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Newell's Dynamic Teapot

VRML World
Author: Paul Fishwick
Overview: Newell's teapot represents a classic benchmark geometric model in the field of Computer Graphics and was used as the icon for the 25th Anniversary of SIGGRAPH. This world contains a VRML teapot on the left hand side of an office desk. On the right side, you find a dynamic model (functional block model) representing the action of 1) pressing the knob to heat water in the teapot, 2) the heating of the water, and 3) the sensing of the water temperature with a thermometer. Inside the 2nd cube, a small system of pipes and tanks captures the semantics of a finite state machine for the change in water temperature from cold to heating to cooling. When a state is active, the red color is intensified. Inside each tank, one finds a blackboard. On each blackboard, one finds a differential equation defining the dynamics of each state.
Model Templates: FBM = Functional Block Model; FSM = Finite State Machine; EQN = Ordinary Differential Equation.
Metaphors: Machine pipeline as FBM; Processing Plant as FSM; Blackboard as EQN.
Simulation: Viewpoints: Initial, Side View, inside Cold State, inside Heating State, inside Cooling State. Execution: press knob below the teapot to turn the model (Pipeline) on and off. Animation: Machine1 turns opaque when the knob is off and semi-transparent when on; The Tank representing the active state intensifies its red color; the temperature maps to color inside the teapot and for Machine3; and the thermostat and clock are active during simulation. Audio: Tank1 (cold state): ambient mechanical; Tank2 (heating state): boiling water; Tank3 (cooling state): high speed wind.
Modeling PROTOs used: FSM (Finite State Machine); FSM-STATE (FSM State); FSM-TRANSITION (FSM Transition); FBM (Functional Block Model); FBM-FUNC (FBM Function); FBM-TRACE (FBM Trace); EQN (Equation).

Object Hierarchy: Objects are defined with an uppercase first letter with each object having its own PROTO; PROTOs are all uppercase in parentheses; fields names are in italics; field values are to the right of field names.


World (SM)
  contains  Room, Desk, Chair, Wall-Artwork, Clock, Thermostat, Teapot
  each created using an uppercase PROTO of the same name as the object
Teapot (TEAPOT)
  contains Water
Water (WATER)
  behavior Pipeline
Pipeline (FBM)
  functions Machine1, Machine2, Machine3
  traces NULL
Machine1 (FBM-FUNC)
  script in Knob
Machine2 (FBM-FUNC)
  behavior Plant
Plant (FSM)
  states Tank1, Tank2, Tank3
  transitions Pipe1, Pipe2, Pipe3, Pipe4
Tank1 (FSM-STATE)
  behavior Board1
Board1 (EQN)
  contains text "x=0" for Cold 
  script
Tank2 (FSM-STATE)
  behavior Board2
Board2 (EQN)
  contains text "x' = a*(100 - x)" for Heating
  script
Tank3 (FSM-STATE)
  behavior Board3
Board3 (EQN)
  contains text "x' = -a*x" for Cooling
  script
Pipe1 (FSM-TRANSITION)
  script
Pipe2 (FSM-TRANSITION)
  script
Pipe3 (FSM-TRANSITION)
  script
Pipe4 (FSM-TRANSITION)
  script
Machine3 (FBM-FUNC)
  script in Thermostat