easy way to drop a volume of fluid?

[Tony_Morev]

is there one?
i don't mean pre-filled scripted grid cells
but rather a custom object (volume)
thanks!

[Ivaylo Katev]

put the object in the exclude list, and make it a brush mode source (see the non solid options of the barrel). set the discharge to be 100 in the first frame and zero after that.

[Tony_Morev]

cool i'll try that
would be a good trick for the manual unless i missed it, and it's already there
does the 100 mean percentage of fill?
and why brushed? what if i have a regular full sphere to drop, wouldn't it have to be injected?
i'm a bit confused ...

BTW "brushed" and "injected" sounds great (if you're in a doctor's office, no guessing what's going to happen next ...), but "surface" and "volume" is easier on the eyes and more appropriate in a context of 3d

also there is an undocumented "inject mode" check-box in the dynamics roll-out under randomize, what does it do?

[Tony_Morev]

actually this is one more reason to split off fluid UI, so you can allow a volume drop in a more intuitive mode, may be by something like setting emission to "volume" and discharge to 0

[Ivaylo Katev]

yes, something like that. 100 means immediately. 50 means that for one second it will be at 50%, but for two seconds will be not 100%, but 75%. every second it fills the *rest* by this percentage.
brushed and injected is not surface and volume. the brush works like the brush in the photoshop - the longer you use it, the bigger is the affect, approaching 100%. the inject mode creates new fluid in the affected volume causing expansion. both of them affect the volume, not the surface.

[Tony_Morev]

brushed and injected is not surface and volume. the brush works like the brush in the photoshop - the longer you use it, the bigger is the affect, approaching 100%. the inject mode creates new fluid in the affected volume causing expansion. both of them affect the volume, not the surface.

... ehhh, i see ... i take it makes some sort of difference in your algorithms ... but what's the practical difference in terms of fluids?
cause in real life it's either a filled volume being poured somewhere or a prolonged flow, which could be approximated to a surface sweating at a certain rate, for fluid simulations at least

i'm starting to think Phoenix is crazy enough to produce raining clouds all by means of simulation ...

[Ivaylo Katev]

in fume fx the brush mode is called "free flow" as i remember. in general to find the perfect name of such a parameter is not easy task

[Tony_Morev]

Ivaylo, i've tried the suggested method of dropping a volume and ... instead of the volume it drops a bunch of metaballs (droplets) that are spaced apart so far that when they finally all blend together i get about 20 % or less of the volume i started with. Any suggestions?

BTW this is a real project scenario, i'm trying tio simulate the waterfall with a pond below it.
In RF (hybrido) i've dropped the prefill for the pond, then ran an untimed sim until i got the pond settled and the waterfall flowing at the desired rate an then turned on the timeline. Nice and easy.

Now i'm looking for ways to do the same in phoenix. The pond basin is irregularly shaped so i'm not sure i can prefill it with the grid somehow ...

thanks!

[Tony_Morev]

my bad i was injecting instead of brushing, will keep you posted on the progress ...

[Tony_Morev]

everything seems to be working ... except for may be too much "tearing" in the fluid mesh
not sure how to fix it

the tearing pattern appears to be relevant to the grid resolution
so, i'm guessing a finer grid might fix it
the only problem is i'm already at 3million cells

[Ivaylo Katev]

can you post an image?

[Tony_Morev]

i think i already erased the cache ...
i'll check when i get home
in any case i'll continue experimenting on the file and if it comes up again i'll post
i did get a couple of splashes explosions with water disappearing

so far comparing it with a very similar simulation in RF, phoenix seems faster
it's not an apples to apples comparison though, too many things differ between the solvers

getting some help with loading a solution frame through script into initial state would be very appreciated

regarding this, say i'm running the pond under the waterfall first to make it settle (splashes are turned off) "sim1"
once it appears stable i want to start the steam flow to create the waterfall above ( this time splashes are on) "sim2"
i also need to wait till the flow to the waterfall is fully established (as for the render part i need a fully running waterfall) "sim3, render output"

how would you recommend to go about switching from simulation to simulation?

to give you an example for RF 1. i run untimed water drop for the pond fill, 2. once settled i run untimed flow. 3 once a good amount is pouring down i start recording the simulation frames for the output into meshes

and another question: what do do i need to do to stop water from growing? you've mentioned there is a way

thanks!

[Tony_Morev]

i'm seeing some the answers in the beer thread, i'll try those

[Tony_Morev]

trying the grid fill to fill up a volume inside by letting the exess fluid fall down
on the pool scene i'm getting strange results, the is no visible cells on the sides of the solver, but it still renders "aquarium" walls

[Ivaylo Katev]

as i see, the preview is adjusted to show only the water-air interface (range 0.1-0.5), not the pure liquid. the "aquarium" is pure liquid with value of 1 and is not visible in the preview. you can change the initialization script to skip the walls, or to enable the wetting and to set some very small druing time.

how would you recommend to go about switching from simulation to simulation?

until the "official" initial load you can use the restore function, renaming the desired cache to correspond to the cache names of the simulator that will use it to initialize. about the untimed sims, well you have to run them timed here or i'm missing some very important reason why they should be untimed?

and another question: what do do i need to do to stop water from growing? you've mentioned there is a way

play with the surface balance parameter.