I'm trying to create steam rising out of a cup of tea… but the client wants quite a specific shape to the steam… whereby the steam twists in a vortex like shape - see image attached/below. It needs to almost look like an hourglass in profile, with the steam pinching together in the middle
I'm a relatively new Houdini user. I'm totally fine with all the Pyro sim side of things (solver shaping etc), but I'm not sure the best way to art direct the smoke into this shape?
Particles? - my instincts say I shouldn't emit from particles though as I feel like it would stop if feeling like the steam is coming from the tea?
Custom velocity forces using geometry fed into the sim? - if so, whats the best way of controlling the velocity angles on geometry (I've got zero experience with VEX!)
I see many posts like these lately – highly complex functions that would be challenging for many advanced Houdini veterans followed by a “I'm a relatively new Houdini user.” or “I've got zero experience with VEX!”
Just because the software is capable of achieving a certain effect, it doesn't mean that such a task is achievable without really knowing the software inside-out and having a lot of experience using it. In Houdini in particular, there really are no shortcuts, and if you're basically asking for someone to do this for you, then at least offer compensation since this is a commercial project.
My advice to you would be to do this in post – you can easily achieve this type of effect in AfterEffects or Fusion using stock video elements and distortion/mesh warp.
I wasn't aware that this was the sort of thing that would challenge even an advanced Houdini user. I've always enjoyed challenging myself and have loved every bit of getting to know Houdini. I've also been surprised about how good its results can be, often without having to get really deep into the technical side of things, especially as the platform becomes more and more artist friendly.
The community has always been so friendly and generous with its advice. I'm in no way asking someone to do this for me. Just some general pointers on the best way to approach this, so I can continue to focus my learning/research in the right area.
I hear what you're saying re AE/Fusion, but unfortunately I don't think that would achieve the right look.
I am not offended, so no apologies necessary. Please understand that there have been a slew of posts recently where the author asks for explanations for very advanced tasks while also admitting to a rather limited knowledge of Houdini. It reminds me of all the various memes floating out there of the kid trying to skip the first three steps of a staircase.
What I think goes a long way toward building trust and wanting people to help you is to at least post a .hip file of where you're at so far. It doesn't have to include any proprietary geometry or textures, in your case even a hollow cylinder in the same place as the cup is sufficient.
What this does is allow us to determine how far along the process you are, what your approach has been so far, and how to correct your file in order to help you achieve a better result.
A quick tip would be to set up your smoke using the recent pyro SOP nodes, and in there you can add various GAS micro solvers to control the flow somehow. You'll quickly realize just how challenging it can be to achieve controllable art-directed results, which is where you might need to opt for some other method of advecting the smoke. It can get quite complicated very quickly as you start dealing with velocity forces as well as other forces to try to keep the shape that you're after.
