Color Modulation

Color modulation is the process in which a texture is modified to add color. There are various strategies used by face libraries. In general, textures are split into color channels, and each channel is filled with a respective color.

Modes

There are 6 modes

Constant

For textures where only one color replacement is needed. The red channel is colorized.

Used by: ShapeBeard, ShapeNose, ShapeForehead, ShapeHair, Fill

rgb = ColorR
a = 1.0

Texture Direct

For textures where no color modulation is required. The texture is “passed through” the shader with no modifications.

Used by: FaceMake, ShapeFaceline, ShapeMask

rgb = TextureRGB
a = TextureA

Rgb Layered

For textures where multiple colors need to be filled.

Used By: Mouth, Eye

rgb = ColorR * TextureR + ColorG * TextureG + ColorB * TextureB
a = TextureA

Alpha

For textures where there is a single color that needs to be filled, and an alpha channel.

Used by: Mustache, Eyebrow, Mole, FaceLine, FaceBeard, ShapeNoseline

rgb = ColorR * TextureR
a = TextureR

Luminance Alpha

For textures that need to fill two colours, and alpha     FFL_MODULATE_MODE_LUMINANCE_ALPHA = 4, // Has Texture

                                           // Has Color (R)

                                           // FragmentR = ColorR * TextureG

                                           // FragmentA = TextureR

                                           // Used by: ShapeGlass

    FFL_MODULATE_MODE_ALPHA_OPA       = 5  // Has Texture

                                           // Has Color (R)

                                           // FragmentRGB = ColorR * TextureR

                                           // FragmentA = 1.0f

                                           // Used by: ShapeCap

}