Hello!

I am writing an urdf for a human model and I am looking for the
cleanest way of allowing rotation along multiple axis. For example,
human head can tilt and pan- I plan to model this by making two
revolute joints - but only one joint is allowed between two links? I
am considering making a new set of links for each movement but I have
doubts as to whether this is the most optimal way. And I am not quite
sure where to place these new links (should I hide them inside
overlapping set of links?). Please let me know if you know a better
way of allowing multiple movements between two links.

Thank you in advance!

Grace Lee