# Latest

**URL:** https://discourse.vtk.org/latest.md?page=241

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

**Page:** 242

---

## [Removing all inputs](https://discourse.vtk.org/t/removing-all-inputs/1505)

<div class="topic-metadata">

**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 4\
**Last updated:** [August 7, 2019, 3:36pm UTC](https://discourse.vtk.org/t/removing-all-inputs/1505 "2019-08-07T15:36:32Z")

</div>

Hi, I have a vtkBooleanOperationPolyDataFilter, ports 0 and 1 have been set with information.When I call RemoveAllInputs(), port 0 has 0 input connections but port 1 still has an input connection. Can any suggest a solu…

---

## [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

---

## [Offset value](https://discourse.vtk.org/t/offset-value/1499)

<div class="topic-metadata">

**Author:** [@Richard\_Thompson](https://discourse.vtk.org/u/Richard_Thompson)\
**Replies:** 0\
**Last updated:** [August 6, 2019, 4:02pm UTC](https://discourse.vtk.org/t/offset-value/1499 "2019-08-06T16:02:42Z")

</div>

Hi, I know vtkDelaunay3D has an offset value. What does this offset value do and does it affect the creation of a convex hull? Thanks.

---

## [LaTeX-like math expressions now supported in posts](https://discourse.vtk.org/t/latex-like-math-expressions-now-supported-in-posts/1496)

<div class="topic-metadata">

**Author:** [@cory.quammen](https://discourse.vtk.org/u/cory.quammen)\
**Replies:** 0\
**Last updated:** [August 6, 2019, 2:29pm UTC](https://discourse.vtk.org/t/latex-like-math-expressions-now-supported-in-posts/1496 "2019-08-06T14:29:15Z")

</div>

We have enabled MathJax via the Discourse Math plugin. Now posts may include nicely formatted math expressions such as f(x) = \\int\_{-y}^{y} \\phi(y)sin(y) dy The code for the expression above is as you would write an in…

---

## [vtkAppendPolyData](https://discourse.vtk.org/t/vtkappendpolydata/1495)

<div class="topic-metadata">

**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 1\
**Last updated:** [August 6, 2019, 12:51pm UTC](https://discourse.vtk.org/t/vtkappendpolydata/1495 "2019-08-06T12:51:39Z")

</div>

Hi, I am inputting multiple contours into a vtkAppendPolyData object, does it matter what order I add these contours? I want to create a convex hull. Say from left to right, I create a large circle, small circle, and la…

---

## [Problem: Rendering an Object with setting own transformations](https://discourse.vtk.org/t/problem-rendering-an-object-with-setting-own-transformations/1470)

<div class="topic-metadata">

**Author:** [@idontknow](https://discourse.vtk.org/u/idontknow)\
**Replies:** 0\
**Last updated:** [August 1, 2019, 3:04pm UTC](https://discourse.vtk.org/t/problem-rendering-an-object-with-setting-own-transformations/1470 "2019-08-01T15:04:29Z")

</div>

Hi, for my AR project i want to render a Cube. The position of the cube is dependent of perspective where I look at the marker. The cube should overlay the marker when I look through the glasses. Currently the cube is …

---

## [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.

---

## [Problems using vtkContourWidget, vtkAppendPolyData, and vtkDelaunay3D](https://discourse.vtk.org/t/problems-using-vtkcontourwidget-vtkappendpolydata-and-vtkdelaunay3d/1480)

<div class="topic-metadata">

**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 2\
**Last updated:** [August 5, 2019, 12:56pm UTC](https://discourse.vtk.org/t/problems-using-vtkcontourwidget-vtkappendpolydata-and-vtkdelaunay3d/1480 "2019-08-05T12:56:17Z")

</div>

Hello, I have a ImageResliceVTKWidget. I can move across a series of medical images. Say I am moving from left to right between images. To create a contour on a certain image, I use the vtkContourWidget. I click multip…

---

## [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…

---

## [How do I write animation video files in VP9 (libvpx) codec format using vtk ?](https://discourse.vtk.org/t/how-do-i-write-animation-video-files-in-vp9-libvpx-codec-format-using-vtk/1478)

<div class="topic-metadata">

**Author:** [@aravind90](https://discourse.vtk.org/u/aravind90)\
**Replies:** 3\
**Last updated:** [August 3, 2019, 2:50am UTC](https://discourse.vtk.org/t/how-do-i-write-animation-video-files-in-vp9-libvpx-codec-format-using-vtk/1478 "2019-08-03T02:50:41Z")

</div>

I was successful in saving animation video using classes vtkAVIWriter and vtkFFMPEGWriter with different codec formats, but I would prefer saving videos in VP9 codec format (libvpx) which is completely royalty free. Has …

---

## [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…

---

## [SC19 Workshop ISAV 2019 paper submission EXTENDED to 15 Aug 2019](https://discourse.vtk.org/t/sc19-workshop-isav-2019-paper-submission-extended-to-15-aug-2019/1472)

<div class="topic-metadata">

**Author:** [@eduque](https://discourse.vtk.org/u/eduque)\
**Replies:** 0\
**Last updated:** [August 1, 2019, 7:19pm UTC](https://discourse.vtk.org/t/sc19-workshop-isav-2019-paper-submission-extended-to-15-aug-2019/1472 "2019-08-01T19:19:09Z")

</div>

ISAV 2019: In Situ Infrastructures for Enabling Extreme-Scale Analysis and Visualization Held in conjunction with SC19: The International Conference on High Performance Computing, Networking, Storage and Analysis ISA…

---

## [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"); …

---

## [Smart PolyDataToImageData](https://discourse.vtk.org/t/smart-polydatatoimagedata/1442)

<div class="topic-metadata">

**Author:** [@Patrick\_Laurin](https://discourse.vtk.org/u/Patrick_Laurin)\
**Replies:** 4\
**Last updated:** [July 30, 2019, 2:43pm UTC](https://discourse.vtk.org/t/smart-polydatatoimagedata/1442 "2019-07-30T14:43:26Z")

</div>

Greetings, I have been trying to create a simple PolyDataToImageData, but I’m unable to update the extent of the image properly! In fact, there’s only one thing that makes me unable to do it right. What blocks me is… I…

---

## [bug for QVTKWidget with Qt5.9 and VTK8.0](https://discourse.vtk.org/t/bug-for-qvtkwidget-with-qt5-9-and-vtk8-0/1457)

<div class="topic-metadata">

**Author:** [@pbazavan](https://discourse.vtk.org/u/pbazavan)\
**Replies:** 1\
**Last updated:** [August 1, 2019, 2:26pm UTC](https://discourse.vtk.org/t/bug-for-qvtkwidget-with-qt5-9-and-vtk8-0/1457 "2019-08-01T14:26:51Z")

</div>

I have a bug when displaying a simple 3D vtk object in a Qt window using QVTKWidget. Hidden surfaces and visible surfaces are not well rendered. I’m using Qt 5.9 and VTK 8.0 on an Ubuntu system. Information on my compu…

---

## [superpose multi-Volume](https://discourse.vtk.org/t/superpose-multi-volume/1458)

<div class="topic-metadata">

**Author:** [@Moun](https://discourse.vtk.org/u/Moun)\
**Replies:** 1\
**Last updated:** [August 1, 2019, 2:23pm UTC](https://discourse.vtk.org/t/superpose-multi-volume/1458 "2019-08-01T14:23:51Z")

</div>

Hello, I need to show multi-volume in the same render. But, I can’t superpose them. How can I do that, please?

---

## [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…

---

## [Color individual vtkCells](https://discourse.vtk.org/t/color-individual-vtkcells/1465)

<div class="topic-metadata">

**Author:** [@Aramos](https://discourse.vtk.org/u/Aramos)\
**Replies:** 0\
**Last updated:** [August 1, 2019, 7:50am UTC](https://discourse.vtk.org/t/color-individual-vtkcells/1465 "2019-08-01T07:50:18Z")

</div>

Hi! I’m working with complex 3D models which I color with a vtkLookupTable, using their point data. This is working just fine, but now I need a way to highlight individual vtkCells by clicking them on the vtkRenderer. …

---

## [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…

---

## [Update information of the topic "Error GLSL 1.50 is not supported"](https://discourse.vtk.org/t/update-information-of-the-topic-error-glsl-1-50-is-not-supported/1450)

<div class="topic-metadata">

**Author:** [@pbazavan](https://discourse.vtk.org/u/pbazavan)\
**Replies:** 0\
**Last updated:** [July 30, 2019, 1:10pm UTC](https://discourse.vtk.org/t/update-information-of-the-topic-error-glsl-1-50-is-not-supported/1450 "2019-07-30T13:10:49Z")

</div>

Hello everybody, I come back to the topic “Error: GLSL 1.50 is not supported”. The error “GLSL 1.50 is not supported. Supported versions are: 1.10, 1.20, 1.30, 1.00 ES, and 3.00 ES” is generated when the context OpenGL…

---

## [Error: 0 connections](https://discourse.vtk.org/t/error-0-connections/1435)

<div class="topic-metadata">

**Author:** [@at123](https://discourse.vtk.org/u/at123)\
**Replies:** 1\
**Last updated:** [July 30, 2019, 12:56pm UTC](https://discourse.vtk.org/t/error-0-connections/1435 "2019-07-30T12:56:05Z")

</div>

Hello, I am trying to create a silhouette which highlights a box. I create a box with the standard lines of code, using vtkCubeSource, …, and vtkActor. 664 silhouette = vtk.vtkPolyDataSilhouette() 665 s…

---

## [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/…

[Previous page](https://discourse.vtk.org/latest.md?page=240)

[Next page](https://discourse.vtk.org/latest.md?page=242)