PROTO SlideInterface [
  exposedField SFNode slide_set NULL
  exposedField SFVec3f location 0 0 0
  exposedField SFVec3f scale 1 1 1
  exposedField SFRotation rotation 0 1 0 0
  exposedField SFFloat transparency 0.9
  exposedField SFColor color 0.4 0.4 0.4
  exposedField SFColor knob 0.5 0.5 0.5
  eventIn SFInt32 dlp
  ]
  {