# Latest

**URL:** https://discourse.vtk.org/latest.md?page=185

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

**Page:** 186

---

## [VTKAxisActor color](https://discourse.vtk.org/t/vtkaxisactor-color/2644)

<div class="topic-metadata">

**Author:** [@Nicolas\_Lenoir](https://discourse.vtk.org/u/Nicolas_Lenoir)\
**Replies:** 5\
**Last updated:** [February 14, 2021, 2:16pm UTC](https://discourse.vtk.org/t/vtkaxisactor-color/2644 "2021-02-14T14:16:50Z")

</div>

Hello, I have a problem with the color change of my VTKAxisActor. I want to make it more visible on my images but when I change the property color, the color is change in memory but I didn’t see any change. To make a te…

---

## [the visibility of the cursor in vtkResliceImageViewer](https://discourse.vtk.org/t/the-visibility-of-the-cursor-in-vtkresliceimageviewer/4388)

<div class="topic-metadata">

**Author:** [@yuhuimoon](https://discourse.vtk.org/u/yuhuimoon)\
**Replies:** 2\
**Last updated:** [February 14, 2021, 2:35am UTC](https://discourse.vtk.org/t/the-visibility-of-the-cursor-in-vtkresliceimageviewer/4388 "2021-02-14T02:35:35Z")

</div>

I use my custom class (SliceViewRender) derived from vtkResliceImageViewer to show vtkImageData slice. I have called SetResliceModeToOblique and the crosshair can display exactly. I want to change the visibility of the c…

---

## [How do I inflate a mesh in vtk?](https://discourse.vtk.org/t/how-do-i-inflate-a-mesh-in-vtk/5178)

<div class="topic-metadata">

**Author:** [@ymmx2](https://discourse.vtk.org/u/ymmx2)\
**Replies:** 5\
**Last updated:** [February 12, 2021, 3:58pm UTC](https://discourse.vtk.org/t/how-do-i-inflate-a-mesh-in-vtk/5178 "2021-02-12T15:58:50Z")

</div>

I displayed a mesh with vtk and I need to make the mesh looking more like it is inflated The mesh has a lot of curves and I’m not able to get the result I expect. Here’s what I tried so far: the original mesh look lik…

---

## [Following the mouse coordinates in Z when I drag a line in space](https://discourse.vtk.org/t/following-the-mouse-coordinates-in-z-when-i-drag-a-line-in-space/5175)

<div class="topic-metadata">

**Author:** [@zandarina](https://discourse.vtk.org/u/zandarina)\
**Replies:** 0\
**Last updated:** [February 12, 2021, 8:17am UTC](https://discourse.vtk.org/t/following-the-mouse-coordinates-in-z-when-i-drag-a-line-in-space/5175 "2021-02-12T08:17:22Z")

</div>

Hello, I am trying to program a gizmo with translation what I want is from the point I click on an axis (point of a line) to keep the same position while I drag the line while I move the mouse. The problem comes with Z …

---

## [Addition: stack vector](https://discourse.vtk.org/t/addition-stack-vector/5168)

<div class="topic-metadata">

**Author:** [@Thomas\_Caissard](https://discourse.vtk.org/u/Thomas_Caissard)\
**Replies:** 8\
**Last updated:** [February 11, 2021, 12:20pm UTC](https://discourse.vtk.org/t/addition-stack-vector/5168 "2021-02-11T12:20:30Z")

</div>

There are some places in VTK that could be improved using an array-like data structure: it would lie on the stack if its size is less than a compile-time knows size (typically twice the cache line size) otherwise lie on …

---

## [Can I display different boxwidgets in different render?](https://discourse.vtk.org/t/can-i-display-different-boxwidgets-in-different-render/5171)

<div class="topic-metadata">

**Author:** [@timeanddoctor](https://discourse.vtk.org/u/timeanddoctor)\
**Replies:** 0\
**Last updated:** [February 11, 2021, 6:17am UTC](https://discourse.vtk.org/t/can-i-display-different-boxwidgets-in-different-render/5171 "2021-02-11T06:17:04Z")

</div>

How can I display different boxwidgets in different render? boxWidget2.SetProp3D(selectActor) boxWidget2.PlaceWidget() boxWidget2.On() boxWidget2.AddObserver(“InteractionEvent”, TransformActor) ren2.AddViewProp(boxW…

---

## [Removal of math.h from VTK headers](https://discourse.vtk.org/t/removal-of-math-h-from-vtk-headers/5163)

<div class="topic-metadata">

**Author:** [@dgobbi](https://discourse.vtk.org/u/dgobbi)\
**Replies:** 5\
**Last updated:** [February 10, 2021, 7:43pm UTC](https://discourse.vtk.org/t/removal-of-math-h-from-vtk-headers/5163 "2021-02-10T19:43:50Z")

</div>

In !7572, I remove #include \<math.h\> from vtkSetGet.h (which is included by all VTK class headers). The reason for the removal is modernization of the code, but of course it will cause some (easily fixed) compile errors …

---

## [Turn off arrow for vtkImplicitPlaneWidget](https://discourse.vtk.org/t/turn-off-arrow-for-vtkimplicitplanewidget/1925)

<div class="topic-metadata">

**Author:** [@banesullivan](https://discourse.vtk.org/u/banesullivan)\
**Replies:** 2\
**Last updated:** [February 10, 2021, 6:12pm UTC](https://discourse.vtk.org/t/turn-off-arrow-for-vtkimplicitplanewidget/1925 "2021-02-10T18:12:59Z")

</div>

Is it possible to turn off the normal vector/arrow for the vtk.vtkImplicitPlaneWidget class? I’d like to have a plane widget that is set to be orthogonal to an axis and I don’t want to accidentally click the arrow to rot…

---

## [How to calculate the cross point between line and mask](https://discourse.vtk.org/t/how-to-calculate-the-cross-point-between-line-and-mask/5159)

<div class="topic-metadata">

**Author:** [@zhang-qiang-github](https://discourse.vtk.org/u/zhang-qiang-github)\
**Replies:** 5\
**Last updated:** [February 10, 2021, 12:58pm UTC](https://discourse.vtk.org/t/how-to-calculate-the-cross-point-between-line-and-mask/5159 "2021-02-10T12:58:21Z")

</div>

For a line, it will intersect with mask for several points, then I want to calculate the intersection point. For example: mask = np.zeros(\[300, 300, 50\]) mask\[:, :, 10:30\] = 1 Then, the line is: p1 = \[100, 100, -1\] …

---

## [Support for pathlib](https://discourse.vtk.org/t/support-for-pathlib/5085)

<div class="topic-metadata">

**Author:** [@fepegar](https://discourse.vtk.org/u/fepegar)\
**Replies:** 13\
**Last updated:** [February 9, 2021, 6:31pm UTC](https://discourse.vtk.org/t/support-for-pathlib/5085 "2021-02-09T18:31:08Z")

</div>

Hi all, Are there any plans to add pathlib support for the Python wrappers? (I’ve been recommended to ping @dgobbi about this)

---

## [Cut of AMR dataset](https://discourse.vtk.org/t/cut-of-amr-dataset/5162)

<div class="topic-metadata">

**Author:** [@hakostra](https://discourse.vtk.org/u/hakostra)\
**Replies:** 0\
**Last updated:** [February 9, 2021, 2:22pm UTC](https://discourse.vtk.org/t/cut-of-amr-dataset/5162 "2021-02-09T14:22:22Z")

</div>

I have a simulation code that write out an hierarchical octree grid structure. The coarsest level is filled, and then comes finer levels on top where refinement is needed. Each level is built of small Cartesian grids of …

---

## [VTK manipulation of image in memory.](https://discourse.vtk.org/t/vtk-manipulation-of-image-in-memory/5157)

<div class="topic-metadata">

**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 3\
**Last updated:** [February 8, 2021, 9:44pm UTC](https://discourse.vtk.org/t/vtk-manipulation-of-image-in-memory/5157 "2021-02-08T21:44:08Z")

</div>

Dear All, I have a 3D .mhd file. Then I visualize that file with VTK. I determine a region of that image to crop. How I reflect the crop in the visualization. Have I to crop the .mhd image in memory and redisplay? Are…

---

## [Need help: Trying to have multiple orthogonal viewpoint of same image.](https://discourse.vtk.org/t/need-help-trying-to-have-multiple-orthogonal-viewpoint-of-same-image/5146)

<div class="topic-metadata">

**Author:** [@wasim92007](https://discourse.vtk.org/u/wasim92007)\
**Replies:** 11\
**Last updated:** [February 8, 2021, 8:02pm UTC](https://discourse.vtk.org/t/need-help-trying-to-have-multiple-orthogonal-viewpoint-of-same-image/5146 "2021-02-08T20:02:09Z")

</div>

Hi, I am trying to add multiple orthogonal views of the same image using vtk.js. I have duplicated the procedure for loading on volume slicing twice to achieve the goal. For some reason, the 2nd view is not working. …

---

## [How to represent multiple actors with one single actor?](https://discourse.vtk.org/t/how-to-represent-multiple-actors-with-one-single-actor/5150)

<div class="topic-metadata">

**Author:** [@11114](https://discourse.vtk.org/u/11114)\
**Replies:** 4\
**Last updated:** [February 8, 2021, 2:41pm UTC](https://discourse.vtk.org/t/how-to-represent-multiple-actors-with-one-single-actor/5150 "2021-02-08T14:41:23Z")

</div>

my problem is I have got a 3D hammer model that formed by multiple cells which means multiple actors and mappers should be present in the scene , so is there any way I can make these hammer represent by a single actor(i.…

---

## [How to calculate the volume and surface area of an actor in vtk js?](https://discourse.vtk.org/t/how-to-calculate-the-volume-and-surface-area-of-an-actor-in-vtk-js/5071)

<div class="topic-metadata">

**Author:** [@Jiayi](https://discourse.vtk.org/u/Jiayi)\
**Replies:** 2\
**Last updated:** [February 7, 2021, 9:31am UTC](https://discourse.vtk.org/t/how-to-calculate-the-volume-and-surface-area-of-an-actor-in-vtk-js/5071 "2021-02-07T09:31:18Z")

</div>

Hello, I have created an actor with the following js code: var polydata = vtk.Common.DataModel.vtkPolyData.newInstance(); polydata.getPoints().setData(Float32Array.from(vertexArray), 3); polydata.getPolys()…

---

## [Learning VTK, with a 3D graphics geometry mindset](https://discourse.vtk.org/t/learning-vtk-with-a-3d-graphics-geometry-mindset/2130)

<div class="topic-metadata">

**Author:** [@cesss](https://discourse.vtk.org/u/cesss)\
**Replies:** 9\
**Last updated:** [February 6, 2021, 10:52pm UTC](https://discourse.vtk.org/t/learning-vtk-with-a-3d-graphics-geometry-mindset/2130 "2021-02-06T22:52:09Z")

</div>

Hi! I’m struggling to understand both the Textbook and the User’s Guide PDFs, because my knowledge is very heavily 3D CG-focused (you know: mesh data, mesh animation, lighting/materials, etc), and while these two books …

---

## [Why does vtkCamera auto adjust camera position after something rendered.](https://discourse.vtk.org/t/why-does-vtkcamera-auto-adjust-camera-position-after-something-rendered/3678)

<div class="topic-metadata">

**Author:** [@veltia](https://discourse.vtk.org/u/veltia)\
**Replies:** 0\
**Last updated:** [July 1, 2020, 7:54am UTC](https://discourse.vtk.org/t/why-does-vtkcamera-auto-adjust-camera-position-after-something-rendered/3678 "2020-07-01T07:54:27Z")

</div>

Hi all, I tried to set vtkCamera to make the origin of world coordinate to be the middle of the render window. It works if theres only a AxesActor display at the orgin. (actorAxes-\>SetPosition(0, 0, 0); But when I t…

---

## [4 pane view similar to Paraview Glance using vtk.js](https://discourse.vtk.org/t/4-pane-view-similar-to-paraview-glance-using-vtk-js/5145)

<div class="topic-metadata">

**Author:** [@wasim92007](https://discourse.vtk.org/u/wasim92007)\
**Replies:** 2\
**Last updated:** [February 5, 2021, 7:21pm UTC](https://discourse.vtk.org/t/4-pane-view-similar-to-paraview-glance-using-vtk-js/5145 "2021-02-05T19:21:34Z")

</div>

Hi, Is there any tutorial/example on creating a 4 pane view similar to Paraview Glance using vtk.js? Thanks in advance.

---

## [Two overlapping vtkPolyData render flashes](https://discourse.vtk.org/t/two-overlapping-vtkpolydata-render-flashes/5136)

<div class="topic-metadata">

**Author:** [@Lisa](https://discourse.vtk.org/u/Lisa)\
**Replies:** 1\
**Last updated:** [February 5, 2021, 2:45pm UTC](https://discourse.vtk.org/t/two-overlapping-vtkpolydata-render-flashes/5136 "2021-02-05T14:45:36Z")

</div>

Hi everybody, I would like to render two overlapping vtkPolyData using two different color(white and yellow) maps in the same renderer. i want to show yellow vtkPolyData. but, The result is as shown in the figure. what …

---

## [About API breaking changes](https://discourse.vtk.org/t/about-api-breaking-changes/1339)

<div class="topic-metadata">

**Author:** [@mwestphal](https://discourse.vtk.org/u/mwestphal)\
**Replies:** 24\
**Last updated:** [February 4, 2021, 9:08am UTC](https://discourse.vtk.org/t/about-api-breaking-changes/1339 "2021-02-04T09:08:50Z")

</div>

On a ParaView MR, we started having a discussion which should be discussed here. https://gitlab.kitware.com/paraview/paraview/merge\_requests/3396 ParaView uses VTK as a submodule and usually the developer that update t…

---

## [Rendering a polyline on the top of other lines](https://discourse.vtk.org/t/rendering-a-polyline-on-the-top-of-other-lines/5069)

<div class="topic-metadata">

**Author:** [@Faizan](https://discourse.vtk.org/u/Faizan)\
**Replies:** 2\
**Last updated:** [February 3, 2021, 6:03pm UTC](https://discourse.vtk.org/t/rendering-a-polyline-on-the-top-of-other-lines/5069 "2021-02-03T18:03:28Z")

</div>

Hello developers, Hello developers, I am stuck in a problem that seems a bit basic but still could not solve it yet. I am using multiple rendering layers to render different kinds of Fiber tracts (Red and orange) over…

---

## [Issue with import vtk in Python](https://discourse.vtk.org/t/issue-with-import-vtk-in-python/5133)

<div class="topic-metadata">

**Author:** [@IVarha](https://discourse.vtk.org/u/IVarha)\
**Replies:** 1\
**Last updated:** [February 3, 2021, 3:35pm UTC](https://discourse.vtk.org/t/issue-with-import-vtk-in-python/5133 "2021-02-03T15:35:13Z")

</div>

Hello VTK community I receive vtk import error in python when I trying to import vtk Traceback (most recent call last): File “/home/varga/venvs/pystn/lib/python3.7/site-packages/vtkmodules/init.py”, line 13, in from …

---

## [crush issue vtk python on google colab](https://discourse.vtk.org/t/crush-issue-vtk-python-on-google-colab/5125)

<div class="topic-metadata">

**Author:** [@COK](https://discourse.vtk.org/u/COK)\
**Replies:** 3\
**Last updated:** [February 3, 2021, 2:43pm UTC](https://discourse.vtk.org/t/crush-issue-vtk-python-on-google-colab/5125 "2021-02-03T14:43:35Z")

</div>

Hello everyone I am trying to use vtk in google colab My tests with simplest vtk code such as circle is returning the crush of kernel each time with an unknown error. I traced back the line that the code crushes with …

---

## [Tutorial using react-vtkjs-viewport](https://discourse.vtk.org/t/tutorial-using-react-vtkjs-viewport/4208)

<div class="topic-metadata">

**Author:** [@donkie](https://discourse.vtk.org/u/donkie)\
**Replies:** 3\
**Last updated:** [February 3, 2021, 2:32pm UTC](https://discourse.vtk.org/t/tutorial-using-react-vtkjs-viewport/4208 "2021-02-03T14:32:03Z")

</div>

Hi, I’ve used VTK before for C++ desktop application and liked it a lot. I’m interested in using VTK on the web, and would like to try it with React. Is there somewhere a tutorial or code that you can point me to please…

---

## [vtkCelllocator slow in the version VTK 9 than VTK 8](https://discourse.vtk.org/t/vtkcelllocator-slow-in-the-version-vtk-9-than-vtk-8/5068)

<div class="topic-metadata">

**Author:** [@Ahmed](https://discourse.vtk.org/u/Ahmed)\
**Replies:** 6\
**Last updated:** [February 3, 2021, 1:41pm UTC](https://discourse.vtk.org/t/vtkcelllocator-slow-in-the-version-vtk-9-than-vtk-8/5068 "2021-02-03T13:41:04Z")

</div>

Hi, I compare the performance of vtkCelllocator in vtk 9 compared to the VTK 8, I use FindClosestPoint method I find that the VTK 9 is 2x more slow than VTK 8 Did some people identify the same problem ? What is the so…

---

## [Get normals coordinates](https://discourse.vtk.org/t/get-normals-coordinates/5124)

<div class="topic-metadata">

**Author:** [@Anastasiia](https://discourse.vtk.org/u/Anastasiia)\
**Replies:** 4\
**Last updated:** [February 3, 2021, 11:35am UTC](https://discourse.vtk.org/t/get-normals-coordinates/5124 "2021-02-03T11:35:14Z")

</div>

Hi VTK community, Is there any options to get X,Y,Z coordinates of the cell normals? Currently I have the following code: normals = vtk.vtkPPolyDataNormals() normals.SetInputConnection(decimate.GetOutputPort()) norm…

---

## [IOS Scencekit support vtp?](https://discourse.vtk.org/t/ios-scencekit-support-vtp/5131)

<div class="topic-metadata">

**Author:** [@menhuan](https://discourse.vtk.org/u/menhuan)\
**Replies:** 0\
**Last updated:** [February 3, 2021, 9:49am UTC](https://discourse.vtk.org/t/ios-scencekit-support-vtp/5131 "2021-02-03T09:49:19Z")

</div>

how do we load vtp by using scenekit.?

---

## [Hidden edges are visible on VTK 9.0.0](https://discourse.vtk.org/t/hidden-edges-are-visible-on-vtk-9-0-0/5112)

<div class="topic-metadata">

**Author:** [@Flagada](https://discourse.vtk.org/u/Flagada)\
**Replies:** 5\
**Last updated:** [February 3, 2021, 9:35am UTC](https://discourse.vtk.org/t/hidden-edges-are-visible-on-vtk-9-0-0/5112 "2021-02-03T09:35:32Z")

</div>

Hi all! I have recently encountered a problem when updating my code from VTK 8 to VTK 9 on my python/qt5/vtk app. The only change in my installation is an update from VTK 8.1.2 to VTK 9.0.0 and this is the strange beha…

---

## [How to load nrrd file types in vtk.js](https://discourse.vtk.org/t/how-to-load-nrrd-file-types-in-vtk-js/5118)

<div class="topic-metadata">

**Author:** [@wasim92007](https://discourse.vtk.org/u/wasim92007)\
**Replies:** 4\
**Last updated:** [February 2, 2021, 6:33pm UTC](https://discourse.vtk.org/t/how-to-load-nrrd-file-types-in-vtk-js/5118 "2021-02-02T18:33:58Z")

</div>

Hi I am a student in college trying to do a project using vtk.js to visualize datasets. The prof. has given me medical volume images and segementation in nrrd format, which vtk.js does not support. Is there any tool avai…

---

## [Cutter Output curve to mesh](https://discourse.vtk.org/t/cutter-output-curve-to-mesh/5116)

<div class="topic-metadata">

**Author:** [@Anish\_Basnet](https://discourse.vtk.org/u/Anish_Basnet)\
**Replies:** 4\
**Last updated:** [February 2, 2021, 4:22pm UTC](https://discourse.vtk.org/t/cutter-output-curve-to-mesh/5116 "2021-02-02T16:22:43Z")

</div>

Hello everyone, Is it possible to convert the output curve of a vtkCutter class to a mesh? I wanted to compute curvatures but vtkCurvatures only takes a polydata mesh as input. I tried using vtkDelaunay2D but the mesh i…

[Previous page](https://discourse.vtk.org/latest.md?page=184)

[Next page](https://discourse.vtk.org/latest.md?page=186)