demonstrate usage of Prototype metadata node

Tools/Animation/DoubleClickTouchSensorExample.x3d

@@ -6,7 +6,7 @@
     <meta content='Double-click TouchSensor design pattern, showing example use.' name='description'/>
     <meta content='Don Brutzman' name='creator'/>
     <meta content='26 May 2003' name='created'/>
-    <meta content='28 November 2019' name='modified'/>
+    <meta content='6 June 2020' name='modified'/>
     <meta content='DoubleClickTouchSensorPrototype.x3d' name='reference'/>
     <meta content='https://www.web3d.org/x3d/specifications/ISO-IEC-19775-FDIS-X3dAbstractSpecification/Part01/components/pointingsensor.html#TouchSensor' name='reference'/>
     <meta content='DoubleClickTouchSensor' name='subject'/>
@@ -34,7 +34,9 @@
       <field accessType='outputOnly' name='hitPoint_changed' type='SFVec3f'/>
       <field accessType='outputOnly' name='hitNormal_changed' type='SFVec3f'/>
       <field accessType='outputOnly' name='hitTexCoord_changed' type='SFVec2f'/>
-      <field accessType='initializeOnly' name='metadata' type='SFNode'/>
+      <field accessType='initializeOnly' name='metadata' type='SFNode' appinfo='can contain one of Metadata nodes'>
+          <!-- initialization node (if any) goes here -->
+      </field>
       <field accessType='initializeOnly' name='traceEnabled' type='SFBool'/>
     </ExternProtoDeclare>
     <!-- ==================== -->
@@ -50,6 +52,9 @@
       <ProtoInstance DEF='TouchSensorActive' name='DoubleClickTouchSensor'>
         <fieldValue name='description' value='double click to initiate time delay and color change'/>
         <fieldValue name='traceEnabled' value='true'/>
+        <fieldValue name='metadata'>
+            <MetadataString name="exampleTerm" value='"exampleValue"'/>
+        </fieldValue>
       </ProtoInstance>
       <!-- ==================== -->
       <Group DEF='TextAnimationGroup'>

Tools/Animation/DoubleClickTouchSensorPrototype.x3d

@@ -6,7 +6,7 @@
     <meta content='Double-click TouchSensor design pattern, implemented as a reusable prototype node.' name='description'/>
     <meta content='Don Brutzman' name='creator'/>
     <meta content='26 May 2004' name='created'/>
-    <meta content='28 November 2019' name='modified'/>
+    <meta content='6 June 2020' name='modified'/>
     <meta content='DoubleClickTouchSensorExample.x3d' name='reference'/>
     <meta content='https://www.web3d.org/x3d/specifications/ISO-IEC-19775-FDIS-X3dAbstractSpecification/Part01/components/pointingsensor.html#TouchSensor' name='reference'/>
     <meta content='DoubleClickTouchSensor' name='subject'/>
@@ -27,7 +27,7 @@
         <field accessType='outputOnly' name='hitPoint_changed' type='SFVec3f'/>
         <field accessType='outputOnly' name='hitNormal_changed' type='SFVec3f'/>
         <field accessType='outputOnly' name='hitTexCoord_changed' type='SFVec2f'/>
-        <field accessType='initializeOnly' name='metadata' type='SFNode'>
+        <field accessType='initializeOnly' name='metadata' type='SFNode' appinfo='can contain one of Metadata nodes'>
           <!-- initialization node (if any) goes here -->
         </field>
         <field accessType='initializeOnly' name='traceEnabled' type='SFBool' value='false'/>

Tools/Animation/FlyingTextExample.x3d

@@ -6,7 +6,7 @@
     <meta content='Prototype definition for a flying text message. Waypoints, time intervals, cycleInterval and text message can be overridden.' name='description'/>
     <meta content='Murat Onder' name='creator'/>
     <meta content='2 June 2004' name='created'/>
-    <meta content='28 November 2019' name='modified'/>
+    <meta content='6 June 2020' name='modified'/>
     <meta content='FlyingTextExample.x3d' name='reference'/>
     <meta content='https://savage.nps.edu/Savage/Tools/Animation/FlyingTextExample.x3d' name='identifier'/>
     <meta content='X3D-Edit 3.2, https://savage.nps.edu/X3D-Edit' name='generator'/>
@@ -24,12 +24,17 @@
       <field accessType='outputOnly' name='hitPoint_changed' type='SFVec3f'/>
       <field accessType='outputOnly' name='hitNormal_changed' type='SFVec3f'/>
       <field accessType='outputOnly' name='hitTexCoord_changed' type='SFVec2f'/>
-      <field accessType='initializeOnly' name='metadata' type='SFNode'/>
+      <field accessType='initializeOnly' name='metadata' type='SFNode' appinfo='can contain one of Metadata nodes'>
+          <!-- initialization node (if any) goes here -->
+      </field>
       <field accessType='initializeOnly' name='traceEnabled' type='SFBool'/>
     </ExternProtoDeclare>
     <ProtoInstance DEF='ExampleDoubleClickTouchSensor' name='DoubleClickTouchSensor'>
       <fieldValue name='description' value='double click to initiate time-delayed event'/>
       <fieldValue name='maxDelayInterval' value='1'/>
+      <fieldValue name='metadata'>
+          <MetadataString name="exampleTerm" value='"exampleValue"'/>
+      </fieldValue>
     </ProtoInstance>
     <ExternProtoDeclare appinfo='Visualize message transfer between two points as flying text' name='FlyingText' url='"../../../Savage/Tools/Animation/FlyingTextPrototype.x3d#FlyingText" "https://savage.nps.edu/Savage/Tools/Animation/FlyingTextPrototype.x3d#FlyingText" "../../../Savage/Tools/Animation/FlyingTextPrototype.wrl#FlyingText" "https://savage.nps.edu/Savage/Tools/Animation/FlyingTextPrototype.wrl#FlyingText"'>
       <field accessType='initializeOnly' name='waypoints' type='MFVec3f'/>