Refilling after an object has passed through some mud /sand?

[harald_martinoff]

Hi all

I simulating an object passing through some mud /sand, like scooping /ploughing.
- The sand / mud piles nicely up on the side of the scoop / plough
- I get a perfect trace / ditch after the scooping /ploughing

My problem is that I like the sand / mud to refill in after the scoop / plough has passed through the sand / mud, after a short while.
- I m working with the Viscosity in Dynamics to find the balance, but not able to get it to "refill" after the plough / scoop
- I have no Foam and no Splashes, and only adjusting the parameters in Dynamic, but m not able to make it work.

Any ideas?

Max 2024
Phoenix 5.20 (Vray 6)

Br
Harald Martinoff

[georgi.zhekov]

Hey Harald,

Can you show us how it looks and possible a reference of what you want to achieve?

Can you also share with us the settings in the Grid and the Dynamics rollout?

Thanks!

[harald_martinoff]

Hi Georgi

Thanks for following it up.
Attached a small preview animation of the digging of a ditch kind of thing, and the Grid and Dynamic. The Voxel count is low for the preview of course. What I want is that the ditch start filling in, not like perfectly, but natural in that after some meters behind the plough it starts filling in. This is subsea ploughing so it is more natural that is starts filling in.
See attached images and animation.

[harald_martinoff]

I was not allowed to attached the small mp4 video Is there a way to upload video-files?

[harald_martinoff]

I made something similar some years ago, but didn't dig with Phoenix and it doesn't collapse and fill in like I want it to do now. You can see the ditch at 2:56.

[georgi.zhekov]

Thanks a lot for these - they were really helpful.

The viscosity is keeping things solid so you will need to lower it over time, but still keep it high in the beginning so that the plow can do its thing.

You can do that using the Particle tuner - you can use the particle age as a condition to lower the viscosity - so a particle with an age over X sec can have a viscosity of 0 ( 0 might be too low in this case, so 0.1 or something in between might work better).
You can also limit the effect only if it's near a dummy geometry so that only certain particles get affected. Here is a simple video that shows how the Particle Tuner works - https://youtu.be/lqe9bLBYM9M?si=L7Rp826ysdCNroHk

[harald_martinoff]

Thank you Georgi

Not really looked into the particle tuner, will do that now Thank you!

Br
Harald Martinoff

[harald_martinoff]

Hi again

I set up the Particle tuner, but really not manage to get it to do what I want. I use (see image too)
When:
"Age" "Is greater than" "1"
Then:
"Viscosity" "Decrease By" "1"

Question:
1 - Value of Age is seconds?
2 - Value of Viscosity is related to the Default Viscosity in Dynamics? (So if Default Viscosity in Dynamics is 1, then when Age is more than 1 second then Decrease by 1 makes the Viscosity 0)? I m not able to see anything like this. The ditch just stay as it is all the way!

[harald_martinoff]

I also tested with animating the Viscosity from 1 to 0.1 during 10 seconds and I don't manage to get the ditch to refill it self. It is no problem that the ditch go exactly back to what it was, as in nature it will not do that, but still no refilling is happening! I have to look more into it

[fixeighted]

Maybe something like this (extremely quick/dirty) would work for this?
It is extremely simple but may do the job.

[harald_martinoff]

Thanks fixeighted.

Will check it out.

Br Harald Martinoff

[georgi.zhekov]

Hey Harald,

Yes the age in the Tuner is in seconds (in case nothing happens - make sure that the Age channel is exported for the Liquid particles in the Output rollout of the simulator, otherwise the Tuner won't work)

As for the Viscosity - it's related to viscosity either set in the Dynamics rollout or via a Liquid Source, it will affect all particles that have a viscosity channel and fulfill the condition set by the Tuner.

[harald_martinoff]

Hi fixeighted

First I though your scene was basically the same setup as I had, just difference because of the plough (and then working better). The plough is totally different, it is more like a "spear" (see image), but when I tried your setup and with the "spear" I see that the sea bottom is filling it self quite ok. Not as much as I kind of though it should, but after some re-thinking I see that it looks quite good and it will not in real life fill it self in totally. Basically it is to find the correct viscosity.
I will make a render and see how it will look!

Thanks

Br
Harald

[fixeighted]

I'm glad it's working out