fluids question

Hi Blenderheads,

what i want to do, is make a ‘rolling’ cube with fluids in it. the gravity should always be Z, like in reallife. if i rotate the whole domain, the problem is that the Z axis is also rotated. so it doenst uses the Global Z axis for the gravity, it uses the Domains Z axis, and the domains z axis is rotated. i also tried to put the fluid into an rotating obstacle, this also doesnt work, the fluid always flows to the domains z-axis, but the obstacle doenst affect it in rotation. it bounces off the obstacle, but if i move or rotate the obstacle, the fluid just stays in place.

i also tried to use 2 domains, but that doenst make sense…

can you help me with this ?

if you cant understand my bad english, just ask, i will post some screenshot or so.


hmm… i don’t know how to fix your problem but you might need to wait for a future build. The only way i can think of is to animate the gravity, though this would be insanely difficult. I wonder if anyone has wrote a script for this? I like your concept. Keep it up, i would like to see this anim! :smiley:

Try creating an inflow and set its axis to -z.

put a cube, in that cube and dont make it rol but stay inside the other as it rolls, but then i suggest you use uvsphere so you don’t suddenly see corners popping out of nowhere. that way you can let your fluid take te constand z axis and make the other roll


thanks for the fast anwers. i also thougt about animating the gravity, but i dunno how to do that. i tryed to put a obstacle into the cube(domain). i tried to rotate the domain, i also tried to rotate the obstacle.

rotate the domain: the z-axis moves
rotate the obstacle: the gravity stays in place, but the obstacle collides only once, if i move it, the liquid behaves like the obstacle isnt moved.

HIX: can you explain it a little better? i have to put a cube into another cube, which one should have wich setting? wich one should be rotated ? i also read about ‘…obstacles should not be moved while animation…’ in the blender documentation wiki.

thanks for you help


inflow objects also dont work. and, i dont want no inflow, because new liquid comes from there anytime, i just want liquid in there from a cube or so. thanks anyway