I'm moving an object and I would like to make a track that "follow it", I would like to make a path stroke (that I will animate, trimming it) from the path of the object I move
There are many ways to do this - here is one:
- Make a null object
- Make a mask path on the null layer using the pen
- Set a single keyframe on the mask's path
- Go to your object (e.g. a star in this example)
- Make a single keyframe on its position
- Copy your mask path keyframe
- Select your position keyframe
- Paste, and you should see your object now moves along the path
To make a tail that follows the star:
- Add a new shape layer with a single line in it
- Make a keyframe on that line's path
- Copy the path from your null
- Paste it into your new shape layer.
- Now you will have a line the same shape as your star's path.
- Add a Trim Paths effect to your Line layer
- Animate the 'End' control on the Trim Paths effect to get the path you need.
This set of scripts is excellent, and free. http://www.redefinery.com/ae/rd_scripts/ It includes scripts such as "shapes to masks" and "masks to shape". Highly recommended
Please tell me you are not looking for optical flow