Additional improvements

- Rename from "amplitude" to "height", since we're defining an unsigned wave that travels from zero to height, not a signed wave that travels from -amplitude to amplitude.
- Clarify the description of the node.

libraries/stdlib/stdlib_defs.mtlx

@@ -2548,11 +2548,11 @@
 
   <!--
     Node: <trianglewave>
-    A triangle wave of the given amplitude and period.
+    A triangle wave that varies between zero and height over the given period.
   -->
   <nodedef name="ND_trianglewave_float" node="trianglewave" nodegroup="math">
     <input name="in" type="float" uiname="in" value="0" />
-    <input name="amplitude" type="float" value="1" />
+    <input name="height" type="float" value="1" />
     <input name="period" type="float" value="1" />
     <output name="out" type="float" />
   </nodedef>

libraries/stdlib/stdlib_ng.mtlx

@@ -1543,7 +1543,7 @@
 
   <!--
     Node: <trianglewave>
-    A triangle wave of the given amplitude and period.
+    A triangle wave that varies between zero and height over the given period.
   -->
   <nodegraph name="NG_trianglewave_float" nodedef="ND_trianglewave_float">
     <absval name="absval1" type="float">
@@ -1570,7 +1570,7 @@
     </subtract>
     <multiply name="multiply3" type="float">
       <input name="in1" type="float" nodename="subtract2" />
-      <input name="in2" type="float" interfacename="amplitude" />
+      <input name="in2" type="float" interfacename="height" />
     </multiply>
     <output name="out" type="float" nodename="multiply3" />
   </nodegraph>