Hasta La Motion!

Hello,
I’m trying to figure out how to create little down-like feathers to match the feathers used in my film’s live-action shots…and then how to convincingly composite them into several shots.

The feathers I need to make will go in:

• a multi-plane composite made of several still photos of trees. A few roto’d live action elements–a girl and horse– will be walking among these trees.
• existing live-action shots (that don’t have feathers in them). Shots with fabricated feathers will be edited into sequences that did have feathers at the time of the shoot. (I’m thinking I’ll have to roughly roto elements in these shots to make the feather composite work?)

I’m working in Shake, Photoshop, and have a very old version of After Effects lying around I could pull out. Anyone have suggestions on how to create and composite feathers?

A screenshot from my film showing the real feathers is shown below.

Suggestions would be greatly appreciated–thank you!!