Smoke flows along a spline without getting trapped

[resort-sand]

Hello
How to make a smoke wisp art directable in term of how it flows?
I want a smoke trail to follow an Spline or a mesh as if it morphs to its shape without being trapped inside it, like if the smoke follows a circle but still dissipating vertically

Cheers

[Dr. Sassi]

Hi resort-sand,

Is this helping?
https://www.youtube.com/live/9eHQtbjDpL4?t=1044&feature=shared
He adjusted it slightly differently, but this looks like what you ask for.

Here is an example, with a different approach:
CV4_2025_drs_24_PYsp_01.c4d

Cheers