Technical Stuff

Maybe because it is an "object." As near as I can figure out, Cel-Look Edges are two-point polygons that just happen to be in the right place, at the right time, all the time.

Because they are two-point polygons, they won't show up in raytraced reflections (since there is -- "physically" -- nothing there to trace!) And, because they are 3D geometry...well...sometimes LightWave has trouble figuring out which piece of geometry (the object or its Cel-Look Edge) has the "right of way."

Picture each "Large"-sized two-point polygon as a cylinder that's 5 pixels thick. The cylinder's start and end points are taken from the elf-girl's geometry. The Edge Z-Scale is set to its default of .998, so the Cel-Look Edge "object" is placed at .998 of the distance between the elf-girl and the camera. Although this Cel-Look Edge "object" is thus placed slightly "in front" of the elf-girl, some parts of the Cel-Look Edge are still getting buried in the elf-girl's polygonal mesh (you'd never get this problem with a simple box!):

The tip-off is that LightWave renders the outside of the Cel-Look Edge beautifully -- clean and smooth. It's the inside of the "ink line" that's driving LightWave nuts -- the inside of the left shoulder; the top ink line of the left armband. Pieces of the ink line are getting chipped away -- and those chipped pieces look an awful lot like the corners and sides of polygons:

Transparent Edges fixes the problem by making those corners and sides disappear before they can obscure the Cel-Look Edge ink line. Doing it all in one pass takes too long (probably because I was using ray-traced shadows), plus it wrecks the look of self-shadows on this cel-shaded character. The two-pass method (one for paint, the other for a clean description of the ink line) takes less time to render, looks nicer, and gives me a greater variety of ink "colors" (since I can make the ink plate anything I like!)

Note: remember to activate the Foreground Fader Alpha switch when using non-black ink plates!