This is straight from the Shake Manuals:
The Domain of Definition (DOD) is a rectangular zone that Shake uses to bind the significant pixels in an image in order to optimize rendering speed. Everything outside of the DOD is considered as background (black by default), and is therefore ignored in most computations. Proper handling of the DOD is an extremely powerful way to speed up your render times.
So, anyone know if there is something similar in Fusion? Or,, do I have the wrong technique in mind?? Thx!