Dear Murat,
Thank you very much for your response. I apologize for the delayed reply. As always, your suggestions are very useful. Yes, I have access to the original models, which were obtained through microCT scanning. All the best, Pablo El lun, 15 dic 2025 a las 15:44, Murat Maga (<[email protected]>) escribió: > > *Consequently, their centroid size differs significantly from that of the > other specimens. I know this is not an issue because the Procrustes > analysis removes size,* > > This phrase is being repeated too often in this forum and it is not a > correct statement. This is only not an issue if you are not going to deal > with size at all, all you do is shape analysis. Most of biological > questions involve size at some point. This is actually a huge data > management issue, and plagues a lot of the 3D data online. Image someone > gives you spreadsheet of thousands of measurements, and some are in inches, > some in millimeters, and some in meters, and you don't know which is which. > Scale/resolution of 3D data are important and not something that needs to > be thought after the fact. > > If you have access to the physical specimen's of these 3D models, scaling > is a simple task: Measure a distance on the model, measure the same > distance on the physical specimen, and ratio of those is the linear scaling > you need to apply to your coordinate and model. Repeat this for every > model. Obviously you will be limited by the error in your measurements, the > angle you take them etc... But it is better than being orders of magnitude > incorrect. > > If you do not have access to the physical specimen, it may not be possible > to scale them. How are these models generated? If these were from microCT > scanning, you might trace the steps back (i.e., data import and why the > resolution came off wrong) and see if you can calculate a scaling > coefficient. > > > > > On Monday, December 15, 2025 at 10:01:38 AM UTC-8 Pablo Fisichella wrote: > >> Dear Morphometers, >> >> I hope you are doing well. I have a basic question, but I don't know how >> to approach it. I digitized 3D landmarks and semilandmarks, but a couple of >> my 3D meshes are on a different scale. Consequently, their centroid size >> differs significantly from that of the other specimens. I know this is not >> an issue because the Procrustes analysis removes size, but I wonder how I >> can rescale these 3D surfaces to obtain CS values similar to those of the >> other specimens. Could someone recommend a procedure for rescaling the 3D >> surfaces or the landmarks themselves? Thank you in advance for any >> recommendations. >> >> All the best, >> >> >> Pablo >> > -- > You received this message because you are subscribed to the Google Groups > "Morphmet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/morphmet2/8aa2b808-9162-432e-8c32-16b1160346e9n%40googlegroups.com > <https://groups.google.com/d/msgid/morphmet2/8aa2b808-9162-432e-8c32-16b1160346e9n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Morphmet" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/morphmet2/CANPrD1i9rbro8YvuXhWFNHWp%2B9-6-0pVM6fDGr69yS7a6RjsBg%40mail.gmail.com.
