worked out the math to drive bb-8’s head omni-directionally using three 4″ omni wheels. it will need to respond quickly and move really fast to stay on a fast-moving body sphere. that’ll take a strong magnet, and strong code. getting there…
code is here: https://github.com/Skwerl/bb8
i should note that for now, i have left/right rotation mapped to the left & right buttons, and holomonic movement forward and back (0° and 180°) only mapped to the up & down buttons. in practice, it wouldn’t need to rotate before moving in a new direction; i would just move it in any direction by calculating the atan2 from a stick or whatever. and separate buttons would control rotation.