After Effects 2: Rotoscoping

Rotoscoping is the cutting out of a moving object or figure from a piece of footage, this could be used over a new background. This is a popular technique frequently used in music videos and sports footage. The process of rotoscoping goes as follows:

·        Import your chosen footage into a 1080p comp set at 25 frames per second.

·        Change the frame rate of the footage to 25 fps

Select footage > file > interpret footage > main.

·        Crop your footage to the chosen size.

·        After Effects > preferences > general.

Switch off “preserve constant vertex and feather point count when editing mask”

Otherwise each mask edit won’t save.

·        Use the pen tool to create a mask of your object/figure

(When the layer is selected).

·        Turn mask path key frame on.

·        After drawing the first mask click ctrl+> to jump to the next frame and add a new keyframe.

·        Once you’ve got a mask layer for all the footage you want, trim the footage to fit.

·        Move to zero and trim the comp to the size of the work you’ve done (including the last frame).

·        Set up a main comp, place the rotoscoping footage at zero.

·        Layer > time > enable time remapping (Alt + Ctrl + T)

·        Add a key frame to the last frame with footage and delete the final blank keyframe.

·        Open After Effects coding (Alt + click stopwatch)

·        After Effects dictionary > property > loop out duration.

·        Drag to cover the full duration of main comp.

·        To loop back and forth copy and paste the first keyframe onto the end.

Below is my first attempt at rotoscoping, however I didn’t have enough time to mask the full one second of footage in the workshop that I wanted to, so it’s not looking quite how I would like.   

Rotoscoping_1 from Eve Whelan on Vimeo.