Since After Effects 17.5 Adobe has introduced Roto Brush 2 which uses artificial intelligence to track your subject's movements.

Summary:
1. Duplicate the layer.
2. Set the resolution to Full.
3. Double click on the new layer.
4. Select Roto Brush Tool.
5. Choose your starting frame wisely. The more precise and stable the frame is, the better the propagation is.
6. Paint green stroke inside the subject.
7. Holding alt/option you can delete portions of selection.
8. Once the base frame is set, start the propagation. You can go backwards and forwards. Depends where your base frame is.
9. When the propagation is finished you should Freeze your work.

....::::Roto Brush effect and Refine Matte effect properties::::....

Use Motion Blur check this option to render the matte with motion blur.

Decontaminate Edge Colors it will clean the color of edge pixels. Background color is removed. It's very helpful with halos and contamination caused by motion blur.

Quality it's quality of detailing around the edges. Standard is a lot faster, but doesn't have as much details around the edges. Best is refined around edges.

Version to select from the two Roto Brush versions 1.0 (Classic) and 2.0. Although new is always better, so let's keep it 2.0.

Finetune Roto Brush Matte you can use these options to refine edges and reduce chatter.

Reduce Chatter reduces erratic changes to edges from one frame to the next one.

Smooth reduces sharpness.

Propagation properties mostly affect all roto brush calculations. Any change here will automatically cause need to propagate everything from a beginning.

Webpage: https://www.editing.ninja
❤ My Instagram:   / kamil.ignatowski  
✉ Email: [email protected]