http://www.lynda.com/After-Effects-CS4-tutorials/beyond-the-basics/772-2.html
14. Mastering Masks and Shape Layers
| Blending masks with mask modes | 02m 20s | |
|---|---|---|
| Creating Bezier paths with the Pen tool | 02m 25s | |
| Adjusting handles and corner points | 04m 49s | |
| Creating shape layers from custom shapes | 04m 21s | |
| Using Auto-trace to create masks | 04m 41s | |
| Working with RotoBezier paths | 02m 52s | |
| "Tweening" mask shapes | 02m 30s | |
| Advanced mask shape animation | 03m 41s | |
| Converting motion paths to masks | 03m 04s | |
| Creating a mask instantly | 01m 13s |