# Latest

**URL:** https://discourse.vtk.org/latest.md?page=153

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

**Page:** 154

---

## [Bind Callback to Interaction](https://discourse.vtk.org/t/bind-callback-to-interaction/7269)

<div class="topic-metadata">

**Author:** [@bernland](https://discourse.vtk.org/u/bernland)\
**Replies:** 3\
**Last updated:** [November 25, 2021, 9:03pm UTC](https://discourse.vtk.org/t/bind-callback-to-interaction/7269 "2021-11-25T21:03:52Z")

</div>

What’s the most top-level approach to capturing interactions in VTK.js? I understand that there are a number of specific methods, such as onMouseMove(), onLeftMouseDown(), etc. Is there a more general way to capture al…

---

## [VTK 9.1 release timing?](https://discourse.vtk.org/t/vtk-9-1-release-timing/6391)

<div class="topic-metadata">

**Author:** [@Dave\_DeMarle](https://discourse.vtk.org/u/Dave_DeMarle)\
**Replies:** 2\
**Last updated:** [November 25, 2021, 1:20pm UTC](https://discourse.vtk.org/t/vtk-9-1-release-timing/6391 "2021-11-25T13:20:37Z")

</div>

Hello, When will the next VTK release happen and will it be tagged 9.1 or something else? Asking for a friend, thanks! Dave

---

## [Is it possible to integrate VTKExtensions in Paraview to VTK?](https://discourse.vtk.org/t/is-it-possible-to-integrate-vtkextensions-in-paraview-to-vtk/7266)

<div class="topic-metadata">

**Author:** [@rockydut](https://discourse.vtk.org/u/rockydut)\
**Replies:** 3\
**Last updated:** [November 25, 2021, 9:15am UTC](https://discourse.vtk.org/t/is-it-possible-to-integrate-vtkextensions-in-paraview-to-vtk/7266 "2021-11-25T09:15:44Z")

</div>

There are many useful functions in VTKExtensions in ParaView. So, it is possible to integrate this package to VTK?

---

## [Does a Python "reader" need to be closed?](https://discourse.vtk.org/t/does-a-python-reader-need-to-be-closed/7261)

<div class="topic-metadata">

**Author:** [@GregVernon](https://discourse.vtk.org/u/GregVernon)\
**Replies:** 2\
**Last updated:** [November 24, 2021, 5:42pm UTC](https://discourse.vtk.org/t/does-a-python-reader-need-to-be-closed/7261 "2021-11-24T17:42:07Z")

</div>

I’m writing a Python script to serve as the black-box simulation interface driver for a DAKOTA project. Essentially, this Python driver generates a simulation model, submits a solver subprocess which creates a new .vtu …

---

## [vtkCutter cutting disconnected cells](https://discourse.vtk.org/t/vtkcutter-cutting-disconnected-cells/7257)

<div class="topic-metadata">

**Author:** [@andreasbuykx](https://discourse.vtk.org/u/andreasbuykx)\
**Replies:** 5\
**Last updated:** [November 24, 2021, 4:51pm UTC](https://discourse.vtk.org/t/vtkcutter-cutting-disconnected-cells/7257 "2021-11-24T16:51:52Z")

</div>

I have an FEA mesh of 3d cells, with results that are discontinuous between cells. I model this by splitting the points such that each cell has its own points. I want to cut through those cells, yielding a single po…

---

## [Punching a polygonal hole into a triangulated surface](https://discourse.vtk.org/t/punching-a-polygonal-hole-into-a-triangulated-surface/7061)

<div class="topic-metadata">

**Author:** [@cobo](https://discourse.vtk.org/u/cobo)\
**Replies:** 42\
**Last updated:** [November 24, 2021, 3:00pm UTC](https://discourse.vtk.org/t/punching-a-polygonal-hole-into-a-triangulated-surface/7061 "2021-11-24T15:00:56Z")

</div>

I have a triangulated surface (a “2.5D” topo surface actually), only triangles, and a closed polygon, and with that polygon I want to “punch” a hole into that triangulated topo surface. From my understanding, this should…

---

## [stlReader.MergingOff() gives bad polyData](https://discourse.vtk.org/t/stlreader-mergingoff-gives-bad-polydata/2745)

<div class="topic-metadata">

**Author:** [@EmileSonneveld](https://discourse.vtk.org/u/EmileSonneveld)\
**Replies:** 4\
**Last updated:** [November 24, 2021, 1:36pm UTC](https://discourse.vtk.org/t/stlreader-mergingoff-gives-bad-polydata/2745 "2021-11-24T13:36:47Z")

</div>

Hi, We have a website using VTK.js that calls VTK-python functions in the backend. The problem is that both versions of VTK read STLs in a different way. VTK-python will merge vertices of the STL (good), and VTK.js will…

---

## [VTK clip: How to clip with cell as the minimum unit](https://discourse.vtk.org/t/vtk-clip-how-to-clip-with-cell-as-the-minimum-unit/7166)

<div class="topic-metadata">

**Author:** [@rockydut](https://discourse.vtk.org/u/rockydut)\
**Replies:** 3\
**Last updated:** [November 24, 2021, 12:54pm UTC](https://discourse.vtk.org/t/vtk-clip-how-to-clip-with-cell-as-the-minimum-unit/7166 "2021-11-24T12:54:34Z")

</div>

I want to clip the model (for finite element simulation). However, the existing clipping methods triangulate the cell. In other word, for a cell, it is either cut or not cut, rather than cutting a part of a cell and tri…

---

## [How to keep its color after being clipped](https://discourse.vtk.org/t/how-to-keep-its-color-after-being-clipped/7263)

<div class="topic-metadata">

**Author:** [@Erikevin](https://discourse.vtk.org/u/Erikevin)\
**Replies:** 0\
**Last updated:** [November 24, 2021, 7:36am UTC](https://discourse.vtk.org/t/how-to-keep-its-color-after-being-clipped/7263 "2021-11-24T07:36:01Z")

</div>

Hi, The original mapper of actor is using color lookup table.After being clipped,how to keep its color?It seems the orginal scalar is not matched with the current ones.Please give some help~ Br, Erikevin

---

## [VTK 9.1 tests failing on Alpine Linux](https://discourse.vtk.org/t/vtk-9-1-tests-failing-on-alpine-linux/7250)

<div class="topic-metadata">

**Author:** [@boomanaiden154](https://discourse.vtk.org/u/boomanaiden154)\
**Replies:** 3\
**Last updated:** [November 24, 2021, 1:02am UTC](https://discourse.vtk.org/t/vtk-9-1-tests-failing-on-alpine-linux/7250 "2021-11-24T01:02:22Z")

</div>

When compiling and running the tests for VTK 9.1 on Alpine Linux, there are about 20 tests that fail, and they are the following: 230 - VTK::IOImportCxx-OBJImport-MixedOrder1 (Failed) 232 - VTK::IOImportCxx-OBJImport-MT…

---

## [Downsampling a 3D image by 2 in all dimensions](https://discourse.vtk.org/t/downsampling-a-3d-image-by-2-in-all-dimensions/7255)

<div class="topic-metadata">

**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 1\
**Last updated:** [November 23, 2021, 2:23pm UTC](https://discourse.vtk.org/t/downsampling-a-3d-image-by-2-in-all-dimensions/7255 "2021-11-23T14:23:10Z")

</div>

Dear All, I want to downsample a MHD (3D, RGB) image by 2 in all dimensions. But because the image is a surface the resulting image is sparse. Has VTK some function to do that with some king of filter (Raised Cosine (??…

---

## [VTK camera, how to get the right vector in world space](https://discourse.vtk.org/t/vtk-camera-how-to-get-the-right-vector-in-world-space/7251)

<div class="topic-metadata">

**Author:** [@cebugdev](https://discourse.vtk.org/u/cebugdev)\
**Replies:** 0\
**Last updated:** [November 23, 2021, 4:28am UTC](https://discourse.vtk.org/t/vtk-camera-how-to-get-the-right-vector-in-world-space/7251 "2021-11-23T04:28:27Z")

</div>

As the title says, how can I get the orientation vectors particularly the right vector of the VTK camera, what matrix can I use to extract this right vector? from documentation, i can see that there are ModelTransform, M…

---

## [Writing ugrid Xdmf3 a time step at a time](https://discourse.vtk.org/t/writing-ugrid-xdmf3-a-time-step-at-a-time/7230)

<div class="topic-metadata">

**Author:** [@olafx](https://discourse.vtk.org/u/olafx)\
**Replies:** 1\
**Last updated:** [November 22, 2021, 10:39pm UTC](https://discourse.vtk.org/t/writing-ugrid-xdmf3-a-time-step-at-a-time/7230 "2021-11-22T22:39:23Z")

</div>

I’m trying to write to a Xdmf3 file (with vtkUnstructuredGrid data) over time, and not all at once. I’ve read the vtkTimeSourceExample source, some of the vtkXdmf3Writer source, and some examples of related usage, but st…

---

## [Thresholding + Cropping tool inconsitencies between labelmap and 3D Volume](https://discourse.vtk.org/t/thresholding-cropping-tool-inconsitencies-between-labelmap-and-3d-volume/7246)

<div class="topic-metadata">

**Author:** [@emil-peter](https://discourse.vtk.org/u/emil-peter)\
**Replies:** 1\
**Last updated:** [November 22, 2021, 4:46pm UTC](https://discourse.vtk.org/t/thresholding-cropping-tool-inconsitencies-between-labelmap-and-3d-volume/7246 "2021-11-22T16:46:10Z")

</div>

Hello, I’m currently working on a thresholding tool to label a dcm file with the given thresholding range and bounding box. I’m using a vtkVolume in combination with a pieceWiseFunction to visualise what will be thresh…

---

## [How can I click one end of a line to drag, while the other end does not move.and the shape of the line segment is a catenary?](https://discourse.vtk.org/t/how-can-i-click-one-end-of-a-line-to-drag-while-the-other-end-does-not-move-and-the-shape-of-the-line-segment-is-a-catenary/7235)

<div class="topic-metadata">

**Author:** [@szdxhwz](https://discourse.vtk.org/u/szdxhwz)\
**Replies:** 2\
**Last updated:** [November 22, 2021, 7:47am UTC](https://discourse.vtk.org/t/how-can-i-click-one-end-of-a-line-to-drag-while-the-other-end-does-not-move-and-the-shape-of-the-line-segment-is-a-catenary/7235 "2021-11-22T07:47:18Z")

</div>

Hello, I am a novice, please advise. I’m working on a project. Click one end of a line to drag, while the other end is not moving, and the shape of the line segment is a catenary. May I ask if you have any suggestions or…

---

## [Question about the cases table of the marching cube](https://discourse.vtk.org/t/question-about-the-cases-table-of-the-marching-cube/7232)

<div class="topic-metadata">

**Author:** [@1116](https://discourse.vtk.org/u/1116)\
**Replies:** 1\
**Last updated:** [November 21, 2021, 11:30am UTC](https://discourse.vtk.org/t/question-about-the-cases-table-of-the-marching-cube/7232 "2021-11-21T11:30:58Z")

</div>

Hello, There is a question regarding the cases table used in the marching cube algorithm. This file (VTK/vtkMarchingCubesTriangleCases.cxx at master · Kitware/VTK · GitHub) list all 256 cases. I’m wondering why each cas…

---

## [Abnormal tube filter radius](https://discourse.vtk.org/t/abnormal-tube-filter-radius/7225)

<div class="topic-metadata">

**Author:** [@marcomusy](https://discourse.vtk.org/u/marcomusy)\
**Replies:** 3\
**Last updated:** [November 21, 2021, 5:53am UTC](https://discourse.vtk.org/t/abnormal-tube-filter-radius/7225 "2021-11-21T05:53:20Z")

</div>

The vtkTubeFilter with fixed radius …is not constant: import vtk from vedo import Line, show pts = \[\[100,0\], \[200,0\], \[200,200\], \[0,200\], \[0,0\]\] poly = Line(pts, closed=True).polydata() tuf = vtk.vtkTubeFilter() tuf.S…

---

## [Resample a Mesh for added complexity](https://discourse.vtk.org/t/resample-a-mesh-for-added-complexity/7228)

<div class="topic-metadata">

**Author:** [@Steven\_Lewis](https://discourse.vtk.org/u/Steven_Lewis)\
**Replies:** 1\
**Last updated:** [November 20, 2021, 1:12am UTC](https://discourse.vtk.org/t/resample-a-mesh-for-added-complexity/7228 "2021-11-20T01:12:28Z")

</div>

Hi, I was wondering if there was a method by which you can resample a surface mesh with a set number of points to a higher complexity given the number of points of another model? I have seen other programs use a similar …

---

## [Java wrapper code changes](https://discourse.vtk.org/t/java-wrapper-code-changes/5834)

<div class="topic-metadata">

**Author:** [@toddy](https://discourse.vtk.org/u/toddy)\
**Replies:** 9\
**Last updated:** [October 13, 2021, 9:39am UTC](https://discourse.vtk.org/t/java-wrapper-code-changes/5834 "2021-10-13T09:39:20Z")

</div>

Recently some significant changes have been merged to the VTK master branch for the Java wrapper code generation. The number of exported data types has been extended to include byte, short, long and float types, so that …

---

## [Can't build VTK examples](https://discourse.vtk.org/t/cant-build-vtk-examples/7198)

<div class="topic-metadata">

**Author:** [@totte\_karlsson](https://discourse.vtk.org/u/totte_karlsson)\
**Replies:** 6\
**Last updated:** [November 19, 2021, 3:42am UTC](https://discourse.vtk.org/t/cant-build-vtk-examples/7198 "2021-11-19T03:42:30Z")

</div>

Hello, I’m new to this forum, and in ‘learning’ mode… :slight\_smile: I have built VTK, version 9.0.3 successfully using Visual Studio 2019 x64. I managed to build one example manually and can verify ‘it works’. Now I …

---

## [Does a vtkMultiBlockDataSet own a copy of its blocks in Python?](https://discourse.vtk.org/t/does-a-vtkmultiblockdataset-own-a-copy-of-its-blocks-in-python/7219)

<div class="topic-metadata">

**Author:** [@adeak](https://discourse.vtk.org/u/adeak)\
**Replies:** 0\
**Last updated:** [November 18, 2021, 11:21pm UTC](https://discourse.vtk.org/t/does-a-vtkmultiblockdataset-own-a-copy-of-its-blocks-in-python/7219 "2021-11-18T23:21:27Z")

</div>

Hello, I’ve been wondering about the data model of a multiblock dataset using the Python API. Using a simplified version of this example: import weakref from vtkmodules.vtkCommonDataModel import vtkMultiBlockDataSet fr…

---

## [Events in web-project-templates-master](https://discourse.vtk.org/t/events-in-web-project-templates-master/7210)

<div class="topic-metadata">

**Author:** [@Luis\_Carlos\_Carneiro](https://discourse.vtk.org/u/Luis_Carlos_Carneiro)\
**Replies:** 6\
**Last updated:** [November 18, 2021, 5:50pm UTC](https://discourse.vtk.org/t/events-in-web-project-templates-master/7210 "2021-11-18T17:50:28Z")

</div>

Dear All, In web-project-templates-master example what the following instructions do? self.getApplication().InvokeEvent(‘StartInteractionEvent’) self.getApplication().InvokeEvent(‘EndInteractionEvent’) self.getApplic…

---

## [How to perform perspective projection using VTK (Python)?](https://discourse.vtk.org/t/how-to-perform-perspective-projection-using-vtk-python/7213)

<div class="topic-metadata">

**Author:** [@user\_42](https://discourse.vtk.org/u/user_42)\
**Replies:** 0\
**Last updated:** [November 18, 2021, 4:43pm UTC](https://discourse.vtk.org/t/how-to-perform-perspective-projection-using-vtk-python/7213 "2021-11-18T16:43:00Z")

</div>

I found an example for perspective projection using C++ here, is there an equivalent Python example/can someone guide me in the right direction on how to get started with this? I want to be able to project a 3D volume.

---

## [Numpy 3D array into VTK data types for volume rendering?](https://discourse.vtk.org/t/numpy-3d-array-into-vtk-data-types-for-volume-rendering/3455)

<div class="topic-metadata">

**Author:** [@Gresliebear](https://discourse.vtk.org/u/Gresliebear)\
**Replies:** 15\
**Last updated:** [November 18, 2021, 4:40pm UTC](https://discourse.vtk.org/t/numpy-3d-array-into-vtk-data-types-for-volume-rendering/3455 "2021-11-18T16:40:55Z")

</div>

Hi, everyone I am attempting to convert 3D numpy array into volume rendering function in pythonVTK or C++ code of VTK. Data type conversion of numpy array data into 3D volumes is an issue for me, I cant seem to find an a…

---

## [Faster Rendering of vtkpoly](https://discourse.vtk.org/t/faster-rendering-of-vtkpoly/7162)

<div class="topic-metadata">

**Author:** [@BastianJuelich](https://discourse.vtk.org/u/BastianJuelich)\
**Replies:** 5\
**Last updated:** [November 18, 2021, 2:31pm UTC](https://discourse.vtk.org/t/faster-rendering-of-vtkpoly/7162 "2021-11-18T14:31:49Z")

</div>

Hey all, i am visualizing sensordata (x,y,z,sensorvalue) with a python vtk app. When Rendering more then 10 million “Points” it gets very laggy. Also when zooming out this is getting worse. Is there a way to improve …

---

## [Errors migrating VS Solution to VTK 9.1.0 (windows)](https://discourse.vtk.org/t/errors-migrating-vs-solution-to-vtk-9-1-0-windows/7205)

<div class="topic-metadata">

**Author:** [@CharInt0](https://discourse.vtk.org/u/CharInt0)\
**Replies:** 2\
**Last updated:** [November 18, 2021, 7:40am UTC](https://discourse.vtk.org/t/errors-migrating-vs-solution-to-vtk-9-1-0-windows/7205 "2021-11-18T07:40:49Z")

</div>

Hi all, I downloaded and successfully built VTK 9.1.0 on Windows 10. Then I tried to update a working Win C++ Visual Studio 2019 .dll project which links to the older vtk 9.0.3. I had a few compilation problems: “…Co…

---

## [Is it possible to rotate an object in real time using a method other than clicking on the screen?](https://discourse.vtk.org/t/is-it-possible-to-rotate-an-object-in-real-time-using-a-method-other-than-clicking-on-the-screen/7079)

<div class="topic-metadata">

**Author:** [@riki](https://discourse.vtk.org/u/riki)\
**Replies:** 3\
**Last updated:** [November 18, 2021, 1:50am UTC](https://discourse.vtk.org/t/is-it-possible-to-rotate-an-object-in-real-time-using-a-method-other-than-clicking-on-the-screen/7079 "2021-11-18T01:50:40Z")

</div>

I started using VTK the other day, and now I’m mainly working on the code for the tutorial. I would like to use VTK to rotate an object by specifying the rotation angle from the GUI, or to read the sensor value and rota…

---

## [vtkPoissonReconstruction Java Wrapper](https://discourse.vtk.org/t/vtkpoissonreconstruction-java-wrapper/7150)

<div class="topic-metadata">

**Author:** [@thomasw](https://discourse.vtk.org/u/thomasw)\
**Replies:** 5\
**Last updated:** [November 18, 2021, 12:53am UTC](https://discourse.vtk.org/t/vtkpoissonreconstruction-java-wrapper/7150 "2021-11-18T00:53:44Z")

</div>

Hi, I compiled successfully VTK 9.1 with Java-Wrappers and module vtkPoissonReconstruction switched on using ninja running Windows 10 and VC2019. But it only produces a PoissonReconstructionModule.java in \[build-dir\]/W…

---

## [writing PointData to UnstructuredGrid (and Xdmf time series)](https://discourse.vtk.org/t/writing-pointdata-to-unstructuredgrid-and-xdmf-time-series/7201)

<div class="topic-metadata">

**Author:** [@olafx](https://discourse.vtk.org/u/olafx)\
**Replies:** 2\
**Last updated:** [November 17, 2021, 4:09pm UTC](https://discourse.vtk.org/t/writing-pointdata-to-unstructuredgrid-and-xdmf-time-series/7201 "2021-11-17T16:09:53Z")

</div>

I’m trying to write only Points and PointData to an UnstructuredGrid type. I can’t find any examples on how to do this so having difficulties figuring it out, but I think I’m 90% of the way there I think. My points wor…

---

## [VTK.js widgetManager.addWidget(vtkLabelWidget) says "widget.getWidgetForView is not a function"](https://discourse.vtk.org/t/vtk-js-widgetmanager-addwidget-vtklabelwidget-says-widget-getwidgetforview-is-not-a-function/6628)

<div class="topic-metadata">

**Author:** [@toro](https://discourse.vtk.org/u/toro)\
**Replies:** 7\
**Last updated:** [November 17, 2021, 3:37pm UTC](https://discourse.vtk.org/t/vtk-js-widgetmanager-addwidget-vtklabelwidget-says-widget-getwidgetforview-is-not-a-function/6628 "2021-11-17T15:37:13Z")

</div>

Hello, I dynamically add vtkLabelWidget to the scene when users click on some checkboxes. The code that is perfectly working is: const widget = vtkLabelWidget.newInstance(); widget.setInteractor(renderWindow.getInt…

[Previous page](https://discourse.vtk.org/latest.md?page=152)

[Next page](https://discourse.vtk.org/latest.md?page=154)