In this page of the online documentation:
https://docs.blender.org/manual/en/latest/grease_pencil/modifiers/generate/line_art.html#edge-types
There is mentioning of the text:
Illumination Filtering
Select feature lines that comes from lit or shaded regions. Will not affect cast shadow and light contour since they are at the border.
The part that I am questioning is:
Will not affect cast shadow and light contour since they are at the border.
As seen in this example:
Three objects have casted their shadows on the plane and their shadows had been captured and circled. What does the text really saying here, do you know?