Billboard
Billboard {
eventIn MFNode addChildren
eventIn MFNode removeChildren
exposedField SFVec3f axisOfRotation 0 1 0 # (-,)
exposedField MFNode children []
field SFVec3f bboxCenter 0 0 0 # (-,)
field SFVec3f bboxSize -1 -1 -1 # (0,) or -1,-1,-1
}
