Hi guys, i belive i found the answear or at least neat solution (depending on how advanced is your mesh).
Import it without collisions, and then use auto convex
then pump this numbers up
depending on what you need.
Hit apply,
and you’ve got yourself simple collision that might be more complex than complex.
Works perfectly for my d12 dices.
Last word: kinda obvious this is performance killer, dont use it when you dont need. Try not to make too many of them.
I know you wont need this, since this is from 2014, but popped for me as first, so it might help somebody.