EXAMPLE (click to run): The following example illustrates use of the Script node (see Figure 3-46). This world defines a toggle button prototype, Button, and a simple combination lock that composes three Button nodes together with a Script node that verifies the combination. Note that the first Script node is defined within the prototype Button. This example is illustrated in both Java and JavaScript:

#VRML V2.0 utf8
PROTO Button [
    exposedField SFNode geom NULL 
    eventOut SFInt32 state_changed ]
{
  Group { children [
    DEF TOS TouchSensor {}
    DEF Toggle Script {
      eventIn SFTime touch
      eventOut SFInt32 which_changed IS state_changed
      url [ "javascript:
        function initialize() {
          // Initialize to 0th child at load time
          which_changed = 0;
        }
        function touch(value, time) {
          // Toggle the button value
          which_changed = !which_changed;
        }"
        # Or Java:
        "ToggleScript.class" ]
    }
    DEF SW Switch {
      whichChoice 0
      choice [
        Shape {     # child 0 - "off"
          geometry IS geom
          appearance DEF A2 Appearance {
            material Material { diffuseColor .3 0 0 }
          }
        }
        Shape {     # choice 1 - "on"
          geometry IS geom
          appearance DEF A1 Appearance {
            material Material { diffuseColor 1 0 0 }
          }
        }
      ]
    }
  ]}
  ROUTE TOS.touchTime TO Toggle.touch
  ROUTE Toggle.which_changed TO SW.set_whichChoice
} # end of Toggle prototype

# Now, create 3 Buttons and wire together with a Script
Transform {
  translation -3 0 0
  children DEF B1 Button { geom Box {} }
}
DEF B2 Button { geom Sphere {} }
Transform {
  translation 3 0 0
  children DEF B3 Button { geom Cone {} }
}
DEF ThreeButtons Script {
  field SFInt32 b1 0
  field SFInt32 b2 0
  field SFInt32 b3 0
  eventIn SFInt32 set_b1
  eventIn SFInt32 set_b2
  eventIn SFInt32 set_b3
  eventOut SFTime startTime
  url [ "javascript:
    function set_b1(value, time) {
      b1 = value;
      if ((b1 == 1) && (b2 == 0) && (b3 == 1)) startTime = time;
    }
    function set_b2(value, time) {
      b2 = value;
      if ((b1 == 1) && (b2 == 0) && (b3 == 1)) startTime = time;
    }
    function set_b3(value, time) {
      b3 = value;
      if ((b1 == 1) && (b2 == 0) && (b3 == 1)) startTime = time;
    }"
    # Or Java:
    "ScriptLogic.class" ]
}
DEF T Transform { children [                 # Explosion effect
  Shape { geometry Sphere {  radius 0.1 } }  # Hidden inside
  DEF SI PositionInterpolator {
    key [ 0.0 1.0 ]
    keyValue [ 0.01 0.01 0.01, 300.0 300.0 300.0 ]
  }
  DEF TS TimeSensor { }
  NavigationInfo { type "EXAMINE" }
] }
ROUTE B1.state_changed TO ThreeButtons.set_b1
ROUTE B2.state_changed TO ThreeButtons.set_b2
ROUTE B3.state_changed TO ThreeButtons.set_b3
ROUTE ThreeButtons.startTime TO TS.startTime
ROUTE TS.fraction_changed TO SI.set_fraction
ROUTE SI.value_changed TO T.set_scale

ToggleScript.java:

/*
 * ToggleScript.java
 * Toggles an integer between 0 to 1 every time a time event
 *   is received
 */
import vrml.*;
import vrml.field.*;
import vrml.node.*;
public class ToggleScript extends Script {
  SFInt32 which_changed;
  public void initialize() {
    which_changed  = (SFInt32) getEventOut("which_changed");
    which_changed.setValue(0);
  }
  public void processEvent( Event e ) {
    String name = e.getName();
    if ( name.equals( "touch" )) {
      which_changed.setValue(1 - which_changed.getValue());
    }
  }
}

ScriptLogic.java:

/*
 * ScriptLogic.java
 * Receives set_b1/2/3 events, when correct combination
 *   is received outputs a startTime event.
 */
import vrml.*;
import vrml.field.*;
import vrml.node.*;
public class ScriptLogic extends Script {
  int b1;
  int b2;
  int b3;
  SFTime startTime;
  public void initialize() {
    startTime  = (SFTime) getEventOut("startTime");
  }
  public void processEvent( Event e ) {
    String name = e.getName();
    if ( name.equals( "set_b1" )) {
      b1 = ((ConstSFInt32)e.getValue()).getValue();
    } else if ( name.equals( "set_b2" )) {
      b2 = ((ConstSFInt32)e.getValue()).getValue();
    } else if ( name.equals( "set_b3" )) {
      b3 = ((ConstSFInt32)e.getValue()).getValue();
    }
    if ((b1 == 1) && (b2 == 0) && (b3 == 1))
      startTime.setValue(e.getTimeStamp());
  }
}