Creating Mattes after rotoscoping in AE 6

[isonlyme]

Hi guys

I'm trying to do Isolate a car then change his background with a 3d scene done in maya, after I rotoscope the car (due to the lack of blue/green screen) i just use the cut out car without adding a matte with auto-trace? I'm kinda confuse since i read that you have to put a white background then create black matte? any good tutorials?

Can someone clarify this for me?

Thanks very much in advance

 

[maruyama]

No no :O

Your rotoscoped material IS ALREADY matted. Black and White? That applies to the matte channel.

When you're done rotoscoping, you should have an isolated image. (In your case, the car).

Use this rotoscoped layer in your comp, above the Maya render:

LAYER TOP = CAR
LAYER BOTTOM = 3D BACKPLATE.

That's it.

If you're rotoscoping in another application, you may need to export an alpha channel with the render - you'll then have more options to explore - but this should get you going.

HTH

Ko

 

[isonlyme]

I though so,
thanks very much for clearing that up!!!

BTW is there a good tutorial or tecnic that i can use to better create rotoscoping. I'm asking beacuse no matter how many points (roto beziers) i do i still can see flickering in the borders and adding more feather it tends to look bad when compising it with the background. I use AE 6.0 production.

Again thanks in advance!!!