|(The following is an excerpt from "Character
Modeling and the Super Cel Shader" -- Jen).
About Cel Shading
One of the most overlooked tools in celshading is the LightWave Modeler.
Edges and the Super Cel Shader, while essential, cannot make any
model look hand-drawn.
The model must have the form of a cartoon. Cartoonists stylize reality,
rendering only those details considered important for the overall design
of the cartoon. Mickey Mouse has no fur or whiskers. Snoopy doesn't have
claws or discernable nostrils. Disney females often lack visible fingernails.
Edges and the Super Cel Shader trace and shade the model -- they cannot
add or subtract details to make a model look like a cartoon. If you don't
want specific details (such as fingernails or nostrils) in a character,
The artist building the model must also have a technical understanding
of how LightWave Edges behave. Edges may "ink" models, but it doesn't "think"
about design. A literal-minded "inker," Edges will trace a line along those
edges of polygons that qualify as "ink lines" in a model. The four key
types of Edges follow these rules:
Layout also offers "Other Edges" (everything not covered by the four key
types of edges above) and "Particle/Line Thickness" (which covers two-point
and one-point polygons, both ignored by the other Edge options).
Silhouette Edges - appear at the edge shared by two single-sided
polygons when the normal of one of those polygons faces the camera, and
the normal of the other polygon faces away from the camera. The edges that
qualify as Silhouette Edges thus change with the angle of the model to
the camera. An edge must be shared by two polygons to qualify as a Silhouette
Edge - Silhouette Edges will never appear on a model that consists of a
single polygon. Double-sided surfaces face the camera at all times, so
Silhouette Edges will never appear on them.
Unshared Edges - appear on edges not shared by any other polygon.
Unshared Edges, when checked, will always appear on a model that consists
of a single polygon. For non-SubPatch models, selecting an area of geometry
and then applying a "Cut and Paste" operation will create an Unshared Edge
at the border of the selection in your object. You might use this trick
to get Edges to help you describe the panels in a spaceship, for example.
(Any overlapping points of a SubPatch model will get "merged" into a shared
edge in Layout, so the "Cut and Paste" trick will only help you sharpen
edges in your model - it will not give you an "Unshared Edge" in Layout).
Sharp Creases - might also be called "UnSmoothed Edges." Whether
or not a given edge qualifies as a "Sharp Crease" depends on the Smoothing
Angle of the surface to which that edge belongs. Lowering the Smoothing
Angle of a surface will increase the number of edges traced; increasing
the Smoothing Angle will decrease the number of "Sharp Crease" edges. If
the "Smoothing" option is left unchecked in the Surface Editor, most (if
not all) of the polygon edges in your model will qualify as "Sharp Creases."
Their territory sometimes overlaps with that of Silhouette Edges, as the
edges of polygons that turn away from the camera might qualify as a "Sharp
Crease." This type of Edge does not care whether the polygons have double-sided
surfaces or not, so you can often use them to put a "Silhouette Edge" on
a double-sided surface.
Surface Borders - this type of Edge will appear at the edge shared
by two polygons when said polygons have different surface names. The polygons
might have the exact same texture parameters, but "Surface Borders" will
not care. If the surface names differ, then the polygons will have an ink
line appear at their shared edge (unless the artist leaves "Surface Borders"
Fortunately for us, Edges consistently follow the above rules.
The modeler, then, can both predict and control where the ink lines will
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