# How to generate a "mean model" between few amount of surface mesh?
**URL:** https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793
**Category:** Development
**Created:** [August 17, 2022, 5:30am UTC](https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793 "2022-08-17T05:30:06Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@joanne40226](https://discourse.slicer.org/u/joanne40226)
#### Post date: [August 17, 2022, 5:30am UTC](https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793/1 "2022-08-17T05:30:06Z")
Hi community, i want to generate a “mean model” between few amount (i will show the schematic diagram with 2 data sets) of surface mesh as shown below.
Besides, the suface mesh are already aligned.
Is there any module that i can generate a “mean model” between them? Thank you for your time.
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### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [August 17, 2022, 10:30am UTC](https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793/2 "2022-08-17T10:30:58Z")
You can use modules in [SlicerMorph](https://slicermorph.github.io/) and [SlicerSALT](https://salt.slicer.org/) extensions for this. A simple PCA (that can be computed by the GPA module of SlicerMorph) can provide you a mean shape, but there are many more tools in these extensions for shape modeling and analysis.
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### Author:  [@joanne40226](https://discourse.slicer.org/u/joanne40226)
#### Post date: [August 18, 2022, 9:14am UTC](https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793/4 "2022-08-18T09:14:40Z")
@lassoan
Hi, now i finished generating landmarks from the surface mesh i got.
However, when building mean shape by them, i follow up your suggestion by using GPA
im not sure if i did it right but i only get one slice() and the 3D visualization seem to be weird
where red and green LMs are my two data sets and pink is the mean shape it generated.
The mean shape it generated seem to be extremely close
Am i wrong when doing that? thank you for your help!
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### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [August 18, 2022, 9:52am UTC](https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793/5 "2022-08-18T09:52:38Z")
@muratmaga @bpaniagua can you recommend modules that can compute mean shape of already aligned models?
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### Author:  [@muratmaga](https://discourse.slicer.org/u/muratmaga)
#### Post date: [August 18, 2022, 5:04pm UTC](https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793/6 "2022-08-18T17:04:15Z")
@joanne40226 please follow this tutorial to assign one of your models as a reference model.
> **[Tutorials/GPA\_2 at main · SlicerMorph/Tutorials - 3D interactive visualization and exporting animations](https://github.com/SlicerMorph/Tutorials/tree/main/GPA_2#3d-interactive-visualization-and-exporting-animations)**
>
> main/GPA\_2
The blue model you will see in the right-hand viewer (#2) will be mean model .
You can then go to the Data module, and right click on the object that says **PCA Warped Volume** and you can export it as a model. Make sure you do not touch the PC sliders (or that they are at 0,0).
If you do want to explore variation, you can use the sliders.
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### Author:  [@joanne40226](https://discourse.slicer.org/u/joanne40226)
#### Post date: [August 19, 2022, 7:04am UTC](https://discourse.slicer.org/t/how-to-generate-a-mean-model-between-few-amount-of-surface-mesh/24793/7 "2022-08-19T07:04:56Z")
@muratmaga @lassoan
Thank you both a lot!
i just figure it out it is bcuz i did not choose the option
so it would be scaled into unit.
after i clicked it, it seems to be good.
Thank you for your time!