# Latest

**URL:** https://discourse.vtk.org/latest.md?page=221

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

**Page:** 222

---

## [VTK-9.0.0.rc1 archive is broken](https://discourse.vtk.org/t/vtk-9-0-0-rc1-archive-is-broken/2764)

<div class="topic-metadata">

**Author:** [@danlipsa](https://discourse.vtk.org/u/danlipsa)\
**Replies:** 4\
**Last updated:** [March 17, 2020, 2:17am UTC](https://discourse.vtk.org/t/vtk-9-0-0-rc1-archive-is-broken/2764 "2020-03-17T02:17:18Z")

</div>

Hi, I downloaded the RC1 archives from https://vtk.org/download/ and both the tar.gz and the zip seem broken: \[~/Downloads\]$ tar xzf VTK-9.0.0.rc1.tar.gz tar: Unexpected EOF in archive tar: Unexpected EOF in archiv…

---

## [is it possible to call a python script in a C++ program](https://discourse.vtk.org/t/is-it-possible-to-call-a-python-script-in-a-c-program/2710)

<div class="topic-metadata">

**Author:** [@embeddedmz](https://discourse.vtk.org/u/embeddedmz)\
**Replies:** 4\
**Last updated:** [March 16, 2020, 5:32pm UTC](https://discourse.vtk.org/t/is-it-possible-to-call-a-python-script-in-a-c-program/2710 "2020-03-16T17:32:32Z")

</div>

Hi, In ParaView’s Catalyst, one can write a Python script and call it from a C++ context, I wonder if this feature can be achieved in pure VTK ? Thanks.

---

## [No rule to make target '/usr/include/python3.6/context.h'](https://discourse.vtk.org/t/no-rule-to-make-target-usr-include-python3-6-context-h/2805)

<div class="topic-metadata">

**Author:** [@jiapei100](https://discourse.vtk.org/u/jiapei100)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 5:21pm UTC](https://discourse.vtk.org/t/no-rule-to-make-target-usr-include-python3-6-context-h/2805 "2020-03-16T17:21:00Z")

</div>

Failed to build VTK with the following ERROR messages: \[ 22%\] Built target vtkFiltersPython-hierarchy make -f CMakeFiles/vtkFiltersPythonPython.dir/build.make CMakeFiles/vtkFiltersPythonPython.dir/depend make\[2\]: Enteri…

---

## [Integrating VTK.js capabilities into a babylon.js-centric GUI?](https://discourse.vtk.org/t/integrating-vtk-js-capabilities-into-a-babylon-js-centric-gui/2670)

<div class="topic-metadata">

**Author:** [@jbl](https://discourse.vtk.org/u/jbl)\
**Replies:** 3\
**Last updated:** [March 16, 2020, 5:11pm UTC](https://discourse.vtk.org/t/integrating-vtk-js-capabilities-into-a-babylon-js-centric-gui/2670 "2020-03-16T17:11:42Z")

</div>

Hello, I work on a proof of concept for a CAE web application, and I am currently narrowing down the list of candidate technologies which I could use. Here is a simplified workflow for the app: interactive creation …

---

## [getting/building libs for r/w vtk and xdmf geometry formats](https://discourse.vtk.org/t/getting-building-libs-for-r-w-vtk-and-xdmf-geometry-formats/2720)

<div class="topic-metadata">

**Author:** [@kcris](https://discourse.vtk.org/u/kcris)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 5:06pm UTC](https://discourse.vtk.org/t/getting-building-libs-for-r-w-vtk-and-xdmf-geometry-formats/2720 "2020-03-16T17:06:34Z")

</div>

Hi, I plan to use vtk libraries for reading/writing various vtk geometry formats (vtk text formats, xdms formats). Vtk sourcecode is huge and I am a bit lost, there are literally hundreds of modules. And I am just get…

---

## [Can .vtk files be used to visualise solutions on 1D meshes?](https://discourse.vtk.org/t/can-vtk-files-be-used-to-visualise-solutions-on-1d-meshes/2830)

<div class="topic-metadata">

**Author:** [@krishnakumar](https://discourse.vtk.org/u/krishnakumar)\
**Replies:** 0\
**Last updated:** [March 16, 2020, 4:30pm UTC](https://discourse.vtk.org/t/can-vtk-files-be-used-to-visualise-solutions-on-1d-meshes/2830 "2020-03-16T16:30:34Z")

</div>

I have a standard diffusion equation solved using a finite element software on a 1D mesh for the concentration values. Can I visualise this using the .vtk or .vtu files? Krishna

---

## [vtkXdmf3Writer not in python pypi distribution ?](https://discourse.vtk.org/t/vtkxdmf3writer-not-in-python-pypi-distribution/2470)

<div class="topic-metadata">

**Author:** [@blignyc](https://discourse.vtk.org/u/blignyc)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 3:52pm UTC](https://discourse.vtk.org/t/vtkxdmf3writer-not-in-python-pypi-distribution/2470 "2020-03-16T15:52:19Z")

</div>

Hello, I just installed the python vtk package on my machine, using « pip install vtk » in a virtual env. I work with MacOS 10, python 3.7 I tried to use the vtkXdmf3Writer class, but I got an error : module ‘vtk’ ha…

---

## [Ospray material library from python](https://discourse.vtk.org/t/ospray-material-library-from-python/2459)

<div class="topic-metadata">

**Author:** [@gilcu2](https://discourse.vtk.org/u/gilcu2)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 3:48pm UTC](https://discourse.vtk.org/t/ospray-material-library-from-python/2459 "2020-03-16T15:48:58Z")

</div>

Hello, I am trying to load an mtl file from python following the C++ code like this: import vtkmodules.vtkRenderingRayTracing as vtkrt osprayMtlLibrary = vtkrt.vtkOSPRayMaterialLibrary() osprayM…

---

## [Cmake error in vtkeigen when building from source](https://discourse.vtk.org/t/cmake-error-in-vtkeigen-when-building-from-source/2451)

<div class="topic-metadata">

**Author:** [@Patrick\_Mineault](https://discourse.vtk.org/u/Patrick_Mineault)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 3:44pm UTC](https://discourse.vtk.org/t/cmake-error-in-vtkeigen-when-building-from-source/2451 "2020-03-16T15:44:11Z")

</div>

I’m trying to build vtk from source on Ubuntu since I’m having trouble accessing vtkXdmfReader in pre-built libraries. Following the instructions here: https://vtk.org/Wiki/VTK/Building/Linux, when running this series of…

---

## [Cannot interact with basic QT/VTK application](https://discourse.vtk.org/t/cannot-interact-with-basic-qt-vtk-application/2447)

<div class="topic-metadata">

**Author:** [@ian.liu88](https://discourse.vtk.org/u/ian.liu88)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 3:36pm UTC](https://discourse.vtk.org/t/cannot-interact-with-basic-qt-vtk-application/2447 "2020-03-16T15:36:55Z")

</div>

I have the following snippet which is correctly displaying a cone shape on screen, but I can’t interact with it, ie pan, rotate, zoom, etc. Should I expect it to be interactive? import sys import PySide2 from PySide2.Qt…

---

## [How to build VTK with vtkParallelTimer](https://discourse.vtk.org/t/how-to-build-vtk-with-vtkparalleltimer/2228)

<div class="topic-metadata">

**Author:** [@toddy](https://discourse.vtk.org/u/toddy)\
**Replies:** 6\
**Last updated:** [March 16, 2020, 2:59pm UTC](https://discourse.vtk.org/t/how-to-build-vtk-with-vtkparalleltimer/2228 "2020-03-16T14:59:27Z")

</div>

Could someone please explain how to get VTK to include vtkParallelTimer? I’ve tried building with VTK\_USE\_MPI and adding a BOOL entry to CMake with VTK\_RENDERINGPARALLELLIC\_SURFACELICPAINTER\_TIMER = ON and VTK\_RENDER…

---

## [vtkMFCWindow in v8.2.0 for Win32 GUI support has an error handling message WM\_MOUSEWHEEL](https://discourse.vtk.org/t/vtkmfcwindow-in-v8-2-0-for-win32-gui-support-has-an-error-handling-message-wm-mousewheel/1921)

<div class="topic-metadata">

**Author:** [@Stilles](https://discourse.vtk.org/u/Stilles)\
**Replies:** 1\
**Last updated:** [March 16, 2020, 2:30pm UTC](https://discourse.vtk.org/t/vtkmfcwindow-in-v8-2-0-for-win32-gui-support-has-an-error-handling-message-wm-mousewheel/1921 "2020-03-16T14:30:58Z")

</div>

Finally, I get here to report this error and hope some one can fix it in later versions. Here is piece code handling WM\_MOUSEWHEEL in vtkMFCWindow.cxx: BOOL vtkMFCWindow::OnMouseWheel(UINT nFlags, short zDelta, CPoin…

---

## [Getting Python version](https://discourse.vtk.org/t/getting-python-version/1563)

<div class="topic-metadata">

**Author:** [@Ron84](https://discourse.vtk.org/u/Ron84)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 2:21pm UTC](https://discourse.vtk.org/t/getting-python-version/1563 "2020-03-16T14:21:17Z")

</div>

Another question for you @dgobbi. How can I detect VTKs Python version? I tried this: execute\_process(COMMAND "${\_vtk}/bin/vtkpython" -c "import sys; sys.stdout.write('.'.join(map(str, sys.version\_info\[:2\])))" OUTPUT\_…

---

## [CloudFlare zlib?](https://discourse.vtk.org/t/cloudflare-zlib/2330)

<div class="topic-metadata">

**Author:** [@dzenanz](https://discourse.vtk.org/u/dzenanz)\
**Replies:** 19\
**Last updated:** [March 16, 2020, 12:55pm UTC](https://discourse.vtk.org/t/cloudflare-zlib/2330 "2020-03-16T12:55:49Z")

</div>

The ITK community has been looking for ways to improve image compression speeds. A low hanging fruit is using CloudFlare fork of zlib, at least as a default option. But as ITK and VTK share CMake-ification of zlib, I wan…

---

## [Does vtkSmartPointer support std::move](https://discourse.vtk.org/t/does-vtksmartpointer-support-std-move/2771)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 4\
**Last updated:** [March 13, 2020, 11:22pm UTC](https://discourse.vtk.org/t/does-vtksmartpointer-support-std-move/2771 "2020-03-13T23:22:54Z")

</div>

As vtkSmartPointer is similar to std::shared\_ptr. I use std::move to vtkSmartPointer object. But I find the pointer of the object is NOT null after std::move. Does vtkSmartPointer support std::move? If supported, what’…

---

## [How to get specific number of seed points using seedwidgetwithcustomcallback?](https://discourse.vtk.org/t/how-to-get-specific-number-of-seed-points-using-seedwidgetwithcustomcallback/2814)

<div class="topic-metadata">

**Author:** [@Pooja](https://discourse.vtk.org/u/Pooja)\
**Replies:** 1\
**Last updated:** [March 13, 2020, 3:07pm UTC](https://discourse.vtk.org/t/how-to-get-specific-number-of-seed-points-using-seedwidgetwithcustomcallback/2814 "2020-03-13T15:07:10Z")

</div>

Hello, I used seedwidgetwithcustomcallback to get seed points of dicom image. But I need only 3 seeds and after that it should not take new point. Could someone please tell me how to do it? It seems PlacePointEvent u…

---

## [vtkImagePlaneWidget default lookup table is an S-curve ramp](https://discourse.vtk.org/t/vtkimageplanewidget-default-lookup-table-is-an-s-curve-ramp/2818)

<div class="topic-metadata">

**Author:** [@simonesneault](https://discourse.vtk.org/u/simonesneault)\
**Replies:** 0\
**Last updated:** [March 13, 2020, 2:02pm UTC](https://discourse.vtk.org/t/vtkimageplanewidget-default-lookup-table-is-an-s-curve-ramp/2818 "2020-03-13T14:02:42Z")

</div>

Hello, just wanted to share that it looks strange (to me) to use an S-Curve ramp as a default in the vtkImagePlaneWidget … When setting a window level from outside, we don’t get the same image than most of the dicom vie…

---

## [I cannot use filter for calculation Hausdorff distance](https://discourse.vtk.org/t/i-cannot-use-filter-for-calculation-hausdorff-distance/2339)

<div class="topic-metadata">

**Author:** [@Inna\_Daymand](https://discourse.vtk.org/u/Inna_Daymand)\
**Replies:** 4\
**Last updated:** [March 13, 2020, 10:30am UTC](https://discourse.vtk.org/t/i-cannot-use-filter-for-calculation-hausdorff-distance/2339 "2020-03-13T10:30:24Z")

</div>

I have VTK 8.2.0 build I want to use vtkHausdorffDistancePointSetFilter filter in my python program according to example https://lorensen.github.io/VTKExamples/site/Python/PolyData/AlignTwoPolyDatas/ but I am getting …

---

## [The vtkPolyData can not be Deleted After some DeleteCell...](https://discourse.vtk.org/t/the-vtkpolydata-can-not-be-deleted-after-some-deletecell/2804)

<div class="topic-metadata">

**Author:** [@tdchen](https://discourse.vtk.org/u/tdchen)\
**Replies:** 3\
**Last updated:** [March 13, 2020, 12:00am UTC](https://discourse.vtk.org/t/the-vtkpolydata-can-not-be-deleted-after-some-deletecell/2804 "2020-03-13T00:00:59Z")

</div>

Hi vtkers I have made a function to simplify a triangle mesh: void UpdateTriangles(vtkIdType ia, vtkIdType ib, vtkPolyData \*pTriangles); The ia and ib are vertex IDs of an edge and pTriangles points to a triangle mesh…

---

## [How to render (visualize) histogram of 3D image](https://discourse.vtk.org/t/how-to-render-visualize-histogram-of-3d-image/2809)

<div class="topic-metadata">

**Author:** [@RomyM](https://discourse.vtk.org/u/RomyM)\
**Replies:** 1\
**Last updated:** [March 12, 2020, 5:10pm UTC](https://discourse.vtk.org/t/how-to-render-visualize-histogram-of-3d-image/2809 "2020-03-12T17:10:30Z")

</div>

Hey, I try to visualize my histogram in order to check peaks in my image (and later on to segment those pixels). However, I try to render it with ren.AddActor(plot), but it only shows a black screen (I think here is the…

---

## [How can I use js files generated with itk-js?](https://discourse.vtk.org/t/how-can-i-use-js-files-generated-with-itk-js/2768)

<div class="topic-metadata">

**Author:** [@claretb](https://discourse.vtk.org/u/claretb)\
**Replies:** 2\
**Last updated:** [March 9, 2020, 7:31am UTC](https://discourse.vtk.org/t/how-can-i-use-js-files-generated-with-itk-js/2768 "2020-03-09T07:31:40Z")

</div>

Hi everyone, especially to you @thewtex :slight\_smile: I followed your instructions in this post : https://discourse.vtk.org/t/porting-c-app-to-vtk-js/2303/10?u=claretb and these helped me a lot. But I have no idea abou…

---

## [Find normal vector from a point cloud](https://discourse.vtk.org/t/find-normal-vector-from-a-point-cloud/2803)

<div class="topic-metadata">

**Author:** [@smlm94](https://discourse.vtk.org/u/smlm94)\
**Replies:** 0\
**Last updated:** [March 11, 2020, 9:58am UTC](https://discourse.vtk.org/t/find-normal-vector-from-a-point-cloud/2803 "2020-03-11T09:58:55Z")

</div>

Hi, experts, 1)I would like to ask about how can I mark a specific normal vector on a specific XYZ coordinate from a PLY point cloud file? 2)How to convert normal vector to a component with x rotation, y rotation and z…

---

## [Align two volumes with different spacing and origin](https://discourse.vtk.org/t/align-two-volumes-with-different-spacing-and-origin/2741)

<div class="topic-metadata">

**Author:** [@Darya\_Berezniak](https://discourse.vtk.org/u/Darya_Berezniak)\
**Replies:** 18\
**Last updated:** [March 11, 2020, 4:46am UTC](https://discourse.vtk.org/t/align-two-volumes-with-different-spacing-and-origin/2741 "2020-03-11T04:46:58Z")

</div>

I have two data sets: a CT volume (Dicom or Nii format) and a segmentation (Nii or Nrrd format) created in Slicer3D. I need to display both of them with correct position of the segmentation. But these two data sets have …

---

## [Calculating Wall shear Stress and Mapping value to isosurface skin.](https://discourse.vtk.org/t/calculating-wall-shear-stress-and-mapping-value-to-isosurface-skin/2800)

<div class="topic-metadata">

**Author:** [@LimTzeSuen](https://discourse.vtk.org/u/LimTzeSuen)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 11:56pm UTC](https://discourse.vtk.org/t/calculating-wall-shear-stress-and-mapping-value-to-isosurface-skin/2800 "2020-03-10T23:56:08Z")

</div>

Greetings all, I’m new to VTK. I’m trying to calculate Wall Shear Stress on a 3D MRI Velocity Dataset. I’ve done the noise filtering, and generated a 3D velocity volume and the construction of vessel skin by using vtkMar…

---

## [Why VTK filters behave strangely when I feed my dataset to them?](https://discourse.vtk.org/t/why-vtk-filters-behave-strangely-when-i-feed-my-dataset-to-them/2795)

<div class="topic-metadata">

**Author:** [@myousefi2016](https://discourse.vtk.org/u/myousefi2016)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 6:26pm UTC](https://discourse.vtk.org/t/why-vtk-filters-behave-strangely-when-i-feed-my-dataset-to-them/2795 "2020-03-10T18:26:29Z")

</div>

I have vtkUnstructuredGrid that has a vector array in it. All the cell types in this vtkUnstructuredGrid are VTK\_VOXEL and my vector array is attributed to the cells (i.e. cell data). Now I want to extract the cell cente…

---

## [Problem Clipping Unstructured Grid with Quadratic Quad Element](https://discourse.vtk.org/t/problem-clipping-unstructured-grid-with-quadratic-quad-element/2790)

<div class="topic-metadata">

**Author:** [@alx](https://discourse.vtk.org/u/alx)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 12:54pm UTC](https://discourse.vtk.org/t/problem-clipping-unstructured-grid-with-quadratic-quad-element/2790 "2020-03-10T12:54:41Z")

</div>

I am having trouble to correctly clip an unstructured grid with vtkClipDataSet. For cells of type VTK\_QUADRATIC\_TRIANGLE the cell data seems to be clipped correctly but for VTK\_QUADRATIC\_QUAD cells the clipping messes …

---

## [OSPRay 2.0 & VTK 9.0 ?](https://discourse.vtk.org/t/ospray-2-0-vtk-9-0/2789)

<div class="topic-metadata">

**Author:** [@rossetantoine](https://discourse.vtk.org/u/rossetantoine)\
**Replies:** 1\
**Last updated:** [March 10, 2020, 12:19pm UTC](https://discourse.vtk.org/t/ospray-2-0-vtk-9-0/2789 "2020-03-10T12:19:50Z")

</div>

OSPRay 2.0 (https://www.ospray.org) is available since a few weeks. Do you know if it will supported in VTK 9.0? Or a time frame? Thanks !

---

## [vtkMarchingCube error...](https://discourse.vtk.org/t/vtkmarchingcube-error/2775)

<div class="topic-metadata">

**Author:** [@Yongun\_Lee](https://discourse.vtk.org/u/Yongun_Lee)\
**Replies:** 4\
**Last updated:** [March 10, 2020, 2:00am UTC](https://discourse.vtk.org/t/vtkmarchingcube-error/2775 "2020-03-10T02:00:24Z")

</div>

I’ve attached the code I wrote below. I want to know the reason. No problem with 64bit, but with 32bit the same problem. SkinExtractor-\> SetValue (0, value); Set the value value to 250.0. vtkSmartPointer\<vtkNamedColor…

---

## [run vtk application using putty and xserver](https://discourse.vtk.org/t/run-vtk-application-using-putty-and-xserver/2785)

<div class="topic-metadata">

**Author:** [@benjamin](https://discourse.vtk.org/u/benjamin)\
**Replies:** 0\
**Last updated:** [March 9, 2020, 10:24pm UTC](https://discourse.vtk.org/t/run-vtk-application-using-putty-and-xserver/2785 "2020-03-09T22:24:24Z")

</div>

Hello, I have compiled the arrow example using vtk 7.1.0 library in a hpc cluster using a putty window in my pc. My problem is when I run the arrow example, a window to visualize the arrow (a visualization of the arrow…

---

## [Is there a way to convert a view of a 3D Actor (for example: a view in the X-Z direction) to a 2D Actor.](https://discourse.vtk.org/t/is-there-a-way-to-convert-a-view-of-a-3d-actor-for-example-a-view-in-the-x-z-direction-to-a-2d-actor/2684)

<div class="topic-metadata">

**Author:** [@kknnnyy](https://discourse.vtk.org/u/kknnnyy)\
**Replies:** 7\
**Last updated:** [March 9, 2020, 9:35pm UTC](https://discourse.vtk.org/t/is-there-a-way-to-convert-a-view-of-a-3d-actor-for-example-a-view-in-the-x-z-direction-to-a-2d-actor/2684 "2020-03-09T21:35:52Z")

</div>

I need to get a 3D view in the X-Y, X-Z, Y-Z directions, so I need to convert a 3D Actor to a 2D Actor. How to get a 2D view (not locking the 3d Actor camera)

[Previous page](https://discourse.vtk.org/latest.md?page=220)

[Next page](https://discourse.vtk.org/latest.md?page=222)