Actually good effect.

Oh my god, these hats are going to EXPLODE! Someone help them!

(Seriously though, this looks great! Great Job.)

I left the blue Engineer in the promo because I thought it looked funny.

I said in a previous comment that the length of all the beams are similar to that of Sunbeams and any closer will make the dissipation obscure the head or will be harder to see on taller hats. If I were to overlay Sunbeams directly on top of this effect, they will be similar in size.

Shortening the length also changes the look and size of the sprites because the effect is based on velocity. There is symmetry on all sides except for the front and bottom and they alternate in length and emission. The emission is predetermined and without emit noise there is no good way to avoid a convergence where all the puffs emit at the same time so the best thing is to only have it happen at very long intervals. This is what happened with the blue Engineer. I also set up the emission such that the left and right side converge which makes it look like there is steam coming out of both ears.

Thanks for the explanation - sounds like a major pain!

Did you build in any symmetry (or close to it) of the emission points? That's a bit hard to gauge from the vid and at least the blu engi suggests that.

I'd argue the length of the beam could be cut by ~10% or so to look better on common hats but it will then probably be too close for something like the towering pillar of hats. IMHO the top beams are the ones that stand out - the bottom/sideway beams are OK.

This then does give off the shape of broccoli but cartoon air puffs share a similar depiction to broccoli instead of a cone or a 'V' shape so that was left as a design choice. The advantage of non random smoke is that I can choose to make it not obscure the face of the player.

Circular emission is the easiest to implement but it still will have the same issues with the direction of the moving smoke.

I have attempted a circular steam emission effect some years ago but that also needed to be confined to preset directions.

All these workarounds only leaves me with an extremely limited set of parameters that I can barely tweak to make the effect look like this. Maybe this is the only way or maybe there is a better way but for that I do not know.

All of what you pointed out with this effect is not because I did not want to do it. It was attempted but failed and was worked around due to the particle engine limitations in this branch of Source and I can explain all of it:

For randomisation: An unknown TF2 update broke emit noise at an engine level in the most labyrinthian way possible and I only found that out myself when the effect was almost finished so I had to remake the entire thing.

For directional randomisation: Sunbeams does it by only emitting a single sprite that must be of uniform length otherwise there are visual issues. This cannot work for pressure beams which are intended to have dissipation, move due to velocity, have slightly different lengths and different emission timings.

Please tell me the directions are randomised. That blu engi litreally looks like a crosshair (I think it was from Ace the Ocarina Maker).

I get you're going for a lengthy trajectory as a proxy for the pressure, but this feels a bit off...
The beam is a bit too collimated for the first 2/3 and only really dissipates afterward, making it more akin to a broccoli than steam, IMHO. I think this would benefit from a bit larger cone of dissipation starting from the base.

You could also use a circular emission with nothing in the middle, that'd be wider and less pronounced, but would require some tweaking to visualise the pressure more. That'd be more like steam emanating from a badly covered opening, rather than from a puncture.

https://imgur.com/a/OTWTCql

The streams are roughly the size of sunbeams. What makes it look big is the dissipation at the end of the streams. I did try making the dissipation smaller but then it didn't look like it was dissipating properly. I also tried making the streams closer to the player but then the overall effect of steam shooting out from the hat was much less noticeable and the dissipation actually covered too much of the player's head. So in the end I just made the steam very transparent such that it is harder to notice it overall in a well lit area. You can see how transparent it is in the video when the player stands in front of some light. The lengthier streams may also fit better on any potentially larger scaled hats.

Looks really cool, the only suggestion i can think of is to maybe make the steam trail a bit shorter because right now the radius is huge— maybe like the size of sunbeams?

Soyjack Rage unusual

you cooked

yes

Steaming if it was good

very high, very pressure