Bob Arning <arning at charm.net> wrote:
> WRT better celestial mechanics within the constraints of EToys, check out OrbitBob2.
> 

I also made a simple orbital mechanics thingie named "Gravity".  It took
a bit of thought, but it eventually dawned on me to represent
acceleration and velocity as morphs.  Computing the acceleration vector
can then take advantage of "move towards" and "move forward by"--no
square roots necessary!

-Lex