rocket engine "spread"

[super gnu]

ive finally got a job where fire has been requested! got meself a phoenix subscription.

i need to do a stylised rocket plume, and handily for a noob, its got a preset as a starting point.


all good, apart from the fact that the client wishes to art-direct (well, duh!)

one request is that the jet and smoke plume are conical rather than straight... i.e spreading out like a spotlight with a wide cone.

i thought that editing the source geometry so it is conical might help, and it does a little, you can see the fire starts spreading out better... but it immediately bunches back up and creates an almost identical straight thin jet.

is there a setting which will cause the fire to "expand" as it leaves the emitter? or a way to get it to respect the emitting objects surface normals better?


on a related note, do any tools exist that would allow ffd style manipulation of a grid/vdb? that would be amazing for art direction.

[Svetlin.Nikolov]

Yes, I'd suggest you use a cone shaped geometry and reduce the conservation (fluidity) quality from the Dynamics rollout - this would tell the fluid to not be like a fluid, but shoot forward like a particle sim instead.

What kind of manipulation do you imagine? I have a list of things I would like to add to Phoenix's cache converter, so maybe I could expand it.

[super gnu]

ahh id just like to be able to stick an ffd modifier on a vdb or sim and physically manipulate it.. i guess that might be problematic being as its a "grid"

seems art directors dont have a lot of patience for simulated stuff.. they want to "make that little flame there longer, and delete that puff of smoke that sticks out, but keep the rest as it is, its perfect"

thinking about it, apart from overall deformations, a set of tools that allow you to paint values into the grid by hand with some nice intuitive brushes might be suuuper cool. not sure how easy painting in three dimensions, inside a semi transparent volume might be though.

[Svetlin.Nikolov]

Ahhh, I get it, yes - we gotta have this in Max soon. It's much easier to do this for particles, so I might warm up with the Particle Shader first

[fixeighted]

Would not several emitters, all angled in an array, do this?
So if the rocket has four engines for example.
Just a thought