Can you write a bit more about your end goal? You wrote above that “I am trying to simulate the stretching of the skin over the advancement of multiple skull segments.”, but this is not very clear for me.
Of course!
The model representative of the bone segments here, also carrying the Model To Model Distance data, is the result of a Fronto-Orbital Advancement planning done using Slicer. I ended-up creating two posts about this problem because I wanted to separate this final step from the entire planning discussion.
My goal was to use either the Bandeau Model itself or the Model To Model Distance data to then warp or deform the skin to match the overall advancement of the bones.
This vector field can be very noisy and discontinuous, so I would not use it to warp a surface. Instead, I would try to use one of the surface registration methods.
I have been using registration methods to warp the model also. So far creating a warp transform from fiducial registration has given me the best results, but the result can only be improved with the addition of more landmark and with manual registration. The limit is 30 landmarks and warp transforms do not support the automatic registration.
I was working on Python script that would use the vertices of the source and target models as landmarks, but the registration was falling apart. If you think this is a viable approach, I can continue to explore this… I was thinking of sorting the vertices along the AP so that vertices would match somewhat better between models. In this case I am still limited by the 30 point limit. Is this a hard limit or just a warning about # computations?
Displacement of rigid bone pieces and geometric interpolation between them will not tell much about how the skin will move or stretch. For that you would probably need to run FEM analysis, for example using FEBio.
I agree. In fact, I was planning to use FEBio too. My hope was to, at the very least, get some sort of nodal displacement field that I can use in FEBio to run the simulation a little more programmatically.
Perhaps I can improve the warp transform and convert it to a grid transform, vector volume, or displacement volume? ![:thinking: :thinking:](https://emoji.discourse-cdn.com/twitter/thinking.png?v=12)
Let me know if this is a little clearer now,