SoPackedColor is similar to
SoBaseColor in that it sets the diffuse color component of the current material. However, it also changes the transparency component. The color and transparency information is packed into unsigned 32-bit
integers:
0xrrggbbaa, where
aa represents the alpha (
0x00 = fully transparent,
0xff = opaque), and
rr,
gg, and
bb represent the red, blue, and green components of the color, respectively. Note that the order (r,g,b,a) of these
components is reversed from the ordering in releases of Inventor prior to 2.1.
If the transparency type is
SoGLRenderAction::SCREEN_DOOR, only the first transparency value will be used. With other transparency types, multiple transparencies
will be used.
SoPackedColor uses less memory than
SoBaseColor or
SoMaterial to store multiple color and transparency values. It can be used in cases where space is critical.