# 2025.10.21 Weekly Meeting

**URL:** <https://discourse.slicer.org/t/2025-10-21-weekly-meeting/44833>\
**Category:** Weekly meetings\
**Created:** [October 20, 2025, 10:03pm UTC](https://discourse.slicer.org/t/2025-10-21-weekly-meeting/44833 "2025-10-20T22:03:35Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Sam\_Horvath](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/sam_horvath/32/3092_2.png) [@Sam\_Horvath](https://discourse.slicer.org/u/Sam_Horvath)\
**Post date:** [October 20, 2025, 10:03pm UTC](https://discourse.slicer.org/t/2025-10-21-weekly-meeting/44833/1 "2025-10-20T22:03:35Z")

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Tomorrow, we will be having our next weekly hangout at **10:00 AM ET until 11:00 AM ET.** a

Anyone is welcome to join at this link: [https://bit.ly/slicer-googlemeet-hosted-by-kitware](https://bit.ly/slicer-googlemeet-hosted-by-kitware)

* * *

> **Weekly Meeting**
>
> **Starts:** October 21, 2025, 10:00am (America/New\_York)\
> **Link:** <https://bit.ly/slicer-googlemeet-hosted-by-kitware>

**Agenda:**

Please post to this thread to put a topic on the agenda! We will try to prioritize agenda items during the meeting.

* * *

Thanks  
Sam and J-Christophe

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**Author:** ![RafaelPalomar](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/rafaelpalomar/32/1436_2.png) [@RafaelPalomar](https://discourse.slicer.org/u/RafaelPalomar)\
**Post date:** [October 21, 2025, 11:52am UTC](https://discourse.slicer.org/t/2025-10-21-weekly-meeting/44833/2 "2025-10-21T11:52:21Z")

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I’m currently trying to create a custom visualization based on surface models where I need my own mappers (for custom shaders). It looks to me that this route would require a custom implementation of `MRMLModelNode`, `MRMLModelDisplayNode` and `MRMLModelDisplayableManager`.

Due to the way `MRMLModelDisplayableManager` filters nodes, it is not possible to simply inherit from `MRMLModelDisplayNode`, as any derived class will be processed by `MRMLModelDisplayableManager`.

It would be great if we can find some time to discuss this. Maybe we can adjust the filtering of DMs so inherited classes can be handled by custom DMs?

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**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [October 21, 2025, 1:44pm UTC](https://discourse.slicer.org/t/2025-10-21-weekly-meeting/44833/3 "2025-10-21T13:44:14Z")

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> [@RafaelPalomar](#):
>
> It would be great if we can find some time to discuss this. Maybe we can adjust the filtering of DMs so inherited classes can be handled by custom DMs?

Related functions:

- [vtkMRMLModelDisplayableManager::ProcessMRMLNodesEvents](https://github.com/Slicer/Slicer/blob/69c917aa750c64cfbea541e9ae1a9f5b675cda49/Libs/MRML/DisplayableManager/vtkMRMLModelDisplayableManager.cxx#L334-L383)
- [vtkMRMLModelDisplayableManager::IsModelDisplayable](https://github.com/Slicer/Slicer/blob/69c917aa750c64cfbea541e9ae1a9f5b675cda49/Libs/MRML/DisplayableManager/vtkMRMLModelDisplayableManager.cxx#L467-L493)

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<div class="post-metadata">

**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [October 28, 2025, 1:40pm UTC](https://discourse.slicer.org/t/2025-10-21-weekly-meeting/44833/4 "2025-10-28T13:40:44Z")

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### Meeting Notes

#### Slicer 5.10

- Target date for tagging the **Slicer 5.10** release is first week of November .
- This release will be the **final version based on Qt 5** , ahead of the transition to Qt 6.

#### LightBox Removal

- Discussed [PR-8776](https://github.com/Slicer/Slicer/pull/8776):  
_`ENH: Simplify Slice view removing LightBox feature`_.
- @Thibault_Pelletier will assist with finalizing the PR.
- This is part of a broader effort to streamline rendering by removing legacy LightBox support.

#### Extending `MRMLDisplayNodes` and `MRMLDisplayableManagers`

- Use case discussed: Creating a **custom 3D View** in the side panel to show custom model visualizations using **custom mappers** (similar to the _Resectogram_ idea from [PW38 SlicerLiver project](https://projectweek.na-mic.org/PW38_2023_GranCanaria/Projects/SlicerLiver/)).

**Key technical considerations:**

- Custom mappers require **custom MRMLDisplayableManagers** , which must be implemented in **C++**.
- While extending `vtkMRMLModelDisplayNode` is tempting for surface models, inherited managers (like `vtkMRMLModelDisplayableManager`) will process **all subclasses** , which may not be desirable.
- One solution is to derive from `vtkMRMLDisplayNode` directly for full control.
- Interaction customization (e.g., changing 3D view controls) can be done via scripting:  
[Example from documentation](https://slicer.readthedocs.io/en/latest/developer_guide/script_repository.html#make-the-3d-view-rotate-using-right-click-and-drag).
- @Thibault_Pelletier referenced the [KitwareMedical/SlicerLayerDisplayableManager](https://github.com/KitwareMedical/SlicerLayerDisplayableManager) module, now integrated in Slicer 5.9 nightlies, as a helpful reference for creating custom rendering pipelines in both **C++ and Python**.

#### Unity-based VR App for Dentistry

- _Alex Myers_ introduced his Unity-based VR application focused on dental workflows.
- Utilizes **Slicer’s TotalSegmentator extension** to generate anatomical models for use in the app.

**Discussion points:**

- Challenges arise due to the **lack of direct access to scientific toolkits** (e.g., PyDICOM, SciPy, ITK, VTK) when using Unity.

- To make the project more relevant for the Slicer community: