Help with custom smoke velocities

[coljwood]

Hi guys,

Wonder if you can help me with a custom smoke effect i'm trying to achieve using the pyro solver. I've done a lot of digging but don't think my knowledge is quite there to piece everything together yet.

I've attached a crude diagram (which may not actual prove that useful) to try help explain what i'm aiming for. Basically, when my smoke is emitted I want it to avoid, or better still flow around area B (using a custom velocity field?). However, the tricky part is that I also want it to draw trails of smoke into, and eventually fill, area A (maybe with some curve forces to draw it in?). I need it to be very clean and have a noticeable separation between the two areas.

Finally, a 'nice to have' would be to have this happen during the simulation, so initially the smoke will flow over the entire area, then area B will push the smoke out and control the flow around it, while area A slowly draws trails back in to fill it.

I thought i'd be at a level now where I could piece things together to achieve this but had no luck. Any help would be appreciated!

(had trouble including the attachment so linked for now).

Cheers,

Col

Edited January 12, 2019 by coljwood

[Atom]

This does not help with guiding the flow around the outside, but it does demonstrate how to push smoke from one shape into another. In this example the smoke starts off as a sphere and is forced into the new position using a GasTargetForce node. The strength of that node is animated to match a cross fade between two different density shapes, the sphere and the torus.

This example uses pre H17 sourcing techniques.

ap_smoke_gas_retarget_011219.hiplc

Edited January 12, 2019 by Atom

[coljwood]

Thanks Atom, managed to get great results using a variation of this technique! I ditched the separation idea in the end anyway and just had the smoke morph straight into the target.