# Support

**URL:** https://discourse.vtk.org/c/support/6.md?page=150

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

**Page:** 151

---

## [Adding all vtkPoints at once](https://discourse.vtk.org/t/adding-all-vtkpoints-at-once/1652)

<div class="topic-metadata">

**Author:** [@jjackso2](https://discourse.vtk.org/u/jjackso2)\
**Replies:** 12\
**Last updated:** [August 28, 2019, 10:12pm UTC](https://discourse.vtk.org/t/adding-all-vtkpoints-at-once/1652 "2019-08-28T22:12:36Z")

</div>

Hi, I have a set of vtkPoints that keeps changing and I wish to refresh the screen with the new data as fast as possible. My problem is it seems like the data has to be in a vtkCell to be displayable. Adding points us…

---

## [Convert png to vti](https://discourse.vtk.org/t/convert-png-to-vti/1649)

<div class="topic-metadata">

**Author:** [@rjsgml5698](https://discourse.vtk.org/u/rjsgml5698)\
**Replies:** 4\
**Last updated:** [August 28, 2019, 4:58am UTC](https://discourse.vtk.org/t/convert-png-to-vti/1649 "2019-08-28T04:58:44Z")

</div>

Hello! I want to convert png to vti. However, the following code does not work correctly. import os import cv2 import numpy as np import pydicom import matplotlib.pylab as plt from glob import glob def dividePa…

---

## [Find the triangle on a sphere](https://discourse.vtk.org/t/find-the-triangle-on-a-sphere/1655)

<div class="topic-metadata">

**Author:** [@Elvis723](https://discourse.vtk.org/u/Elvis723)\
**Replies:** 4\
**Last updated:** [August 28, 2019, 3:21am UTC](https://discourse.vtk.org/t/find-the-triangle-on-a-sphere/1655 "2019-08-28T03:21:19Z")

</div>

Hi! I want to find the triangle that contains a certain point on a sphere in vtk. How should I do that? I knew that spheres in vtk are by default approximated by triangles. Thanks in advance!

---

## [Streamlines using unstructered grid.](https://discourse.vtk.org/t/streamlines-using-unstructered-grid/793)

<div class="topic-metadata">

**Author:** [@sariug](https://discourse.vtk.org/u/sariug)\
**Replies:** 2\
**Last updated:** [August 26, 2019, 9:33pm UTC](https://discourse.vtk.org/t/streamlines-using-unstructered-grid/793 "2019-08-26T21:33:05Z")

</div>

Hello, I am quite new to VTK library. I have a data which is unstructered grid. While paraview is able to visualize it in a second, I couldnt find a way to do it in c++. Does any of you have experience with this ? Be…

---

## [sending vtk from server to client](https://discourse.vtk.org/t/sending-vtk-from-server-to-client/1653)

<div class="topic-metadata">

**Author:** [@sariug](https://discourse.vtk.org/u/sariug)\
**Replies:** 0\
**Last updated:** [August 26, 2019, 9:11pm UTC](https://discourse.vtk.org/t/sending-vtk-from-server-to-client/1653 "2019-08-26T21:11:41Z")

</div>

Hello all, In my server-client application(C++) I use VTK for streamline creating. I use UDP for server-client communication due to broadcasting reasong. However, since vtk files are more than 65 kb. I cant send them a…

---

## [How can I write vtkStructuredGrid data in Parallel by using MPI?](https://discourse.vtk.org/t/how-can-i-write-vtkstructuredgrid-data-in-parallel-by-using-mpi/1644)

<div class="topic-metadata">

**Author:** [@myousefi2016](https://discourse.vtk.org/u/myousefi2016)\
**Replies:** 0\
**Last updated:** [August 23, 2019, 1:48pm UTC](https://discourse.vtk.org/t/how-can-i-write-vtkstructuredgrid-data-in-parallel-by-using-mpi/1644 "2019-08-23T13:48:39Z")

</div>

I have a C++ program that use MPI for parallelization. I’m trying to write my output as vtkStructuredGrid format in parallel. In fact, I have this function to write the vtk files: void vtkParallelWriter(int argc, char \*…

---

## [how to make the same window width/level at MPR](https://discourse.vtk.org/t/how-to-make-the-same-window-width-level-at-mpr/1638)

<div class="topic-metadata">

**Author:** [@pingdan](https://discourse.vtk.org/u/pingdan)\
**Replies:** 1\
**Last updated:** [August 23, 2019, 5:10am UTC](https://discourse.vtk.org/t/how-to-make-the-same-window-width-level-at-mpr/1638 "2019-08-23T05:10:32Z")

</div>

I can get MPR views use vtkImagePlaneWidget vtkResliceCursorWidget and so on. I can through SetInteractorStyle function to set mouse event. when I change one of the views’s window width/level with drag mouse, I wish the…

---

## [vtkAppendPolyData - performance increase?](https://discourse.vtk.org/t/vtkappendpolydata-performance-increase/1590)

<div class="topic-metadata">

**Author:** [@Mskovmand](https://discourse.vtk.org/u/Mskovmand)\
**Replies:** 8\
**Last updated:** [August 22, 2019, 11:14am UTC](https://discourse.vtk.org/t/vtkappendpolydata-performance-increase/1590 "2019-08-22T11:14:46Z")

</div>

Hello there, I’m trying to visualize a highly dense mesh. I have the coordinates and the connectivity of said coordinates. I have already succeeded in showing the mesh, however, after my initial testing, I received a s…

---

## [Extracting Triangles from PolyData while keeping geometry and topology](https://discourse.vtk.org/t/extracting-triangles-from-polydata-while-keeping-geometry-and-topology/1557)

<div class="topic-metadata">

**Author:** [@burgadon](https://discourse.vtk.org/u/burgadon)\
**Replies:** 7\
**Last updated:** [August 22, 2019, 10:29am UTC](https://discourse.vtk.org/t/extracting-triangles-from-polydata-while-keeping-geometry-and-topology/1557 "2019-08-22T10:29:13Z")

</div>

Hello, I’m trying to extract triangles from a PolyData object depending on the direction in which the triangle faces. These PolyData objects are shaped like a slice of pineapple. Round with a hole in the middle and much…

---

## [Add simple slider to QVTKOpenGLWidget](https://discourse.vtk.org/t/add-simple-slider-to-qvtkopenglwidget/1631)

<div class="topic-metadata">

**Author:** [@NewProggie](https://discourse.vtk.org/u/NewProggie)\
**Replies:** 0\
**Last updated:** [August 21, 2019, 1:01pm UTC](https://discourse.vtk.org/t/add-simple-slider-to-qvtkopenglwidget/1631 "2019-08-21T13:01:24Z")

</div>

Hi all, I’m trying to add a simple VTK based 2D slider to a QVTKOpenGLWidget, but it doesn’t show up no matter what I’ve tried. Following is a minimized example that shows what I’m trying to do. Can anybody help me out …

---

## [vtkPProbeFilter?](https://discourse.vtk.org/t/vtkpprobefilter/1619)

<div class="topic-metadata">

**Author:** [@Sean](https://discourse.vtk.org/u/Sean)\
**Replies:** 0\
**Last updated:** [August 19, 2019, 6:27pm UTC](https://discourse.vtk.org/t/vtkpprobefilter/1619 "2019-08-19T18:27:51Z")

</div>

I am trying to develop a real time data probe application and the vtkProbeFilter seems with lagging (probing image generation delay) issue on my case. I felt that one potential solution is parallel data processing throug…

---

## [Animating using vtk.js](https://discourse.vtk.org/t/animating-using-vtk-js/1604)

<div class="topic-metadata">

**Author:** [@Misha](https://discourse.vtk.org/u/Misha)\
**Replies:** 3\
**Last updated:** [August 19, 2019, 2:02pm UTC](https://discourse.vtk.org/t/animating-using-vtk-js/1604 "2019-08-19T14:02:10Z")

</div>

Hi, I have vtk files with data that changes over time. Is it possible to animate the data?

---

## [Save PolyData to CSV using vtkDelimitedTextWriter](https://discourse.vtk.org/t/save-polydata-to-csv-using-vtkdelimitedtextwriter/986)

<div class="topic-metadata">

**Author:** [@NWRichmond](https://discourse.vtk.org/u/NWRichmond)\
**Replies:** 4\
**Last updated:** [May 22, 2019, 1:03am UTC](https://discourse.vtk.org/t/save-polydata-to-csv-using-vtkdelimitedtextwriter/986 "2019-05-22T01:03:19Z")

</div>

I have a VTK file containing 83 points, and I’m trying to use the Python VTK module (no Paraview, no NumPy) to save this data as a CSV file. After looking at a variety of examples, I wrote a script which aims to read the…

---

## [Textured Terrain being inverted](https://discourse.vtk.org/t/textured-terrain-being-inverted/1558)

<div class="topic-metadata">

**Author:** [@tbenega](https://discourse.vtk.org/u/tbenega)\
**Replies:** 2\
**Last updated:** [August 19, 2019, 1:16pm UTC](https://discourse.vtk.org/t/textured-terrain-being-inverted/1558 "2019-08-19T13:16:40Z")

</div>

Hello guys, In my script, I’m applying a texture to a terrain that I’ve created using points. The issue is that when I’ve elevation (z \> 0) the texture is flipped by Z as you can see on the attached image (left is the o…

---

## [Fine Grid 100x100](https://discourse.vtk.org/t/fine-grid-100x100/1493)

<div class="topic-metadata">

**Author:** [@Vaya\_Putra](https://discourse.vtk.org/u/Vaya_Putra)\
**Replies:** 2\
**Last updated:** [August 17, 2019, 3:55pm UTC](https://discourse.vtk.org/t/fine-grid-100x100/1493 "2019-08-17T15:55:03Z")

</div>

hi i want to make unstructured grid 100x100x1 by using calculation in excel then i write in vtk file. i figure out the error in line 443 but still struggle. if there anyone do same problem with me . so i can not vis…

---

## [How to probe a polygonal mesh on a polydata?](https://discourse.vtk.org/t/how-to-probe-a-polygonal-mesh-on-a-polydata/1323)

<div class="topic-metadata">

**Author:** [@bdemin](https://discourse.vtk.org/u/bdemin)\
**Replies:** 4\
**Last updated:** [August 15, 2019, 10:46am UTC](https://discourse.vtk.org/t/how-to-probe-a-polygonal-mesh-on-a-polydata/1323 "2019-08-15T10:46:30Z")

</div>

I’m running a multi-body simulation of a vehicle driving on a rocky terrain and need to get the elevation data of the terrain. The terrain is built from 2 parts: 2D grid of elevation data. “Rocks” which are defined a…

---

## [which function can get the slice size extract by vtkImageReslice?](https://discourse.vtk.org/t/which-function-can-get-the-slice-size-extract-by-vtkimagereslice/1584)

<div class="topic-metadata">

**Author:** [@pingdan](https://discourse.vtk.org/u/pingdan)\
**Replies:** 7\
**Last updated:** [August 15, 2019, 8:32am UTC](https://discourse.vtk.org/t/which-function-can-get-the-slice-size-extract-by-vtkimagereslice/1584 "2019-08-15T08:32:36Z")

</div>

I want to get a slice by codes as below, and I can get the image.but I want to know how to get the slice image’s size, its width and height. static double obliqueX\[3\] = { cos(angle), 0, -sin(angle) }; static double o…

---

## [Different behaviour of DecimatePro and SmoothPolyData depending on OS](https://discourse.vtk.org/t/different-behaviour-of-decimatepro-and-smoothpolydata-depending-on-os/1583)

<div class="topic-metadata">

**Author:** [@vianamp](https://discourse.vtk.org/u/vianamp)\
**Replies:** 1\
**Last updated:** [August 14, 2019, 5:54pm UTC](https://discourse.vtk.org/t/different-behaviour-of-decimatepro-and-smoothpolydata-depending-on-os/1583 "2019-08-14T17:54:20Z")

</div>

Hi guys. Quick question. I am running a combination of DecimatePro + SmoothPolyData on a mesh of about 70K vertices. I am getting different results depending on the OS I use. Running on OS X I get a final mesh with abou…

---

## [Fixed Point ray cast does not render properly 2 components](https://discourse.vtk.org/t/fixed-point-ray-cast-does-not-render-properly-2-components/1581)

<div class="topic-metadata">

**Author:** [@P.TURLAIS](https://discourse.vtk.org/u/P.TURLAIS)\
**Replies:** 0\
**Last updated:** [August 14, 2019, 2:33pm UTC](https://discourse.vtk.org/t/fixed-point-ray-cast-does-not-render-properly-2-components/1581 "2019-08-14T14:33:38Z")

</div>

Hi, I have some troubles with FixedPointVolumeRayCastMapper when using 2 components. I have created a simple test in Python. The dataset is a set of planes convolved with a sinc with 3 lobes along the x axis. The tran…

---

## [QVTKWidget render window is outside main Qt app window](https://discourse.vtk.org/t/qvtkwidget-render-window-is-outside-main-qt-app-window/1539)

<div class="topic-metadata">

**Author:** [@Edoardo\_Pasca](https://discourse.vtk.org/u/Edoardo_Pasca)\
**Replies:** 10\
**Last updated:** [August 14, 2019, 12:31pm UTC](https://discourse.vtk.org/t/qvtkwidget-render-window-is-outside-main-qt-app-window/1539 "2019-08-14T12:31:53Z")

</div>

Hi all, I put together a VTK viewer in Python. I also extended QVTKWidget to host the viewer in a Qt app. It all looks and works fine with Qt 5.9.7 and VTK 8.1.2 on windows (in a conda environment). If I set up the “sa…

---

## [Problems and questions using vtkSmartVolumeMapper for large volume streaming and rendering](https://discourse.vtk.org/t/problems-and-questions-using-vtksmartvolumemapper-for-large-volume-streaming-and-rendering/656)

<div class="topic-metadata">

**Author:** [@csparker247](https://discourse.vtk.org/u/csparker247)\
**Replies:** 18\
**Last updated:** [August 14, 2019, 9:29am UTC](https://discourse.vtk.org/t/problems-and-questions-using-vtksmartvolumemapper-for-large-volume-streaming-and-rendering/656 "2019-08-14T09:29:02Z")

</div>

I need to volume render datasets with a wide range of volume sizes: 5-120GBs is common and 120GB+ are rare but still happen. This will mostly be for non-interactive scenarios (predefined animations or stills), so I can a…

---

## [how to get the image postion](https://discourse.vtk.org/t/how-to-get-the-image-postion/1535)

<div class="topic-metadata">

**Author:** [@pingdan](https://discourse.vtk.org/u/pingdan)\
**Replies:** 2\
**Last updated:** [August 13, 2019, 8:12am UTC](https://discourse.vtk.org/t/how-to-get-the-image-postion/1535 "2019-08-13T08:12:39Z")

</div>

as the graph.I show a picture in a renderer, and I know the renderer size and the picture size.when I press left button down, I can get a point position in the renderer. I want to judge if the point locate on picture. …

---

## [intersection two stl](https://discourse.vtk.org/t/intersection-two-stl/1550)

<div class="topic-metadata">

**Author:** [@vahid\_rastgoo](https://discourse.vtk.org/u/vahid_rastgoo)\
**Replies:** 7\
**Last updated:** [August 13, 2019, 1:46am UTC](https://discourse.vtk.org/t/intersection-two-stl/1550 "2019-08-13T01:46:03Z")

</div>

Hello beloveds How to find out if two stl files collided or collapsed in vtk with python But I don’t want to use the vtkcollisiondetectionfilter class, is there any other way?

---

## [glFog or depth cueing](https://discourse.vtk.org/t/glfog-or-depth-cueing/1566)

<div class="topic-metadata">

**Author:** [@fcollman](https://discourse.vtk.org/u/fcollman)\
**Replies:** 1\
**Last updated:** [August 13, 2019, 1:15am UTC](https://discourse.vtk.org/t/glfog-or-depth-cueing/1566 "2019-08-13T01:15:31Z")

</div>

I couldn’t figure out how in vtk to get a rendering effect like ‘fog’ where things fade as they get farther away from the camera. This is sometimes called ‘depth cueing’ such as in this product… http://docs.pixologic.c…

---

## [Python VTK for visualization in a jupyter notebook running on docker](https://discourse.vtk.org/t/python-vtk-for-visualization-in-a-jupyter-notebook-running-on-docker/622)

<div class="topic-metadata">

**Author:** [@harp](https://discourse.vtk.org/u/harp)\
**Replies:** 8\
**Last updated:** [August 12, 2019, 10:45pm UTC](https://discourse.vtk.org/t/python-vtk-for-visualization-in-a-jupyter-notebook-running-on-docker/622 "2019-08-12T22:45:04Z")

</div>

Hi - I’d like to use python vtk to visualize objects in a jupyter notebook. I am able to run the notebook locally on my machine and it works. However, I am unable to run it when the jupyter notebook is running in docker …

---

## [is it possible to use vtkDistanceToCamera to keep an actor size fixed without using vtkGlyph3D](https://discourse.vtk.org/t/is-it-possible-to-use-vtkdistancetocamera-to-keep-an-actor-size-fixed-without-using-vtkglyph3d/1559)

<div class="topic-metadata">

**Author:** [@embeddedmz](https://discourse.vtk.org/u/embeddedmz)\
**Replies:** 1\
**Last updated:** [August 12, 2019, 2:45pm UTC](https://discourse.vtk.org/t/is-it-possible-to-use-vtkdistancetocamera-to-keep-an-actor-size-fixed-without-using-vtkglyph3d/1559 "2019-08-12T14:45:59Z")

</div>

Hi, First of all, there’s this example : https://vtk.org/Wiki/VTK/Examples/Cxx/Visualization/DistanceToCamera that shows how to keep 2 arrows size fixed, whatever the camera zoom level using vtkDistanceToCamera and vtkG…

---

## [OSPRay features supported in vtkOSPRayRenderNode](https://discourse.vtk.org/t/ospray-features-supported-in-vtkosprayrendernode/1489)

<div class="topic-metadata">

**Author:** [@Sean\_Curtis](https://discourse.vtk.org/u/Sean_Curtis)\
**Replies:** 7\
**Last updated:** [August 12, 2019, 1:41pm UTC](https://discourse.vtk.org/t/ospray-features-supported-in-vtkosprayrendernode/1489 "2019-08-12T13:41:16Z")

</div>

I’m having difficulty reasoning about documented OSPRay functionality and how to access it via VTK. Is there some definitive document somewhere that articulates that mapping that I’ve missed? Or is there some philosophic…

---

## [Segfault with QVTKWidget](https://discourse.vtk.org/t/segfault-with-qvtkwidget/1545)

<div class="topic-metadata">

**Author:** [@Gib\_Bogle](https://discourse.vtk.org/u/Gib_Bogle)\
**Replies:** 2\
**Last updated:** [August 11, 2019, 11:40pm UTC](https://discourse.vtk.org/t/segfault-with-qvtkwidget/1545 "2019-08-11T23:40:16Z")

</div>

The following code works on Windows, but the last line causes a crash on Linux (Ubuntu 16.04): (page\_VTK points to a QMdiArea widget that has been created on a form) qvtkWidget = new QVTKWidget(page\_VTK,QFlag(0)); QVB…

---

## [Empty position in Rectlinear \_grid dataset](https://discourse.vtk.org/t/empty-position-in-rectlinear-grid-dataset/1512)

<div class="topic-metadata">

**Author:** [@Jiaxiang\_Wang](https://discourse.vtk.org/u/Jiaxiang_Wang)\
**Replies:** 1\
**Last updated:** [August 11, 2019, 4:16am UTC](https://discourse.vtk.org/t/empty-position-in-rectlinear-grid-dataset/1512 "2019-08-11T04:16:38Z")

</div>

Hi, For a rectlinear grid data set vtk file, it give the range of x,y,z coordinate. Then for each position, it will give a voxel (a number). Is there a way to declare that position doesn’t contain any voxel. For exampl…

---

## [How can I use a vtk interactor with an external event loop?](https://discourse.vtk.org/t/how-can-i-use-a-vtk-interactor-with-an-external-event-loop/335)

<div class="topic-metadata">

**Author:** [@langer](https://discourse.vtk.org/u/langer)\
**Replies:** 1\
**Last updated:** [August 9, 2019, 11:32am UTC](https://discourse.vtk.org/t/how-can-i-use-a-vtk-interactor-with-an-external-event-loop/335 "2019-08-09T11:32:48Z")

</div>

I have a program that has a GUI written in gtk+2 and uses vtk for 3D graphics. Currently we handle all mouse and keyboard events in gtk+2, and don’t use a vtkRenderWindowInteractor at all. We call vtk methods in respo…

[Previous page](https://discourse.vtk.org/c/support/6.md?page=149)

[Next page](https://discourse.vtk.org/c/support/6.md?page=151)