# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=127

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

**Page:** 128

---

## [Catch error on vtkDICOMWriter](https://discourse.vtk.org/t/catch-error-on-vtkdicomwriter/3664)

<div class="topic-metadata">

**Author:** [@flaviu2](https://discourse.vtk.org/u/flaviu2)\
**Replies:** 11\
**Last updated:** [July 1, 2020, 12:36pm UTC](https://discourse.vtk.org/t/catch-error-on-vtkdicomwriter/3664 "2020-07-01T12:36:54Z")

</div>

I have the following code: vtkDICOMMRGenerator\* pGenerator = vtkDICOMMRGenerator::New(); vtkDICOMWriter\* pWriter = vtkDICOMWriter::New(); pWriter-\>SetInputConnection(m\_pImageExtractor-\>GetOutputPort()); pWriter-\>SetGene…

---

## [Subdivision filter](https://discourse.vtk.org/t/subdivision-filter/3642)

<div class="topic-metadata">

**Author:** [@pourarab](https://discourse.vtk.org/u/pourarab)\
**Replies:** 6\
**Last updated:** [July 1, 2020, 9:44am UTC](https://discourse.vtk.org/t/subdivision-filter/3642 "2020-07-01T09:44:02Z")

</div>

Hello dear users / developers, As input i have a polygon like following image : I used vtkLinearSubdivisionFilter to subdivide these triangles so i got this result : I want to have equilateral triangles as result,…

---

## [Error building examples](https://discourse.vtk.org/t/error-building-examples/3583)

<div class="topic-metadata">

**Author:** [@Tomasso](https://discourse.vtk.org/u/Tomasso)\
**Replies:** 14\
**Last updated:** [June 30, 2020, 10:55pm UTC](https://discourse.vtk.org/t/error-building-examples/3583 "2020-06-30T22:55:16Z")

</div>

I’m new to VTK. I built and installed VTK-8.2 on ubuntu 18.04.4. I want to build all the examples, and am following the directions at this link. . When I type ‘make’ I get: make Scanning dependencies of target AnimateA…

---

## [vtkXMLMultiBlockDataWriter does not appear to export field data](https://discourse.vtk.org/t/vtkxmlmultiblockdatawriter-does-not-appear-to-export-field-data/3669)

<div class="topic-metadata">

**Author:** [@scotsman60](https://discourse.vtk.org/u/scotsman60)\
**Replies:** 1\
**Last updated:** [June 29, 2020, 8:48pm UTC](https://discourse.vtk.org/t/vtkxmlmultiblockdatawriter-does-not-appear-to-export-field-data/3669 "2020-06-29T20:48:31Z")

</div>

Hello!!! I’m using vtkMultBlockDatasets and I want to attach metadata to some of the Blocks, persist that metadata to disk and then use it when I read the file later. So far, I’ve been successful using the provided NAM…

---

## [Convert VTK to binary large object (BLOB)](https://discourse.vtk.org/t/convert-vtk-to-binary-large-object-blob/3597)

<div class="topic-metadata">

**Author:** [@rishyak](https://discourse.vtk.org/u/rishyak)\
**Replies:** 2\
**Last updated:** [June 29, 2020, 3:29pm UTC](https://discourse.vtk.org/t/convert-vtk-to-binary-large-object-blob/3597 "2020-06-29T15:29:16Z")

</div>

Hi everyone, I’m using PyVista to make .vtk and .vtk files of my NumPy array. I need to store these on an SQLAlchemy database to work with a web app. Unfortunately, the server can only store in binary large object (BLO…

---

## [Questions about Paraview](https://discourse.vtk.org/t/questions-about-paraview/3666)

<div class="topic-metadata">

**Author:** [@rw20](https://discourse.vtk.org/u/rw20)\
**Replies:** 1\
**Last updated:** [June 29, 2020, 2:59pm UTC](https://discourse.vtk.org/t/questions-about-paraview/3666 "2020-06-29T14:59:10Z")

</div>

Hello, I am new to using Paraview and just have a couple of questions about it. I wanted to know if the software supports any method of reducing the number of samples of an uploaded point cloud. I also was wondering if …

---

## [Visualization of a mhd color file](https://discourse.vtk.org/t/visualization-of-a-mhd-color-file/3663)

<div class="topic-metadata">

**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 3\
**Last updated:** [June 29, 2020, 8:14am UTC](https://discourse.vtk.org/t/visualization-of-a-mhd-color-file/3663 "2020-06-29T08:14:10Z")

</div>

Dear All, Could you please provide a VTK script to read and visualize in color a .mhd file of MET\_UCHAR\_ARRAY of 3 dimensions (RGB)? Thanks, Luis Gonçalves

---

## [GetPolys() vertex indices weird order](https://discourse.vtk.org/t/getpolys-vertex-indices-weird-order/3662)

<div class="topic-metadata">

**Author:** [@panicbuttonvfx](https://discourse.vtk.org/u/panicbuttonvfx)\
**Replies:** 5\
**Last updated:** [June 29, 2020, 2:30am UTC](https://discourse.vtk.org/t/getpolys-vertex-indices-weird-order/3662 "2020-06-29T02:30:03Z")

</div>

Hi, When I retrieve the polygon data from a mesh (the cube below as an example), I get something like this: \>\>\> vtk\_to\_numpy(mesh.GetPolys().GetData()) \>\>\> \[ 4 0 1 3 2 4 4 6 7 5 4 8 10 11 9 4 12 13 15 14 …

---

## [How to convert vtkImageData to vtkPolyData](https://discourse.vtk.org/t/how-to-convert-vtkimagedata-to-vtkpolydata/3635)

<div class="topic-metadata">

**Author:** [@beginner](https://discourse.vtk.org/u/beginner)\
**Replies:** 11\
**Last updated:** [June 28, 2020, 6:38pm UTC](https://discourse.vtk.org/t/how-to-convert-vtkimagedata-to-vtkpolydata/3635 "2020-06-28T18:38:15Z")

</div>

I’m trying to use the GetPoints method in vtkPolyData to generate a 3D mesh from an image. Currently, I parsed the image as a vtkImageData. How do I convert vtkImageData to vtkPolyData? Or are there any alternative ways …

---

## [Rendering cutting planes created with OpenFOAM](https://discourse.vtk.org/t/rendering-cutting-planes-created-with-openfoam/3580)

<div class="topic-metadata">

**Author:** [@obihoernchen\_x](https://discourse.vtk.org/u/obihoernchen_x)\
**Replies:** 2\
**Last updated:** [June 27, 2020, 2:38pm UTC](https://discourse.vtk.org/t/rendering-cutting-planes-created-with-openfoam/3580 "2020-06-27T14:38:23Z")

</div>

Hello everyone, I am working on a Python script to process an OpenFOAM simulation automatically. I’d like to do in Python with vtk, because the rest of my post processing is also in Python. My goal is to render all the …

---

## [Cutting/slicing for XML Unstructured Grid Data](https://discourse.vtk.org/t/cutting-slicing-for-xml-unstructured-grid-data/3653)

<div class="topic-metadata">

**Author:** [@sugeng](https://discourse.vtk.org/u/sugeng)\
**Replies:** 0\
**Last updated:** [June 26, 2020, 7:06am UTC](https://discourse.vtk.org/t/cutting-slicing-for-xml-unstructured-grid-data/3653 "2020-06-26T07:06:16Z")

</div>

Dear All, I have a main code for cutting/slicing process using vtkCutter below. The code in general is working well but the only problem is the scalar values obtained from the input file are not correctly captured by v…

---

## [Constants/enums in Activiz](https://discourse.vtk.org/t/constants-enums-in-activiz/3637)

<div class="topic-metadata">

**Author:** [@MMoussa](https://discourse.vtk.org/u/MMoussa)\
**Replies:** 3\
**Last updated:** [June 26, 2020, 4:25am UTC](https://discourse.vtk.org/t/constants-enums-in-activiz/3637 "2020-06-26T04:25:58Z")

</div>

How do I get access to constants like VTK\_HEXAHEDRON from within Activiz (C# wrapper)? Thank you.

---

## [reading ascii stl files with QVTK](https://discourse.vtk.org/t/reading-ascii-stl-files-with-qvtk/3622)

<div class="topic-metadata">

**Author:** [@mat](https://discourse.vtk.org/u/mat)\
**Replies:** 7\
**Last updated:** [June 26, 2020, 3:40am UTC](https://discourse.vtk.org/t/reading-ascii-stl-files-with-qvtk/3622 "2020-06-26T03:40:58Z")

</div>

Hello, I am trying to make a script work on ubuntu 18.04, with python 3.6, vtk 9.0.0 and Pyside2. vtkSTLReader can read both binary and ascii files when used with a vtkRenderWindowInteractor . But, when I use a QVTKRen…

---

## [VTK 8.9 - Many (Multi) View Camera Capture Methods?](https://discourse.vtk.org/t/vtk-8-9-many-multi-view-camera-capture-methods/3617)

<div class="topic-metadata">

**Author:** [@staumrel](https://discourse.vtk.org/u/staumrel)\
**Replies:** 3\
**Last updated:** [June 26, 2020, 3:28am UTC](https://discourse.vtk.org/t/vtk-8-9-many-multi-view-camera-capture-methods/3617 "2020-06-26T03:28:50Z")

</div>

I’m currently working on integrating stereoscopic displays with some software developed using VTK (built heavily off of ParaView and in Qt, as well). I’m pretty new to graphics programming, so I may be missing some obvio…

---

## [Generate Rotational Maximum Intensity Projections](https://discourse.vtk.org/t/generate-rotational-maximum-intensity-projections/3650)

<div class="topic-metadata">

**Author:** [@divya\_chou](https://discourse.vtk.org/u/divya_chou)\
**Replies:** 1\
**Last updated:** [June 25, 2020, 4:11pm UTC](https://discourse.vtk.org/t/generate-rotational-maximum-intensity-projections/3650 "2020-06-25T16:11:21Z")

</div>

I have been redirected here from ITK discourse. I am very new to using ITK, and am working using SITK on Python. I have 3D PET scans. From each 3D matrix, I have generated 2 MIPs at 90 degrees - Sagittal and Coronal. Th…

---

## [vtkSelectEnclosedPoints detects wrong Points inside which should be on the border](https://discourse.vtk.org/t/vtkselectenclosedpoints-detects-wrong-points-inside-which-should-be-on-the-border/3641)

<div class="topic-metadata">

**Author:** [@ElCamino](https://discourse.vtk.org/u/ElCamino)\
**Replies:** 3\
**Last updated:** [June 25, 2020, 4:09pm UTC](https://discourse.vtk.org/t/vtkselectenclosedpoints-detects-wrong-points-inside-which-should-be-on-the-border/3641 "2020-06-25T16:09:56Z")

</div>

Hi everybody, I´m trying to do a simplified collision detection between two polydata (.stl) objects in Python. I want to know if one object is inside the other object. I followed the “CellsInsideObject” Example: “https:…

---

## [Rotate all three cursors synchronously for vtkResliceImageViewer](https://discourse.vtk.org/t/rotate-all-three-cursors-synchronously-for-vtkresliceimageviewer/3648)

<div class="topic-metadata">

**Author:** [@NewProggie](https://discourse.vtk.org/u/NewProggie)\
**Replies:** 0\
**Last updated:** [June 25, 2020, 2:05pm UTC](https://discourse.vtk.org/t/rotate-all-three-cursors-synchronously-for-vtkresliceimageviewer/3648 "2020-06-25T14:05:30Z")

</div>

I am using three different vtkResliceImageViewer based viewers for axial, coronal and sagittal views for medical images and like to synchronously rotate all three cursors (or rather planes). I found vtkImageOrthoPlanes w…

---

## [build stand alone visitbridge with vtk](https://discourse.vtk.org/t/build-stand-alone-visitbridge-with-vtk/3619)

<div class="topic-metadata">

**Author:** [@kayarre](https://discourse.vtk.org/u/kayarre)\
**Replies:** 4\
**Last updated:** [June 24, 2020, 9:51pm UTC](https://discourse.vtk.org/t/build-stand-alone-visitbridge-with-vtk/3619 "2020-06-24T21:51:39Z")

</div>

I would like to build standalone visitbridge with vtk and vtk bindings?. Is that possible? I feel like I want more but not the whole paraview “kitchen sink” more how much would the interface have to change? generally …

---

## [vtkRenderWindow segfault when accessing Interactor variable](https://discourse.vtk.org/t/vtkrenderwindow-segfault-when-accessing-interactor-variable/3576)

<div class="topic-metadata">

**Author:** [@Pietersielie](https://discourse.vtk.org/u/Pietersielie)\
**Replies:** 1\
**Last updated:** [June 24, 2020, 11:57am UTC](https://discourse.vtk.org/t/vtkrenderwindow-segfault-when-accessing-interactor-variable/3576 "2020-06-24T11:57:48Z")

</div>

Hi everyone, Not sure if this is the correct venue, so please forgive my inexperience. I have an application that uses VTK with QT, on Ubuntu 20.04 LTS. It compiles just fine and most of the application works. However,…

---

## [Write multiple timesteps for Multiblockdataset](https://discourse.vtk.org/t/write-multiple-timesteps-for-multiblockdataset/3611)

<div class="topic-metadata">

**Author:** [@Sprychipper](https://discourse.vtk.org/u/Sprychipper)\
**Replies:** 1\
**Last updated:** [June 23, 2020, 7:44pm UTC](https://discourse.vtk.org/t/write-multiple-timesteps-for-multiblockdataset/3611 "2020-06-23T19:44:28Z")

</div>

Hello , how do i create a multiblock dataset with multiple timesteps/steps. I have looked at the documentation and API without any success. I used the following example as basis \[CompositeDataSet\] https://lorensen.gith…

---

## [Fail to use vtk on mac 10.15](https://discourse.vtk.org/t/fail-to-use-vtk-on-mac-10-15/3195)

<div class="topic-metadata">

**Author:** [@sjtu-xx](https://discourse.vtk.org/u/sjtu-xx)\
**Replies:** 2\
**Last updated:** [June 23, 2020, 9:51am UTC](https://discourse.vtk.org/t/fail-to-use-vtk-on-mac-10-15/3195 "2020-06-23T09:51:50Z")

</div>

I’m trying to use vtk on my macbook(13inch, catalina 10.15.4). But when I try to use QVTKOpenGLNativeWidget, it complained that “2020-05-02 14:22:05.581 ( 0.410s) \[ 62F0D5\]vtkOpenGLRenderWindow.c:582 ERR| …

---

## [Volume rendering significantly slower in C++ compared to Python](https://discourse.vtk.org/t/volume-rendering-significantly-slower-in-c-compared-to-python/3503)

<div class="topic-metadata">

**Author:** [@harold.absalom](https://discourse.vtk.org/u/harold.absalom)\
**Replies:** 4\
**Last updated:** [June 23, 2020, 8:09am UTC](https://discourse.vtk.org/t/volume-rendering-significantly-slower-in-c-compared-to-python/3503 "2020-06-23T08:09:56Z")

</div>

I am trying to render a volume, read from an NRRD file. This is using VTK 8.2. The file is about 700MB, and simply loading it and displaying it in Python seems to happen quite quickly, with the first frame rendering unde…

---

## [VTK9 - Black viewport when using rubber band style](https://discourse.vtk.org/t/vtk9-black-viewport-when-using-rubber-band-style/3515)

<div class="topic-metadata">

**Author:** [@panicbuttonvfx](https://discourse.vtk.org/u/panicbuttonvfx)\
**Replies:** 9\
**Last updated:** [June 23, 2020, 2:55am UTC](https://discourse.vtk.org/t/vtk9-black-viewport-when-using-rubber-band-style/3515 "2020-06-23T02:55:04Z")

</div>

Hi, When using any sort of rubber band style (e.g. vtkInteractorStyleRubberBandZoom, vtkInteractorStyleRubberBandPick, etc…), the viewport turns black while dragging (the marquee selection line is visible), and goes bac…

---

## [Volume rendering issue](https://discourse.vtk.org/t/volume-rendering-issue/3435)

<div class="topic-metadata">

**Author:** [@Sandra](https://discourse.vtk.org/u/Sandra)\
**Replies:** 6\
**Last updated:** [June 22, 2020, 11:17am UTC](https://discourse.vtk.org/t/volume-rendering-issue/3435 "2020-06-22T11:17:00Z")

</div>

Mapping data for volume rendering gives strange results when the max value is set to something lower than the highest value in the vtk-file. The volume that is supposed to be shown is there, but there is also a “ghost-…

---

## [OpenGL delay load issue](https://discourse.vtk.org/t/opengl-delay-load-issue/3610)

<div class="topic-metadata">

**Author:** [@FS\_K](https://discourse.vtk.org/u/FS_K)\
**Replies:** 0\
**Last updated:** [June 22, 2020, 9:11am UTC](https://discourse.vtk.org/t/opengl-delay-load-issue/3610 "2020-06-22T09:11:30Z")

</div>

I’m using VTK 8.2 and I want to use OpenGL delay load to be able to switch in software rendering when necessary. I followed the steps described here: https://vtk.org/doc/nightly/html/vtkTestOpenGLVersion\_8h.html#a863adb…

---

## [Getting size of vtkTextActor in python](https://discourse.vtk.org/t/getting-size-of-vtktextactor-in-python/3578)

<div class="topic-metadata">

**Author:** [@Nibba2018](https://discourse.vtk.org/u/Nibba2018)\
**Replies:** 3\
**Last updated:** [June 21, 2020, 2:29pm UTC](https://discourse.vtk.org/t/getting-size-of-vtktextactor-in-python/3578 "2020-06-21T14:29:47Z")

</div>

Hello everyone, I would like to know the width and height of a vtkTextActor in python. According to the documentation, the GetSize and GetBoundingBox should provide me the height and width and those said methods require v…

---

## [Why single click works, but double click does not?](https://discourse.vtk.org/t/why-single-click-works-but-double-click-does-not/3599)

<div class="topic-metadata">

**Author:** [@rodrigomologni](https://discourse.vtk.org/u/rodrigomologni)\
**Replies:** 2\
**Last updated:** [June 20, 2020, 1:44am UTC](https://discourse.vtk.org/t/why-single-click-works-but-double-click-does-not/3599 "2020-06-20T01:44:51Z")

</div>

Would anyone know to tell me why single click works, but double click does not, please? import vtk def left\_button(obj, e): print(e) source = vtk.vtkSphereSource() mapper = vtk.vtkPolyDataMapper() mapper.SetInput…

---

## [How to set a transparent Button on QVTKWidget based on QT](https://discourse.vtk.org/t/how-to-set-a-transparent-button-on-qvtkwidget-based-on-qt/3586)

<div class="topic-metadata">

**Author:** [@lllaa](https://discourse.vtk.org/u/lllaa)\
**Replies:** 2\
**Last updated:** [June 19, 2020, 7:47am UTC](https://discourse.vtk.org/t/how-to-set-a-transparent-button-on-qvtkwidget-based-on-qt/3586 "2020-06-19T07:47:06Z")

</div>

Just like this pic shows.Although I set the button rgba(x,x,x,40) which is transparent in my code,the button named “Adjust” is not transparent in the blue QVTKWidget .

---

## [Render Background white and transparent](https://discourse.vtk.org/t/render-background-white-and-transparent/2480)

<div class="topic-metadata">

**Author:** [@Ana\_Margarida\_Mota](https://discourse.vtk.org/u/Ana_Margarida_Mota)\
**Replies:** 10\
**Last updated:** [June 19, 2020, 7:18am UTC](https://discourse.vtk.org/t/render-background-white-and-transparent/2480 "2020-06-19T07:18:03Z")

</div>

Dear colleagues, I need to set the render background to white (until then everything is OK with renderer-\>SetBackground(1.0,1.0,1.0)) and TRANSPARENT (otherwise my image doesn’t appear, it is everything white). That’s …

---

## [How can I color the point by vtkPolyData](https://discourse.vtk.org/t/how-can-i-color-the-point-by-vtkpolydata/3574)

<div class="topic-metadata">

**Author:** [@11110](https://discourse.vtk.org/u/11110)\
**Replies:** 1\
**Last updated:** [June 17, 2020, 7:38pm UTC](https://discourse.vtk.org/t/how-can-i-color-the-point-by-vtkpolydata/3574 "2020-06-17T19:38:24Z")

</div>

Hi, my ply file like this ply format ascii 1.0 element vertex 1722844 property float x property float y property float z property uchar red property uchar green property uchar blue element face 0 property lis…

[Previous page](https://discourse.vtk.org/c/support/6.md?page=126)

[Next page](https://discourse.vtk.org/c/support/6.md?page=128)