Thanks! This sounds like a good idea, at least it would make it much more convenient for data analysis. I’ll give it a try soon. I also need to check with the surgeon if he wants the orbital wall particularly well segmented.
What I did to “lift” the plate out of the orbit was by registering the landmarks at the under surface to those at the upper surface and then transform the undeformed plate accordingly. Iterate the process for a few time would “lift” the plate up.
I was then able to project all the points from the plate to the upper orbital surface and run a TPS deformation to adapt the plane to the surface of the orbit (visually satisfied at least).
For repeatability, I am thinking about using something similar to Model-to-Model distance to calculate a scalar value at the plate (e.g., Python code model-to-model distance - #2 by smrolfe). If the scalar values become all negative, it means the plate has “lifted” to just a position just above the orbit. If this sounds reasonable, is there a way to calculate signed distance between particular landmarks and a surface?