# Create average model with shapevariationanalyzer

**URL:** <https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581>\
**Category:** SlicerSALT\
**Created:** [July 26, 2018, 8:27am UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581 "2018-07-26T08:27:30Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![aseman](https://avatars.discourse-cdn.com/v4/letter/a/c0e974/32.png) [@aseman](https://discourse.slicer.org/u/aseman)\
**Post date:** [July 26, 2018, 8:27am UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/1 "2018-07-26T08:27:30Z")

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Slicer version:4.8.1  
Hi 3D slicer experts:  
I want to compare the average of two group models to each other, so I use the shapevariationanalyzer module for computing the average models . It computes the mean group for me without any error ; but it doesn’t show the mean in the preview of Group’s mean Tab( even it doesn’t show any scene in this Tab). How I can see the mean group?  
thanks

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**Author:** ![aseman](https://avatars.discourse-cdn.com/v4/letter/a/c0e974/32.png) [@aseman](https://discourse.slicer.org/u/aseman)\
**Post date:** [August 2, 2018, 6:28pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/2 "2018-08-02T18:28:54Z")

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Hi 3D slicer experts  
Unfortunately , I didn’t recieve any feedbacks for my question. I compute the average of models with shapevariationanalyzer module without error, but it doesn’t show any scene ; and the output csv and vtk file (Mean Groups. csv and meanGroup [i] .vtk) is empty(the number of points is zero).Have you any idea about this problem?  
thanks a lot

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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:** [August 3, 2018, 6:15pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/3 "2018-08-03T18:15:04Z")

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@bpaniagua can you help?

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**Author:** ![fedorov](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/fedorov/32/14_2.png) [@fedorov](https://discourse.slicer.org/u/fedorov)\
**Post date:** [August 3, 2018, 6:36pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/4 "2018-08-03T18:36:11Z")

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@lassoan should this topic be moved from “Support” to the [“SlicerSALT” community](https://discourse.slicer.org/c/community/slicer-salt) instead of assigning the “slicersalt” tag?

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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:** [August 3, 2018, 9:12pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/5 "2018-08-03T21:12:13Z")

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Good point, I’ll update the tag, see if it helps reducing the response time.

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**Author:** ![bpaniagua](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/bpaniagua/32/20_2.png) [@bpaniagua](https://discourse.slicer.org/u/bpaniagua)\
**Post date:** [August 16, 2018, 7:30pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/6 "2018-08-16T19:30:29Z")

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Hi all,

Sorry for the delay in replying. @juanprietob could you please address this question?  
Thank you,

Bea

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**Author:** ![bpaniagua](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/bpaniagua/32/20_2.png) [@bpaniagua](https://discourse.slicer.org/u/bpaniagua)\
**Post date:** [August 16, 2018, 7:31pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/7 "2018-08-16T19:31:30Z")

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Aseman,

Could you please tell us more about your input data?  
Thank you,

Bea

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**Author:** ![juanprietob](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/juanprietob/32/6306_2.png) [@juanprietob](https://discourse.slicer.org/u/juanprietob)\
**Post date:** [August 17, 2018, 2:20pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/8 "2018-08-17T14:20:45Z")

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Hi,  
I can help you solve this issue. Do you know if your input shapes have the same number of points? Otherwise this module won’t work.

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**Author:** ![aseman](https://avatars.discourse-cdn.com/v4/letter/a/c0e974/32.png) [@aseman](https://discourse.slicer.org/u/aseman)\
**Post date:** [August 22, 2018, 5:06pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/9 "2018-08-22T17:06:08Z")

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Hi,  
Execuse me for the delay in repliying. I have a number of heart models(vtk files) , Figure 1 at the bottom, and I could calculate the average of them using the shapevariationAnalyzer module(Figure 2 at the bottom) . for this purpose I converted vtk files into the csv files using the creation of csv file for classification Groups Tab. then calculted the average using the computation of mean group Tab.but this average is irregular and does not look like the shape of the input heart models.  
1-is the mean obtained correct?  
2-is it’s irregular shape because of inadequate input data?

 ![figure1](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/b/3/b387c60ebd967d7c9d34c9f080d54514413026de.png)  
 ![figure2](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/b/3/b301bef183509bf529f020cd476e479665f3ae6f.png)

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**Author:** ![lili-yu22](https://avatars.discourse-cdn.com/v4/letter/l/dbc845/32.png) [@lili-yu22](https://discourse.slicer.org/u/lili-yu22)\
**Post date:** [January 3, 2025, 4:43am UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/10 "2025-01-03T04:43:35Z")

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can you help me ?I use the population analysis module in slicersalt5.0.0.I get the PCA mean of the group 1,but the color is always black,no matter I change it to become white .how can I do.

 ![IMG_20250102_132404](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/9/f981260c49a3f5e2853cb74768e6be5e9429d60e.jpeg)

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**Author:** ![bpaniagua](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/bpaniagua/32/20_2.png) [@bpaniagua](https://discourse.slicer.org/u/bpaniagua)\
**Post date:** [March 17, 2025, 3:24pm UTC](https://discourse.slicer.org/t/create-average-model-with-shapevariationanalyzer/3581/11 "2025-03-17T15:24:07Z")

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That is probably due to bad triangulation / bad normals. What happens if you try to process it in the surface toolbox? i.e. clean mesh