How to have an object move along a trim path while the path and the object are both moving as well

[Houtwater]

Hello! I have a line drawing I created in Illustrator that I copied into AE. I added a trim path to it and also position points so it will draw as it moves into frame. I also want to add a "lit" fuse to the path and have it move along the path as it draws. My isssue is I can't figure out how to have the fuse move on the same position points as the path from side to side because it already is using position points that I copied from the drawing path to have it follow along the trim path. I tried using a camera layer with a null object but I tried it a couple different ways and nothing worked right. Any help is appreciated!

Thank you

[Mylenium · Accepted solution]

Pre-compose the path and the sparkle, move the whole layer in the parent comp and add whatever else you need to do.

Mylenium

[Houtwater]

That was it, thank you so much!

[Rick Gerard]

Follow these steps:

1. Set path keyframes to animate the shape layer path
2. Add Trim Paths to make the path disappear
3. Apply Window/Create Nulls From Paths.jsx/Trace Tract path to create a Null that follows the path
4. Turn off Loop in the Loop checkbox in the Trace Paths Effects Control Panel
5. Match up the Progress keyframes on the Null to the Trim Paths keyframes on the Shape Layer
6. Add your sparks effect or footage, and make sure the Anchor Point is at the center of the sparks
7. Shift + Parent the Sparks layer to the Trace Path null.

All done:

The whole thing should take less than 5 minutes. This is a lot easier to control and more flexible than pre-composing.

You could even tie the Start Trim Paths property to the Progress Property in the Trace null, so you only have one property to edit so you have complete control over the speed. The project file has Trim Paths tied to the Progress slider.