ALPHA CHANNEL
Jimbo:
>> Do you know of anyone that is successfully keying (very clean) over video
>> without chroma-keying?
The BEST method of doing this is with an A/B/C roll system, where A is the live
video background, B is the animation, and C is the alpha channel.
Just render with alpha ON and alpha split ON, and take the resulting 8 bit
files out to tape for your C roll.
We do all our broadcast titles this way, as well as many other types of
animation where we must do live compositing.
Greg Pyros