The BCC Light Matte filter uses applied light to create or modify an alpha
channel. Rays of light spread from the light source point in all directions.
As the rays expand, their intensities are affected by the luminosities of the
pixels that they cross. The farther from the source the rays extend, the less
they are affected by the intensities of new pixels that they crosses. This
process is referred to as attenuation, since the affect of the pixels on the
intensity of the rays attenuates, or lessens, over time.
The filter allows users to determine which source color channel is used to
create the light and to calculate the intensities of the source pixels. Pixels
with higher values in the selected channel are considered to have higher
The built in PixelChooser, with integrated mocha planar tracking allows for
greater control over which areas of the image the filter should affect.
[To learn more about this filter, and see a breakdown of the various controls,
please click here.](https://www.borisfx.com/helpdocs/?page_id=864 “BCC Light
Matte Help Documentation” )