Keep lung from different subjects has the same number of nodes/ landmarks


I need to do the segmentation for lung in different subjects. And then I need to conduct principal component analysis (PCA).
Because usually PCA needs the landmarks information, and every subject must have the same number of correponding landmarks.
I am wondering if it is possible that in 3D slicer, when I export my segmentation file as stl file, it can make every subject’s stl has same number of nodes. So that I can directly use node information in STL file instead of marking the landmark manually.

Or is there any plug-in that I can use to change the node information of stl/ segmentation model to make it corresponding to my reference STL model. Because what I want is just to make every lung geometrical model has the exactly same number of nodes.

Best regards,