How can I move the mask manually?

[mehmeta8892198]

Hi,

For like an hour i am working on a project, this project contains a image that moves and i need to mask it.

I am trying to move the mask manually, and i am nearly doing it(i thought ) then this problem showed up:
I was moving the mask frame by frame by pressing page down button then i realized it was doing an animation???What i mean is the mask starts with a dot(and goes for 20 frames) and ends with the final shape(final frames shape) there is no problem with ending shape but i dont want it to become step by step last shape i want to mask reshape every frame.

Thanks for your support!

(my grammar is not that good)

[Roei Tzoref]

page down moves one frame, it does not move the mask. if you want to animate a mask path you should set a keyframe for the mask path and adjust the shape by manually moving the vertices in the composition panel. you don't have to work frame by frame. set the start shape and the end shape and let after effects do the work for you.

you can read about mask shapes here: Create and customize shapes and masks in After Effects

here's an article on manipulating mask shapes: https://www.provideocoalition.com/managing_moving_masks/

[mehmeta8892198]

I already said that i moved my mask manually when i move the frames. And I dont want to "Animate" the mask I want it to track an object like a ball flying on sky.

[Roei Tzoref]

if you want to track a mask there are tracking mask options: Using the After Effects Mask Tracker this will make Ae do for you and create frame by frame keyframes but with much better chance of doing it accurately. this is not the best option for traditional rotoscoping. you can also use 2d or 3d tracking and attach your mask to the tracking null. and there's also the rotobrush feature.

[mehmeta8892198 · Accepted solution]

I have solved the problem with turning off the preserve constant vertex and feather count option on preferences >  general box
Thanks for your support anyway!