Stroking a path over time

[EdwardMartinIII]

Hiya!

I'm trying to do an Indiana Jones style animated map, with a travelling red line.

I've got the PSD file of the map and there's already a happy curved path on it.

I know I've got some set amount of time (something like eight seconds) and in that time, I want a smooth line travelling from one end of the path to the other.

Any ideas?

Thanks!

Cheers,


Edward

"Cut a hole in the door. Hang a flap. Criminy, why didn't I think of this earlier?!" -- inventor of the cat door

 

[scrambled2]

Just animate a mask over the red path over time. keyframe the mask shape from 0 to 8 seconds

 

[EdwardMartinIII]

Thanks for answering, scrambled2.

Yeah, we eventually did that.

Although it's an acceptable solution, it had an unintended glitch: The cut point was always a straight line, plus on tight curves, that straight line sometimes cut weird angles.

My preference would have been a nice rounded tip to the line, a circle of the same diameter (or at least a good approximation). I thought about cutting a curved edge in the mask, but the exacerbating factor here is that the path it must follow curves around in a tight "S" shape. So, it becomes somewhat complicated to try using only a singular mask.

A solution I'm considering (although we've already rendered the piece, I might re-render it for a better result) is to use a bunch of smaller stationary masks just covering up sections of the line. For example, take a deck of playing cards and lay 'em out on the floor with the ends overlapping, to form a big "S". Then, the last card (which will be a little larger) has a semi-circle cut out of it. I slide-via-motion that last card all along the line. Once I can lift up one of the cards-in-a-line, I will do so.

The practical result of this (I hope) is that the line has a rounded tip as it travels smoothly along, even when it curls around tightly.

Do you suppose that would work?

Cheers,


Edward

"Cut a hole in the door. Hang a flap. Criminy, why didn't I think of this earlier?!" -- inventor of the cat door