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)
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
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.
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…
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.
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
here is my current scene file, in case anyone can shed any light on the intial fill wobbling or ideas for foam control / previewing
i feel like by upping the scene scale i could get the fluid to settle but then the splash scale would feel wrong, currently feels a bit out of whack with the size of the glass / strawberry
25 frames might indeed be insufficient for the liquid to settle - I’m afraid you need a longer pre-roll, or maybe you could use a weak Drag force on the liquid?
If the CPU is dual, it’s possible that the simulation would run even faster on just a single node - do you get a choice for multiple NUMA nodes so you can exclude all but one?
Maybe the Liquid resimulation would work for you? It allows you to keep the liquid shape as it is in the original simulation, but to change the Foam settings over the existing liquid.
Yes, I have two nodes there, but I don’t know how to disable the other one. They are selected (blue), non selected (grey), but there is no other options or check box or something...
Sorry for stealing this thread for my own question…
ah thanks i didn’t know that NUMA trick either - will give that a try along with a longer pre-roll and liquid re-sim. thanks for the assistance guys im getting there
(Im looking at a new i9 chip especially for simulating would fewer cores at higher clock speed be better foe phoenix fd?)
