Auto-adjust ground wetness to maximum of noise-spike filtered rain-norm or user-set wetness

Environment/environment.xml

@@ -435,7 +435,8 @@
     <scattering type="double" userarchive="n">0.7</scattering>
     <dust-cover-factor type="double" userarchive="y">0.0</dust-cover-factor>
     <lichen-cover-factor type="double" userarchive="y">0.0</lichen-cover-factor>
-    <wetness type="double" userarchive="y">0.0</wetness>
+    <wetness-set type="double" userarchive="y">0.0</wetness-set>
+    <wetness type="double" userarchive="n">0.0</wetness>
     <snow-thickness-factor type="double" userarchive="y">1.0</snow-thickness-factor>
   </surface>
 

Environment/local-weather-rules.xml

@@ -834,4 +834,16 @@
      <min>0.0</min>
      <max>1.0</max>
   </filter>
+
+
+  <filter>
+    <name>EnvironmentInterpolator:Precipitation:SurfaceWetness</name>
+    <type>noise-spike</type>
+    <max-rate-of-change>0.004</max-rate-of-change>
+    <input>/environment/rain-norm</input>
+    <output>/environment/surface/wetness</output>
+    <min><property>/environment/surface/wetness-set</property></min>
+    <max>1.0</max>
+  </filter>
+
 </PropertyList>

gui/dialogs/environment-settings.xml

@@ -321,7 +321,7 @@
       <min>0.0</min>
       <max>0.7</max>
       <live>true</live>
-      <property>/environment/surface/wetness</property>
+      <property>/environment/surface/wetness-set</property>
       <binding>
         <command>dialog-apply</command>
         <object-name>wetness</object-name>