Hi…

Sorry for the snappy title but I have to ask…
At the moment I can find no way of applying a force (say, gravity) to one flip source and that gravity to NOT affect another source. Say I wanted fluid to move up through another fluid to form a shape using a field force, but not be affected by gravity , which affects the fluid being pushed through.

Coming from a Maya background this would be easy…You just assign a field to a particle system but not to the other, but the two sytems will still interact.

Because the forces are applied after the flip solver it makes it impossible (as far as I can see) to split them up this way.

Any ideas how th approach this? Could some kind of grouping work? I see you can assign groups inside forces but can't see how to assign groups to the separate fluids.
Thanks,
Nick

In the merge node you can set the relationship between inputs.

Or you can use a “colliderel” node (= Collide Relationship).

And in the gravity node you can exclude one of your fluid by writing * ^objectName.



EDIT : and keep in mind that if your gravity node is upper than one of your fluid object in the tree, it won't affect it.

if you are using H13, use POP forces in DOPs so you can easily use POP groups/streams to apply your forces to or you can literally have per-particle control if you wish

(the group masking in DOP forces will not work for you since it only works on DOP objects, so if you have one FLIP object and no matter how many sources/emitters, it's still the same object so you can't use DOP groups to distinguish between particles by emitter)

Cool thanks guys I'll give it a go…

Thanks, I learned a thing too !