Using expressions to create a bouncy flash-like mouse trail effect

[Mike Clasby]

Well, here’s the place to start, Dan’s “Creating Trails” page:

https://www.motionscript.com/mastering-expressions/follow-the-leader.html

Down towards the bottom, “Follow the Null”.

I dunno how, but it looks like fun (your example) so I’ll try to noodle it out.

[Coverbee]

like magic to me
great stuff

[Waldemar Werbel]

thanks yikes. quality link.

—
w.werbel. uk.

https://dialspace.dial.pipex.com/town/pipexdsl/r/arar48/cv/

[Mike Clasby]

Ok, I’ve got a reasonable facsimile of the bouncy Flash Mouse Trail animation(as defined by me, maybe you won’t think so) but not rotation yet, maybe later, anyway here goes.

Basically I ripped off Dan (again) from an earlier post:

Name: Dan Ebberts
Date: Sep 24, 2003 at 7:46:52 am
Subject: Re: Delay with expressions

I’m not sure what you’re after. Is it that you want the follower layer to have the time-delayed motion of the leader layer, but relative to its own initial position? If so, try this:

p = thisComp.layer(index -1).position;
value + p.valueAtTime(time – 1) – p.valueAtTime(0)

Dan

So animate the Kite’s (layer 1) position
I had 4 layers (small oval solids) as the “streamer” (kite tail).
Place them where you want them to start, mine weren’t touching and not hanging in a straight vertical line, but a bit staggered vertically. Using Dan’s expression with a little stair-stepped wiggle added, and stair stepped time delay, I used these four expressions on the four followers, closest (layer 2) to farthest down (layer 5).

layer 2

p = thisComp.layer(index -1).position;
wiggle (.3,10) + p.valueAtTime(time – .06) – p.valueAtTime(0)

layer 3

p = thisComp.layer(index -1).position;
wiggle (.5,10) + p.valueAtTime(time – .1) – p.valueAtTime(0)

layer 4

p = thisComp.layer(index -1).position;
wiggle (.8,10) + p.valueAtTime(time – .15) – p.valueAtTime(0)

layer 5

p = thisComp.layer(index -1).position;
wiggle (1,10) + p.valueAtTime(time – .2) – p.valueAtTime(0)

There probably is a neat way with expressions to do the stair-stepping with index-1 but I dunno. Anyways I like the look, it stretches out and closes up depending on the speed of the kite’s movements. Works in 2D or 3D. Hmmm, now about that rotation for 3D…

PS. This might be one of those cascading expressions, Dan would know, that grind slower if the comp is long time-wise or there are to many followers, but it didn’t slow down on my relatively new machine in a 15 sec comp (NTSC) with 4 followers.

[Waldemar Werbel]

Cheers for having a look at this for me yikes.

Have been (and still am a bit…) up against it, so I won’t get a chance to have a proper look at your expressions in action until early on next week. for now, dan’s expressions you pointed me towards have done the trick.

Thanks for your help mate!

—
w.werbel. uk.

https://dialspace.dial.pipex.com/town/pipexdsl/r/arar48/cv/