# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=138

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

**Page:** 139

---

## [Using a matrix to color 3-D surface plot](https://discourse.vtk.org/t/using-a-matrix-to-color-3-d-surface-plot/2783)

<div class="topic-metadata">

**Author:** [@ATL\_Flaneur](https://discourse.vtk.org/u/ATL_Flaneur)\
**Replies:** 0\
**Last updated:** [March 9, 2020, 7:27pm UTC](https://discourse.vtk.org/t/using-a-matrix-to-color-3-d-surface-plot/2783 "2020-03-09T19:27:03Z")

</div>

I’m learning VTK and trying to create an interactive 3-D surface plot where I have one 2-D array of scalars that gives the surface elevation and another 2-D array of RGB tuples that gives the color for that part of the s…

---

## [Read a multi-frames DICOM dataset with VTK](https://discourse.vtk.org/t/read-a-multi-frames-dicom-dataset-with-vtk/2777)

<div class="topic-metadata">

**Author:** [@RomyM](https://discourse.vtk.org/u/RomyM)\
**Replies:** 3\
**Last updated:** [March 9, 2020, 2:53pm UTC](https://discourse.vtk.org/t/read-a-multi-frames-dicom-dataset-with-vtk/2777 "2020-03-09T14:53:21Z")

</div>

Hello, With vtkDICOMImageReader() I tried to read a single 3D DICOM file. Unfortunately, this reader does not handle multi-frames DICOM datasets (as documented https://vtk.org/doc/nightly/html/classvtkDICOMImageReader.h…

---

## [Volume rendering Error](https://discourse.vtk.org/t/volume-rendering-error/2690)

<div class="topic-metadata">

**Author:** [@Alex1](https://discourse.vtk.org/u/Alex1)\
**Replies:** 5\
**Last updated:** [March 7, 2020, 10:28am UTC](https://discourse.vtk.org/t/volume-rendering-error/2690 "2020-03-07T10:28:54Z")

</div>

Hi all, I have a Problem with the volume rendering. If I try to use the vtkSmartVolumeMapper i get the following Error: ERROR: vtkSmartVolumeMapper (000002A431C3C1B0): Could not find the requested vtkDataArray! 0, 0, -…

---

## [itk/vtk dimensions and coordinates](https://discourse.vtk.org/t/itk-vtk-dimensions-and-coordinates/2752)

<div class="topic-metadata">

**Author:** [@Tracy\_Nk](https://discourse.vtk.org/u/Tracy_Nk)\
**Replies:** 1\
**Last updated:** [March 6, 2020, 4:57pm UTC](https://discourse.vtk.org/t/itk-vtk-dimensions-and-coordinates/2752 "2020-03-06T16:57:34Z")

</div>

sorry this might be obvious but I’ve used itkvtkglue to view an ITK image on VTK. now that it is a VTK image, will the coordinates and dimensions (pixels length and width) of the image be identical to the ITK image? Th…

---

## [Decimation](https://discourse.vtk.org/t/decimation/2763)

<div class="topic-metadata">

**Author:** [@steersteer](https://discourse.vtk.org/u/steersteer)\
**Replies:** 1\
**Last updated:** [March 6, 2020, 4:59am UTC](https://discourse.vtk.org/t/decimation/2763 "2020-03-06T04:59:30Z")

</div>

Hi, I’m trying to decimate a mesh because I have far too many triangles for the mesh to be useable. So far I have been using: def Decimation(meshname): reader = vtk.vtkSTLReader() reader.SetFileName(meshnam…

---

## [How to tell if a vtkImageData object contains any pixel/voxel data](https://discourse.vtk.org/t/how-to-tell-if-a-vtkimagedata-object-contains-any-pixel-voxel-data/2765)

<div class="topic-metadata">

**Author:** [@MichelleKline](https://discourse.vtk.org/u/MichelleKline)\
**Replies:** 4\
**Last updated:** [March 5, 2020, 11:42pm UTC](https://discourse.vtk.org/t/how-to-tell-if-a-vtkimagedata-object-contains-any-pixel-voxel-data/2765 "2020-03-05T23:42:18Z")

</div>

Hello, What is the most straight-forward way to determine whether a vtkImageData object is “empty”. In other words, whether or not it contains any pixel/voxel data? Thank you, Michelle K.

---

## [How to Isosurface for nc/netcdf Data?](https://discourse.vtk.org/t/how-to-isosurface-for-nc-netcdf-data/2448)

<div class="topic-metadata">

**Author:** [@Alex1](https://discourse.vtk.org/u/Alex1)\
**Replies:** 8\
**Last updated:** [March 5, 2020, 6:52pm UTC](https://discourse.vtk.org/t/how-to-isosurface-for-nc-netcdf-data/2448 "2020-03-05T18:52:52Z")

</div>

Hi all, I am trying to read a .nc file with the vtkNetCDFCFReader and use a vtkContourFilter on it. But as soon as I use the vtkContourFilter I see nothing but a black window. What am I doing wrong? My Code: string in…

---

## [get color array from PolyDataFilter](https://discourse.vtk.org/t/get-color-array-from-polydatafilter/2755)

<div class="topic-metadata">

**Author:** [@ShaneKirkbride](https://discourse.vtk.org/u/ShaneKirkbride)\
**Replies:** 5\
**Last updated:** [March 5, 2020, 2:47pm UTC](https://discourse.vtk.org/t/get-color-array-from-polydatafilter/2755 "2020-03-05T14:47:10Z")

</div>

I’m trying to get an array of colors and their corresponding vertices from a polyData distance filter similiar to this: https://lorensen.github.io/VTKExamples/site/Cxx/PolyData/DistancePolyDataFilter/ I saw this post bu…

---

## [Lines -\> Polylines -\> Polygons](https://discourse.vtk.org/t/lines-polylines-polygons/2759)

<div class="topic-metadata">

**Author:** [@cobo](https://discourse.vtk.org/u/cobo)\
**Replies:** 2\
**Last updated:** [March 5, 2020, 2:11pm UTC](https://discourse.vtk.org/t/lines-polylines-polygons/2759 "2020-03-05T14:11:06Z")

</div>

Maybe this is just a naming question, but what I want to achieve is: Read some linear data that are either already polylines, but maybe also just line segments with common end points that need to be joined first. C…

---

## [vtk SliderWidget in Qt environment](https://discourse.vtk.org/t/vtk-sliderwidget-in-qt-environment/2761)

<div class="topic-metadata">

**Author:** [@lyz](https://discourse.vtk.org/u/lyz)\
**Replies:** 0\
**Last updated:** [March 5, 2020, 12:44pm UTC](https://discourse.vtk.org/t/vtk-sliderwidget-in-qt-environment/2761 "2020-03-05T12:44:22Z")

</div>

I am learning vtk example in Qt environment. I tested this example SliderWidget. I just change the code as below: sliderWidget-\>SetInteractor(this-\>ui-\>qvtkWidget-\>GetInteractor()); However, the SliderWidget doesn’t s…

---

## [cap a vtkClipPolyData does not work propertly. Weird behaviour](https://discourse.vtk.org/t/cap-a-vtkclippolydata-does-not-work-propertly-weird-behaviour/2655)

<div class="topic-metadata">

**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 3\
**Last updated:** [March 5, 2020, 9:50am UTC](https://discourse.vtk.org/t/cap-a-vtkclippolydata-does-not-work-propertly-weird-behaviour/2655 "2020-03-05T09:50:00Z")

</div>

Hi i´d like to cap the parts i clip and i used the code of this example http://www.vtk.org/Wiki/VTK/Examples/Cxx/Meshes/CapClip And i also tried this: for (int i = 0; i \< (int)clipFilters\_.size(); i++) { clipFil…

---

## [MassProperties](https://discourse.vtk.org/t/massproperties/2753)

<div class="topic-metadata">

**Author:** [@ShaneKirkbride](https://discourse.vtk.org/u/ShaneKirkbride)\
**Replies:** 3\
**Last updated:** [March 4, 2020, 8:54pm UTC](https://discourse.vtk.org/t/massproperties/2753 "2020-03-04T20:54:37Z")

</div>

I’m looking at the vtkMassProperties class. How is the mass computed with no knowledge of the pixel or slice spacing of the PolyData?

---

## [vtkWindowToImageFilter giving artifacts](https://discourse.vtk.org/t/vtkwindowtoimagefilter-giving-artifacts/2749)

<div class="topic-metadata">

**Author:** [@aditya-krish](https://discourse.vtk.org/u/aditya-krish)\
**Replies:** 0\
**Last updated:** [March 4, 2020, 5:51am UTC](https://discourse.vtk.org/t/vtkwindowtoimagefilter-giving-artifacts/2749 "2020-03-04T05:51:35Z")

</div>

OS: Ubuntu 18.04 Server I am running an API which processes an input mesh, takes screenshots of it and return some output. Other parts of the screen appearing as ghosts in the screenshot, lower left corner if the disp…

---

## [GUISupportQtOpenGL](https://discourse.vtk.org/t/guisupportqtopengl/2733)

<div class="topic-metadata">

**Author:** [@Jaafar\_Nasrabadi](https://discourse.vtk.org/u/Jaafar_Nasrabadi)\
**Replies:** 3\
**Last updated:** [March 4, 2020, 2:52am UTC](https://discourse.vtk.org/t/guisupportqtopengl/2733 "2020-03-04T02:52:10Z")

</div>

GUISupportQtOpenGL hi. i installed QT5.14.1 (VS 2015 ) with QT offline installer before compiling VTK unstable, but an error occurred. i used vtk-unstable, VS2015(update 1) , cmake 3.16.4 and QT5.14.1( VS 2015) . i used …

---

## [Using Gradient Filter](https://discourse.vtk.org/t/using-gradient-filter/2734)

<div class="topic-metadata">

**Author:** [@ShaneKirkbride](https://discourse.vtk.org/u/ShaneKirkbride)\
**Replies:** 1\
**Last updated:** [March 3, 2020, 4:18am UTC](https://discourse.vtk.org/t/using-gradient-filter/2734 "2020-03-03T04:18:33Z")

</div>

I’m trying to use the GradentFilter example: https://vtk.org/Wiki/VTK/Examples/Cxx/PolyData/GradientFilter I can’t get my mesh to show the color changes the way the one in the picture shows. Is there some example data …

---

## [Getting sample data to test VTK](https://discourse.vtk.org/t/getting-sample-data-to-test-vtk/2729)

<div class="topic-metadata">

**Author:** [@phedayat](https://discourse.vtk.org/u/phedayat)\
**Replies:** 2\
**Last updated:** [March 3, 2020, 1:45am UTC](https://discourse.vtk.org/t/getting-sample-data-to-test-vtk/2729 "2020-03-03T01:45:49Z")

</div>

The main reason I’m using VTK is to use VMTK. However, I don’t have any sample data to test VMTK with. Is there any place where I can find sample .vtp or .voi files?

---

## [How to build vtk](https://discourse.vtk.org/t/how-to-build-vtk/2707)

<div class="topic-metadata">

**Author:** [@awa5114](https://discourse.vtk.org/u/awa5114)\
**Replies:** 7\
**Last updated:** [March 2, 2020, 6:36am UTC](https://discourse.vtk.org/t/how-to-build-vtk/2707 "2020-03-02T06:36:39Z")

</div>

I would like to build vtk for two purposes: Run examples/come up with own examples in C++ Contribute to development in case I find a bug or possible enhancement So far I have gone through the following steps: Forked…

---

## [Does VTK-8.9 Support GLTFExport?](https://discourse.vtk.org/t/does-vtk-8-9-support-gltfexport/2730)

<div class="topic-metadata">

**Author:** [@ShaneKirkbride](https://discourse.vtk.org/u/ShaneKirkbride)\
**Replies:** 2\
**Last updated:** [March 2, 2020, 3:12am UTC](https://discourse.vtk.org/t/does-vtk-8-9-support-gltfexport/2730 "2020-03-02T03:12:19Z")

</div>

Hello I’m trying to export a PolyData object to GLTF format. I got the example here: https://lorensen.github.io/VTKExamples/site/Cxx/IO/GLTFExporter/ I get this error in cmake: Skipping GLTFExporter: Could not find t…

---

## [\[VTK8.9\] vtkCutter not show scalar information](https://discourse.vtk.org/t/vtk8-9-vtkcutter-not-show-scalar-information/2662)

<div class="topic-metadata">

**Author:** [@Yue\_JIN](https://discourse.vtk.org/u/Yue_JIN)\
**Replies:** 3\
**Last updated:** [March 2, 2020, 2:34am UTC](https://discourse.vtk.org/t/vtk8-9-vtkcutter-not-show-scalar-information/2662 "2020-03-02T02:34:49Z")

</div>

Hi everybody, I use vtkCutter to show a section of an unstructuredgrid. My code works well in vtk 8.2. But in vtk 8.9, the actor of vtkCutter becomes white like shown in the picture attached. All these actors are rendere…

---

## [VTK (pyqt): problem about coordinate conversion: display vs world](https://discourse.vtk.org/t/vtk-pyqt-problem-about-coordinate-conversion-display-vs-world/2727)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 1\
**Last updated:** [March 1, 2020, 2:07pm UTC](https://discourse.vtk.org/t/vtk-pyqt-problem-about-coordinate-conversion-display-vs-world/2727 "2020-03-01T14:07:19Z")

</div>

I am using VTK in my project, and I meet a problem about the coordinate convertion: from display coordinate vs world coordiante. First, I show a cone and set the window size to (500, 500). Then, I calcualte the world po…

---

## [Algorithm to Convert a CT Image to an X-ray image](https://discourse.vtk.org/t/algorithm-to-convert-a-ct-image-to-an-x-ray-image/2726)

<div class="topic-metadata">

**Author:** [@Uncheajax](https://discourse.vtk.org/u/Uncheajax)\
**Replies:** 2\
**Last updated:** [March 1, 2020, 2:03pm UTC](https://discourse.vtk.org/t/algorithm-to-convert-a-ct-image-to-an-x-ray-image/2726 "2020-03-01T14:03:59Z")

</div>

Hello, Can someone assist with the steps or algorithm to convert a CT image to an X-ray image.

---

## [Build VTK with TBB](https://discourse.vtk.org/t/build-vtk-with-tbb/2686)

<div class="topic-metadata">

**Author:** [@Max](https://discourse.vtk.org/u/Max)\
**Replies:** 4\
**Last updated:** [February 28, 2020, 4:37pm UTC](https://discourse.vtk.org/t/build-vtk-with-tbb/2686 "2020-02-28T16:37:45Z")

</div>

Hello, can anyone guide me how to build VTK with VTK\_SMP\_IMPLEMENTATION\_TYPE = TBB on Windows? I downloaded TBB from https://github.com/intel/tbb/releases. tbb-2020.1-win.zip Unfortunately, I don’t know which folders…

---

## [How to reduce Moire pattern](https://discourse.vtk.org/t/how-to-reduce-moire-pattern/2716)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 1\
**Last updated:** [February 28, 2020, 11:08am UTC](https://discourse.vtk.org/t/how-to-reduce-moire-pattern/2716 "2020-02-28T11:08:43Z")

</div>

I use vtkTubeFilter to build some tube models in the scene. When the camera is far from the model, I can see the Moire pattern.(picture 1) The model is built correctly. When the camera is near to it, it renders well.(pic…

---

## [Area widget](https://discourse.vtk.org/t/area-widget/2722)

<div class="topic-metadata">

**Author:** [@flaviu2](https://discourse.vtk.org/u/flaviu2)\
**Replies:** 0\
**Last updated:** [February 28, 2020, 11:03am UTC](https://discourse.vtk.org/t/area-widget/2722 "2020-02-28T11:03:49Z")

</div>

Hello all of you. Is there a widget that is similar with distance and angle widget but who can measure area of a surface (rectangle, circle, etc.) ? I thought that border is my widget, but this border widget doesn’t fol…

---

## [load C-Style Images without using vtkImageImport](https://discourse.vtk.org/t/load-c-style-images-without-using-vtkimageimport/2708)

<div class="topic-metadata">

**Author:** [@Yongun\_Lee](https://discourse.vtk.org/u/Yongun_Lee)\
**Replies:** 0\
**Last updated:** [February 27, 2020, 7:59am UTC](https://discourse.vtk.org/t/load-c-style-images-without-using-vtkimageimport/2708 "2020-02-27T07:59:55Z")

</div>

Hello. I have a question. Is there a way to load \* C-Style Images \* without using vtkImageImport? Passing an image buffer using vtkImageImport will refresh the image buffer each time. Is there a way to add image slices …

---

## [vtkGL2PSExporter end line trouble](https://discourse.vtk.org/t/vtkgl2psexporter-end-line-trouble/2711)

<div class="topic-metadata">

**Author:** [@Nicolas\_Lenoir](https://discourse.vtk.org/u/Nicolas_Lenoir)\
**Replies:** 3\
**Last updated:** [February 27, 2020, 4:56pm UTC](https://discourse.vtk.org/t/vtkgl2psexporter-end-line-trouble/2711 "2020-02-27T16:56:34Z")

</div>

Hello, I post this topic because I have a problem when I export a render window conatining vtkCaptionActor in PDF or SVG file by using vtkGL2PSExporter. When this object is export the containing text appear without end l…

---

## [Calling SetSize(X, Y) or Getsize() on a vtkRenderWindow has some undefined behaviors](https://discourse.vtk.org/t/calling-setsize-x-y-or-getsize-on-a-vtkrenderwindow-has-some-undefined-behaviors/2703)

<div class="topic-metadata">

**Author:** [@jjackso2](https://discourse.vtk.org/u/jjackso2)\
**Replies:** 0\
**Last updated:** [February 26, 2020, 10:22pm UTC](https://discourse.vtk.org/t/calling-setsize-x-y-or-getsize-on-a-vtkrenderwindow-has-some-undefined-behaviors/2703 "2020-02-26T22:22:13Z")

</div>

Title. This will result in GetSize() returning values different from X and Y in SetSize(X, Y) called prior. Most often than not, if you try calling SetSize() multiple times with the same values it will end up working …

---

## [Updating vtkPointInterpolator](https://discourse.vtk.org/t/updating-vtkpointinterpolator/2657)

<div class="topic-metadata">

**Author:** [@michael23](https://discourse.vtk.org/u/michael23)\
**Replies:** 1\
**Last updated:** [February 26, 2020, 12:13pm UTC](https://discourse.vtk.org/t/updating-vtkpointinterpolator/2657 "2020-02-26T12:13:46Z")

</div>

Hi, I am using the vtkPointInterpolator to interpolate the scalars of some points onto a surface. vtkSmartPointer\<vtkDoubleArray\> scalars = vtkSmartPointer\<vtkDoubleArray\>::New(); scalars-\>SetName("sca"); scalars-\>SetN…

---

## [Render 3D objects to constant size in 2D.](https://discourse.vtk.org/t/render-3d-objects-to-constant-size-in-2d/2660)

<div class="topic-metadata">

**Author:** [@aries24](https://discourse.vtk.org/u/aries24)\
**Replies:** 4\
**Last updated:** [February 26, 2020, 12:00pm UTC](https://discourse.vtk.org/t/render-3d-objects-to-constant-size-in-2d/2660 "2020-02-26T12:00:22Z")

</div>

We are creating an application using VTK to visualize a network of nodes and connecting edges in 3D. In a previous version of this application, visualization was solely done in 2D. Since these networks may have large va…

---

## [How to check if a line intersects with (triangular) cell?](https://discourse.vtk.org/t/how-to-check-if-a-line-intersects-with-triangular-cell/2672)

<div class="topic-metadata">

**Author:** [@normanius](https://discourse.vtk.org/u/normanius)\
**Replies:** 6\
**Last updated:** [February 26, 2020, 10:39am UTC](https://discourse.vtk.org/t/how-to-check-if-a-line-intersects-with-triangular-cell/2672 "2020-02-26T10:39:52Z")

</div>

Dear all I would like to test if a line intersects with a triangle. If the line is not lying in the same plane as triangle this is done easily with vtkTriangle.IntersectWithLine(). But how can I detect a collision if t…

[Previous page](https://discourse.vtk.org/c/support/6.md?page=137)

[Next page](https://discourse.vtk.org/c/support/6.md?page=139)