SmartBody characters will automatically blink at an interval between 4 and 8 seconds. The blinking is triggered by activating FACS units 45 LEFT and 45 RIGHT. Thus, in order for characters to blink, they must have those FACS units defined. Please consult the section on Configuring Visemes and Facial Animations for more details on how to set up a Face Definition that contains those FACS units.
In order to change the blinking interval, the attributes eyelid.blinkPeriodMin and eyelid.blinkPeriodMax can be set on the character. For example:
mycharacter = scene.getCharacter(name)
mycharacter.setDoubleAttribute("eyelid.blinkPeriodMin", 5)
mycharacter.setDoubleAttribute("eyelid.blinkPeriodMax", 9)