# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=40

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

**Page:** 41

---

## [Setting a vtkImageBlend base layer to Transparent](https://discourse.vtk.org/t/setting-a-vtkimageblend-base-layer-to-transparent/12329)

<div class="topic-metadata">

**Author:** [@Seun](https://discourse.vtk.org/u/Seun)\
**Replies:** 8\
**Last updated:** [September 22, 2023, 12:42pm UTC](https://discourse.vtk.org/t/setting-a-vtkimageblend-base-layer-to-transparent/12329 "2023-09-22T12:42:25Z")

</div>

Hello everyone, Is it possible for the vtkimageBlend initial layerthe one SetInputConnection(…) to have a transparency of 0.0. From what I understand I've not been able to set its alpha to 0.0 and have it render properl…

---

## [how to get the files used in the tutorial, for example XX.mhd?](https://discourse.vtk.org/t/how-to-get-the-files-used-in-the-tutorial-for-example-xx-mhd/12341)

<div class="topic-metadata">

**Author:** [@888yyh](https://discourse.vtk.org/u/888yyh)\
**Replies:** 1\
**Last updated:** [September 22, 2023, 12:33pm UTC](https://discourse.vtk.org/t/how-to-get-the-files-used-in-the-tutorial-for-example-xx-mhd/12341 "2023-09-22T12:33:07Z")

</div>

I want to implement the experiments, while i do not know how to download the file used in the example. for instance “parser.add\_argument(‘filename’, help=‘Input volume e.g. Frog/frogtissue.mhd.’)” where is the frogtis…

---

## [Creation of triangular mesh](https://discourse.vtk.org/t/creation-of-triangular-mesh/12320)

<div class="topic-metadata">

**Author:** [@Mattia\_C](https://discourse.vtk.org/u/Mattia_C)\
**Replies:** 1\
**Last updated:** [September 22, 2023, 7:07am UTC](https://discourse.vtk.org/t/creation-of-triangular-mesh/12320 "2023-09-22T07:07:39Z")

</div>

Hello everyone, I’m new to VTK and making my way trough it. I’m working on a ray-casting project, where I’m supposed to run an algorithm that finds the point of intersection of rays with terrain. My code works like th…

---

## [how to run the example through cmake?](https://discourse.vtk.org/t/how-to-run-the-example-through-cmake/12342)

<div class="topic-metadata">

**Author:** [@888yyh](https://discourse.vtk.org/u/888yyh)\
**Replies:** 0\
**Last updated:** [September 22, 2023, 2:51am UTC](https://discourse.vtk.org/t/how-to-run-the-example-through-cmake/12342 "2023-09-22T02:51:20Z")

</div>

i am a newbie to vtk and cmake. https://examples.vtk.org/site/Cxx/Visualization/FrogSlice/#download-and-build-frogslice i downloaded and extracted the FrogSlice.tar,however i did not find the directory build.i can not…

---

## [Which mapper class is used with input vtkImageData](https://discourse.vtk.org/t/which-mapper-class-is-used-with-input-vtkimagedata/12315)

<div class="topic-metadata">

**Author:** [@dbtruong](https://discourse.vtk.org/u/dbtruong)\
**Replies:** 2\
**Last updated:** [September 22, 2023, 1:44am UTC](https://discourse.vtk.org/t/which-mapper-class-is-used-with-input-vtkimagedata/12315 "2023-09-22T01:44:31Z")

</div>

Hello all I have a dicom image set and want to display it in 3D using vtk python. is there any mapper class that should be used or not?

---

## [Interactor style as a first person shooter](https://discourse.vtk.org/t/interactor-style-as-a-first-person-shooter/12338)

<div class="topic-metadata">

**Author:** [@hamid\_badi](https://discourse.vtk.org/u/hamid_badi)\
**Replies:** 0\
**Last updated:** [September 21, 2023, 6:35pm UTC](https://discourse.vtk.org/t/interactor-style-as-a-first-person-shooter/12338 "2023-09-21T18:35:12Z")

</div>

Hello, I tried to play with all the interactor styles to get as closed as possible as first-person shooter camera behavior, but without success. Has anyone ever managed to get the camera to work like a 3D game? Best r…

---

## [walk on the model](https://discourse.vtk.org/t/walk-on-the-model/2104)

<div class="topic-metadata">

**Author:** [@xuexl](https://discourse.vtk.org/u/xuexl)\
**Replies:** 3\
**Last updated:** [September 21, 2023, 5:56pm UTC](https://discourse.vtk.org/t/walk-on-the-model/2104 "2023-09-21T17:56:03Z")

</div>

how to set the camera, then moving the camera like a man walk on the model.

---

## [Extract Patch Data from vtkOpenFOAMReader](https://discourse.vtk.org/t/extract-patch-data-from-vtkopenfoamreader/12335)

<div class="topic-metadata">

**Author:** [@poval](https://discourse.vtk.org/u/poval)\
**Replies:** 0\
**Last updated:** [September 21, 2023, 2:54pm UTC](https://discourse.vtk.org/t/extract-patch-data-from-vtkopenfoamreader/12335 "2023-09-21T14:54:16Z")

</div>

Hi everyone, I’m a vtk newcomer and I have started writing a c++ program to convert an openfoam mesh to another mesh format. So far, I managed to extract the internal mesh adapting the example. I can also list the name…

---

## [Selecting Surface Cells](https://discourse.vtk.org/t/selecting-surface-cells/12256)

<div class="topic-metadata">

**Author:** [@Mordrago](https://discourse.vtk.org/u/Mordrago)\
**Replies:** 2\
**Last updated:** [September 21, 2023, 1:50pm UTC](https://discourse.vtk.org/t/selecting-surface-cells/12256 "2023-09-21T13:50:48Z")

</div>

Hello! While implementing the code using VTK, I encountered a problem with selecting a cell on the grid surface. I am only concerned with marking the visible cells from the user’s perspective(camera position). Selectin…

---

## [RubberBandPick - Rectangle Position](https://discourse.vtk.org/t/rubberbandpick-rectangle-position/12333)

<div class="topic-metadata">

**Author:** [@Mordrago](https://discourse.vtk.org/u/Mordrago)\
**Replies:** 0\
**Last updated:** [September 21, 2023, 1:40pm UTC](https://discourse.vtk.org/t/rubberbandpick-rectangle-position/12333 "2023-09-21T13:40:06Z")

</div>

Hello! It is possible to get Rectangle\[ GetStartPosition(), GetEndPosition() \] size and posttion while using vtkInteractorStyleRubberBandPick? It is about the same choice as vtkInteractorStyleRubberBand2D.

---

## [Do not use GPU when running vtk-python code for 3D rendering](https://discourse.vtk.org/t/do-not-use-gpu-when-running-vtk-python-code-for-3d-rendering/12317)

<div class="topic-metadata">

**Author:** [@dbtruong](https://discourse.vtk.org/u/dbtruong)\
**Replies:** 4\
**Last updated:** [September 21, 2023, 2:45am UTC](https://discourse.vtk.org/t/do-not-use-gpu-when-running-vtk-python-code-for-3d-rendering/12317 "2023-09-21T02:45:45Z")

</div>

Hello all I tested the code using vtk-python for 3D rendering. Can it run if the computer does not have a GPU?

---

## [Loading image data to GPU](https://discourse.vtk.org/t/loading-image-data-to-gpu/12316)

<div class="topic-metadata">

**Author:** [@dbtruong](https://discourse.vtk.org/u/dbtruong)\
**Replies:** 4\
**Last updated:** [September 21, 2023, 1:48am UTC](https://discourse.vtk.org/t/loading-image-data-to-gpu/12316 "2023-09-21T01:48:20Z")

</div>

Hello all For example I have 1000 dicom images. When I read that image folder into the pipeline for 3D rendering, how much resources will it take to load image data into the GPU?

---

## [Exploring VTK-Based 3D Modeling of Floating-Point RTStruct Contours in 3D Slicer](https://discourse.vtk.org/t/exploring-vtk-based-3d-modeling-of-floating-point-rtstruct-contours-in-3d-slicer/12328)

<div class="topic-metadata">

**Author:** [@ranjan](https://discourse.vtk.org/u/ranjan)\
**Replies:** 1\
**Last updated:** [September 20, 2023, 7:35pm UTC](https://discourse.vtk.org/t/exploring-vtk-based-3d-modeling-of-floating-point-rtstruct-contours-in-3d-slicer/12328 "2023-09-20T19:35:27Z")

</div>

We’re interested in understanding how VTK can facilitate the conversion of RTStruct contour data, which includes floating-point coordinates, into 3D models. Specifically, we have several key questions: Does VTK offer a …

---

## [vtkHardwarePicker and vtkImageData](https://discourse.vtk.org/t/vtkhardwarepicker-and-vtkimagedata/12277)

<div class="topic-metadata">

**Author:** [@Michael\_Jackson](https://discourse.vtk.org/u/Michael_Jackson)\
**Replies:** 4\
**Last updated:** [September 20, 2023, 3:21pm UTC](https://discourse.vtk.org/t/vtkhardwarepicker-and-vtkimagedata/12277 "2023-09-20T15:21:45Z")

</div>

we are trying to use the vtkHardwarePicker to give information about a user hovered location in a data set. With unstructured grids this seems to be working correctly. However with vtkImageData when the user hovers over …

---

## [How to write an STL or PLY in binary to bytes](https://discourse.vtk.org/t/how-to-write-an-stl-or-ply-in-binary-to-bytes/12305)

<div class="topic-metadata">

**Author:** [@JeffreyWardman](https://discourse.vtk.org/u/JeffreyWardman)\
**Replies:** 3\
**Last updated:** [September 20, 2023, 6:38am UTC](https://discourse.vtk.org/t/how-to-write-an-stl-or-ply-in-binary-to-bytes/12305 "2023-09-20T06:38:12Z")

</div>

e.g. in Python, for both STLs and PLYs, I want to output a byte string rather than write directly to a file so I can use it in an API request. E.g. something similar to vtk.vtkDataSetWriter() writer = vtk.vtkSTLWriter(…

---

## [vtkResliceCursor how to fix horizontal images if vtkCamera Roll not working](https://discourse.vtk.org/t/vtkreslicecursor-how-to-fix-horizontal-images-if-vtkcamera-roll-not-working/12322)

<div class="topic-metadata">

**Author:** [@BJladika](https://discourse.vtk.org/u/BJladika)\
**Replies:** 0\
**Last updated:** [September 20, 2023, 6:16am UTC](https://discourse.vtk.org/t/vtkreslicecursor-how-to-fix-horizontal-images-if-vtkcamera-roll-not-working/12322 "2023-09-20T06:16:40Z")

</div>

Hello. I tested two version of vtk 9.0.1 and 9.2.6. Sometimes ResliceCursor displays alternative planes horizontally (instead vertically) if original image is Sagittal/Coronal plane and I’m not sure how to actually fix …

---

## [Time dependent information](https://discourse.vtk.org/t/time-dependent-information/12312)

<div class="topic-metadata">

**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\
**Replies:** 0\
**Last updated:** [September 18, 2023, 6:05pm UTC](https://discourse.vtk.org/t/time-dependent-information/12312 "2023-09-18T18:05:16Z")

</div>

Where can I find an example of the use of RequestUpdateTimeDependentInformation and RequestUpdateTime and what is the rationale of having both? Thanks in advance Jens

---

## [VTK image using slicer resulted Empty spaces](https://discourse.vtk.org/t/vtk-image-using-slicer-resulted-empty-spaces/12302)

<div class="topic-metadata">

**Author:** [@ahmed.elmalky](https://discourse.vtk.org/u/ahmed.elmalky)\
**Replies:** 4\
**Last updated:** [September 18, 2023, 2:23pm UTC](https://discourse.vtk.org/t/vtk-image-using-slicer-resulted-empty-spaces/12302 "2023-09-18T14:23:49Z")

</div>

We have a medical imaging viewer support slicing in Axial, Sagittal and coronal directions using vtkImageReslice and i’d like to add Oblique slicing the result looks fine but i have a stupid issue in the resulted image …

---

## [VTK widgets don't seem to work inside QVTKOpenGLNativeWidget (in Qt)](https://discourse.vtk.org/t/vtk-widgets-dont-seem-to-work-inside-qvtkopenglnativewidget-in-qt/4603)

<div class="topic-metadata">

**Author:** [@kerim](https://discourse.vtk.org/u/kerim)\
**Replies:** 4\
**Last updated:** [September 18, 2023, 7:35am UTC](https://discourse.vtk.org/t/vtk-widgets-dont-seem-to-work-inside-qvtkopenglnativewidget-in-qt/4603 "2023-09-18T07:35:05Z")

</div>

Hi, I’m trying to launch VTK widget example in Qt. So I’ve rewriten the code to use it in Qt and I now have something like: MyMainWindow::MyMainWindow(){ // A renderer and render window vtkSmartPoin…

---

## [About center of vtkImageReslice](https://discourse.vtk.org/t/about-center-of-vtkimagereslice/12257)

<div class="topic-metadata">

**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\
**Replies:** 1\
**Last updated:** [September 18, 2023, 6:01am UTC](https://discourse.vtk.org/t/about-center-of-vtkimagereslice/12257 "2023-09-18T06:01:42Z")

</div>

Hi: I want to get an oblique slice by picking a point on the CT image and rotating with mouse move. Please see codes below. So far everything works fine except that the resliced image will be repositioned to the center …

---

## [vtkLightActor rendered size](https://discourse.vtk.org/t/vtklightactor-rendered-size/12303)

<div class="topic-metadata">

**Author:** [@sboogert](https://discourse.vtk.org/u/sboogert)\
**Replies:** 0\
**Last updated:** [September 17, 2023, 2:42pm UTC](https://discourse.vtk.org/t/vtklightactor-rendered-size/12303 "2023-09-17T14:42:19Z")

</div>

I am trying to use vtkLightActor but the data I am visualising is rather large, so 10 m so 10000 mm. All my datas units are mm, so when I put add vtkLightActor to my renderer, it appears very small. I would expect I need…

---

## [picking from assembly, vtkaxesactor](https://discourse.vtk.org/t/picking-from-assembly-vtkaxesactor/12300)

<div class="topic-metadata">

**Author:** [@thefloe](https://discourse.vtk.org/u/thefloe)\
**Replies:** 0\
**Last updated:** [September 17, 2023, 6:06am UTC](https://discourse.vtk.org/t/picking-from-assembly-vtkaxesactor/12300 "2023-09-17T06:06:09Z")

</div>

Hi, I’m developing a visualization for procedural generated meshes and found VTK unstructured mesh to be a convenient way to render the generated meshes. I’m new to VTK and just slowing getting used to the inner working…

---

## [Wrong coordinate from display to world](https://discourse.vtk.org/t/wrong-coordinate-from-display-to-world/12291)

<div class="topic-metadata">

**Author:** [@liuzhongshu](https://discourse.vtk.org/u/liuzhongshu)\
**Replies:** 1\
**Last updated:** [September 16, 2023, 9:52pm UTC](https://discourse.vtk.org/t/wrong-coordinate-from-display-to-world/12291 "2023-09-16T21:52:49Z")

</div>

I am using vtkCoordinate to convert mouse click pixel to world coordinate, When I do the convert, I backup the current camera clipping range and change to a clipping range when first click, then do the convert. var pos…

---

## [Where can I find feasible methods for parallelizing rendering?](https://discourse.vtk.org/t/where-can-i-find-feasible-methods-for-parallelizing-rendering/12297)

<div class="topic-metadata">

**Author:** [@hbwhzc](https://discourse.vtk.org/u/hbwhzc)\
**Replies:** 0\
**Last updated:** [September 16, 2023, 4:16am UTC](https://discourse.vtk.org/t/where-can-i-find-feasible-methods-for-parallelizing-rendering/12297 "2023-09-16T04:16:05Z")

</div>

Hi all, I have found that when using a personal computer to render a million level grid, there will be lag. I want to optimize it through CPU multiprocessing or simply using GPU, but I can hardly find a method that only…

---

## [Show VDB with vtkOpenVDBReader in jupyterlab](https://discourse.vtk.org/t/show-vdb-with-vtkopenvdbreader-in-jupyterlab/12258)

<div class="topic-metadata">

**Author:** [@Will\_Will](https://discourse.vtk.org/u/Will_Will)\
**Replies:** 5\
**Last updated:** [September 15, 2023, 1:50am UTC](https://discourse.vtk.org/t/show-vdb-with-vtkopenvdbreader-in-jupyterlab/12258 "2023-09-15T01:50:11Z")

</div>

Hello all, I am a newbie for VTK, now trying to use Python vtkmodules’ vtkOpenVDBReader as a reader to read vdb files and rendering in jupyterlab. I reference this SimpleCone example in Kitware/trame with replacing the…

---

## [VTK DICOMImageReader Error](https://discourse.vtk.org/t/vtk-dicomimagereader-error/12281)

<div class="topic-metadata">

**Author:** [@Junhyuk\_Park](https://discourse.vtk.org/u/Junhyuk_Park)\
**Replies:** 0\
**Last updated:** [September 14, 2023, 5:50am UTC](https://discourse.vtk.org/t/vtk-dicomimagereader-error/12281 "2023-09-14T05:50:50Z")

</div>

Hello, everyone! I got an unknown error while using the VTK library on Python, so I need help if anyone knows. There are DICOM files that open normally in ITK snap, but there is data that fails when creating a maximum …

---

## [where to download the relative input files of examples?](https://discourse.vtk.org/t/where-to-download-the-relative-input-files-of-examples/12276)

<div class="topic-metadata">

**Author:** [@david999](https://discourse.vtk.org/u/david999)\
**Replies:** 1\
**Last updated:** [September 13, 2023, 7:37am UTC](https://discourse.vtk.org/t/where-to-download-the-relative-input-files-of-examples/12276 "2023-09-13T07:37:40Z")

</div>

I am using the examples of VTK in C++, but there are only source codes, without the input files such as images, 3d models, and so on, so it is a problem for quickly to learn the usage of vtk. Who can help me out of it? W…

---

## [How to draw a 3D screw using VTK?](https://discourse.vtk.org/t/how-to-draw-a-3d-screw-using-vtk/12238)

<div class="topic-metadata">

**Author:** [@wulicheng](https://discourse.vtk.org/u/wulicheng)\
**Replies:** 5\
**Last updated:** [September 12, 2023, 6:00am UTC](https://discourse.vtk.org/t/how-to-draw-a-3d-screw-using-vtk/12238 "2023-09-12T06:00:37Z")

</div>

How to draw the 3D screw like the flowing picture show? I need some suggestion.

---

## [GUISupport QtQuick with two render windows](https://discourse.vtk.org/t/guisupport-qtquick-with-two-render-windows/12265)

<div class="topic-metadata">

**Author:** [@eustache](https://discourse.vtk.org/u/eustache)\
**Replies:** 0\
**Last updated:** [September 11, 2023, 7:34pm UTC](https://discourse.vtk.org/t/guisupport-qtquick-with-two-render-windows/12265 "2023-09-11T19:34:38Z")

</div>

I am trying to re-write https://github.com/Kitware/VTK/blame/master/GUISupport/QtQuick/Testing/Cxx/TestQQuickVTKRenderItemWidget.qml.in with two VTKRenderWindow instead of one, I cannot make it work (it’s rendering a si…

---

## [Hover Points and Hover Cells: Best way to implement from UI](https://discourse.vtk.org/t/hover-points-and-hover-cells-best-way-to-implement-from-ui/12249)

<div class="topic-metadata">

**Author:** [@Michael\_Jackson](https://discourse.vtk.org/u/Michael_Jackson)\
**Replies:** 8\
**Last updated:** [September 11, 2023, 7:18pm UTC](https://discourse.vtk.org/t/hover-points-and-hover-cells-best-way-to-implement-from-ui/12249 "2023-09-11T19:18:15Z")

</div>

We have a VTK based Qt6 application that we are building and we would like to add the feature that would allow the user to hover their mouse over a point/cell in the VTK scene and have a pop up that gives information abo…

[Previous page](https://discourse.vtk.org/c/support/6.md?page=39)

[Next page](https://discourse.vtk.org/c/support/6.md?page=41)