Issue with the warping

Bugs
,
1

Hello,

I have observed an issue when using the warping method on subjects for which I don't have an MRI.

The warping procedure (option "warp", 2% error) works well where there are head points to fit to, but the new head model generates with a dip between the ear and the temples, where there are no digitized points (see below the resulting head model):

Failed_Warp 1
Failed_Warp 1790×645 40.2 KB

As a consequence, temporal and inferior frontal areas get squished on the cortex model (see attached picture)

I joined the file to the head points, maybe I did something wrong in the processing but I've observed it on many participant - actually, all of them but certain head shapes minimize the issue will for others it's aggravated.
I'd be interested to know if other people have observed the same deformation when using the warp method.

If you have an idea of where the issue might come from, or what method could be used to avoid it, I'd love to get your feedback on this issue !

Best,

Antoine

2

@antoinebk, can you also share raw .pos file with the head points?

3

sub-MS58806_ses-20250515_headshape.pos (3.3 KB)

I think this is what you want ?

4

The issue seems to be the lack of more points in places between the current ones and the XY plane (of the SCS).

One solution that you can try is to improve the alignment between the head points and the Default anatomy and the perform Scale instead of warping, to avoid the observed deformation.

Results with manual alignment + scale:

image
image570×450 36.5 KB