unstable initial fill problems and liquid smoothing

[squintnic]

Hi there,
I have a job that requires a strawberry to be dropped into a champagne glass amongst other things and am having some trouble with a few things.

1) getting the liquid to settle without artifacting. the liquid is a intial fill closed volume inside the glass with a push modifier so it intersects. the SPF is 15 and the scene scale is 1.1 (i had it at .2 but was getting boiling) and 100m or so cells.
the first few frames have the liquid jumping up and down and then artifacting down low on the liquid volume. i know you can do liquid smoothing with particles but these artifacts seem too big to smooth.

I have attached the first 5 frames showing the liquid surface jumping up and down (sorry they wouldnt upload in order)

[squintnic]

next up is the artifacts on the lower part of the glass - where it flickers on and off

[squintnic]

and later in the sequence where (these are not bubbles)

[squintnic]

and some test animation renders wide and close

https://www.dropbox.com/s/o33gmmsl60...ss_01.mov?dl=0
https://www.dropbox.com/s/puz7b8u1g0...ss_02.mov?dl=0

and my scene file
https://www.dropbox.com/s/1knvljhaut...st_03.max?dl=0

[squintnic]

settings
https://www.dropbox.com/s/r4d6fkcwfp...56.07.png?dl=0

i was hoping i could get some assistance to try and work out how to fix this up? im going to try and 200m cell sim and SPF 15 overnight and see how that goes, im also slowing it down a little as its a bit fast.
also having trouble understanding how to get bubbles to work effectively and how to have better control over them. i have examined the beer preset but get a bit lost after that when reading about the settings

cheers!

[Svetlin.Nikolov]

Hey,

Increase your scene scale further if the liquid takes more time than you'd like to settle, or alternatively, leave if for some frames and then run the rest of the dynamics.

The render artifacts might be from the way the liquid mesh interacts with the glass mesh. The best way to deal with these currently is to set the glass geometry as an inverse cutter for the liquid simulator and change the render mode from Mesh to Isosurface because the Mesh mode does not play well with cutter currently. This will increase the render times though.

Give that a shot.

Cheers!

[squintnic]

nice one hadnt thought of changing the render mode, currently 1.5 days into a new high res sim so will try after this is done
cheers

[squintnic]

ok have stopped this sim to see if there is much difference on a 140m sim - the water shape and detail is working for me but i still have quite nasty artifacts
i have tried 4 things

1) mesh mode just to see - 140m cells
2) iso mode with cutter
3)iso mode cutter and push modifier on to cut more
4)iso mode cutter and even push modifier on .... glass looks too thick though doing this.
5)screen shot

it seems like the worst artifacts are at the bottom of the glass and the top ones can be cleared more easily

[squintnic]

and my last option is seperate cutter object (non renderedable) that pushes further into the isosurface and the normal renderable glass with a smaller push
this kind of works but introduces double refractions and weirdness at the base of the glass

any more ideas? what are other people doing to get high res product style animations done with phoenix?

[squintnic]

another issue i hope can be solved by scene scale and presiming 25 frames before the main part is this foam issue, where it introduces foam and lots of splashing around....

https://www.dropbox.com/s/swqn1zdene...ss_03.mov?dl=0
https://www.dropbox.com/s/9uuz55mbha...ss_04.mov?dl=0

[squintnic]

double post

[Svetlin.Nikolov]

Haven't seen such issues with similar scenes actually. It would be best if you could send us the scene so we can investigate.

Cheers!

[Svetlin.Nikolov]

Ahhh, sorry, my bad - so we're gonna take a look at the scene hopefully during the next couple of days.

[Svetlin.Nikolov]

Hey, sorry for the long delay - so a few suggestions:
- Definitely use rendering in isosurface Mode + Cutter geometry + Inverse cutter.

- Approach 1: Get a very latest nightly build where the Isosurface parameter is exposed in the Rendering rollout of the Liquid simulator and drop the Isosurface level to about 0.05 - this would inflate the mesh with a subvoxel amount enough for the mesh to cross the glass geometry and be entirely sliced by the Cutter, so the artifacts to disappear. This would be a render-time solution and would not require simulating the sequence again.

- Approach 2: Simulate again with a thinner glass geometry set to non-renderable, and exclude the current glass from interaction with the simulation, but render with it and use it as cutter geometry.

The purpose of both approaches would be to have the liquid volume intersect over its entire surface with the glass geometry. A third approach would be to apply a modifier and inflate the mesh, but this would very likely look weird for liquid splashes in animation.

Hope this helps!

[squintnic]

Hi Svetlin,
Thanks a lot for those tips - we are getting closer and i have got rid of the artifacting but still cant get the liquid to settle (fixed the foam emission by starting a new file) even with 25 frames of preroll simulation.
You can see here how its still wobbling around at start. Any tips for testing the foam before simming? This 225 frame sim took over 24 hrs for 74m cells on a dual xeon writing to local RAID 0 SSD

https://www.dropbox.com/s/evmolrm7l1...ss_07.mov?dl=0
close up (25 frames - https://www.dropbox.com/s/05uugn9lkc...ss_08.mov?dl=0