Reverse path of mask on After Effects

[MimiTip]

Hello,

I'd like to reverse the path of a mask on After Effects in order to make an animation without the path going all over. Do you know how I can do it?

[Jose Panadero]

I think you have not a native option inside AE for masks. You have it for shape layers. Anyway you can use a very helpful tool  from aescripts called ReverseMaskPath. https://aescripts.com/reversemaskpath/

[MimiTip]

Thank you for the video, but there is no explanation about the window we have to open in order to use the tools.

[MimiTip]

Ok, I guessed the person opened the drop-list under "Window", but how do we get the ReversePathMask.jsx when we don't find it?

[jayk47221154]

Copy mask path and paste it on Position property of a null, Right click on any keyframe > Keyframe assistant > Time-Reverse keyframes. now copy keyframes back to mask path. and you're done.

[Rick Gerard]

It would really help if we had a little clearer understanding of your design goals and workflow. I'm not sure what I mean when you say you want to reverse a mask path. I am guessing that you are animating the shape of a path and are running into problems when you rotate the entire mask. Mask Points animate from one position to another in a straight line. You can get away with fixing some problem animations by using the Mask Interpolation panel, you can change the first vertex, and you can time reverse keyframes. Many times you just have to add a bunch more keyframes. 

Show us some screenshots of the mask in position 1 and the mask in position 2 and explain the problem and we can probably help. You could always use the Create Nulls From Paths script/Points follow nulls, then parent all the nulls to a controller null and rotate and scale the controller null to make the mask behave properly. That's the only way I know of to accurately get an accurate motion path for a mask vertex.

[MimiTip]

I would like to make wings flutter thanks to three drawings made on Illustrator. I did it once, it works ! The problem is that the points are not going to the right "future" points because path is reversed for the first move.

I use a mask indeed because I didn't find a way to animate a shape with traces imported from Illustrator.

[Rick Gerard]

Make sure the number of points don't change, make sure the first vertex is in the right place, try the Mask Interpolation Panel. Try cutting and pasting the same keyframe. 

Make sure the paths in Illustrator all have the same number of points, or better yet, set up a blend in Illustrator and then import the AI file as a comp following this tutorial. That's the best way to animate between one shape and another. I use it all the time and have for many years.

[MimiTip]

Thank you for the help ! I've had a look on the video. Indeed, I've found yesterday the solution by managing the shapes on Illustrator before to import them on After Effects.

Thank you again,

Have a good day !