Hi everyone, 

I am working on my thesis on parametric modeling. As part of my research, I used IMA Subdivision Surfaces in 3DEXPERIENCE to model a ship hull and employed macros to systematically modify its shape.

I have some questions about IMA Subdivision Surfaces: could someone explain to me in more detail how they are defined? Are they NURBS surfaces or subdivision surfaces like the ones used in Blender? 

Additionally, is there any research paper or post where this topic has already been discussed in detail?

Thank you in advance for your help!