# Failed to establish point to point coreposndence

**URL:** <https://discourse.slicer.org/t/failed-to-establish-point-to-point-coreposndence/15735>\
**Category:** SlicerSALT\
**Tags:** spharm-pdm\
**Created:** [January 29, 2021, 8:15am UTC](https://discourse.slicer.org/t/failed-to-establish-point-to-point-coreposndence/15735 "2021-01-29T08:15:15Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Maxibers](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/maxibers/32/1876_2.png) [@Maxibers](https://discourse.slicer.org/u/Maxibers)\
**Post date:** [January 29, 2021, 8:15am UTC](https://discourse.slicer.org/t/failed-to-establish-point-to-point-coreposndence/15735/1 "2021-01-29T08:15:16Z")

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I’m having trouble in establishing point to point corespondence.  
Long story short i’m trying to analyze tmj condyle heads remodeling. So after the SPHARM-PDM process on some, but not all, the condyle heads i cannot get the correct correspondence. In the attached pics there’s an example, sometimes is way more off.

![PRE SURG](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/8/a/8a90c89d277536b4236167678df25e9c26228df3.png)  
 ![POST SURG](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/2/1/21458d17cefa83599cf4eec433e650aa8d5fd688.png)  
 ![BOTH](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/e/4/e4ddfaf1ec99801e144cd88f1c94b730a0d94e3d.png)

Am i missing something or doing something wrong? Maybe the original mesh is too round and spharm fails to align it?  
Thanks in advance

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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:** [February 1, 2021, 6:17pm UTC](https://discourse.slicer.org/t/failed-to-establish-point-to-point-coreposndence/15735/2 "2021-02-01T18:17:45Z")

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Hi Massimo,  
Sometimes SPHARM-PDM is not enough to produce the correct alignment of your shape population.  
When this is the case, you should use the RigidAlignment module to further increase shape correspondence.

This module has been renamed in the latest [SlicerSALT](http://salt.slicer.org/download/) to SPHARM-PDM Shape Correspondence Improvement.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/f/1f4eb7b09014ec1573a1f8518d1490fc7b063d77.png)

This is a link to a [tutorial](https://docs.google.com/presentation/d/1_Od20WHcl6IKxN-n1yIYMmDC9sUmkZXFj2YXCAkHQKA/edit?usp=sharing), please keep in mind that the module is now named differently.

I hope this helps,

Juan

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<div class="post-metadata">

**Author:** ![Maxibers](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/maxibers/32/1876_2.png) [@Maxibers](https://discourse.slicer.org/u/Maxibers)\
**Post date:** [February 1, 2021, 9:20pm UTC](https://discourse.slicer.org/t/failed-to-establish-point-to-point-coreposndence/15735/3 "2021-02-01T21:20:27Z")

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thank you very much for your help