# Increasing ALPACA Non-Rigid Alignment

**URL:** <https://discourse.slicer.org/t/increasing-alpaca-non-rigid-alignment/28906>\
**Category:** Support\
**Tags:** registration\
**Created:** [April 14, 2023, 10:11am UTC](https://discourse.slicer.org/t/increasing-alpaca-non-rigid-alignment/28906 "2023-04-14T10:11:27Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [April 14, 2023, 3:30pm UTC](https://discourse.slicer.org/t/increasing-alpaca-non-rigid-alignment/28906/3 "2023-04-14T15:30:30Z")

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> [@evaherbst](#):
>
> The meshes only have 4,000 vertices unfortunately so I was not able to test higher point densities.

How many points are you left with during the pointcloud conversion? (ALPACA should report the number of points). If it is too few, that might be the problem.

> [@evaherbst](#):
>
> I have tried changing the alpha value but no success.

Try changing both alpha and beta values together. Increasing CPD iterations will probably be useful as well.

Finally, the current ALPACA module will be deprecated soon, and we will switch to an ITK based implementation (instead of open3d we are currently using). Make sure you start using, it is already available with SlicerMorph (it is called ALPACA-preview), but it is hidden.

Go to **Application Setting-\>Developer-\>Enable developer mode.**  
then, open the module finder, and check Testing.

![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/5/6/560648f84e96392ff7b4ab542d6f1eb02bf6c9c5.png)

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