Help Temporarily make fluids in a container ignore other colliders/fluids

[josemendez]

Oh, there are collision filters for particles. Does that mean I could also leave everything in one 2D simulation and make my scenario work by just changing the collision filters for inside-a-grabbed-glass fluid particles (and again when they leave the grabbed glass due to being poured out)? Or is collision between fluids not controlled by collision filters?

Hi Tobias,

No, fluid particles don't collide with each other (as they would behave like solids otherwise). Fluids work by calculating density at each particle's position, doing a weighted sum of the mass of neighboring particles. Then they apply a pressure force proportional to the difference between the measured density and a target density. This doesn't allow for collision filtering to take place.

http://obi.virtualmethodstudio.com/manua...sions.html

Please note that fluid particles do not collide with each other, only granulars (gravel, pebbles) do. Fluid particles interact with each other trough density constraints, so there will be no contacts between fluid particles reported by the solver. With fluids, you can use advection or diffusion instead to get information about a particle's neighborhood.

You should instead move the emitter to a different solver (you will also need to re-emit active particles and set their positions afterwards), or use a 3D simulation and move fluids in the Z axis.

kind regards,