velocity

[Mylenium]

Fortunately AE already does this for you.

thisLayer.velocity

Mylenium

[Pour Myl

[Nicholas Toth]

Can’t get it to work properly.

the name of the text layer is VELOCITY and the layer we’re tracking is called PARTICLE.
I applied a numbers effect to velocity.

The error that I’m getting is

Error occured at line 1.
Comp: ‘particle’
Layer: 1(“velocity”)
Property: “value/offset/random max’

[Mylenium]

Yeah, sorry, my mistake. Just like position and scale, velocity is an array property with two separate components. Anyway, I think you’re just interested in the absolute speed, so thisComp.layer(“PARTICLE”).speed should work. You can attach this value directly to the text layer using concatenation, eleminating the need for the numbers effect:

“VELOCITY” + thisComp.layer(“PARTICLE”).speed

You may wanna use rounding, though, otherwise your text layer can get very long. So it could be

“VELOCITY” + Math.round(thisComp.layer(“PARTICLE”).speed)

Mylenium

[Pour Myl

[Nicholas Toth]

I just jumped into the manual (which is nice that v7 shipped with a manual…) and picked out the speed expression because it is 1D (so they say…)

I set it up the same exact way thisComp.layer(“Particle”).speed to the source text of an empty text layer and I’m still erroring.
Do I have to rewrite it along the lines of calculating the particle’s position speed?

Nevermind, I just did that and it worked. I needed to track the transformation of the position with this:

thisComp.layer(“Particle”).transform.position.speed

Thanks Mylenium — I appreciate it.

[Nicholas Toth]

anyway to insert text BEFORE the expression numbers?

I was thinking:

“Velocity = ” thisComp.layer(“Particle”).transform.position.speed

doesn’t work though.

[Colin Braley]

I think you just forgot the plus sign (the string concatenation operator if you want to get fancy)

Try this:

“Velocity = ” + thisComp.layer(“Particle”).transform.position.speed

~Colin