Exporting surface model after applying transformation

Hello, I am having trouble with some features of Slicer, and would be grateful for advice. Images are copied for reference.

I have 3 models - 1) Initial (Green), 2) Final (Yellow), 3) Shell (Purple)

What I am trying to do is to transform the “Initial” (Green) to match “Final” (Yellow), and apply that transformation to “Shell” (Purple). I used SlicerCMF’s surface-based registration feature for this, and when I applied the transformation to the “Shell” (Purple), it worked exactly as I had intended (here the transformation matrix is named “SurfaceReg”).


But when I export the “Shell” (Purple), and open it in another software (Meshmixer), it give me the original, untransformed model. Here, “Shell” is in brown.

Again, I would be really grateful for any advice. Thank you!!

Did you harden the transform before exporting?

That worked perfectly - embarrassingly, I did not know that feature. Thank you so much, and sorry to clutter the forum with such an amateur question!!