Hi guys,

I'm trying out a couple of fluid RnD sims with custom velocity fields. Currently, I am trying to create a large maelstrom in the ocean and I haven't been able to get my custom velocity field to generate the type of swirl to create a a maelstrom. The fluid are rotating, but it doesn't seem to generate the vortex swirl I was hoping.

My scene scale is large at 500x350x400m wave tank size. I have a custom velocity volume field which is basically a cross product of position against {0,1,0} to get the swirl direction.

I think I am missing out on a thing or two to get the effect I want. Hopefully, someone can shed some light for me?

Thanks.

Hey,

So I tried this technique, hopefully this is what you are looking for:

>> Made an inverted cone and scatter some points in it using a points from volume ( PS: scatter dosen't really help since we need velocity inside the cone as well and all scatter does is scatter points on the geo surface )

>> Created a circle and then created a N on it and then make the N spiraling outwards, using a simple cross prod function

>> Trasferred this N to the points in the cone and converted the N to v

>> Used these cone points to make a VDB from particles and used the v to make “vel” ( you can go crazy with this vel field in a VOP, but I just kept it simple and straightforward for now )

>> Used a pop advect by volume node inside DOPS ( figured since we are simulating particles this should work )

>> Sourced the above velField into this node and then switched it to Update Velocity

And it works!

I am attaching the file I made changes to, all the changes I made a coloured in yellow

Hopefully that gives you a starting point to make it more awesome!

Cheers!

Hey Yash,

Thanks for the help and advise. I'm really thankful. This has been helpful in understanding the different ways we can manipulate flip fluids with custom fields.

This is a great starting point to dive further into.

Thanks!