How do I maintain the offset in trim paths when the size changes

[wibofe5FA9]

I have created a trim paths animation & I have a specific offset. This offset changes when I change the size of rectangle / any shape. Is there any expression to maintain the offset?

Thanks!

[Mylenium · Accepted solution]

Not really. You would have to re-create the entire Bezièr formula as expression code more or less. AE doesn't provide access to parameters liek relative and absolute path lengths and one would have to do the calculations. For a simple rectangle it would be easy - 2*a + 2*b with a and b being the side lengths. Similarly you could accomodate rounded corners by including the 2*r*Pi, but that#s pretty much where it ends. Any more complex shape will require additional calculations with growing complexity. Some of the burden could likely be taken off your shoulders by buying scripts like Trails from AEScripts, though, that set up expressions for these calculations.

Mylenium