# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=151

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

**Page:** 152

---

## [find the actor that another actor is intersecting with](https://discourse.vtk.org/t/find-the-actor-that-another-actor-is-intersecting-with/1379)

<div class="topic-metadata">

**Author:** [@svabhishek29](https://discourse.vtk.org/u/svabhishek29)\
**Replies:** 9\
**Last updated:** [August 9, 2019, 11:23am UTC](https://discourse.vtk.org/t/find-the-actor-that-another-actor-is-intersecting-with/1379 "2019-08-09T11:23:35Z")

</div>

hi, i have a situation in which i have a sphere in a field of multiple randomly placed cubes, the sphere is controlled by keyboard and when the sphere intersects a cube or collides with a cube i want to change the color …

---

## [Linking VTK static libraries](https://discourse.vtk.org/t/linking-vtk-static-libraries/1534)

<div class="topic-metadata">

**Author:** [@Gib\_Bogle](https://discourse.vtk.org/u/Gib_Bogle)\
**Replies:** 1\
**Last updated:** [August 9, 2019, 1:08am UTC](https://discourse.vtk.org/t/linking-vtk-static-libraries/1534 "2019-08-09T01:08:21Z")

</div>

I am trying to port a program that uses VTK in a Qt GUI from Windows to Linux. To keep this as straightforward as possible I’m sticking with the Qt and VTK versions that I’ve been using: Qt-4.8.6 and VTK-5.10. The VTK …

---

## [Images exported from OSPRay renders have channel values that max out at 254](https://discourse.vtk.org/t/images-exported-from-ospray-renders-have-channel-values-that-max-out-at-254/1531)

<div class="topic-metadata">

**Author:** [@Sean\_Curtis](https://discourse.vtk.org/u/Sean_Curtis)\
**Replies:** 0\
**Last updated:** [August 8, 2019, 9:33pm UTC](https://discourse.vtk.org/t/images-exported-from-ospray-renders-have-channel-values-that-max-out-at-254/1531 "2019-08-08T21:33:19Z")

</div>

I’ve encountered two instances that suggest there’s some funny truncating taking place somewhere in either OSPRay or the OSPRay/VTK interface. Essentially, it comes down to the fact that colors are not coming back quite …

---

## [Rendering issue with vtkImageViewer2 and Qt (works with vtkImageViewer)](https://discourse.vtk.org/t/rendering-issue-with-vtkimageviewer2-and-qt-works-with-vtkimageviewer/1529)

<div class="topic-metadata">

**Author:** [@NewProggie](https://discourse.vtk.org/u/NewProggie)\
**Replies:** 0\
**Last updated:** [August 8, 2019, 7:28pm UTC](https://discourse.vtk.org/t/rendering-issue-with-vtkimageviewer2-and-qt-works-with-vtkimageviewer/1529 "2019-08-08T19:28:51Z")

</div>

Hello my fellow VTK users, I want to embed an instance of vtkImageViewer2 into my Qt5 application to visualize a series of DICOM images. I’m currently experiencing some rendering issues because the widget doesn’t displa…

---

## [Documentation - Add a path to where the class is in the VTK directory.](https://discourse.vtk.org/t/documentation-add-a-path-to-where-the-class-is-in-the-vtk-directory/1389)

<div class="topic-metadata">

**Author:** [@amaclean](https://discourse.vtk.org/u/amaclean)\
**Replies:** 2\
**Last updated:** [August 8, 2019, 10:41am UTC](https://discourse.vtk.org/t/documentation-add-a-path-to-where-the-class-is-in-the-vtk-directory/1389 "2019-08-08T10:41:38Z")

</div>

When looking at the classes in VTK Class List It would be nice to add in \*\* Detailed Description\*\* an indication as to where the class is in the VTK source. For example, in the case of /vtkSubdivideTetra, in \*\* Detaile…

---

## [wglMakeCurrent failed in MakeCurrent()](https://discourse.vtk.org/t/wglmakecurrent-failed-in-makecurrent/1516)

<div class="topic-metadata">

**Author:** [@Wenye\_He](https://discourse.vtk.org/u/Wenye_He)\
**Replies:** 0\
**Last updated:** [August 8, 2019, 2:48am UTC](https://discourse.vtk.org/t/wglmakecurrent-failed-in-makecurrent/1516 "2019-08-08T02:48:00Z")

</div>

I got an error, vtkWin32OpenGLRenderWindow (0000024A62E4C270): wglMakeCurrent failed in MakeCurrent(), error: The handle is invalid. What is this error and how to fix it? I create one mainwindow to display 3D model an…

---

## [Color specific mesh elements](https://discourse.vtk.org/t/color-specific-mesh-elements/1447)

<div class="topic-metadata">

**Author:** [@anon64829896](https://discourse.vtk.org/u/anon64829896)\
**Replies:** 3\
**Last updated:** [August 7, 2019, 11:11am UTC](https://discourse.vtk.org/t/color-specific-mesh-elements/1447 "2019-08-07T11:11:36Z")

</div>

Hi! I want to plot my STL-Model (or general 3D object) using VTK. For this, I used the STLReader. My next step is to give some facets of the model different colors, so e.g.: Face 1-10 shall be red Face 11 - 20 shall …

---

## [What are the requirements of a device for "RenderLinesAsTubes" to work?](https://discourse.vtk.org/t/what-are-the-requirements-of-a-device-for-renderlinesastubes-to-work/1503)

<div class="topic-metadata">

**Author:** [@Tharun](https://discourse.vtk.org/u/Tharun)\
**Replies:** 0\
**Last updated:** [August 7, 2019, 9:55am UTC](https://discourse.vtk.org/t/what-are-the-requirements-of-a-device-for-renderlinesastubes-to-work/1503 "2019-08-07T09:55:48Z")

</div>

Our application use the property “RenderLinesAsTubes”. In all of the Desktop PCs we tested, it works fine but in some Laptops, our application crashes. There is also comment below in “vtkProperty.h” for using the proper…

---

## [vtkmCleanGrid - non VTK-m version?](https://discourse.vtk.org/t/vtkmcleangrid-non-vtk-m-version/1483)

<div class="topic-metadata">

**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 3\
**Last updated:** [August 7, 2019, 12:57am UTC](https://discourse.vtk.org/t/vtkmcleangrid-non-vtk-m-version/1483 "2019-08-07T00:57:09Z")

</div>

Is there a non-VTK-m version of vtkmCleanGrid? I’m looking for a standard VTK algorithm to clean unstructured grids

---

## [I can't pick two points and draw line with MPR](https://discourse.vtk.org/t/i-cant-pick-two-points-and-draw-line-with-mpr/1395)

<div class="topic-metadata">

**Author:** [@pingdan](https://discourse.vtk.org/u/pingdan)\
**Replies:** 5\
**Last updated:** [August 6, 2019, 2:22am UTC](https://discourse.vtk.org/t/i-cant-pick-two-points-and-draw-line-with-mpr/1395 "2019-08-06T02:22:10Z")

</div>

I use vtkImagePlaneWidget to display four views of MPR. Now I want to pick two points with mouse and draw line at one view. but I find I can’t pick points and draw lines.

---

## [Stymied by "Unrecognized OpenGL version" error on Ubuntu](https://discourse.vtk.org/t/stymied-by-unrecognized-opengl-version-error-on-ubuntu/1492)

<div class="topic-metadata">

**Author:** [@fletcher](https://discourse.vtk.org/u/fletcher)\
**Replies:** 0\
**Last updated:** [August 5, 2019, 9:21pm UTC](https://discourse.vtk.org/t/stymied-by-unrecognized-opengl-version-error-on-ubuntu/1492 "2019-08-05T21:21:32Z")

</div>

I’m building an application using Qt, and have successfully added some VTK functionality on a Macbook, but when I tried to install and use VTK in my Ubuntu environment, I receive the runtime error: Unrecognized OpenGL ve…

---

## [Undefined references when attempting to link against static build of VTK when using qmake](https://discourse.vtk.org/t/undefined-references-when-attempting-to-link-against-static-build-of-vtk-when-using-qmake/1488)

<div class="topic-metadata">

**Author:** [@tmeier](https://discourse.vtk.org/u/tmeier)\
**Replies:** 0\
**Last updated:** [August 5, 2019, 8:05pm UTC](https://discourse.vtk.org/t/undefined-references-when-attempting-to-link-against-static-build-of-vtk-when-using-qmake/1488 "2019-08-05T20:05:28Z")

</div>

I am attempting to statically link against VTK while using qmake. I understand that this use case has next to zero support, but I’ve gotten it to work when using shared libraries, so I imagine I can’t be too far off from…

---

## [Scenelight + GPU Volume Rendering - incorrect & inconsistent lighting](https://discourse.vtk.org/t/scenelight-gpu-volume-rendering-incorrect-inconsistent-lighting/1454)

<div class="topic-metadata">

**Author:** [@gw99](https://discourse.vtk.org/u/gw99)\
**Replies:** 0\
**Last updated:** [July 30, 2019, 4:03pm UTC](https://discourse.vtk.org/t/scenelight-gpu-volume-rendering-incorrect-inconsistent-lighting/1454 "2019-07-30T16:03:18Z")

</div>

Hi, I’m trying to set up volume rendering with Scene Lights rather than using the default Head Light. This is part of a larger project, where I am using vtk external rendering. I was getting significantly different rend…

---

## [How to extract surface from polydata](https://discourse.vtk.org/t/how-to-extract-surface-from-polydata/321)

<div class="topic-metadata">

**Author:** [@Frank](https://discourse.vtk.org/u/Frank)\
**Replies:** 11\
**Last updated:** [August 5, 2019, 3:13pm UTC](https://discourse.vtk.org/t/how-to-extract-surface-from-polydata/321 "2019-08-05T15:13:47Z")

</div>

I use vtkCylinderSource and vtkAppendPolyData to create some cylinders that intersect. Now I want to extract the surface of them. How can I do that. The data looks like the following.

---

## [Handle point data arrays with vtkAppendFilter?](https://discourse.vtk.org/t/handle-point-data-arrays-with-vtkappendfilter/1479)

<div class="topic-metadata">

**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 0\
**Last updated:** [August 3, 2019, 7:21am UTC](https://discourse.vtk.org/t/handle-point-data-arrays-with-vtkappendfilter/1479 "2019-08-03T07:21:57Z")

</div>

I’m using the vtkAppendFilter to generate a vtkUnstructuredGrid from two meshes but the input meshes have duplicate points and cells. The MergePoints option for vtkAppendFilter is great however it doesn’t properly handl…

---

## [upgrade VTK](https://discourse.vtk.org/t/upgrade-vtk/1466)

<div class="topic-metadata">

**Author:** [@Saadana](https://discourse.vtk.org/u/Saadana)\
**Replies:** 4\
**Last updated:** [August 2, 2019, 5:07pm UTC](https://discourse.vtk.org/t/upgrade-vtk/1466 "2019-08-02T17:07:02Z")

</div>

Hello, I want to upgrade from version 8.1.2 to the latest version 8.2.0. Is it necessary to remove the entire version 8.1.2 to reinstall VTK 8.2.0? What do I have to do to install it in both release and debug modes? T…

---

## [vtkCubeAxesActor2D, setting label format for individual axis](https://discourse.vtk.org/t/vtkcubeaxesactor2d-setting-label-format-for-individual-axis/1436)

<div class="topic-metadata">

**Author:** [@francek](https://discourse.vtk.org/u/francek)\
**Replies:** 3\
**Last updated:** [August 1, 2019, 3:23pm UTC](https://discourse.vtk.org/t/vtkcubeaxesactor2d-setting-label-format-for-individual-axis/1436 "2019-08-01T15:23:05Z")

</div>

Hi, I fail to set different label format for each axis in vtkCubeAxesActor2D. When I run CubeAxesActor2D example and replace line axes2-\>SetLabelFormat("%6.4g"); by axes2-\>GetXAxisActor2D()-\>SetLabelFormat("%3.1f"); …

---

## [Problem with vtkCharts in Qt](https://discourse.vtk.org/t/problem-with-vtkcharts-in-qt/1461)

<div class="topic-metadata">

**Author:** [@Jothybasu\_Selvaraj](https://discourse.vtk.org/u/Jothybasu_Selvaraj)\
**Replies:** 1\
**Last updated:** [August 1, 2019, 2:12pm UTC](https://discourse.vtk.org/t/problem-with-vtkcharts-in-qt/1461 "2019-08-01T14:12:38Z")

</div>

Hello, I am using vtk7.1 in my project and all vtk functions work in my Qt application except vtkCharts. I am trying to run the vtkCharts example form vtk examples at https://vtk.org/Wiki/VTK/Examples/Cxx/Plotting/Lin…

---

## [Cannot get Sphere VTK example to work.](https://discourse.vtk.org/t/cannot-get-sphere-vtk-example-to-work/1428)

<div class="topic-metadata">

**Author:** [@mkhalil](https://discourse.vtk.org/u/mkhalil)\
**Replies:** 7\
**Last updated:** [July 31, 2019, 10:52am UTC](https://discourse.vtk.org/t/cannot-get-sphere-vtk-example-to-work/1428 "2019-07-31T10:52:29Z")

</div>

Hi All!! So, I am new to VTK. I want to use VTK to visualize and volume render MRI DICOM images. I have been trying to make the sphere example work (https://vtk.org/Wiki/VTK/Examples/Cxx/GeometricObjects/Sphere). But w…

---

## [use openmp with StaticCellLocator](https://discourse.vtk.org/t/use-openmp-with-staticcelllocator/1453)

<div class="topic-metadata">

**Author:** [@Dmitriy\_L](https://discourse.vtk.org/u/Dmitriy_L)\
**Replies:** 0\
**Last updated:** [July 30, 2019, 3:08pm UTC](https://discourse.vtk.org/t/use-openmp-with-staticcelllocator/1453 "2019-07-30T15:08:51Z")

</div>

I’m trying to make routine to get cell index by point coordinates in unstructured 3D mesh to be used with OpenMP parallelized code. As far as I understand the documentation for vtkStaticCellLocator (https://vtk.org/doc/n…

---

## [Validation of coordinates and interaction](https://discourse.vtk.org/t/validation-of-coordinates-and-interaction/1449)

<div class="topic-metadata">

**Author:** [@lonewolf](https://discourse.vtk.org/u/lonewolf)\
**Replies:** 1\
**Last updated:** [July 30, 2019, 12:52pm UTC](https://discourse.vtk.org/t/validation-of-coordinates-and-interaction/1449 "2019-07-30T12:52:33Z")

</div>

Hi there, I know VTK is used in many different scientific and corporate applications, and it is extremely reliable. However, I would like to know if and how VTK has been validated with DICOM data. What I mean is, after…

---

## [How to perform morphological closing in VTK](https://discourse.vtk.org/t/how-to-perform-morphological-closing-in-vtk/1438)

<div class="topic-metadata">

**Author:** [@msmerps](https://discourse.vtk.org/u/msmerps)\
**Replies:** 0\
**Last updated:** [July 29, 2019, 2:33pm UTC](https://discourse.vtk.org/t/how-to-perform-morphological-closing-in-vtk/1438 "2019-07-29T14:33:47Z")

</div>

Hi all, I am attempting to perform morphological closing on a binary 3D volume (all voxels have values of 0 or 1). It looks like I can use the method vtkImageOpenClose3D for this: https://vtk.org/Wiki/VTK/Examples/Cxx/…

---

## [ColoredElevationMap speed](https://discourse.vtk.org/t/coloredelevationmap-speed/1279)

<div class="topic-metadata">

**Author:** [@silajim](https://discourse.vtk.org/u/silajim)\
**Replies:** 6\
**Last updated:** [July 29, 2019, 12:57pm UTC](https://discourse.vtk.org/t/coloredelevationmap-speed/1279 "2019-07-29T12:57:29Z")

</div>

Hi, I’ve been searching the interwebs for the past days (3-4) but I cannot find a solution to my problem. I want to color a pointcloud of about 40 million points by height, I took a look into the ColoredElevationMap ex…

---

## [Update a custom uniform in a modified shader](https://discourse.vtk.org/t/update-a-custom-uniform-in-a-modified-shader/1366)

<div class="topic-metadata">

**Author:** [@Jellby](https://discourse.vtk.org/u/Jellby)\
**Replies:** 5\
**Last updated:** [July 25, 2019, 5:25pm UTC](https://discourse.vtk.org/t/update-a-custom-uniform-in-a-modified-shader/1366 "2019-07-25T17:25:16Z")

</div>

I have modified the default vtkOpenGLPolyDataMapper along the lines of https://github.com/dmreagan/vtk-shaders (case 1). I have also added a new uniform, which I can set as it is done for diffuseColor in https://github.c…

---

## [In OSX vtk window does not get the focus - continued](https://discourse.vtk.org/t/in-osx-vtk-window-does-not-get-the-focus-continued/1418)

<div class="topic-metadata">

**Author:** [@normanius](https://discourse.vtk.org/u/normanius)\
**Replies:** 0\
**Last updated:** [July 25, 2019, 2:23pm UTC](https://discourse.vtk.org/t/in-osx-vtk-window-does-not-get-the-focus-continued/1418 "2019-07-25T14:23:31Z")

</div>

After the nabble mailing list has been shut down, I’d like to continue the discussion about the window-to-front issue on MacOS here on discourse… Preceding discussion: http://vtk.1045678.n5.nabble.com/In-OSX-vtk-window-…

---

## [how to make unstructured Grid](https://discourse.vtk.org/t/how-to-make-unstructured-grid/1412)

<div class="topic-metadata">

**Author:** [@Vaya\_Putra](https://discourse.vtk.org/u/Vaya_Putra)\
**Replies:** 0\
**Last updated:** [July 24, 2019, 2:59pm UTC](https://discourse.vtk.org/t/how-to-make-unstructured-grid/1412 "2019-07-24T14:59:34Z")

</div>

hello for my practice i already done by manually make unstructured grid 5x5x1 i define coordinate node, connectivity, etc for small grid is done but my problem is how to make grid 100x100x4 i used VTK for better vis…

---

## [AffineWidget rotation interaction non-functional?](https://discourse.vtk.org/t/affinewidget-rotation-interaction-non-functional/1404)

<div class="topic-metadata">

**Author:** [@rdbrn](https://discourse.vtk.org/u/rdbrn)\
**Replies:** 0\
**Last updated:** [July 24, 2019, 7:12am UTC](https://discourse.vtk.org/t/affinewidget-rotation-interaction-non-functional/1404 "2019-07-24T07:12:28Z")

</div>

I want to use an AffineWidget to let the user shift and rotate an actor. The shift (translation) part works fine. However the rotation part of the widget seems to be broken? There is a circle drawn but it does not mo…

---

## [How to convert the coordinate between pixel and physical (vtkImageReslice)?](https://discourse.vtk.org/t/how-to-convert-the-coordinate-between-pixel-and-physical-vtkimagereslice/1391)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 4\
**Last updated:** [July 24, 2019, 2:43am UTC](https://discourse.vtk.org/t/how-to-convert-the-coordinate-between-pixel-and-physical-vtkimagereslice/1391 "2019-07-24T02:43:14Z")

</div>

I reslice a 2D image from a 3D volume image by vtkImageReslice. Then, I convert the image (matrix， numpy) from vtkImageReslice.GetOutput(). My question is: for one pixel (x, y) in image, what’s the coordinate in 3D volum…

---

## [3D rendering for polydata points](https://discourse.vtk.org/t/3d-rendering-for-polydata-points/1365)

<div class="topic-metadata">

**Author:** [@vasya\_slot](https://discourse.vtk.org/u/vasya_slot)\
**Replies:** 1\
**Last updated:** [July 21, 2019, 9:35pm UTC](https://discourse.vtk.org/t/3d-rendering-for-polydata-points/1365 "2019-07-21T21:35:33Z")

</div>

I am a VTK beginner. I have a large number of points with some attribute value for each point. I want to build a 3D volume in VTK / Paraview with the ability to apply various filters. I tried to use Delaunau3D in Paravi…

---

## [how to save the result of vtkCutter as opencv::Mat](https://discourse.vtk.org/t/how-to-save-the-result-of-vtkcutter-as-opencv-mat/1393)

<div class="topic-metadata">

**Author:** [@wangfeng](https://discourse.vtk.org/u/wangfeng)\
**Replies:** 1\
**Last updated:** [July 21, 2019, 1:45pm UTC](https://discourse.vtk.org/t/how-to-save-the-result-of-vtkcutter-as-opencv-mat/1393 "2019-07-21T13:45:50Z")

</div>

Hi, good evening. I got the the result of vtkCutter, and rendered it very well.Next, I want to save the result of vtkCutter as opencv::Mat. but I can not get scalarPointer of the image . What should I do, help me please …

[Previous page](https://discourse.vtk.org/c/support/6.md?page=150)

[Next page](https://discourse.vtk.org/c/support/6.md?page=152)