Variational Calculus

Gabriel's pursuit of a spherical spline differential equation probably goes back farther than 1985, when Ken Shoemake had "Animating Rotation with Quaternion Curves" published at that year's Siggraph. Steve, the dear friend that he is, spent 90 minutes on the phone talking me through the twisty bits. While Gabriel and Kajia appear to have been snubbed thirty years ago, their work stunningly rejected then as "a homework problem", it remains an inspiration to me today. I am sofa king blessed to have such a great mentor and friend. Steve's homework problem for me?... A reminder and gentle introduction to variational calculus through the Feynman lecture "The Principle of Least Action". What a great read!