Shape jumps across composition when path pasted after effects

[markh17861918]

Hello, so I am having a major problem and I have been searching forums for the past day and a half trying to find an answer and haven't found any so I've resulted in making my own in hopes of finding the answer!

I am trying to have a shape move along a tilted oval path. For now, I have simplified the design into simple shapes: (The oval in this picture is just to show you the shape of the path)

Now when I paste the path that I created with the pen tool onto the position layer of the arrow shape, the arrow always jumps to the other side of the composition:

How can I make sure the shape stays in the same spot when the path is pasted on the layer?

I am a beginner in After Effects so I may be missing something really obvious

[Mylenium]

Well, you could adjust the nachor point and point order by defining a new first point for the path. These are simply limitations in teh workflow. You have to be super-exact and prepare your content suitably. AE has no magic way of knowing the relations between your pasted paths and the layers it is applied to. It's all just abstract data.

Mylenium

[Colin Holgate]

It turns out AE does have a magic way to do this.

First to say that I know nothing about AE, you're already miles ahead of me. But, I am extremely good with Google searching, and I now know a lot more about AE!

Before you copy the pen ellipse, select its path, then with the Selection Tool select a handle where you want the animation to start. If there isn't something there to select, use the pen tool to add a handle. Once it's selected go to Layer/Mask and Shape Path/Set First Vertex.

Now copy the path and paste it onto the position of your arrow, and the arrow will jump to the location of the first vertex you set.

[Rick Gerard · Accepted solution]

Rules for turning a vector path (mask or shape layer path) into a motion path.

1. The layer containing the path must be at 100% scale, at the default comp center position, and the rotation has to be zero - In other words, everything has to be reset
2. When selecting the path you want to copy, if you want the entire path to be copied you have to make sure that the entire path property is selected and not just a few of the points on the path. The easiest way to do this is to simply set a keyframe then either cut it (Ctrl/Cmnd + x) or copy the keyframe. Most of the time just selecting the Path will work, but sometimes this will fail
3. If the path you are copying is animated the resulting motion path will be a series of motion paths that match each keyframe followed by a straight line return from the first vertex to the new position of the first vertex in the path. If the first vertex changes position this can result in unexpected motion between keyframes.
4. The motion path will always start at the first vertex in the path on the path and move counter clockwise for a closed path. If you need to reverse the path then you use the keyframe assistant and time reverse the keyframes.
5. The layer you want to follow the path will always move to the first vertex when you paste so that is where the anchor point will be.
6. If you set a position keyframe before you paste your copied vector path you will always  a new motion path starting at the current time indicator. Sometimes just selecting the position property does not work but using Alt/Option + p and then paste (Ctrl/Cmnd + v) will always give you a motion path starting at the CTI.

I hope this helps. It looks to me like your only problem is that you did not expect what happened. From your screenshot it looks like the anchor point of the layer containing the arrow is in the center of the triangle and it moved to the first vertex. That is exactly what should happen.

If you want to arrowhead to be there but the arrow to be pointed in the a different direction then you have to either set the transform options (Ctrl/Cmnd + Alt/Option + o) to auto orient to the path or adjust the rotation property of the layer manually.

If you expected the arrow to follow the path and bend around it then you did not follow the right workflow. You needed to create the path using a shape layer, apply trim paths to get a line segment to move around the path by animating the start and end points of trim path, then create the arrowhead on another shape layer, copy the path and paste to the arrowhead position and auto orient to the path. Your comp would look something like this:

[markh17861918]

Thank you! I haven't seen any tutorials about adding a trim path - after I do, do I select "Path 1" as well as "Trim Path 1" and copy it onto the position layer of the arrow?

[Rick Gerard]

Let me give you a quick step by step.

1. Create a new HD comp that is 7 to 10 seconds long
2. Select the pen tool
3. Make sure fill is turned off and stroke is set to something like 8 pixels
4. Draw a closed path by clicking and or clicking and dragging in the Comp Panel until you have closed the path
5. Press the U key twice to reveal all properties of the shape layer
6. Find the Path property on the Shape layer and click the stopwatch to set the first keyframe for the path
7. Ctrl/Cmnd + x to cut the keyframe and copy it into memory
8. With the first shape layer selected in the timeline press the enter key and rename the layer Path
9. Deselect the path layer and select the parametric Polygon tool
10. Make sure stroke is turned off and fill is set to the same color as the fill on the layer below
11. Draw a small polygon anywhere in the comp panel
12. Press the U key twice to reveal all modified properties of the new shape layer
13. Change the number of sides to 3
14. Change the size to something like 80 pixels
15. Set the Transform PolyStar>rotation property to 90º
16. Set the Transform Poly Star>position to 0,0 to move the poly star to the center of the shape layer so it lines up with the anchor point
17. Move the CTI (current time indicator) to the where you want the animation to start
18. Press Alt/Option + p to reveal the position property of the top shape layer and set a keyframe
19. Paste using Ctrl/Cmnd + v to paste the path you copied to motion path for the shape layer
20. Just for fun, with the Shape layer selected press the enter key and rename the layer Arrowhead
21. With the arrowhead layer selected and the position property selected right click on the keyframes to go to the Keyframe Assistant and select time reverse keyframes to make the arrowhead travel in a clockwise direction
22. Press Alt/Option + Ctrl/Cmnd + o to bring up the Auto Orient tool and select Orient along path
23. Check the movement of the Arrowhead. It should perfectly follow the path
24. Click on the last position keyframe and drag it to the right or right to adjust the timing of the move
25. Deselect the Arrowhead layer and select the path layer
26. Press the U key twice to reveal all modified properties
27. Find the Shape 1 under Contents and select it
28. Find the little ADD button at the top right corner of the timeline switches and modes column in the contents line
29. Select and add Trim Paths to Shape 1
30. Move the CTI down the timeline a bit to get the arrowhead started along it's path
31. Set a keyframe for Trim Paths and adjust Start to move the line to the arrowhead
32. Move down the timeline to the last position keyframe and adjust the Start position to make the line connect to the arrowhead again
33. Adjust the end position to adjust the length of the arrow head. If you keep the difference between the start and end the same you will have a constant length for your line.

That's about it. Pretty simple. The only limitation is that you can't make the trim paths go through the first vertex but you if you really need to start the arrow with the tip at the first vertex just open up the path property, select the last point before the first vertex, or add a point where you want the end of the arrow to be and make that the first vertex. You'll have to then stop the arrow before it gets to the last keyframe. There are a couple of ways to get the arrow to make a complete loop around the path. Let me know if you need that kind of thing. If you look carefully at the screenshot that I posted you'll see pretty much what I described.

[Colin Holgate]

I think that "quick" does not mean what you think it means! (to paraphrase The Princess Bride)

[Rick Gerard]

It took longer to type the list than it takes to do it.