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poppy71
02-26-2010, 12:08 PM
In our professional work, LW lacks these render buffer channels that would increase efficiency and power of compositing with Fusion or other programs.

The Fusion 6 manual describes the function of these channels:

Coverage:

This option enables rendering of the coverage channel. The coverage channel contains information about which pixels in the z-buffer provide coverage (are overlapping with other objects). This helps tools that use the Z-buffer to provide a small degree of antialiasing. The value of the pixels in this channel indicate as a percentage how much of the pixel is composed of the foreground object.

BgColor:

This option enables rendering of the BgColor channel. This channel contains the color values from objects behind the pixels described in the coverage channel.

Lightwolf
02-26-2010, 01:10 PM
There seems to be a lot of renderers that don't generate these properly. I've actually thought about getting these out of LW via a plugin for some time and have yet to find a decent solution that covers all cases.

A decent work around is to render at double res (with a lower AA), apply the 3D effects in Fusion and then scale down.
It does increase the time required for a comp, but leads to decent enough results and even has some advantages over the coverage buffer (which basically fails if a pixel consists of samples from more than two surfaces, or more than a single surface and the background).

Cheers,
Mike