# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=26

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

**Page:** 27

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## [how to use filter on dicom image when using vtkjs](https://discourse.vtk.org/t/how-to-use-filter-on-dicom-image-when-using-vtkjs/13781)

<div class="topic-metadata">

**Author:** [@dbtruong](https://discourse.vtk.org/u/dbtruong)\
**Replies:** 0\
**Last updated:** [April 24, 2024, 8:33am UTC](https://discourse.vtk.org/t/how-to-use-filter-on-dicom-image-when-using-vtkjs/13781 "2024-04-24T08:33:57Z")

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Hello all, I have used the filter on the dicom image like the code below import { useRef, useEffect } from 'react'; import './viewport.css'; // Load the rendering pieces we want to use (for both WebGL and WebGPU) impo…

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## [Coming up with ideas to visually represent multiple properties of a point in space](https://discourse.vtk.org/t/coming-up-with-ideas-to-visually-represent-multiple-properties-of-a-point-in-space/13778)

<div class="topic-metadata">

**Author:** [@george-xiao](https://discourse.vtk.org/u/george-xiao)\
**Replies:** 0\
**Last updated:** [April 23, 2024, 6:40pm UTC](https://discourse.vtk.org/t/coming-up-with-ideas-to-visually-represent-multiple-properties-of-a-point-in-space/13778 "2024-04-23T18:40:30Z")

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Hi! I’m new to using vtk so if someone could point me in the right direction about my problem that’d be great! Currently I have 4 views which each want to render a large number of points. Three of these views are planar…

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## [vtkImageResliceMapper & vtkCellPicker](https://discourse.vtk.org/t/vtkimagereslicemapper-vtkcellpicker/13775)

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**Author:** [@Raumik\_Rana1](https://discourse.vtk.org/u/Raumik_Rana1)\
**Replies:** 0\
**Last updated:** [April 23, 2024, 11:44am UTC](https://discourse.vtk.org/t/vtkimagereslicemapper-vtkcellpicker/13775 "2024-04-23T11:44:15Z")

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this.resliceMapper = vtkImageResliceMapper.newInstance(); this.reslicePlane = vtkPlane.newInstance(); this.reslicePlane.setNormal(ViewType\[2\]); this.reslicePlane.setOrigin(\[ this.vtkImageData.getCen…

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## [JavaVTK Example Android Crash（vtk8.2）](https://discourse.vtk.org/t/javavtk-example-android-crash-vtk8-2/13764)

<div class="topic-metadata">

**Author:** [@jiajiadelequ](https://discourse.vtk.org/u/jiajiadelequ)\
**Replies:** 0\
**Last updated:** [April 22, 2024, 7:14am UTC](https://discourse.vtk.org/t/javavtk-example-android-crash-vtk8-2/13764 "2024-04-22T07:14:32Z")

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I have successfully compiled the static library for arm64 version of vtk8.2 using ndk r21e, and when I integrated it into the JavaVTK Android Example, I was able to successfully build the APK. However, during runtime, it…

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## [How do I construct a surface bordered by two perimeters?](https://discourse.vtk.org/t/how-do-i-construct-a-surface-bordered-by-two-perimeters/13758)

<div class="topic-metadata">

**Author:** [@djames](https://discourse.vtk.org/u/djames)\
**Replies:** 0\
**Last updated:** [April 20, 2024, 1:32pm UTC](https://discourse.vtk.org/t/how-do-i-construct-a-surface-bordered-by-two-perimeters/13758 "2024-04-20T13:32:23Z")

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Below is a script that constructs a square perimeter with a triangle perimeter inside I would like to construct a surface between the triangle and the square. Is there a way to do this without e.g. manually constructing…

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## [JavaVTK Android Black Screen](https://discourse.vtk.org/t/javavtk-android-black-screen/13725)

<div class="topic-metadata">

**Author:** [@jiajiadelequ](https://discourse.vtk.org/u/jiajiadelequ)\
**Replies:** 3\
**Last updated:** [April 19, 2024, 5:52am UTC](https://discourse.vtk.org/t/javavtk-android-black-screen/13725 "2024-04-19T05:52:00Z")

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I run this example project in Android Studio, and at the beginning, the scene did not render and it was a black screen until foo -\>Interactor -\>HandleMotionEvent (action, eventPointer, numPtrs, xPtr, yPtr, idPtr, metaSta…

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## [ColorLevel/Window in vtkImageCPRMapper](https://discourse.vtk.org/t/colorlevel-window-in-vtkimagecprmapper/13741)

<div class="topic-metadata">

**Author:** [@steveryuan](https://discourse.vtk.org/u/steveryuan)\
**Replies:** 1\
**Last updated:** [April 18, 2024, 4:40pm UTC](https://discourse.vtk.org/t/colorlevel-window-in-vtkimagecprmapper/13741 "2024-04-18T16:40:45Z")

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Hi everyone, I was using vtkImageCPRMapper for CPR reconstruction (vtk.js 29.8.0). However, when I tried to set the values of ProjectionSlabNumberOfSamples and ProjectionSlabThickness for projection, the color window o…

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## [polydata surface border as polyline](https://discourse.vtk.org/t/polydata-surface-border-as-polyline/5451)

<div class="topic-metadata">

**Author:** [@bistek](https://discourse.vtk.org/u/bistek)\
**Replies:** 8\
**Last updated:** [April 18, 2024, 3:02pm UTC](https://discourse.vtk.org/t/polydata-surface-border-as-polyline/5451 "2024-04-18T15:02:31Z")

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Hello, I’d like to obtain the border of a polydata triangulated surface as a polyline. With the following code (where tri\_surf is the triangulated surface polydata), I get all the edges on the border, but they are not o…

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## [a problem of 3d data](https://discourse.vtk.org/t/a-problem-of-3d-data/13740)

<div class="topic-metadata">

**Author:** [@czgchd](https://discourse.vtk.org/u/czgchd)\
**Replies:** 4\
**Last updated:** [April 18, 2024, 12:46pm UTC](https://discourse.vtk.org/t/a-problem-of-3d-data/13740 "2024-04-18T12:46:15Z")

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dear everyone :slight\_smile: i have a txt file, data is following :slight\_smile: x y z color 0 2 3 0.5 1 2 4 0.2 3 2 5 0.1 i want to build the 3d heatmap with VTK but i do not know to perform it…

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## [DICOM upside down using vtkDICOMImageReader](https://discourse.vtk.org/t/dicom-upside-down-using-vtkdicomimagereader/13735)

<div class="topic-metadata">

**Author:** [@lo\_andrew](https://discourse.vtk.org/u/lo_andrew)\
**Replies:** 0\
**Last updated:** [April 18, 2024, 8:28am UTC](https://discourse.vtk.org/t/dicom-upside-down-using-vtkdicomimagereader/13735 "2024-04-18T08:28:28Z")

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Hi, I was using vtkGDCMImageReader from vtkgdcm (build from GDCM with USE\_VTK on) to import DICOM data and toggling the FileLowerLeftOn() to solve the upside down issue. Recently when I changed from vtkGDCMImageReader …

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## [how do i get the coordinates of atoms from the output of the 'vtkPDBReader' object?](https://discourse.vtk.org/t/how-do-i-get-the-coordinates-of-atoms-from-the-output-of-the-vtkpdbreader-object/13686)

<div class="topic-metadata">

**Author:** [@erya123](https://discourse.vtk.org/u/erya123)\
**Replies:** 1\
**Last updated:** [April 17, 2024, 10:29am UTC](https://discourse.vtk.org/t/how-do-i-get-the-coordinates-of-atoms-from-the-output-of-the-vtkpdbreader-object/13686 "2024-04-17T10:29:02Z")

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the vtkPDBReader object can read the PDB file. how could it get the information of molecule of protein and amino acid , the coordinates of the atom, etc? Thanks for your reply!

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## [DropFilesEvent not working?](https://discourse.vtk.org/t/dropfilesevent-not-working/13724)

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**Author:** [@scotsman60](https://discourse.vtk.org/u/scotsman60)\
**Replies:** 1\
**Last updated:** [April 17, 2024, 7:01am UTC](https://discourse.vtk.org/t/dropfilesevent-not-working/13724 "2024-04-17T07:01:22Z")

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I read in the V9.0 release note that vtkRenderWindow now supports a DropFilesEvent that should allow me to get the names of the files that are dropped. However, when I add an Observer to my render window and then drop f…

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## [PLYreader on web but not showing data](https://discourse.vtk.org/t/plyreader-on-web-but-not-showing-data/13692)

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**Author:** [@\_BarryWang](https://discourse.vtk.org/u/_BarryWang)\
**Replies:** 5\
**Last updated:** [April 16, 2024, 2:22pm UTC](https://discourse.vtk.org/t/plyreader-on-web-but-not-showing-data/13692 "2024-04-16T14:22:45Z")

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Hey everyone,right now I’m working on a project that can show ply file on web pages. I discovered that some file can be shown but somehow the file I downsampled cannot be shown. Here is the code below: const container…

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## [Need a noninvasive vtkActor::GetProperty()](https://discourse.vtk.org/t/need-a-noninvasive-vtkactor-getproperty/13700)

<div class="topic-metadata">

**Author:** [@whereismymoney](https://discourse.vtk.org/u/whereismymoney)\
**Replies:** 6\
**Last updated:** [April 16, 2024, 11:24am UTC](https://discourse.vtk.org/t/need-a-noninvasive-vtkactor-getproperty/13700 "2024-04-16T11:24:12Z")

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Unfortunately vtkProperty\* vtkActor::GetProperty( ) will automatically create a vtkProperty object if one has not yet been created. I would like something like GetProperty() but it should return a Null pointer if the …

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## [How to translate the only one axis of the crosshair ?](https://discourse.vtk.org/t/how-to-translate-the-only-one-axis-of-the-crosshair/13716)

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**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 0\
**Last updated:** [April 16, 2024, 1:10am UTC](https://discourse.vtk.org/t/how-to-translate-the-only-one-axis-of-the-crosshair/13716 "2024-04-16T01:10:32Z")

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I want to achieve the following effect， but i do not have lean JS langague. Can someone give me any proposes?

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## [Unexpected background due to opacity in volume rendering](https://discourse.vtk.org/t/unexpected-background-due-to-opacity-in-volume-rendering/13714)

<div class="topic-metadata">

**Author:** [@huaweiping](https://discourse.vtk.org/u/huaweiping)\
**Replies:** 0\
**Last updated:** [April 15, 2024, 5:53pm UTC](https://discourse.vtk.org/t/unexpected-background-due-to-opacity-in-volume-rendering/13714 "2024-04-15T17:53:52Z")

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Hi all, I’m using the vtkVolume to render my oceanography dataset. The valid scalar value is originally in a NetCDF file accompanied by NaN, so I read it in C++ and convert it into a vtkImageData. It seems the NaN is set…

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## [The result of matrix transformation is abnormal（Black shadow）.](https://discourse.vtk.org/t/the-result-of-matrix-transformation-is-abnormal-black-shadow/13712)

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**Author:** [@wshunvx](https://discourse.vtk.org/u/wshunvx)\
**Replies:** 0\
**Last updated:** [April 15, 2024, 9:53am UTC](https://discourse.vtk.org/t/the-result-of-matrix-transformation-is-abnormal-black-shadow/13712 "2024-04-15T09:53:41Z")

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if \_\_name\_\_ == '\_\_main\_\_': mgs = \[\] poly = vtkCylinderSource() poly.SetResolution(20) poly.SetRadius(12) poly.SetHeight(2) poly.CappingOn() poly.Update() mgs.append(poly.GetOutput()) …

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## [strange result when show polygon using vtkPolyData](https://discourse.vtk.org/t/strange-result-when-show-polygon-using-vtkpolydata/13710)

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**Author:** [@baker-Xie](https://discourse.vtk.org/u/baker-Xie)\
**Replies:** 0\
**Last updated:** [April 15, 2024, 3:04am UTC](https://discourse.vtk.org/t/strange-result-when-show-polygon-using-vtkpolydata/13710 "2024-04-15T03:04:03Z")

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I want to show a simple polygon using vtkPolyData / vtkPolygon , but seems the result is strange Points points-\>InsertNextPoint(0, -1, 2); points-\>InsertNextPoint(1, -0.5, 2); points-\>InsertNextPoint(2, -3,…

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## [Crash when the render window is called](https://discourse.vtk.org/t/crash-when-the-render-window-is-called/13709)

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**Author:** [@Xiao\_Xu](https://discourse.vtk.org/u/Xiao_Xu)\
**Replies:** 0\
**Last updated:** [April 14, 2024, 1:59am UTC](https://discourse.vtk.org/t/crash-when-the-render-window-is-called/13709 "2024-04-14T01:59:03Z")

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Hi, I am writing a python program to calculate the curvature of a 3D vtk model and show the result with a colormap. However, every time when I start the render window and the render window interactor, a crash happens. I …

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## [3D reconstruction of an object from slices in cylindrical coordinate system](https://discourse.vtk.org/t/3d-reconstruction-of-an-object-from-slices-in-cylindrical-coordinate-system/13684)

<div class="topic-metadata">

**Author:** [@Viktor\_Sokolov](https://discourse.vtk.org/u/Viktor_Sokolov)\
**Replies:** 3\
**Last updated:** [April 12, 2024, 7:27pm UTC](https://discourse.vtk.org/t/3d-reconstruction-of-an-object-from-slices-in-cylindrical-coordinate-system/13684 "2024-04-12T19:27:54Z")

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Hello everyone! I want to reconstruct a pyramid from its slices stored in .jpeg images in order to test 3D reconstruction algorithms and familiarize myself with the VTK library. I’ve read the main chapters of the VTK boo…

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## [How to use a customized font to vtkVectorText](https://discourse.vtk.org/t/how-to-use-a-customized-font-to-vtkvectortext/13695)

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**Author:** [@bassfaye](https://discourse.vtk.org/u/bassfaye)\
**Replies:** 1\
**Last updated:** [April 12, 2024, 2:55pm UTC](https://discourse.vtk.org/t/how-to-use-a-customized-font-to-vtkvectortext/13695 "2024-04-12T14:55:46Z")

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Hello, I want to set some text to vtkVectorText but with Arrial Black font. Can someone tell me how to do this? I try with vtkTextActor but I can’t use the text as a polydata because I want to use customized text in a b…

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## [Mesh an implicit function (python lambda)](https://discourse.vtk.org/t/mesh-an-implicit-function-python-lambda/3838)

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**Author:** [@T4mmi](https://discourse.vtk.org/u/T4mmi)\
**Replies:** 1\
**Last updated:** [April 12, 2024, 6:07am UTC](https://discourse.vtk.org/t/mesh-an-implicit-function-python-lambda/3838 "2024-04-12T06:07:29Z")

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Hi all, I’m looking for a VTK way to mesh any custom implicit function (as a python lambda with a signature of type List\[float\[3\]\] -\> float) From what I read vtkSampleFunction \> vtkMarchingCubes seems the way to go but…

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## [Face edges ordering](https://discourse.vtk.org/t/face-edges-ordering/13699)

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**Author:** [@PeterFranzSeequent](https://discourse.vtk.org/u/PeterFranzSeequent)\
**Replies:** 0\
**Last updated:** [April 11, 2024, 9:00pm UTC](https://discourse.vtk.org/t/face-edges-ordering/13699 "2024-04-11T21:00:46Z")

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Hi, I need to iterate over the edges of a face of a 3D cell, doing something like vtkCell \* face = myCell-\>GetFace(0) for (int i=0; i \< face-\>GetNumberOfEdges(); i++) { vtkCell \* edge = face-\>GetEdge(i); } Can I be …

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## [How to perform cinematic rendering of dental CBCT dataset.](https://discourse.vtk.org/t/how-to-perform-cinematic-rendering-of-dental-cbct-dataset/13659)

<div class="topic-metadata">

**Author:** [@Marty](https://discourse.vtk.org/u/Marty)\
**Replies:** 3\
**Last updated:** [April 11, 2024, 3:57pm UTC](https://discourse.vtk.org/t/how-to-perform-cinematic-rendering-of-dental-cbct-dataset/13659 "2024-04-11T15:57:00Z")

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I want to create a cinematic rendering of a dental CBCT scan created with Carestream Dental’s CS9600 unit. The images are native DICOM. I have tried VolView with and without the FilesManager. Nothing works. Please let me…

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## [How does vtkIntegrateAttribute integrate over point data?](https://discourse.vtk.org/t/how-does-vtkintegrateattribute-integrate-over-point-data/13696)

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**Author:** [@Robert\_Sawko](https://discourse.vtk.org/u/Robert_Sawko)\
**Replies:** 0\
**Last updated:** [April 11, 2024, 2:45pm UTC](https://discourse.vtk.org/t/how-does-vtkintegrateattribute-integrate-over-point-data/13696 "2024-04-11T14:45:36Z")

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I’ve been using the integrate variables filter in ParaView which maps to vtkIntegrateAttribute. My dataset has both point and cell data and the filter helpfully gives integrals for both though only the cell data has volu…

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## [vtkWarpVector seems to be stripping off my arrays?](https://discourse.vtk.org/t/vtkwarpvector-seems-to-be-stripping-off-my-arrays/13685)

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**Author:** [@rexthor](https://discourse.vtk.org/u/rexthor)\
**Replies:** 3\
**Last updated:** [April 10, 2024, 2:23pm UTC](https://discourse.vtk.org/t/vtkwarpvector-seems-to-be-stripping-off-my-arrays/13685 "2024-04-10T14:23:53Z")

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I have a thermomechanical FEM dataset that includes “deformation” vectors. The data comes to me in a giant collection NumPy arrays. The data may have cell connectivity, wherever it is created - but I never see it, and ha…

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## [why don't the website of example tell the name of input file?](https://discourse.vtk.org/t/why-dont-the-website-of-example-tell-the-name-of-input-file/13284)

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**Author:** [@erya123](https://discourse.vtk.org/u/erya123)\
**Replies:** 3\
**Last updated:** [April 10, 2024, 11:51am UTC](https://discourse.vtk.org/t/why-dont-the-website-of-example-tell-the-name-of-input-file/13284 "2024-04-10T11:51:31Z")

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https://examples.vtk.org/site/Cxx/PolyData/ColorDisconnectedRegionsDemo/ the website contains an example,but it doesn’t describe the name of input file. how do i check the name of input file?

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## [Getting visible part of actor, if any](https://discourse.vtk.org/t/getting-visible-part-of-actor-if-any/13679)

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**Author:** [@rdbrn](https://discourse.vtk.org/u/rdbrn)\
**Replies:** 1\
**Last updated:** [April 9, 2024, 4:27pm UTC](https://discourse.vtk.org/t/getting-visible-part-of-actor-if-any/13679 "2024-04-09T16:27:52Z")

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I would like to add annotations to my rendered view. For this I need to know if an actor is visible (ie: not occluded by other actors) and, if it is partially occluded, which part is visible. All my actors are created …

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## [Accessing data values along a view ray during ray casting](https://discourse.vtk.org/t/accessing-data-values-along-a-view-ray-during-ray-casting/13677)

<div class="topic-metadata">

**Author:** [@sdutta](https://discourse.vtk.org/u/sdutta)\
**Replies:** 0\
**Last updated:** [April 9, 2024, 5:28am UTC](https://discourse.vtk.org/t/accessing-data-values-along-a-view-ray-during-ray-casting/13677 "2024-04-09T05:28:17Z")

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Is there a way that VTK can provide me the data value and the coordinate of the sample points along a view ray during ray casting algorithm? My goal is to collect all samples from different viewpoints using VTK ray cast…

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## [Crop volume outside the boundary of an NIFTI image](https://discourse.vtk.org/t/crop-volume-outside-the-boundary-of-an-nifti-image/13670)

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**Author:** [@dzzhang](https://discourse.vtk.org/u/dzzhang)\
**Replies:** 2\
**Last updated:** [April 8, 2024, 5:29pm UTC](https://discourse.vtk.org/t/crop-volume-outside-the-boundary-of-an-nifti-image/13670 "2024-04-08T17:29:04Z")

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I am trying to crop a VOI of an NIFTI image. In some cases, part of the VOI is outside the image and I would like to keep the VOI size unchanged. And set the pixel value of the part outside the image to 0. 3D slicer can …

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