# Development **URL:** https://discourse.vtk.org/c/development/7.md?page=10 [Latest](https://discourse.vtk.org/latest.md) · [Categories](https://discourse.vtk.org/categories.md) · [Tags](https://discourse.vtk.org/tags.md) **Page:** 11 --- ## [MPR Viewer in Qt/VTK: Reslices not displaying in Coronal, and Sagittal views](https://discourse.vtk.org/t/mpr-viewer-in-qt-vtk-reslices-not-displaying-in-coronal-and-sagittal-views/13975)
**Author:** [@christeen](https://discourse.vtk.org/u/christeen)\ **Replies:** 4\ **Last updated:** [August 2, 2024, 4:38am UTC](https://discourse.vtk.org/t/mpr-viewer-in-qt-vtk-reslices-not-displaying-in-coronal-and-sagittal-views/13975 "2024-08-02T04:38:38Z")
I’m a beginner in developing Qt/VTK applications and I’m working on creating a multiplanar reconstruction (MPR) viewer. I successfully load the DICOM data path using appropriate methods. The volume rendering process exe… --- ## [How to show more inside a vtkRenderWindow?](https://discourse.vtk.org/t/how-to-show-more-inside-a-vtkrenderwindow/14335)
**Author:** [@learn\_forever](https://discourse.vtk.org/u/learn_forever)\ **Replies:** 0\ **Last updated:** [July 31, 2024, 12:59pm UTC](https://discourse.vtk.org/t/how-to-show-more-inside-a-vtkrenderwindow/14335 "2024-07-31T12:59:49Z")
I had a model rendered inside a vtkRenderWindow. See blue area inside the following image. If not change the camera position, focus point and view angle, can we make the gray area also show inside the render window? --- ## [Is there any widget in VTK C++/ Python similar to ImageCroppingWidget in VTK JS ?](https://discourse.vtk.org/t/is-there-any-widget-in-vtk-c-python-similar-to-imagecroppingwidget-in-vtk-js/14327)
**Author:** [@phong](https://discourse.vtk.org/u/phong)\ **Replies:** 0\ **Last updated:** [July 30, 2024, 2:40pm UTC](https://discourse.vtk.org/t/is-there-any-widget-in-vtk-c-python-similar-to-imagecroppingwidget-in-vtk-js/14327 "2024-07-30T14:40:39Z")
Hi All, VTK Js offers beautiful ImageCroppingWidget : vtk.js . Widget has many handles : face handles, edge handles, corner handles (green spheres) . I wonder if there is any widget in VTK c++/ Python has the same handl… --- ## [LineWidth with vtkEllipseWidget](https://discourse.vtk.org/t/linewidth-with-vtkellipsewidget/14325)
**Author:** [@Juan\_Augusto\_Tardivo](https://discourse.vtk.org/u/Juan_Augusto_Tardivo)\ **Replies:** 0\ **Last updated:** [July 30, 2024, 1:30pm UTC](https://discourse.vtk.org/t/linewidth-with-vtkellipsewidget/14325 "2024-07-30T13:30:21Z")
Hello, i have this code: widget = vtkEllipseWidget.newInstance({ modifierBehavior: { None: { \[BehaviorCategory.PLACEMENT\]: ShapeBehavior\[BehaviorCategory.PLACEMENT\].CLICK\_AND\_DRAG, \[BehaviorCategory.POINTS\]: ShapeBe… --- ## [New Isocontouring filter for discrete, labled volumetric data: vtkSurfaceNets3D](https://discourse.vtk.org/t/new-isocontouring-filter-for-discrete-labled-volumetric-data-vtksurfacenets3d/10614)
**Author:** [@will.schroeder](https://discourse.vtk.org/u/will.schroeder)\ **Replies:** 18\ **Last updated:** [July 29, 2024, 8:06pm UTC](https://discourse.vtk.org/t/new-isocontouring-filter-for-discrete-labled-volumetric-data-vtksurfacenets3d/10614 "2024-07-29T20:06:38Z")
There is a new isocontouring algorithm available in VTK master: vtkSurfaceNets3D. Unlike classic algorithms such as marching cubes or flying edges that operate on continuous scalar fields, vtkSurfaceNets3D operates on di… --- ## [FourPaneViewer (now in WASM)](https://discourse.vtk.org/t/fourpaneviewer-now-in-wasm/14306)
**Author:** [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)\ **Replies:** 5\ **Last updated:** [July 29, 2024, 1:48pm UTC](https://discourse.vtk.org/t/fourpaneviewer-now-in-wasm/14306 "2024-07-29T13:48:20Z")
Hi Guys Working on a good way to wrap VTK to WASM. Right now, I am facing a problem that I had earlier with the FourPaneViewer after updating to VTK 9, the cursor actors disappears. My old fix, which works for OpenGL wa… --- ## [How to customize vtkBoxRepresentation in python to have 15 points](https://discourse.vtk.org/t/how-to-customize-vtkboxrepresentation-in-python-to-have-15-points/14288)
**Author:** [@phong](https://discourse.vtk.org/u/phong)\ **Replies:** 1\ **Last updated:** [July 24, 2024, 3:37pm UTC](https://discourse.vtk.org/t/how-to-customize-vtkboxrepresentation-in-python-to-have-15-points/14288 "2024-07-24T15:37:12Z")
Hi All, I see that class vtkBoxRepresentation has only 7 green points (6 center points in faces + 1 point in the middle of the box) like this : Now I want to have a reprentation which has 15 point (7 points vtkBoxR… --- ## [I got a completely black window，when I run example.](https://discourse.vtk.org/t/i-got-a-completely-black-window-when-i-run-example/14282)
**Author:** [@LItterBoy-GB](https://discourse.vtk.org/u/LItterBoy-GB)\ **Replies:** 3\ **Last updated:** [July 24, 2024, 9:14am UTC](https://discourse.vtk.org/t/i-got-a-completely-black-window-when-i-run-example/14282 "2024-07-24T09:14:18Z")
\#include \ #include \ #include \ #include \ #include \ #include \ #include \ #include \ #include \ **Author:** [@sabaya](https://discourse.vtk.org/u/sabaya)\ **Replies:** 2\ **Last updated:** [July 24, 2024, 7:01am UTC](https://discourse.vtk.org/t/vtkcgalregionfairing-error/14262 "2024-07-24T07:01:29Z") Hey there, I’ve performed a boolean operation on my two polydata sets. Additionally, I’ve identified the intersection line between them. Next, I found the neighbors of the intersection points and saved them in a vtkPoint… --- ## [StructuredGrid and RectilinearGrid in VTKHDF format](https://discourse.vtk.org/t/structuredgrid-and-rectilineargrid-in-vtkhdf-format/14275)
**Author:** [@jpmorr](https://discourse.vtk.org/u/jpmorr)\ **Replies:** 4\ **Last updated:** [July 22, 2024, 3:21pm UTC](https://discourse.vtk.org/t/structuredgrid-and-rectilineargrid-in-vtkhdf-format/14275 "2024-07-22T15:21:44Z")
Hi, I’ve got a quick question about StructuredGrid and RectilinearGrid data in the newer VTKHDF format. While it’s quite easy to represent these using the ImageData or UnstructuredGrid file formats already defined (with… --- ## [Setting precision for algorithms the saved files](https://discourse.vtk.org/t/setting-precision-for-algorithms-the-saved-files/14265)
**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\ **Replies:** 0\ **Last updated:** [July 22, 2024, 12:40am UTC](https://discourse.vtk.org/t/setting-precision-for-algorithms-the-saved-files/14265 "2024-07-22T00:40:17Z")
Hello, Is it possible to change vtk algorithm precision to double and also save as double in .vtk format? I am currently using Surface Nets 3d Thank you, Rafael Scatena --- ## [IsConvex() of "vtkPolyhedron" may give wrong result?](https://discourse.vtk.org/t/isconvex-of-vtkpolyhedron-may-give-wrong-result/13635)
**Author:** [@guaguameikong](https://discourse.vtk.org/u/guaguameikong)\ **Replies:** 5\ **Last updated:** [July 19, 2024, 2:00pm UTC](https://discourse.vtk.org/t/isconvex-of-vtkpolyhedron-may-give-wrong-result/13635 "2024-07-19T14:00:49Z")
My vtk version is 9.1, C++. I use vtkUnstructrudeGrid to store my data, and pick one vtkCell from the ugrid, translate to vtkPolyhedron, check if IsConvex(). put an example below, the right result of IsConvex() is true… --- ## [Python threading improvements](https://discourse.vtk.org/t/python-threading-improvements/14247)
**Author:** [@dgobbi](https://discourse.vtk.org/u/dgobbi)\ **Replies:** 2\ **Last updated:** [July 17, 2024, 7:43pm UTC](https://discourse.vtk.org/t/python-threading-improvements/14247 "2024-07-17T19:43:41Z")
This is a brief announcement of how VTK has recently changed for Python threading. In the VTK master branch, the Python wrappers have been improved so that the Python GIL (global interpreter lock) is released during cal… --- ## [\#version must be on the first line in a program and only whitespace are allowed in the declaration](https://discourse.vtk.org/t/version-must-be-on-the-first-line-in-a-program-and-only-whitespace-are-allowed-in-the-declaration/14249)
**Author:** [@jiajiadelequ](https://discourse.vtk.org/u/jiajiadelequ)\ **Replies:** 0\ **Last updated:** [July 17, 2024, 9:15am UTC](https://discourse.vtk.org/t/version-must-be-on-the-first-line-in-a-program-and-only-whitespace-are-allowed-in-the-declaration/14249 "2024-07-17T09:15:41Z")
Hello, I would like to know how to solve this problem I am using VTK9.3 Crash Infomation is as follows: 2024-07-17 17:08:04.102 21795-21863 VTK com.example.vtk2 E ERROR: In vtk… --- ## [Reversed triangles in vtkPolyData created from points and cells](https://discourse.vtk.org/t/reversed-triangles-in-vtkpolydata-created-from-points-and-cells/14223)
**Author:** [@gongwaner](https://discourse.vtk.org/u/gongwaner)\ **Replies:** 14\ **Last updated:** [July 16, 2024, 7:34am UTC](https://discourse.vtk.org/t/reversed-triangles-in-vtkpolydata-created-from-points-and-cells/14223 "2024-07-16T07:34:41Z")
Hi, I want to create a mesh vtkPolyData from points and triangles. Here’s my mesh topology. Given the topology, I can create vtkPolyData from the points and triangles. suedocode: auto points = vtkSmartPointer\ **Author:** [@Andreas\_Scalas](https://discourse.vtk.org/u/Andreas_Scalas)\ **Replies:** 1\ **Last updated:** [July 15, 2024, 4:53pm UTC](https://discourse.vtk.org/t/bug-on-vtkpolydata-with-vtkpolygons-visualization/14241 "2024-07-15T16:53:39Z") Hi there. I am trying to visualize some polyhedrons using VTK and I am doing so creating a vtkPolyData to which I add some vtkCells based on vtkPoints. The code is the following: import vtk vertices = \[ (22.139882… --- ## [Get coordinates from VTKBorderWidget](https://discourse.vtk.org/t/get-coordinates-from-vtkborderwidget/14235)
**Author:** [@KSJ](https://discourse.vtk.org/u/KSJ)\ **Replies:** 0\ **Last updated:** [July 15, 2024, 12:02pm UTC](https://discourse.vtk.org/t/get-coordinates-from-vtkborderwidget/14235 "2024-07-15T12:02:49Z")
Hello, I have a program where i am loading a DICOM directory and displaying the sagittal 2d image . In that image i am using a VTKBorderWidget to select a particular region and give that region to VTKExtractVOI. this i… --- ## [VTK actor disappears](https://discourse.vtk.org/t/vtk-actor-disappears/14226)
**Author:** [@w330820350](https://discourse.vtk.org/u/w330820350)\ **Replies:** 4\ **Last updated:** [July 15, 2024, 2:10am UTC](https://discourse.vtk.org/t/vtk-actor-disappears/14226 "2024-07-15T02:10:33Z")
In vtkOpenGLRenderer, there are already more than three plane images (vtkImageSlice). Among them, rotation, scaling, and translation can all be displayed correctly. However, after I added some vtkActors, the images could… --- ## [Why does not vtkUnstructuredGrid work with Delauney?](https://discourse.vtk.org/t/why-does-not-vtkunstructuredgrid-work-with-delauney/14217)
**Author:** [@Northern\_Condor1](https://discourse.vtk.org/u/Northern_Condor1)\ **Replies:** 1\ **Last updated:** [July 13, 2024, 11:38am UTC](https://discourse.vtk.org/t/why-does-not-vtkunstructuredgrid-work-with-delauney/14217 "2024-07-13T11:38:45Z")
Hello dear VTK developers Could you please clarify why vtkUnstructuredGrid\* dataset = vtkUnstructuredGrid::SafeDownCast( delaunay-\>GetOutputDataObject(0) ); Does not work? Thanks! --- ## [Where to contribute example?](https://discourse.vtk.org/t/where-to-contribute-example/14208)
**Author:** [@dzenanz](https://discourse.vtk.org/u/dzenanz)\ **Replies:** 3\ **Last updated:** [July 12, 2024, 2:41pm UTC](https://discourse.vtk.org/t/where-to-contribute-example/14208 "2024-07-12T14:41:14Z")
Starting off from PolyDataToImageDataStencil.py, I created this Python example to convert input STL mesh into a 3D binary mask in MetaImage format. Where is the best place to contribute it? #!/usr/bin/env python from v… --- ## [How to construct dataset with topology missing?](https://discourse.vtk.org/t/how-to-construct-dataset-with-topology-missing/14216)
**Author:** [@Northern\_Condor1](https://discourse.vtk.org/u/Northern_Condor1)\ **Replies:** 2\ **Last updated:** [July 12, 2024, 11:19am UTC](https://discourse.vtk.org/t/how-to-construct-dataset-with-topology-missing/14216 "2024-07-12T11:19:03Z")
Hi! Could you please clarify, how to construct a dataset of tetrahedrons if I have only a list of coordinates, and the topology is missing? Best Regards. Mike --- ## [Master branch build failure vs2017](https://discourse.vtk.org/t/master-branch-build-failure-vs2017/14185)
**Author:** [@dgobbi](https://discourse.vtk.org/u/dgobbi)\ **Replies:** 4\ **Last updated:** [July 11, 2024, 9:04pm UTC](https://discourse.vtk.org/t/master-branch-build-failure-vs2017/14185 "2024-07-11T21:04:50Z")
I’m seeing a compile error with vs2017, which is still a supported compiler according to the VTK build instructions: vtkTableBasedClipCases.cxx Internal Compiler Error in C:\\Program Files (x86)\\Microsoft Visual Stud… --- ## [Is Kitware VolView support Grayscale Softcopy Presentation State?](https://discourse.vtk.org/t/is-kitware-volview-support-grayscale-softcopy-presentation-state/14207)
**Author:** [@luferau](https://discourse.vtk.org/u/luferau)\ **Replies:** 0\ **Last updated:** [July 11, 2024, 10:30am UTC](https://discourse.vtk.org/t/is-kitware-volview-support-grayscale-softcopy-presentation-state/14207 "2024-07-11T10:30:32Z")
Hello, I have ORTHANC server where I want to render DICOM documents that contains Grayscale Softcopy Presentation State text and graphical annotations. One of the possibilities is to use a ORTHANC VolView plugin. Howeve… --- ## [perimeter of output of vtkFeatureEdges](https://discourse.vtk.org/t/perimeter-of-output-of-vtkfeatureedges/14200)
**Author:** [@sabaya](https://discourse.vtk.org/u/sabaya)\ **Replies:** 2\ **Last updated:** [July 11, 2024, 6:22am UTC](https://discourse.vtk.org/t/perimeter-of-output-of-vtkfeatureedges/14200 "2024-07-11T06:22:52Z")
hey there. I have used the vtkFeatureEdges to get line representation of where my data intersects with a plane (i cutted it wih vtkClipPolyData). I am wondering if there is a way to calculate and access the perimeter of… --- ## [The issue with white contour lines displayed on the front actor](https://discourse.vtk.org/t/the-issue-with-white-contour-lines-displayed-on-the-front-actor/14197)
**Author:** [@Tianming](https://discourse.vtk.org/u/Tianming)\ **Replies:** 1\ **Last updated:** [July 10, 2024, 9:10am UTC](https://discourse.vtk.org/t/the-issue-with-white-contour-lines-displayed-on-the-front-actor/14197 "2024-07-10T09:10:52Z")
Hello everyone, I have encountered a small problem. I created two actors, half cylinder A and vector arrow B, with half cylinder A at the back. When I set the transparency of A to be relatively small, about 0.16 (full t… --- ## [SIGFPE at startup with versions 9.3.0 and 9.3.1](https://discourse.vtk.org/t/sigfpe-at-startup-with-versions-9-3-0-and-9-3-1/14184)
**Author:** [@TLCFEM](https://discourse.vtk.org/u/TLCFEM)\ **Replies:** 6\ **Last updated:** [July 9, 2024, 3:43pm UTC](https://discourse.vtk.org/t/sigfpe-at-startup-with-versions-9-3-0-and-9-3-1/14184 "2024-07-09T15:43:56Z")
The following is identified as spam hence cannot be posted in the gitlab repo. Thus, it is here. 9.2.6 is working with my case, 9.30 and 9.3.1 are not. SIGFPE is thrown during startup at this location. bt: #0 0x0000… --- ## [Does vtkTriangleFilter alters the mesh when applied to a quad mesh?](https://discourse.vtk.org/t/does-vtktrianglefilter-alters-the-mesh-when-applied-to-a-quad-mesh/14176)
**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\ **Replies:** 2\ **Last updated:** [July 7, 2024, 12:20pm UTC](https://discourse.vtk.org/t/does-vtktrianglefilter-alters-the-mesh-when-applied-to-a-quad-mesh/14176 "2024-07-07T12:20:54Z")
Hello, I want to process a quad mesh outside vtk. But the process is further simplified if I work with triangles. Does the vtkTriangleFilter alter the mesh when applied to a quad mesh? Or does it just split the quads i… --- ## [Is it possible to write field data with vtkSTLWriter?](https://discourse.vtk.org/t/is-it-possible-to-write-field-data-with-vtkstlwriter/14177)
**Author:** [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)\ **Replies:** 2\ **Last updated:** [July 7, 2024, 12:15pm UTC](https://discourse.vtk.org/t/is-it-possible-to-write-field-data-with-vtkstlwriter/14177 "2024-07-07T12:15:28Z")
Hello, I saved my triangle mesh to STL format with vtk. But it didn’t contain any cell field information besides normals. Here is a copy of the ASCII file written: Thank you --- ## [Understanding vtkStaticCellLocator](https://discourse.vtk.org/t/understanding-vtkstaticcelllocator/13998)
**Author:** [@Sai\_Chaitanya\_Rodda](https://discourse.vtk.org/u/Sai_Chaitanya_Rodda)\ **Replies:** 5\ **Last updated:** [July 4, 2024, 3:46pm UTC](https://discourse.vtk.org/t/understanding-vtkstaticcelllocator/13998 "2024-07-04T15:46:57Z")
Hello Everyone, I have a case where I need to perform hundreds of thousands or millions IntersectWithLine calls through a cell locator on a geometry dataset that might have millions of cells present in it. In order to p… --- ## [VTK in QML](https://discourse.vtk.org/t/vtk-in-qml/7556)
**Author:** [@loiczimm](https://discourse.vtk.org/u/loiczimm)\ **Replies:** 13\ **Last updated:** [July 4, 2024, 12:21am UTC](https://discourse.vtk.org/t/vtk-in-qml/7556 "2024-07-04T00:21:16Z")
Hello, I’m trying to integrate VTK9.1 in a QML project. I’m using Qt6.2. The integration seems to be straight forward at first but then I realized that the VTK item is no drawn on the correct layer as it shoud in QML. V… [Previous page](https://discourse.vtk.org/c/development/7.md?page=9) [Next page](https://discourse.vtk.org/c/development/7.md?page=11)