How to stick (scattererd) points to a flip fluid surface with obviously changing topology

[Chawki]

Can't manage to get it to work with attribinterpolate or primuv with transfered UV's
Any idea of the proper technique to use?


Thanks.

C. 

[bengaet]

you could resim without reseeding if possible so point numbers don't change, then just use points from the simulation and delete the rest.

otherwise you could try using the velocity field to advect your custom particles

[MRsquabu]

Hi,
if you used flipsolver, go under Particle motion, behaviour, tick on Add ID. This generates an ID for every point in your sim. Now you can group by id in sob level and use those faces (by deleting others that are not the ID selected)  to scatter your points. be aware you probably must use a timeshift and freeze the scatter and use a pointdeform to drive the scattered points.

[Chawki]

Thank you,

I tried the resim option, it works but the problem is that more points a generated with the liquid flow growing, I need constant point numbers from start to finish with constant ID numbers so I can copy-to-point other geo on it without having them appearing progressively in time

I'm not sure how to get the velocity field from a flip fluid and how to have point following on the surface of the meshed flip sim.

[bengaet]

without reseeding you can just delete points having a higher pointnumber than a certain value

if (@ptnum > 1000){
	removepoint(0, @ptnum);
}

i've attached a sample file with some different approaches and some sticky notes as well, i hope that is helpful

you can get the velocity field out of a flip sim with an import dop fields, for one solution i fed it into a solver and for another one a setup a popsim with pop advect by volumes. both approaches use reseeding.

i also tested a quick setup with reseeding turned off.

hope this helps!

flipvel.hipnc

[Chawki]

Absolutely fantastic ! excatly what I was looking for.
Thank you for taking the time to make a detailed and very well explained setup

[edversicherung]

@bengaet looked into your hip.file too and have some wild jittering going on when raying the points back on the surface. is there a way to smooth this somehow?

[bengaet]

On 7/25/2024 at 11:30 PM, edversicherung said:

@bengaet looked into your hip.file too and have some wild jittering going on when raying the points back on the surface. is there a way to smooth this somehow?

can you provide your hipfile?

[edversicherung]

hey @bengaet here you go-

i cleaned the file and adjusted everything so it should be working. particle seperation is not very high at the moment so its sims faster.

thanks for looking into it

Pipette_upside_cleaned01.hiplc