smoothing the fluid and freezing the fire

[Tony_Morev]

Ivaylo, what's the best way to smooth the grid stepping artifacts in the fluid?
And how do i freeze a fire sim to show 1 sim frame through the entire timeline? So far the best i was able to get is some kind of double stacked effect where the playing full sim is still there, but the frozen frame is also present. (this is on 1.2)

thanks!

[Da_elf]

there was a tutorial on freezing time (and freezing the flame into ice)

[Ivaylo Katev]

Ivaylo, what's the best way to smooth the grid stepping artifacts in the fluid?

there are two types of these artifacts
- on the liquid-geometry interface, use the gizmo option
- on the liquid-air interface, decrease the sharpness, or static surface correction, if the liquid is near to settled state

And how do i freeze a fire sim to show 1 sim frame through the entire timeline?

the best way is to animate the simulation timescale, like in the "freezing flame" scene. however, if the simulation is already done, you can use the input control that provides two different approaches:
- animated play speed
- animated frame number
keep in mind that if you use the input tools the intermediate frames will be generated using interpolation. this can lead to clearly visible artifacts when the play speed is too low, that's why i would recommend to use the simulation time scale not the input tools.

[Tony_Morev]

what do you mean by "decrease the sharpness"?
i don't see any controls named "sharpness" or anything similar ....
jitter and soft boundaries don't seem to matter for fluids, as far as i can tell, any number i try produces exactly the same rendering

[Ivaylo Katev]

the sharpness parameter is in the place of the old "approach steps" parameter.

[1022design]

Hi
Liquids rollout -> Sharpness(approach steps)

[Ivaylo Katev]

should say that the difference is more than the name

[Tony_Morev]

ok thanks!
mine still says "approach steps"
time to get a newer version i guess

[Ivaylo Katev]

yes, it's time
btw the rise/boiling is fixed, i remember that you had problems with it.

[Tony_Morev]

yes, it's time
btw the rise/boiling is fixed, i remember that you had problems with it.

can you elaborate on that a little
i got the new one and it does look a bit different
the surface correction hack missing for one
so, was there really a bug in there somewhere?
and what should we expect now that it's gone ... hopefully

did all advection methods become more stable?
cause you are saying rising AND boiling and those belong to Classic and Forward transfer respectively

thanks!!!

[Ivaylo Katev]

you mean the surface tension? it is removed from the UI only, because is not stable enough.if one needs it the listener can be used.
the advection methods are not changed, they were stable and work fine. actually the conservation was the guilty one and unfortunatelly the fix affects all the simulations. seems like you have no access to the beta forum did you? there was a message about the last beta update

[Tony_Morev]

beta forum? what's that?

i just had an interesting sim last night
everything was running fine for a while with fluid and splashes and then in the course of 3-4 frames i got myself an .... eehhh ... an explosion at a noodle factory
splashes flying in ray beams everywhere!
it's a cool effect, but max of course didn't appreciate it at all

[Ivaylo Katev]

bidirectional conservation? i'm about to remove it from the UI too

[Tony_Morev]

nope
smooth

i tried to continue from the last good frame and it kept crashing in about the same timeframe
no special effects though just pain old crash, i think with a memory leak

turning off the splashes allowed me to keep calculating, but it took all the fun out of it

a was running forward transfer if that matters ...

[Ivaylo Katev]

yes, we have already reports about the crash problem, but the explosion is disturbing. did you use the "affect liquid" option?