Background {
  eventIn      SFBool   set_bind
  exposedField MFFloat  groundAngle  []
  exposedField MFColor  groundColor  []
  exposedField MFString backUrl      []
  exposedField MFString bottomUrl    []
  exposedField MFString frontUrl     []
  exposedField MFString leftUrl      []
  exposedField MFString rightUrl     []
  exposedField MFString topUrl       []
  exposedField MFFloat  skyAngle     []
  exposedField MFColor  skyColor     [ 0 0 0 ]
  eventOut     SFBool   isBound
}