I've been generating overlays using my script throughout the project. Now that everything relevant is implemented (spatial alignment, time alignment, physics checks) I can generate the final set of overlays. The script will automatically sort the overlays based on whether or not they passed the physics checks.
I have to look at each individual overlay and determine whether or not it looks natural. This is very subjective and there are a lot of borderline cases where I'm not sure what to do...
The goal is to sort all the overlays into sets of Natural & Physically Correct, Unnatural & Physically Correct, Natural & Not Physically Correct, Unnatural & Not Physically Correct. Doing so will give a broad overview of how well the physics checks are working in terms of classifying an overlay as natural or not.
Based on the results of the generated overlays, I think the physics checks do a solid job of filtering out the bad, unnatural overlays as failing the checks. However, there are some overlays that fail the checks but look natural. There are actually a lot of overlays that pass the physics checks but look unnatural. So from an even rudimentary analysis we can see that physical correctness is not enough to guarantee that an overlay looks natural.