AA white edge

[timmatron]

Whenever I do things like object & tree passes, black never seems to work out. Always leaves that ugly little fringe.

[RErender]

In PS it is Layer/matting/remove black matte to remove the black edges.

In Combustion in the footage controls there is a "premultiply" button with a color swatch. The color swatch controls what color pixels remove at the edge of the alpha, in your case setting it to the background blue color would fix it. I don't know what it is in AE but it must have something similar.

[DaForce]

Thats the one.. thanks Eric

[CarlosBZ]

PS (v 8.0) layer/matting/defringe/ 2 pixels

works very very good.

but best idea was first render is b/ground to tree pass.

[Da_elf]

i dont go for pre-ultiplied that often, i usually prefer straight.