While watching Neon Genesis 3.0+1.0 I saw this bottle floating in one brief shot, I thought it'd be a fun short project.
I used a simple bone skeleton for the lid and drinking tube while the inner bag is a morph target, sadly Marmoset viewer doesn't support that yet so the bag is stationary in the viewers. I'm sure it could be optimised better or with some extra loops in certain places to smooth out the animation, however it's been a good learning project for what it is.
I also did a Mari/Unit 08 version just for fun.
1 8k texture and 2 materials for the transparent and solid materials in Marmoset.
I hope you enjoy.