To accomplish the specific look we were after, a lot of R&D went into investigating different plugins, echo & delay methods, various expressions (and best values for them) on various properties; we tried “smooth,” speed and velocity manipulation — and then found that Trapcode Particular would accomplish much of what we were after with only a few adjustments.
The main trail is created by having Particular emit enough particles to draw a solid line, with the “Life” property set fairly low (so that the movement speed controls the length). A “smooth” expression was put onto this property, so that while it still responded to keyframed animation there was an additional blending of the animation, adding to the organic feel.
The secondary “wispy” motion was accomplished using the “Air” physics in Particular. Setting Air Resistance really high means that the tail feels like it’s moving through molasses, clumping up as it gets further from the emitter.
Any additional, smaller trails beside or in front of the main tail were animated either by hand, or by duplicating the whole tail rig and tweaking settings, at the preference of the artist.
Asking artists to dig deep deep deep into nested effects settings while they’re trying to animate a scene is almost always a no-go.
To simplify the task of animating the tail for the animators, we rigged the above properties (and a few others) to Expression Control sliders, so that the animators could quickly and easily animate the look and feel of the tail without needing to twirl properties forever.
Zack Lovatt focuses on toolkitting, building custom studio pipelines, expression rigging projects, and creating data-driven animation workflows.