Slow motion with the Flip solver?

[Nkal]

Hello,

I have a basic question,

I have a simulation of liquid with the Flip solver which includes splash and foam, and I only have velocity channels exported with them (do i need the id as well?).

What is the correct workflow if i want to slow this down around 4 times?

I've been trying the following on a test with ID export enabled since input play back requires an id:

1 - I input a playback number in this case 0.1 or 0.2 in the Input dialog "play speed" setting and set interpolation as "velocity".

2 - I turn on Re-simulation particles only assuming flip solver is particle based and i disregard the grid and "use Time blend controls" "slow down" method.

but it seems that this isn't working either and the particles disappear entirely when i hit sim again, Am i missing a step or two?

preferably a method which can slow the sim down with only velocity channel exported would be ideal for me since i don't have to repeat my sims.

Perhaps a brief step by step walk through to achieve this would be most helpful.

Thanks,

[Ivaylo Katev]

the resimulation is still not working in the flip solver, fpr now yor only option is to use direct simulation with time scale 0.25 , or perhaps play speed 0.25 with velocity based blending.

[Nkal]

Oh I see, Unfortunately time scale does change the behavior of the liquid dramatically, however i've been trying to blend particles with velocity play speed as you suggested, Unfortunately this is only blending somewhat the foam and splashes but it is not not blending at all the actual flip solved liquid sim and it just skips frames during playback is this normal? or am i missing a step?

Many thanks for the quick reply.

[Ivaylo Katev]

perhaps it's broken, i suppose the flip exports wrong velocity

[Nkal]

Oh Ok, any chance of seeing this addressed in the near future?

Hope so : ).

Meanwhile i'll keep trying whatever other options are on the table.

[Ivaylo Katev]

of course

[SnipeyX]

has the status of play speed velocity interpolation for flip solver changed for phoenix3?

I'm still trying to understand the basics of all this but in my initial tests the past few days i did a sim and exported velocity. Then changed play speed to 0.5 with interpolation set to velocity, but when i rendered i got skipping frames, every other frame was different, so all my odd frames looked like one sim and all my even frames looked like a different sim. I haven't done any re-simulation workflows yet, so lots of room for user error here too.

[Svetlin.Nikolov]

Hey,

You should not change the interpolation type - leave it at 'Interpolation' and the particles should be blended and meshed automatically - the resimulation is currently needed for retiming only fire/smoke simulations. You just need to make sure you have the IDs of the particles - velocity is not needed for blending them, but you could use it for motion blur. Ping us if Interpolation+IDs does not do the trick

Cheers!

[flipbook]

Hmmm.. I thought I would try this and made sure I export the ID of all the particles (liquid, foam, splash, mist) and set playback speed to 0.5 and sent to render. It is stuttering a lot. I may have a slightly older Phoenix 3 on the farm from last week or so but it is not older than a week.

[Svetlin.Nikolov]

Interesting - would it be possible to have a look?

[flipbook]

In the morning I'll update phoenix on the farm and render it out for you to see