# How do figure out superficial area of the green part which is covered by red?

**URL:** <https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612>\
**Category:** Support\
**Created:** [July 10, 2021, 7:47am UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612 "2021-07-10T07:47:36Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![QSX747](https://avatars.discourse-cdn.com/v4/letter/q/71c47a/32.png) [@QSX747](https://discourse.slicer.org/u/QSX747)\
**Post date:** [July 10, 2021, 7:47am UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/1 "2021-07-10T07:47:36Z")

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![1111](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/b/d/bd97684efe475bbe6fd6537ecbab29db917aa3b7.jpeg)  
Hi!  
Based on the preoperative MRI, I am trying to reconstruct the sellar region tumor( green part) and the surrounding peritumor capsule( red part) by using 3Dslicer, and try to calculate the coverage of the sellar diaphragm barrier through the reconstruction of the sellar diaphragm barrier, so as to further study the risk of intraoperative cerebrospinal fluid leakage. The core problem was: is it possible to figure out the superficial area of green part which is covered by red? and how?  
Thanks !

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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:** [July 14, 2021, 3:15am UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/2 "2021-07-14T03:15:06Z")

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It is not a trivial task, but you can try the following. Export the segmentation to models, then compute distance between the two meshes (using Model to Model Distance extension). Then extract the parts that are at a certain distance range. You can experiment with the threshold range in Models module, in Display → Scalars → Threshold.

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**Author:** ![QSX747](https://avatars.discourse-cdn.com/v4/letter/q/71c47a/32.png) [@QSX747](https://discourse.slicer.org/u/QSX747)\
**Post date:** [July 19, 2021, 5:58am UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/3 "2021-07-19T05:58:47Z")

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I have try the Models section but I can’t compute distance between the two meshes (using Model to Model Distance extension) as you said before, Can you provide more details on this kind of calculation method ? Or show a simple example ? thank you very much!

 ![1626674417(1)](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/6/6/66d663fef436858dc4699fa9e9d0870b7346ec40.jpeg)

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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:** [July 19, 2021, 11:35am UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/4 "2021-07-19T11:35:53Z")

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> [@QSX747](#):
>
> I have try the Models section but I can’t compute distance between the two meshes (using Model to Model Distance extension)

Please describe what you did, what you expected to happen, and what happened instead.

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**Author:** ![QSX747](https://avatars.discourse-cdn.com/v4/letter/q/71c47a/32.png) [@QSX747](https://discourse.slicer.org/u/QSX747)\
**Post date:** [July 19, 2021, 4:37pm UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/5 "2021-07-19T16:37:16Z")

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I think I’m stuck at the first step. I exported the two segmentations to models as the picture shows, then I try to find the “model to model distance extension” in the models section menu but I couldn’t . All I can do were just changing the look of the model and clipping selected model(I was confused about this clipping also). My goal is to figure out the superficial area of specific part which is covered by the other part, for example can we calculate the surface area of the skull covered by the green part ?

 ![111](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/a/fa69fb6d9aea94f47879920f4cfd2beac0e3463d.jpeg)

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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:** [July 19, 2021, 4:45pm UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/6 "2021-07-19T16:45:18Z")

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Model to model distance module takes model nodes as inputs. You can export the segmentation to model node by right-clicking on it in Data module.

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<div class="post-metadata">

**Author:** ![QSX747](https://avatars.discourse-cdn.com/v4/letter/q/71c47a/32.png) [@QSX747](https://discourse.slicer.org/u/QSX747)\
**Post date:** [July 20, 2021, 7:50am UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/7 "2021-07-20T07:50:35Z")

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I can not find the model node 🥶

 ![962627475f8b0edb525520f9bf54b53](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/0/00f0d18e210725766eee03d8f7c170a5c0e3758b.jpeg)

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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:** [July 20, 2021, 11:41am UTC](https://discourse.slicer.org/t/how-do-figure-out-superficial-area-of-the-green-part-which-is-covered-by-red/18612/8 "2021-07-20T11:41:11Z")

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Select the “Export visible segments to models” menu item.