Rotoscoping

Cutting a subject out of footage frame by frame, by drawing or painting a matte around it. It is what you do when there is no green screen to key.

In Premation

Animated masks do it by hand. The Roto Brush seeds a matte and carries it across frames with optical flow, and Object Matte segments a subject with a neural model. Both are newer and less proven than After Effects' Roto Brush 3.

Read the docs: Motion tracking

Related terms

• Chroma key
• Mask
• Optical flow