PROTO Layer3D[
          exposedField SFVec3f bboxSize   -1 -1 -1        
          exposedField SFVec3f bboxCenter 0 0 0
          eventIn MFNode addChildrenLayer
          eventIn MFNode removeChildrenLayer
          exposedField MFNode childrenLayer []
          exposedField SFVec2f translation 0 0
          exposedField SFInt32 depth 0
          exposedField SFVec2f size -1 -1
          exposedField SFNode background NULL
          exposedField SFNode fog NULL
          exposedField SFNode navigationInfo NULL
          exposedField SFNode viewpoint NULL
          exposedField MFNode children []
          eventIn MFNode addChildren
          eventIn MFNode removeChildren
          ]