Back-face filled method (Underfill)

#rigging #Artist

What is back-face filled / underfill method?

Basically underfill is treating the lineart as a solid big shape filled with the line color, and move the lineart underneath the base color flat layer.

Traditional/common layer order:

lineart: common thin lines (Top)
|
textures / shading
|
color flat: define the mask area for textures and shades (Bottom)

Back-face filled / underfill method:

textures / shading (Top)
|
color flat: define the mask area for textures and shades
|
lineart: converted to a filled big shape (Bottom)

Using Back-face filled method, lineart can allows smooth merging transitions in line weight and creating a more 3D-like, volumetric look.

Applied Examples

Examples of back-face filled method for face can be found here:

@Vil_Rib shows how they managed to create clean face line with underfill method

@maoxyart shows example of changing line weight to achieve 3D inverted-hull-like face outline

Examples of back-face filled mascot & special effects:

@kawase1234567 generously shows many great examples on mascot, vfx, hair etc. to learn from.

Examples of underfill method for art layers cutting:

@meowao shows their PSD layers of female body texture