:22Z")

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VTK is primarily a rasterization-focused visualiser but I’ve been making some progress on an exporter for making scientific figures that can be used in publications. Typically scientific journals expect vector graphics (…

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## [vtkCubeAxesActor SetBold bu](https://discourse.vtk.org/t/vtkcubeaxesactor-setbold-bu/10601)

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**Author:** [@BlueKnight7](https://discourse.vtk.org/u/BlueKnight7)\
**Replies:** 0\
**Last updated:** [February 2, 2023, 8:28pm UTC](https://discourse.vtk.org/t/vtkcubeaxesactor-setbold-bu/10601 "2023-02-02T20:28:46Z")

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Working with the online example: https://kitware.github.io/vtk-examples/site/Cxx/Utilities/DetermineActorType/ When I use the following, I don’t see that the font is drawn bold. cubeAxesActor-\>GetLabelTextProperty(0)-\>…

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## [Change color of vtkCubeAxesActor](https://discourse.vtk.org/t/change-color-of-vtkcubeaxesactor/10584)

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**Author:** [@BlueKnight7](https://discourse.vtk.org/u/BlueKnight7)\
**Replies:** 2\
**Last updated:** [February 2, 2023, 7:56pm UTC](https://discourse.vtk.org/t/change-color-of-vtkcubeaxesactor/10584 "2023-02-02T19:56:20Z")

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Referring to example: https://kitware.github.io/vtk-examples/site/Cxx/Utilities/DetermineActorType/ Notice that with this example the axes and axes labels are in white. After looking at the on-line documentation and …

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## [question about mesh color mapping](https://discourse.vtk.org/t/question-about-mesh-color-mapping/10578)

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**Author:** [@xianger.qi](https://discourse.vtk.org/u/xianger.qi)\
**Replies:** 1\
**Last updated:** [February 2, 2023, 6:52pm UTC](https://discourse.vtk.org/t/question-about-mesh-color-mapping/10578 "2023-02-02T18:52:42Z")

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I divide the volume data into two parts, firstly, one is color with green and the other is color with white then to extract isosurface. when the tools is moving and touch with the white part, the white region will be col…

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## [Stream trace on a shell?](https://discourse.vtk.org/t/stream-trace-on-a-shell/10587)

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**Author:** [@rexthor](https://discourse.vtk.org/u/rexthor)\
**Replies:** 0\
**Last updated:** [February 1, 2023, 8:33pm UTC](https://discourse.vtk.org/t/stream-trace-on-a-shell/10587 "2023-02-01T20:33:27Z")

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Hi - I have a surface defined as an unstructured grid composed of vtkTriangles. It is roughly a dish shape, and has a vector array (flow velocity) at each cell center. Is there a way to trace a streamline on this surface…

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## [How to convert polyData to imageData](https://discourse.vtk.org/t/how-to-convert-polydata-to-imagedata/10575)

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**Author:** [@jongzzi\_GanJang](https://discourse.vtk.org/u/jongzzi_GanJang)\
**Replies:** 1\
**Last updated:** [February 1, 2023, 3:58pm UTC](https://discourse.vtk.org/t/how-to-convert-polydata-to-imagedata/10575 "2023-02-01T15:58:51Z")

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Thank you for watching this post. The above example is a stencil image of origin, spacing, dimensions, and contour data drawn from reference. Even if you put in any content data, there is a hole in the top. I don’t…

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## [How to separate skin from bone using gradient opacity function?](https://discourse.vtk.org/t/how-to-separate-skin-from-bone-using-gradient-opacity-function/10574)

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**Author:** [@zbz](https://discourse.vtk.org/u/zbz)\
**Replies:** 1\
**Last updated:** [February 1, 2023, 2:31pm UTC](https://discourse.vtk.org/t/how-to-separate-skin-from-bone-using-gradient-opacity-function/10574 "2023-02-01T14:31:13Z")

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How to separate skin from bone using gradient opacity function?

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## [How do I add a widget to change the gradient opacity function in real time to change the 3D reconstructed image?](https://discourse.vtk.org/t/how-do-i-add-a-widget-to-change-the-gradient-opacity-function-in-real-time-to-change-the-3d-reconstructed-image/10576)

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**Author:** [@zbz](https://discourse.vtk.org/u/zbz)\
**Replies:** 1\
**Last updated:** [February 1, 2023, 2:27pm UTC](https://discourse.vtk.org/t/how-do-i-add-a-widget-to-change-the-gradient-opacity-function-in-real-time-to-change-the-3d-reconstructed-image/10576 "2023-02-01T14:27:51Z")

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## [I add a plane to the renderer but it does not display](https://discourse.vtk.org/t/i-add-a-plane-to-the-renderer-but-it-does-not-display/10579)

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**Author:** [@Javi-r](https://discourse.vtk.org/u/Javi-r)\
**Replies:** 1\
**Last updated:** [February 1, 2023, 1:47pm UTC](https://discourse.vtk.org/t/i-add-a-plane-to-the-renderer-but-it-does-not-display/10579 "2023-02-01T13:47:50Z")

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I add the plan in this way but nothing is displayed. const planeSource = vtkPlaneSource.newInstance({xResolution: 100, yResolution: 100 }); const planeMapper = vtkMapper.newInstance(); const planeActor = vtkActor.newIns…

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## [offering simple example of using vtk.js from angular](https://discourse.vtk.org/t/offering-simple-example-of-using-vtk-js-from-angular/10562)

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**Author:** [@JohnSkinner](https://discourse.vtk.org/u/JohnSkinner)\
**Replies:** 2\
**Last updated:** [February 1, 2023, 2:18am UTC](https://discourse.vtk.org/t/offering-simple-example-of-using-vtk-js-from-angular/10562 "2023-02-01T02:18:09Z")

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I see there are instructions for using vtk.js for react and vue, here and am offering an example with instructions for using vtk.js from Angular. I’m also looking for suggestions to improve the way I’ve done the integr…

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## [vtkPolyDataReader2](https://discourse.vtk.org/t/vtkpolydatareader2/10563)

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**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 2\
**Last updated:** [January 31, 2023, 6:59pm UTC](https://discourse.vtk.org/t/vtkpolydatareader2/10563 "2023-01-31T18:59:57Z")

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I am making a PolyDataFileSeriesReader similar to what is found in ParaView for ImageData, but supporting streaming (to save memory) in the situation where all files are processed as a whole. Further, it supports tempora…

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## [Is anything blocking the removal of Python2 support from VTK?](https://discourse.vtk.org/t/is-anything-blocking-the-removal-of-python2-support-from-vtk/10468)

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**Author:** [@ben.boeckel](https://discourse.vtk.org/u/ben.boeckel)\
**Replies:** 7\
**Last updated:** [January 31, 2023, 3:00pm UTC](https://discourse.vtk.org/t/is-anything-blocking-the-removal-of-python2-support-from-vtk/10468 "2023-01-31T15:00:47Z")

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Is anyone aware of blockers to removing Python2 support from VTK? It has been deprecated since 9.1.0, untested for…a long time, and has been EOL itself for 3 years now. Things removing Python2 support gets us: around …

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## [Changing dimensions and number of scalar components for vtkImageData](https://discourse.vtk.org/t/changing-dimensions-and-number-of-scalar-components-for-vtkimagedata/10550)

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**Author:** [@kit](https://discourse.vtk.org/u/kit)\
**Replies:** 6\
**Last updated:** [January 31, 2023, 1:43pm UTC](https://discourse.vtk.org/t/changing-dimensions-and-number-of-scalar-components-for-vtkimagedata/10550 "2023-01-31T13:43:08Z")

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Hi All, I have vtkImageData object with dimensions (nx,ny,nz) with 1 scalar component, but for various reasons, I’d like to be able to work on it as a vtkImageData with dimensions (ny,nz,1) and nx scalar components with…

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## [vtkContourGrid example](https://discourse.vtk.org/t/vtkcontourgrid-example/10455)

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**Author:** [@BlueKnight7](https://discourse.vtk.org/u/BlueKnight7)\
**Replies:** 8\
**Last updated:** [January 31, 2023, 3:17am UTC](https://discourse.vtk.org/t/vtkcontourgrid-example/10455 "2023-01-31T03:17:11Z")

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I am looking for a vtkContourGrid example since I couldn’t find one with the online vtkContourGrid class documentation. I have scalar cell data assigned to my vtkUnstructuredGrid object. Based on the vtkContourFilter e…

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## [Does VTK has a class which can write NRRD file?](https://discourse.vtk.org/t/does-vtk-has-a-class-which-can-write-nrrd-file/10556)

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**Author:** [@Sterben\_01](https://discourse.vtk.org/u/Sterben_01)\
**Replies:** 4\
**Last updated:** [January 31, 2023, 1:45am UTC](https://discourse.vtk.org/t/does-vtk-has-a-class-which-can-write-nrrd-file/10556 "2023-01-31T01:45:26Z")

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Hi! I’m trying to find a class which is like vtkNrrdWriter. But I didn’t find it. Is there some way I can get the same result? I want to write the file to NRRD format.

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## [SetFontSize on vtkCubeAxesActor bug?](https://discourse.vtk.org/t/setfontsize-on-vtkcubeaxesactor-bug/520)

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**Author:** [@tomtomatron](https://discourse.vtk.org/u/tomtomatron)\
**Replies:** 3\
**Last updated:** [January 31, 2023, 12:16am UTC](https://discourse.vtk.org/t/setfontsize-on-vtkcubeaxesactor-bug/520 "2023-01-31T00:16:40Z")

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How can I set the font size of the TitleTextProperty of a vtkCubeAxesActor? The code below does not result in the specified font size of the vtkCubeAxesActor when plotting. import vtk ca = vtk.vtkCubeAxesActor() ca.G…

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## [Universal Scene Description (USD) scene importer/exporter?](https://discourse.vtk.org/t/universal-scene-description-usd-scene-importer-exporter/6452)

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**Author:** [@lassoan](https://discourse.vtk.org/u/lassoan)\
**Replies:** 4\
**Last updated:** [January 30, 2023, 11:00pm UTC](https://discourse.vtk.org/t/universal-scene-description-usd-scene-importer-exporter/6452 "2023-01-30T23:00:11Z")

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Are there any plans for adding importer/exporter for Universal Scene Description (USD) format? It looks like a very nice and widely supported file format for data exchange, which is much friendlier than low-level glTF fi…

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## [VTK9 create different stencil than vtk8](https://discourse.vtk.org/t/vtk9-create-different-stencil-than-vtk8/10560)

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**Author:** [@lucas\_rouhier](https://discourse.vtk.org/u/lucas_rouhier)\
**Replies:** 6\
**Last updated:** [January 30, 2023, 5:01pm UTC](https://discourse.vtk.org/t/vtk9-create-different-stencil-than-vtk8/10560 "2023-01-30T17:01:45Z")

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Hello, I am having some weird results while trying to update my VTK. I am converting a VTK polydata to Image data with the following code: vtkSmartPointer VtkPolyDataToImage(vtkPolyData\* poly, vtkImageData\* templateIm…

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## [How to set camera orientation to see a sphere that is ON polydata actor.](https://discourse.vtk.org/t/how-to-set-camera-orientation-to-see-a-sphere-that-is-on-polydata-actor/10544)

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**Author:** [@dexter](https://discourse.vtk.org/u/dexter)\
**Replies:** 3\
**Last updated:** [January 30, 2023, 2:39pm UTC](https://discourse.vtk.org/t/how-to-set-camera-orientation-to-see-a-sphere-that-is-on-polydata-actor/10544 "2023-01-30T14:39:20Z")

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Hi, In my render window I have 2 actors, a little red sphere and a brain surface, the sphere takes different positions on the brain surface in each render. I need to change the orientation of the camera depending on th…

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## [vtkLabeledDataMapper =\> all texts disappearing issue](https://discourse.vtk.org/t/vtklabeleddatamapper-all-texts-disappearing-issue/10402)

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**Author:** [@Olivier](https://discourse.vtk.org/u/Olivier)\
**Replies:** 7\
**Last updated:** [January 30, 2023, 8:46am UTC](https://discourse.vtk.org/t/vtklabeleddatamapper-all-texts-disappearing-issue/10402 "2023-01-30T08:46:19Z")

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Hi friends, I’m using a vtkLabeledDataMapper to display multiple strings at 3D positions. Mapper is filled in with a vtkPolyData containing points (for positions) and data arrays (one for strings and one for types = te…

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## [VTK ImageBasedLighting does not work in WebAssembly](https://discourse.vtk.org/t/vtk-imagebasedlighting-does-not-work-in-webassembly/10553)

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**Author:** [@ZLong-Li](https://discourse.vtk.org/u/ZLong-Li)\
**Replies:** 0\
**Last updated:** [January 29, 2023, 3:47am UTC](https://discourse.vtk.org/t/vtk-imagebasedlighting-does-not-work-in-webassembly/10553 "2023-01-29T03:47:05Z")

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Hello， I used ImageBased Lighting in vtk9.1, which works well on the desktop side, but does not work in WebAssembly. thanks！

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## [Build failure due to VTK\_EXTRA\_COMPILER\_WARNINGS=ON](https://discourse.vtk.org/t/build-failure-due-to-vtk-extra-compiler-warnings-on/10533)

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**Author:** [@waebbl](https://discourse.vtk.org/u/waebbl)\
**Replies:** 9\
**Last updated:** [January 28, 2023, 8:12am UTC](https://discourse.vtk.org/t/build-failure-due-to-vtk-extra-compiler-warnings-on/10533 "2023-01-28T08:12:22Z")

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Hello, I received a bug report\[1\] where a debug build failed in vtkioss/Ioss\_Compare.C. On Gentoo Linux we still use CMAKE\_BUILD\_TYPE=RelWithDebInfo for debug builds and let the user choose most of the parameters needed…

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## [MIP - Max Intensity Projection with Bones](https://discourse.vtk.org/t/mip-max-intensity-projection-with-bones/10220)

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**Author:** [@tigerhu7](https://discourse.vtk.org/u/tigerhu7)\
**Replies:** 5\
**Last updated:** [January 28, 2023, 2:19am UTC](https://discourse.vtk.org/t/mip-max-intensity-projection-with-bones/10220 "2023-01-28T02:19:21Z")

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Dear All, I am working on a project on visualizating MIP of carotid-cerebral arteries of two types, namely with bone shown and without. The results are like these. Here, I succeeded in vislualization top image ( r…

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## [Creating a new CMakeLists.txt for building and using vtkOSPRay\* with c++](https://discourse.vtk.org/t/creating-a-new-cmakelists-txt-for-building-and-using-vtkospray-with-c/10526)

<div class="topic-metadata">

**Author:** [@Spacetracker](https://discourse.vtk.org/u/Spacetracker)\
**Replies:** 13\
**Last updated:** [January 27, 2023, 4:18pm UTC](https://discourse.vtk.org/t/creating-a-new-cmakelists-txt-for-building-and-using-vtkospray-with-c/10526 "2023-01-27T16:18:06Z")

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I successfully built OSPRay and VTK 9/8 with it and the Rendering vtkExamples and Tests/Testing are working. I am having difficulty updating my own CMakeLists.txt file for c++ to “make” the includes and libraries known …

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## [vtkAssembly transform propagation](https://discourse.vtk.org/t/vtkassembly-transform-propagation/10547)

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**Author:** [@TartaPise](https://discourse.vtk.org/u/TartaPise)\
**Replies:** 0\
**Last updated:** [January 26, 2023, 1:27pm UTC](https://discourse.vtk.org/t/vtkassembly-transform-propagation/10547 "2023-01-26T13:27:49Z")

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Hello everyone, I noticed that using vtkAssembly-\>SetUserTransform() does not update the corresponding vtkActors transform thus their center and orientation. Do you think this makes sense? Wouldn’t it be better to propag…

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## [Why would I need to sweep polygonal data when working with contours?](https://discourse.vtk.org/t/why-would-i-need-to-sweep-polygonal-data-when-working-with-contours/10541)

<div class="topic-metadata">

**Author:** [@SebastianWilke](https://discourse.vtk.org/u/SebastianWilke)\
**Replies:** 1\
**Last updated:** [January 26, 2023, 6:57am UTC](https://discourse.vtk.org/t/why-would-i-need-to-sweep-polygonal-data-when-working-with-contours/10541 "2023-01-26T06:57:57Z")

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Hi! A comment in this PolyDataContourToImageData example claims: // sweep polygonal data (this is the important thing with contours!) I am working with contours read from a DICOM file and would like to avoid errors …

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