# Model identity at fiducial location

**URL:** https://discourse.slicer.org/t/model-identity-at-fiducial-location/16456
**Category:** Support
**Created:** [March 9, 2021, 5:00pm UTC](https://discourse.slicer.org/t/model-identity-at-fiducial-location/16456 "2021-03-09T17:00:51Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![maloman](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@maloman](https://discourse.slicer.org/u/maloman)
#### Post date: [March 9, 2021, 5:00pm UTC](https://discourse.slicer.org/t/model-identity-at-fiducial-location/16456/1 "2021-03-09T17:00:52Z")

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Hi all,

I am trying to do a simple thing: For a fiducial markups list i want to output the model in a model list each fiducial point is intersecting with.

Currently I am using a cumbersome approach where i convert the fiducial RAS coordinates to a VolumeNode space of a Labelmap that has all the models in it. I then sample each point in that space.

Is there an easier way to script this directly without the conversions to labelmap?

Thanks in advance

Jan

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### Author: ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [March 9, 2021, 6:14pm UTC](https://discourse.slicer.org/t/model-identity-at-fiducial-location/16456/2 "2021-03-09T18:14:45Z")

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What you do is a very robust and efficient method of determining which models contain the selected point position. If you need to pick many thousands points then I would recommend keep using this method.

If you just want to pick models at the current point position (or hundreds of positions but not hundreds of thousands of positions) then it is simpler to [get the model displayable manager from the view](https://www.slicer.org/wiki/Documentation/Nightly/ScriptRepository#Get_displayable_manager_of_a_certain_type_for_a_certain_view) and use its [Pick3D](http://apidocs.slicer.org/master/classvtkMRMLModelDisplayableManager.html#a2fb2b057ef3571dae97c1c8ef73bf289) and [GetPickedNodeID](http://apidocs.slicer.org/master/classvtkMRMLModelDisplayableManager.html#a58918fec5e28c222b26bc36470b04640) methods.

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### Author: ![maloman](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@maloman](https://discourse.slicer.org/u/maloman)
#### Post date: [March 9, 2021, 7:14pm UTC](https://discourse.slicer.org/t/model-identity-at-fiducial-location/16456/3 "2021-03-09T19:14:36Z")

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Thanks Andras, I guess i will continue using that approach then 🙂