# Development

**URL:** https://discourse.slicer.org/c/dev/5.md?no_subcategories=false&page=93

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

**Page:** 94

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## [Python non-blocking networking](https://discourse.slicer.org/t/python-non-blocking-networking/11725)

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**Author:** [@talmazov](https://discourse.slicer.org/u/talmazov)\
**Replies:** 5\
**Last updated:** [May 30, 2020, 12:53am UTC](https://discourse.slicer.org/t/python-non-blocking-networking/11725 "2020-05-30T00:53:07Z")

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Hey all, I’ve been pretty successful writing this socket client on slicer. it works but it is not responsive receiving the data, i imagine it is an issue with threading and blocking i start my client via a thread def …

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## [New "good first issue" label in Slicer issue tracker](https://discourse.slicer.org/t/new-good-first-issue-label-in-slicer-issue-tracker/11732)

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**Author:** [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Replies:** 1\
**Last updated:** [May 29, 2020, 4:46pm UTC](https://discourse.slicer.org/t/new-good-first-issue-label-in-slicer-issue-tracker/11732 "2020-05-29T16:46:23Z")

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New “good first issue” label To help identify issues relevant for new contributors, we just added the good first issue label to the issue tracker. What is the a “good first issue” ? There are no single way to answer th…

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## [From DICOM scalar volume to retrieve header attributes/tags](https://discourse.slicer.org/t/from-dicom-scalar-volume-to-retrieve-header-attributes-tags/11740)

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**Author:** [@szhang](https://discourse.slicer.org/u/szhang)\
**Replies:** 7\
**Last updated:** [May 29, 2020, 12:42am UTC](https://discourse.slicer.org/t/from-dicom-scalar-volume-to-retrieve-header-attributes-tags/11740 "2020-05-29T00:42:21Z")

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Hello Probably a very basic question, after loading the DICOM stack as a scalar volume, how in the code can I obtain one of the header tag information (e.g. Patient Position, or Reconstruction Kernel)? If there are some…

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## [Adding slider widget to Segmentations module](https://discourse.slicer.org/t/adding-slider-widget-to-segmentations-module/11754)

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**Author:** [@loubna](https://discourse.slicer.org/u/loubna)\
**Replies:** 1\
**Last updated:** [May 28, 2020, 6:08pm UTC](https://discourse.slicer.org/t/adding-slider-widget-to-segmentations-module/11754 "2020-05-28T18:08:49Z")

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Hi, I am trying to add slider widget on the main window of segmentation module (see atteched image). I would want this slider to interact with my reconstruction method (i.e. allow me to change the tolerance value whi…

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## [Export many segments as Dicom RTSS](https://discourse.slicer.org/t/export-many-segments-as-dicom-rtss/11741)

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**Author:** [@loubna](https://discourse.slicer.org/u/loubna)\
**Replies:** 2\
**Last updated:** [May 28, 2020, 5:30pm UTC](https://discourse.slicer.org/t/export-many-segments-as-dicom-rtss/11741 "2020-05-28T17:30:25Z")

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Hi; Is it possible to create many segments in slicer and export them as DICOM RTSS. I know how can I export one segment as Dicom RTSS in order to display it as planar contours (https://discourse.slicer.org/t/create-a-se…

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## [Export segment to labelmap broken in May 25 nightly](https://discourse.slicer.org/t/export-segment-to-labelmap-broken-in-may-25-nightly/11736)

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**Author:** [@hherhold](https://discourse.slicer.org/u/hherhold)\
**Replies:** 3\
**Last updated:** [May 27, 2020, 8:29pm UTC](https://discourse.slicer.org/t/export-segment-to-labelmap-broken-in-may-25-nightly/11736 "2020-05-27T20:29:45Z")

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In the last few days, exporting a segment to a labelmap stopped working. Works fine in May 21 nightly, doesn’t work in May 25 nightly (latest build, downloaded for Mac this morning). I have a debug build, I’m happy to h…

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## [Passing hierarchies to CLIs](https://discourse.slicer.org/t/passing-hierarchies-to-clis/11706)

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**Author:** [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Replies:** 2\
**Last updated:** [May 26, 2020, 1:39pm UTC](https://discourse.slicer.org/t/passing-hierarchies-to-clis/11706 "2020-05-26T13:39:26Z")

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Hello. I’m trying to develop a CLI module which takes a set of models as input and gives a set of models as output. It seems to be possible to use vtkMRMLModelHierarchy nodes for this, but is it possible to use vtkMRMLS…

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## [Lzma error while running module and its not importing meshio](https://discourse.slicer.org/t/lzma-error-while-running-module-and-its-not-importing-meshio/11705)

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**Author:** [@Saima](https://discourse.slicer.org/u/Saima)\
**Replies:** 1\
**Last updated:** [May 26, 2020, 12:11pm UTC](https://discourse.slicer.org/t/lzma-error-while-running-module-and-its-not-importing-meshio/11705 "2020-05-26T12:11:23Z")

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Hi Andras, I am getting the following error. Could you please help how can I resolve it in slicer 4.11.0-2020-02-25. Traceback (most recent call last): File “/home/saima/slicer/Slicer-4.11.0-2019-09-17-linux-amd64/Ima…

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## [vtkMRMLModelHierarchyNode nodes imported as subject hierarchies](https://discourse.slicer.org/t/vtkmrmlmodelhierarchynode-nodes-imported-as-subject-hierarchies/11707)

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**Author:** [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Replies:** 2\
**Last updated:** [May 26, 2020, 10:50am UTC](https://discourse.slicer.org/t/vtkmrmlmodelhierarchynode-nodes-imported-as-subject-hierarchies/11707 "2020-05-26T10:50:19Z")

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Hello, I create a model hierarchy (based on vtkMRMLModelHierarchyNode objects) and save the mrml scene. When I open that scene, the model hierarchy has been turned into a subject hierarchy. Is that the expected behaviou…

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## [Custom Signal/Slots with PythonQt](https://discourse.slicer.org/t/custom-signal-slots-with-pythonqt/3278)

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**Author:** [@mcfly3001](https://discourse.slicer.org/u/mcfly3001)\
**Replies:** 8\
**Last updated:** [May 25, 2020, 7:04pm UTC](https://discourse.slicer.org/t/custom-signal-slots-with-pythonqt/3278 "2020-05-25T19:04:07Z")

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Hi all, the signal/slot system of Qt is a very helpful mechanism for implementing callbacks. I was wondering if I can create my own signals and slots with PythonQt but had no success so far. In other projects where I u…

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## [Export segmentation Into another predifined model](https://discourse.slicer.org/t/export-segmentation-into-another-predifined-model/11685)

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**Author:** [@siaeleni](https://discourse.slicer.org/u/siaeleni)\
**Replies:** 1\
**Last updated:** [May 25, 2020, 3:20am UTC](https://discourse.slicer.org/t/export-segmentation-into-another-predifined-model/11685 "2020-05-25T03:20:14Z")

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Hi, I am not sure what is the best way to export a segmentation to a predefined empty vtkMRMLModelNode? Assume that I have a vtkMRMLModelNode named “Model”. I currently use the following shNode = slicer.mrmlScene.Ge…

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## [Problem Q3DC extension](https://discourse.slicer.org/t/problem-q3dc-extension/11374)

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**Author:** [@crisandr](https://discourse.slicer.org/u/crisandr)\
**Replies:** 7\
**Last updated:** [May 21, 2020, 5:20am UTC](https://discourse.slicer.org/t/problem-q3dc-extension/11374 "2020-05-21T05:20:00Z")

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Hello friends, I installed the Q3DC extension in version 4.10.2 and 4.11.0 In the manage extesions menu if I can see the installed extension. but it does not appear in the Quantification section or when looking for it in…

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## [Display two 2D images simultaneously](https://discourse.slicer.org/t/display-two-2d-images-simultaneously/11322)

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**Author:** [@rohan\_n](https://discourse.slicer.org/u/rohan_n)\
**Replies:** 6\
**Last updated:** [May 19, 2020, 11:35pm UTC](https://discourse.slicer.org/t/display-two-2d-images-simultaneously/11322 "2020-05-19T23:35:19Z")

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Hello, I would like to display two 2D images at the same time in the Slicer window. For example, show image1 in the red slice and image2 in the yellow slice. What would be the syntax of the code that would allow me to …

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## [What is the Shallow Copy and DeepCopy](https://discourse.slicer.org/t/what-is-the-shallow-copy-and-deepcopy/11615)

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**Author:** [@loubna](https://discourse.slicer.org/u/loubna)\
**Replies:** 2\
**Last updated:** [May 19, 2020, 11:31pm UTC](https://discourse.slicer.org/t/what-is-the-shallow-copy-and-deepcopy/11615 "2020-05-19T23:31:45Z")

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Hi to everyone; SomeOne can tell me what is the difference between Shallow Copy, DeepCopy and simple affectation? for exemple: what is the difference between: 1- vtkImagedata\* image = filter-\>GetOutput(); 2- image -\>S…

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## [Generate a filled contour from contour in SlicerRT](https://discourse.slicer.org/t/generate-a-filled-contour-from-contour-in-slicerrt/11621)

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**Author:** [@loubna](https://discourse.slicer.org/u/loubna)\
**Replies:** 3\
**Last updated:** [May 19, 2020, 8:23pm UTC](https://discourse.slicer.org/t/generate-a-filled-contour-from-contour-in-slicerrt/11621 "2020-05-19T20:23:20Z")

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Hi; I want construct a filled contour (vtkimagedata) from contour points in Slicer RT. This is the code i have implemented : vtkPoints\* pointsSlice // the set of 3D points of the contour int nbpoin…

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## [Cannot launch QT Creator on MacOS](https://discourse.slicer.org/t/cannot-launch-qt-creator-on-macos/11620)

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**Author:** [@che85](https://discourse.slicer.org/u/che85)\
**Replies:** 2\
**Last updated:** [May 19, 2020, 5:25pm UTC](https://discourse.slicer.org/t/cannot-launch-qt-creator-on-macos/11620 "2020-05-19T17:25:25Z")

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Hi all, I am trying to launch QT Creator for debugging the nightly build, but it’s not launching. Platform: macOS Mojave SlicerBuild: succeeded QT version: 5.14.2 QT creator: 4.12 I created a gist here (using expor…

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## [Building on Mac 10.14 Mojave](https://discourse.slicer.org/t/building-on-mac-10-14-mojave/4554)

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**Author:** [@hjmjohnson](https://discourse.slicer.org/u/hjmjohnson)\
**Replies:** 33\
**Last updated:** [May 19, 2020, 1:44pm UTC](https://discourse.slicer.org/t/building-on-mac-10-14-mojave/4554 "2020-05-19T13:44:44Z")

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After running into: ./cryptlib.h:62:11: fatal error: 'stdlib.h' file not found # include \<stdlib.h\> ^~~~~~~~~~ 1 error generated. I found: https://github.com/frida/frida/issues/338#issuecomment-426777849 Fo…

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## [Workaround for errors when showing AnnotationRuler Label text in 2D slice view](https://discourse.slicer.org/t/workaround-for-errors-when-showing-annotationruler-label-text-in-2d-slice-view/11608)

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**Author:** [@jamesobutler](https://discourse.slicer.org/u/jamesobutler)\
**Replies:** 1\
**Last updated:** [May 19, 2020, 12:09am UTC](https://discourse.slicer.org/t/workaround-for-errors-when-showing-annotationruler-label-text-in-2d-slice-view/11608 "2020-05-19T00:09:58Z")

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I’m hoping there is a workaround to solve an issue I’m getting with showing the label text of an AnnotationRuler label in the 2D slice views. I’m still needing to use this AnnotationRuler object instead of transitioning…

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## [Extract the 3 componenets x,y,z of gradiant filter](https://discourse.slicer.org/t/extract-the-3-componenets-x-y-z-of-gradiant-filter/11581)

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**Author:** [@loubna](https://discourse.slicer.org/u/loubna)\
**Replies:** 1\
**Last updated:** [May 16, 2020, 10:14pm UTC](https://discourse.slicer.org/t/extract-the-3-componenets-x-y-z-of-gradiant-filter/11581 "2020-05-16T22:14:10Z")

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Hi; I have applied two filters on 3d vtkImagedata (binary volume) in order to compute the gradient at each (i,j,k) voxel like: vtkImageGaussianSmooth \*gaussianFilter = vtkImageGaussianSmooth::New(); gaussianFilter-\>Se…

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## [Reading and writing xml file for slicer.vtkMRMLAnnotationROINode](https://discourse.slicer.org/t/reading-and-writing-xml-file-for-slicer-vtkmrmlannotationroinode/11548)

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**Author:** [@rohan\_n](https://discourse.slicer.org/u/rohan_n)\
**Replies:** 3\
**Last updated:** [May 16, 2020, 10:18pm UTC](https://discourse.slicer.org/t/reading-and-writing-xml-file-for-slicer-vtkmrmlannotationroinode/11548 "2020-05-16T22:18:04Z")

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Does anyone have any good examples to share for how the WriteXML() and ReadXMLAttributes() functions of vtkMRMLAnnotationROINode are used? I did see this link: https://apidocs.slicer.org/master/classvtkMRMLAnnotationRO…

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## [Compute normal vectors from planar contours](https://discourse.slicer.org/t/compute-normal-vectors-from-planar-contours/11238)

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**Author:** [@loubna](https://discourse.slicer.org/u/loubna)\
**Replies:** 19\
**Last updated:** [May 16, 2020, 9:47pm UTC](https://discourse.slicer.org/t/compute-normal-vectors-from-planar-contours/11238 "2020-05-16T21:47:36Z")

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Hi, Is it possible to compute normal vectors for each 3D point of planar contour in SlicerRT? If yes , how we can do it. thank’s in advance

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## [Slicer in Nvidia on AWS webinar](https://discourse.slicer.org/t/slicer-in-nvidia-on-aws-webinar/11565)

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**Author:** [@pieper](https://discourse.slicer.org/u/pieper)\
**Replies:** 1\
**Last updated:** [May 15, 2020, 9:51pm UTC](https://discourse.slicer.org/t/slicer-in-nvidia-on-aws-webinar/11565 "2020-05-15T21:51:18Z")

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Nvidia ran a webinar yesterday that’s available for replay if you sign in. It covers setting up a amazon AWS server to train and deploy models. Lots of good details if you ever need to do that. I didn’t know in advanc…

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## [How do you get the slice view your cursor is over?](https://discourse.slicer.org/t/how-do-you-get-the-slice-view-your-cursor-is-over/11542)

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**Author:** [@mjg](https://discourse.slicer.org/u/mjg)\
**Replies:** 2\
**Last updated:** [May 14, 2020, 7:51pm UTC](https://discourse.slicer.org/t/how-do-you-get-the-slice-view-your-cursor-is-over/11542 "2020-05-14T19:51:17Z")

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Hello, How do you get the slice view (Red, Yellow, Green) your cursor is over? Thank you!

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## [Trouble with Qt, and QtQuick not being properly included in macos .app](https://discourse.slicer.org/t/trouble-with-qt-and-qtquick-not-being-properly-included-in-macos-app/11510)

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**Author:** [@jamesjcook](https://discourse.slicer.org/u/jamesjcook)\
**Replies:** 1\
**Last updated:** [May 14, 2020, 4:48pm UTC](https://discourse.slicer.org/t/trouble-with-qt-and-qtquick-not-being-properly-included-in-macos-app/11510 "2020-05-14T16:48:34Z")

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I’m working with a customized slicer app we branched off several years ago and I’ve got to re-establish a development environment. We’ve got a layer of qtquick on top of slicer simplifying the interface, and some custom…

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## [Pop value from table](https://discourse.slicer.org/t/pop-value-from-table/11530)

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**Author:** [@PaoloZaffino](https://discourse.slicer.org/u/PaoloZaffino)\
**Replies:** 1\
**Last updated:** [May 14, 2020, 2:49pm UTC](https://discourse.slicer.org/t/pop-value-from-table/11530 "2020-05-14T14:49:59Z")

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Hi all, I havev a question about table. I have a table with two columns and I want to pop the last value, shift all the elements and insert a new value just for a single column. Basically I need to have always the sam…

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## [BUG - ScreenCapture always deletes temp files (with fix and pull request)](https://discourse.slicer.org/t/bug-screencapture-always-deletes-temp-files-with-fix-and-pull-request/11535)

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**Author:** [@hherhold](https://discourse.slicer.org/u/hherhold)\
**Replies:** 0\
**Last updated:** [May 14, 2020, 12:40pm UTC](https://discourse.slicer.org/t/bug-screencapture-always-deletes-temp-files-with-fix-and-pull-request/11535 "2020-05-14T12:40:48Z")

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Hey all, I found an issue with ScreenCapture this morning where it would delete the temp files even if “image series” is selected. This would result in Slicer making the image series and then deleting it. The file delet…

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## [Show segmentation only for specific volumes](https://discourse.slicer.org/t/show-segmentation-only-for-specific-volumes/11525)

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**Author:** [@giovform](https://discourse.slicer.org/u/giovform)\
**Replies:** 0\
**Last updated:** [May 13, 2020, 6:49pm UTC](https://discourse.slicer.org/t/show-segmentation-only-for-specific-volumes/11525 "2020-05-13T18:49:46Z")

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Is there a way to programmatically show a segmentation only for some specific volumes in my scene?

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## [How to output the image to slicer view?](https://discourse.slicer.org/t/how-to-output-the-image-to-slicer-view/11517)

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**Author:** [@sunshine\_boycn](https://discourse.slicer.org/u/sunshine_boycn)\
**Replies:** 2\
**Last updated:** [May 13, 2020, 1:20pm UTC](https://discourse.slicer.org/t/how-to-output-the-image-to-slicer-view/11517 "2020-05-13T13:20:26Z")

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Dear everybody: I am following the tutorials on “Programming in Slicer4” implementing the demo “Implemen:ng the Laplace\* Operator”. Everything is fine. The problems come out when I tried to modify the program using C++…

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## [« SegmentEditorExtraEffects »](https://discourse.slicer.org/t/segmenteditorextraeffects/11488)

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**Author:** [@loubna](https://discourse.slicer.org/u/loubna)\
**Replies:** 2\
**Last updated:** [May 11, 2020, 1:58pm UTC](https://discourse.slicer.org/t/segmenteditorextraeffects/11488 "2020-05-11T13:58:22Z")

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Hi; How can I integrate « SegmentEditorExtraEffects » extension in the 3d slicer (built version 4.10.2).? Thank’s in advance

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## [How to get help when programming extension with slicer using loadable module?](https://discourse.slicer.org/t/how-to-get-help-when-programming-extension-with-slicer-using-loadable-module/11483)

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**Author:** [@sunshine\_boycn](https://discourse.slicer.org/u/sunshine_boycn)\
**Replies:** 5\
**Last updated:** [May 11, 2020, 3:13pm UTC](https://discourse.slicer.org/t/how-to-get-help-when-programming-extension-with-slicer-using-loadable-module/11483 "2020-05-11T15:13:25Z")

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Dear everybody: I have tried a lot of tutorials on the website on how to programming the slicer extension using c++. I could built a very simple extension and load it successfully. However, what I found difficult is how…

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