From 269a999c4d7f0b9fa3d479e1b66fa6776d0bdf24 Mon Sep 17 00:00:00 2001
From: "gral@who.net" <gral@who.net>
Date: Sat, 28 Aug 2010 00:13:52 +0200
Subject: [PATCH 1/4] Adding season colour in forest/herbtundra/glacier effects

---
 Effects/forest.eff     | 27 +++++++++++++++++++++++++++
 Effects/glacier.eff    | 27 +++++++++++++++++++++++++++
 Effects/herbtundra.eff | 27 +++++++++++++++++++++++++++
 Shaders/forest.frag    | 17 ++++++++++-------
 4 files changed, 91 insertions(+), 7 deletions(-)

diff --git a/Effects/forest.eff b/Effects/forest.eff
index 2ab35deb6..78bc67924 100644
--- a/Effects/forest.eff
+++ b/Effects/forest.eff
@@ -34,6 +34,13 @@
     <depth-factor type="float">0.04</depth-factor>
     <canopy-height type="float">15.0</canopy-height>
     <quality-level><use>/sim/rendering/quality-level</use></quality-level>
+    
+    <!-- sets the season color -->
+    <season-red type="float">0.12</season-red>
+    <season-green type="float">0.86</season-green>
+    <season-blue type="float">0.0</season-blue>
+    <!-- end season color -->
+    
   </parameters>
   <generate>
     <tangent type="int">6</tangent>
@@ -173,6 +180,26 @@
         <type>float</type>
         <value><use>quality-level</use></value>
       </uniform>
+      <uniform>
+      	<name>red</name>
+      	<type>float</type>
+      	<value><use>season-red</use></value>
+      </uniform>
+      <uniform>
+      	<name>green</name>
+      	<type>float</type>
+      	<value><use>season-green</use></value>
+      </uniform>
+      <uniform>
+      	<name>blue</name>
+      	<type>float</type>
+		<value><use>season-blue</use></value>
+      </uniform>
+      <uniform>
+      	<name>alpha</name>
+      	<type>float</type>
+      	<value>0.0</value>
+      </uniform>
     </pass>
   </technique>
 </PropertyList>
diff --git a/Effects/glacier.eff b/Effects/glacier.eff
index 641c37be0..c6e58025a 100644
--- a/Effects/glacier.eff
+++ b/Effects/glacier.eff
@@ -34,6 +34,13 @@
     <depth-factor type="float">0.01</depth-factor>
     <canopy-height type="float">15.0</canopy-height>
     <quality-level><use>/sim/rendering/quality-level</use></quality-level>
+    
+    <!-- sets the season color -->
+    <season-red type="float">0.12</season-red>
+    <season-green type="float">0.86</season-green>
+    <season-blue type="float">0.0</season-blue>
+    <!-- end season color -->
+    
   </parameters>
   <generate>
     <tangent type="int">6</tangent>
@@ -173,6 +180,26 @@
         <type>float</type>
         <value><use>quality-level</use></value>
       </uniform>
+      <uniform>
+      	<name>red</name>
+      	<type>float</type>
+      	<value><use>season-red</use></value>
+      </uniform>
+      <uniform>
+      	<name>green</name>
+      	<type>float</type>
+      	<value><use>season-green</use></value>
+      </uniform>
+      <uniform>
+      	<name>blue</name>
+      	<type>float</type>
+		<value><use>season-blue</use></value>
+      </uniform>
+      <uniform>
+      	<name>alpha</name>
+      	<type>float</type>
+      	<value>0.0</value>
+      </uniform>
     </pass>
   </technique>
 </PropertyList>
diff --git a/Effects/herbtundra.eff b/Effects/herbtundra.eff
index 0d30ff2fd..ece1a4817 100644
--- a/Effects/herbtundra.eff
+++ b/Effects/herbtundra.eff
@@ -33,6 +33,13 @@
     <snow-level><use>/sim/rendering/snow-level-m</use></snow-level>
     <depth-factor type="float">0.01</depth-factor>
     <canopy-height type="float">15.0</canopy-height>
+    
+    <!-- sets the season color -->
+    <season-red type="float">0.12</season-red>
+    <season-green type="float">0.86</season-green>
+    <season-blue type="float">0.0</season-blue>
+    <!-- end season color -->
+    
     <quality-level><use>/sim/rendering/quality-level</use></quality-level>
   </parameters>
   <generate>
@@ -173,6 +180,26 @@
         <type>float</type>
         <value><use>quality-level</use></value>
       </uniform>
+      <uniform>
+      	<name>red</name>
+      	<type>float</type>
+      	<value><use>season-red</use></value>
+      </uniform>
+      <uniform>
+      	<name>green</name>
+      	<type>float</type>
+      	<value><use>season-green</use></value>
+      </uniform>
+      <uniform>
+      	<name>blue</name>
+      	<type>float</type>
+		<value><use>season-blue</use></value>
+      </uniform>
+      <uniform>
+      	<name>alpha</name>
+      	<type>float</type>
+      	<value>0.0</value>
+      </uniform>
     </pass>
   </technique>
 </PropertyList>
diff --git a/Shaders/forest.frag b/Shaders/forest.frag
index e54016026..0dc6c620e 100644
--- a/Shaders/forest.frag
+++ b/Shaders/forest.frag
@@ -15,6 +15,8 @@ uniform sampler2D SampleTex2;
 uniform sampler2D NormalTex;
 uniform float depth_factor;
 
+uniform float red, green, blue, alpha;
+
 uniform float quality_level; // From /sim/rendering/quality-level
 uniform float snowlevel; // From /sim/rendering/snow-level-m
 
@@ -102,7 +104,7 @@ void main (void)
 	fogFactor = exp2(-gl_Fog.density * gl_Fog.density * fogCoord * fogCoord * LOG2);
 	float biasFactor = exp2(-0.00000002 * fogCoord * fogCoord * LOG2);
 
-	float n=0.02;
+	float n=0.06;
 	n += nvL[0]*0.4;
 	n += nvL[1]*0.6;
 	n += nvL[2]*2.0;
@@ -126,9 +128,10 @@ void main (void)
 	
 	//draw floor where !steep, and another blurb for smoothing transitions
 	vec4 c3, c4, c5, c3a, c4a, c5a;
-	c3 = mix(vec4(n-0.88, n-0.14, -n, 0.0), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.3));
-	c4 = mix(vec4(n-0.88, n-0.74, -n, 0.0), c1, smoothstep(0.990, 0.890, abs(normalize(Normal).z)+nvL[2]*0.9));
-	c4a = mix(vec4(n-0.76, n-0.66, -n, 0.3), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.32));
+	float subred = 1.0 - red; float subgreen = 1.0 - green; float subblue = 1.0 - blue;
+	c3 = mix(vec4(n-subred, n-subgreen, -n, alpha), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.3));
+	c4 = mix(vec4(n-subred, n-subgreen-0.6, -n, alpha), c1, smoothstep(0.990, 0.890, abs(normalize(Normal).z)+nvL[2]*0.9));
+	c4a = mix(vec4(n-subred+0.12, n-subgreen-0.52, -n, 0.0), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.32));
 	c5 = mix(c3, c4, 1.0);
 	c5a = mix(c3, c4a, 1.0);
 	
@@ -173,10 +176,10 @@ void main (void)
 	diffuse = gl_Color.rgb * max(0.8, dot(N, l)) * max(0.9, dot(VNormal, gl_LightSource[0].position.xyz));
 	}
 	
-	//should come as varying!
-	vec4 constantColor = vec4(1.0, 1.0, 1.0, 0.0);
 
-    vec4 ambient_light = gl_LightSource[0].diffuse * constantColor * vec4(diffuse, 1.0);
+	//vec4 constantColor = vec4(1.0, 1.0, 1.0, 0.0);
+
+    vec4 ambient_light = gl_LightSource[0].diffuse * vec4(diffuse, 0.0);
 
 	c1 *= ambient_light;
 	vec4 finalColor = c1;

From 71a7c8cf72556eac37a88d289aa418f388897f36 Mon Sep 17 00:00:00 2001
From: "gral@who.net" <gral@who.net>
Date: Sat, 28 Aug 2010 00:38:20 +0200
Subject: [PATCH 2/4] Removed different colorstrips, flickering between
 forest/herbtundra

---
 Effects/herbtundra.eff | 2 +-
 Shaders/forest.frag    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Effects/herbtundra.eff b/Effects/herbtundra.eff
index ece1a4817..db4129177 100644
--- a/Effects/herbtundra.eff
+++ b/Effects/herbtundra.eff
@@ -11,7 +11,7 @@
         <internal-format>normalized</internal-format>
     </texture>
     <texture n="3">
-        <image>Textures/Terrain/herbtundra-colors.png</image>
+        <image>Textures/Terrain/forest-colors.png</image>
         <filter>linear-mipmap-linear</filter>
         <wrap-s>mirror</wrap-s>
         <internal-format>normalized</internal-format>
diff --git a/Shaders/forest.frag b/Shaders/forest.frag
index 0dc6c620e..de5a60a3d 100644
--- a/Shaders/forest.frag
+++ b/Shaders/forest.frag
@@ -187,5 +187,5 @@ void main (void)
 	if(gl_Fog.density == 1.0)
 		fogFactor=1.0;
 
-	gl_FragColor = mix(gl_Fog.color ,finalColor, fogFactor);
+	gl_FragColor = mix(gl_Fog.color,finalColor, fogFactor);
 }

From 7bf4dc5795ea323bd394af6d5590acaa116d0595 Mon Sep 17 00:00:00 2001
From: "gral@who.net" <gral@who.net>
Date: Sat, 28 Aug 2010 00:54:06 +0200
Subject: [PATCH 3/4] Reactivate blue for forest.frag

---
 Effects/forest.eff     | 2 +-
 Effects/glacier.eff    | 2 +-
 Effects/herbtundra.eff | 2 +-
 Shaders/forest.frag    | 9 +++------
 4 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/Effects/forest.eff b/Effects/forest.eff
index 78bc67924..e189b587a 100644
--- a/Effects/forest.eff
+++ b/Effects/forest.eff
@@ -38,7 +38,7 @@
     <!-- sets the season color -->
     <season-red type="float">0.12</season-red>
     <season-green type="float">0.86</season-green>
-    <season-blue type="float">0.0</season-blue>
+    <season-blue type="float">0.22</season-blue>
     <!-- end season color -->
     
   </parameters>
diff --git a/Effects/glacier.eff b/Effects/glacier.eff
index c6e58025a..da9a06146 100644
--- a/Effects/glacier.eff
+++ b/Effects/glacier.eff
@@ -38,7 +38,7 @@
     <!-- sets the season color -->
     <season-red type="float">0.12</season-red>
     <season-green type="float">0.86</season-green>
-    <season-blue type="float">0.0</season-blue>
+    <season-blue type="float">0.22</season-blue>
     <!-- end season color -->
     
   </parameters>
diff --git a/Effects/herbtundra.eff b/Effects/herbtundra.eff
index db4129177..5f97c2112 100644
--- a/Effects/herbtundra.eff
+++ b/Effects/herbtundra.eff
@@ -37,7 +37,7 @@
     <!-- sets the season color -->
     <season-red type="float">0.12</season-red>
     <season-green type="float">0.86</season-green>
-    <season-blue type="float">0.0</season-blue>
+    <season-blue type="float">0.22</season-blue>
     <!-- end season color -->
     
     <quality-level><use>/sim/rendering/quality-level</use></quality-level>
diff --git a/Shaders/forest.frag b/Shaders/forest.frag
index de5a60a3d..4641a8000 100644
--- a/Shaders/forest.frag
+++ b/Shaders/forest.frag
@@ -129,9 +129,9 @@ void main (void)
 	//draw floor where !steep, and another blurb for smoothing transitions
 	vec4 c3, c4, c5, c3a, c4a, c5a;
 	float subred = 1.0 - red; float subgreen = 1.0 - green; float subblue = 1.0 - blue;
-	c3 = mix(vec4(n-subred, n-subgreen, -n, alpha), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.3));
-	c4 = mix(vec4(n-subred, n-subgreen-0.6, -n, alpha), c1, smoothstep(0.990, 0.890, abs(normalize(Normal).z)+nvL[2]*0.9));
-	c4a = mix(vec4(n-subred+0.12, n-subgreen-0.52, -n, 0.0), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.32));
+	c3 = mix(vec4(n-subred, n-subgreen, -n-subblue, 0.0), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.3));
+	c4 = mix(vec4(n-subred, n-subgreen-0.6, -n-subblue, 0.0), c1, smoothstep(0.990, 0.890, abs(normalize(Normal).z)+nvL[2]*0.9));
+	c4a = mix(vec4(n-subred+0.12, n-subgreen-0.52, -n-subblue, 0.3), c1, smoothstep(0.990, 0.970, abs(normalize(Normal).z)+nvL[2]*1.32));
 	c5 = mix(c3, c4, 1.0);
 	c5a = mix(c3, c4a, 1.0);
 	
@@ -175,9 +175,6 @@ void main (void)
 	c1 = mix(c1, c5, clamp(0.65, n*0.5, 0.6));
 	diffuse = gl_Color.rgb * max(0.8, dot(N, l)) * max(0.9, dot(VNormal, gl_LightSource[0].position.xyz));
 	}
-	
-
-	//vec4 constantColor = vec4(1.0, 1.0, 1.0, 0.0);
 
     vec4 ambient_light = gl_LightSource[0].diffuse * vec4(diffuse, 0.0);
 

From 45dd7055e5663695dc9dc7d860b1ef41c177a61a Mon Sep 17 00:00:00 2001
From: Torsten Dreyer <Torsten@t3r.de>
Date: Sat, 28 Aug 2010 20:31:44 +0200
Subject: [PATCH 4/4] Implementation of weather interpolation using
 property-rules

---
 Environment/clouds-altitude-interpolate.xml |  41 +++
 Environment/clouds-altitude-set.xml         |  43 +++
 Environment/clouds-coverage.xml             |  37 ++
 Environment/clouds-thickness.xml            |  29 ++
 Environment/environment.xml                 |  12 +-
 Environment/interpolator.xml                | 111 ++++++
 Environment/layer-heading-offset.xml        |  36 ++
 Environment/layer-speed-change.xml          |  39 ++
 Environment/metarinterpolator.xml           | 375 ++++++++++++++++++++
 9 files changed, 718 insertions(+), 5 deletions(-)
 create mode 100644 Environment/clouds-altitude-interpolate.xml
 create mode 100644 Environment/clouds-altitude-set.xml
 create mode 100644 Environment/clouds-coverage.xml
 create mode 100644 Environment/clouds-thickness.xml
 create mode 100644 Environment/interpolator.xml
 create mode 100644 Environment/layer-heading-offset.xml
 create mode 100644 Environment/layer-speed-change.xml
 create mode 100644 Environment/metarinterpolator.xml

diff --git a/Environment/clouds-altitude-interpolate.xml b/Environment/clouds-altitude-interpolate.xml
new file mode 100644
index 000000000..1bcd1b1fe
--- /dev/null
+++ b/Environment/clouds-altitude-interpolate.xml
@@ -0,0 +1,41 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<PropertyList>
+  <params>
+    <from>environment/metar/clouds/layer[0]/elevation-ft</from>
+    <to>/environment/clouds/layer[0]/elevation-ft</to>
+  </params>
+  <name>MetarController:clouds:altitude_interpolate</name>
+  <type>noise-spike</type>
+  <max-rate-of-change>8.333</max-rate-of-change>
+  <enable>
+    <condition>
+      <property>/environment/metar/valid</property>
+      <greater-than>
+        <property alias="../../../../params/from"/>
+        <value>-9000</value>
+      </greater-than>
+      <greater-than>
+        <property alias="../../../../params/to"/>
+        <value>-9000</value>
+      </greater-than>
+    </condition>
+  </enable>
+  <input alias="../params/from"/>
+  <output alias="../params/to"/>
+</PropertyList>
diff --git a/Environment/clouds-altitude-set.xml b/Environment/clouds-altitude-set.xml
new file mode 100644
index 000000000..edd834a49
--- /dev/null
+++ b/Environment/clouds-altitude-set.xml
@@ -0,0 +1,43 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<PropertyList>
+  <params>
+    <from>environment/metar/clouds/layer[0]/elevation-ft</from>
+    <to>/environment/clouds/layer[0]/elevation-ft</to>
+  </params>
+  <name>MetarController:clouds:altitude_set</name>
+  <type>gain</type>
+  <gain>1.0</gain>
+  <enable>
+    <condition>
+      <property>/environment/metar/valid</property>
+      <or>
+        <less-than>
+          <property alias="../../../../../params/from"/>
+          <value>-9000</value>
+        </less-than>
+        <less-than>
+          <property alias="../../../../../params/to"/>
+          <value>-9000</value>
+        </less-than>
+      </or>
+    </condition>
+  </enable>
+  <input alias="../params/from"/>
+  <output alias="../params/to"/>
+</PropertyList>
diff --git a/Environment/clouds-coverage.xml b/Environment/clouds-coverage.xml
new file mode 100644
index 000000000..83e2fdbbe
--- /dev/null
+++ b/Environment/clouds-coverage.xml
@@ -0,0 +1,37 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<PropertyList>
+  <params>
+    <from>/environment/metar/clouds/layer[0]/coverage-type</from>
+    <to>environment/clouds/layer[0]/coverage-type</to>
+  </params>
+  <name>MetarController:clouds:coverage</name>
+  <type>gain</type>
+  <gain>1.0</gain>
+  <enable>
+    <condition>
+      <property>/environment/metar/valid</property>
+      <not-equals>
+        <property alias="../../../../params/from"/>
+        <property alias="../../../../params/to"/>
+      </not-equals>
+    </condition>
+  </enable>
+  <input alias="../params/from"/>
+  <output alias="../params/to"/>
+</PropertyList>
diff --git a/Environment/clouds-thickness.xml b/Environment/clouds-thickness.xml
new file mode 100644
index 000000000..89e64573a
--- /dev/null
+++ b/Environment/clouds-thickness.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<PropertyList>
+  <name>MetarController:clouds:thickness</name>
+  <enable>
+    <condition>
+      <property>/environment/metar/valid</property>
+    </condition>
+  </enable>
+  <input>/environment/metar/clouds/layer[0]/thickness-ft</input>
+  <output>/environment/clouds/layer[0]/thickness-ft</output>
+  <type>noise-spike</type>
+  <max-rate-of-change>8.3333</max-rate-of-change>
+</PropertyList>
diff --git a/Environment/environment.xml b/Environment/environment.xml
index d20eda081..71e44e61e 100644
--- a/Environment/environment.xml
+++ b/Environment/environment.xml
@@ -43,7 +43,7 @@
     </scenario>
     <scenario>
       <name>Stormy Monday</name>
-      <metar>XXXX 012345Z 28035G50KT 9999 TSRA SCT022CB BKN030 13/09 Q1005</metar>
+      <metar>XXXX 012345Z 28035G50KT 250V300 9999 TSRA SCT022CB BKN030 13/09 Q1005</metar>
       <description>You're out for an adventure? Gusty winds blowing from the west
                    and isolated thunderstorms should be avoided. Fasten your seatbelt!</description>
     </scenario>
@@ -169,31 +169,33 @@
   </config>
 
   <clouds>
-   <status>true</status>
    <layer n="0">
     <coverage>clear</coverage>
-    <elevation-ft>4000</elevation-ft>
+    <elevation-ft>-9999</elevation-ft>
     <thickness-ft>600</thickness-ft>
     <transition-ft>150</transition-ft>
     <span-m>40000</span-m>
    </layer>
    <layer n="1">
     <coverage>clear</coverage>
-    <elevation-ft>19500</elevation-ft>
+    <elevation-ft>-9999</elevation-ft>
     <thickness-ft>65</thickness-ft>
     <transition-ft>25</transition-ft>
     <span-m>40000</span-m>
    </layer>
    <layer n="2">
     <coverage>clear</coverage>
+    <elevation-ft>-9999</elevation-ft>
     <span-m>40000</span-m>
    </layer>
    <layer n="3">
     <coverage>clear</coverage>
+    <elevation-ft>-9999</elevation-ft>
     <span-m>40000</span-m>
    </layer>
-   <layer n="5">
+   <layer n="4">
     <coverage>clear</coverage>
+    <elevation-ft>-9999</elevation-ft>
     <span-m>40000</span-m>
    </layer>
   </clouds>
diff --git a/Environment/interpolator.xml b/Environment/interpolator.xml
new file mode 100644
index 000000000..761bb608c
--- /dev/null
+++ b/Environment/interpolator.xml
@@ -0,0 +1,111 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<!--
+  Interpolate the values of /environment/interpolated/* over time
+  and write the results to /environment/*, the environment of our
+  aircraft
+  All filters are enabled on /environment/config/enabled=true
+-->
+<PropertyList>
+  
+  <filter>
+    <name>EnvironmentInterpolator:temperature-sea-level-degc</name>
+    <enable>
+      <condition>
+        <property>/environment/config/enabled</property>
+      </condition>
+    </enable>
+    <input>/environment/config/interpolated/temperature-sea-level-degc</input>
+    <output>/environment/temperature-sea-level-degc</output>
+    <type>noise-spike</type>
+    <max-rate-of-change>0.1667</max-rate-of-change>
+  </filter>
+  
+  <filter>
+    <name>EnvironmentInterpolator:dewpoint-sea-level-degc</name>
+    <enable>
+      <condition>
+        <property>/environment/config/enabled</property>
+      </condition>
+    </enable>
+    <input>/environment/config/interpolated/dewpoint-sea-level-degc</input>
+    <output>/environment/dewpoint-sea-level-degc</output>
+    <type>noise-spike</type>
+    <max-rate-of-change>0.1667</max-rate-of-change>
+  </filter>
+  
+  <filter>
+    <!--
+      transfer the interpolated QNH to the global environment
+      limit the rate of change to approx 1hpa/sec
+    -->
+    <name>EnvironmentInterpolator:pressure-sea-level-inhg</name>
+    <type>noise-spike</type>
+    <max-rate-of-change>0.03</max-rate-of-change>
+    <enable>
+      <condition>
+        <property>/environment/config/enabled</property>
+      </condition>
+    </enable>
+    <input>/environment/config/interpolated/pressure-sea-level-inhg</input>
+    <output>/environment/pressure-sea-level-inhg</output>
+  </filter>
+
+  <filter>
+    <name>EnvironmentInterpolator:visibility-m</name>
+    <enable>
+      <condition>
+        <property>/environment/config/enabled</property>
+      </condition>
+    </enable>
+    <input>/environment/config/interpolated/visibility-m</input>
+    <output>/environment/visibility-m</output>
+    <type>exponential</type>
+    <filter-time>10</filter-time>
+  </filter>
+
+  <!-- 
+    filter the wind vector by filtering the cartesian representation
+  -->
+  <filter>
+    <name>EnvironmentInterpolator:wind-from-north</name>
+    <enable>
+      <condition>
+        <property>/environment/config/enabled</property>
+      </condition>
+    </enable>
+    <input>/environment/config/interpolated/wind-from-north-fps</input>
+    <output>/environment/wind-from-north-fps</output>
+    <type>exponential</type>
+    <filter-time>5</filter-time>
+  </filter>
+
+  <filter>
+    <name>EnvironmentInterpolator:wind-from-east</name>
+    <enable>
+      <condition>
+        <property>/environment/config/enabled</property>
+      </condition>
+    </enable>
+    <input>/environment/config/interpolated/wind-from-east-fps</input>
+    <output>/environment/wind-from-east-fps</output>
+    <type>exponential</type>
+    <filter-time>5</filter-time>
+  </filter>
+
+</PropertyList>
diff --git a/Environment/layer-heading-offset.xml b/Environment/layer-heading-offset.xml
new file mode 100644
index 000000000..363f71560
--- /dev/null
+++ b/Environment/layer-heading-offset.xml
@@ -0,0 +1,36 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<PropertyList>
+  <name>MetarController:layer:wind-from-heading-deg</name>
+  <type>gain</type>
+  <gain>1.0</gain>
+  <enable>
+    <condition>
+      <property>/environment/metar/valid</property>
+    </condition>
+  </enable>
+  <input>
+    <property>/environment/config/boundary/entry[0]/wind-from-heading-deg</property>
+    <offset>/environment/config/boundary/entry[1]/wind-heading-change-deg</offset>
+  </input>
+  <output>/environment/config/boundary/entry[1]/wind-from-heading-deg</output>
+  <period>
+    <min>0</min>
+    <max>360</max>
+  </period>
+</PropertyList>
diff --git a/Environment/layer-speed-change.xml b/Environment/layer-speed-change.xml
new file mode 100644
index 000000000..6cce732f4
--- /dev/null
+++ b/Environment/layer-speed-change.xml
@@ -0,0 +1,39 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<PropertyList>
+  <name>MetarController:layer:wind-speed-kt</name>
+  <type>gain</type>
+  <gain>1.0</gain>
+  <enable>
+    <condition>
+      <property>/environment/metar/valid</property>
+    </condition>
+  </enable>
+  <input>
+    <expression>
+      <product>
+        <property>/environment/config/boundary/entry[0]/wind-speed-kt</property>
+        <sum>
+          <property>/environment/config/boundary/entry[1]/wind-speed-change-rel</property>
+          <value>1.0</value>
+        </sum>
+      </product>
+    </expression>
+  </input>
+  <output>/environment/config/boundary/entry[1]/wind-speed-kt</output>
+</PropertyList>
diff --git a/Environment/metarinterpolator.xml b/Environment/metarinterpolator.xml
new file mode 100644
index 000000000..35775635f
--- /dev/null
+++ b/Environment/metarinterpolator.xml
@@ -0,0 +1,375 @@
+<?xml version="1.0" ?>
+<!--
+ This file is part of FlightGear, the free flight simulator
+ http://www.flightgear.org/
+
+ Copyright (C) 2009 Torsten Dreyer, Torsten (at) t3r _dot_ de
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+-->
+<!--
+  Interpolate the METAR weather values over time and write
+  the environment values in /environment/config/*
+  All filters are enabled if /environment/metar/valid=true
+  -->
+<PropertyList> 
+  <filter>
+    <!-- 
+      transfer the METAR QNH to the interpolation controller
+      limit the rate of change to approx 0.01hpa/sec
+    -->
+    <name>MetarController:pressure-sea-level-inhg</name>
+    <type>noise-spike</type>
+    <max-rate-of-change>0.0003</max-rate-of-change>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>/environment/metar/pressure-sea-level-inhg</input>
+    <output>/environment/config/boundary/entry/pressure-sea-level-inhg</output>
+    <output>/environment/config/aloft/entry/pressure-sea-level-inhg</output>
+  </filter>
+
+  <filter>
+    <!-- 
+      transfer the sea-level temperature to each layer of
+      interpolation controller. We have no idea here about
+      the temperature gradient, so just assume ISA.
+    -->
+    <name>MetarController:temperature-sea-level-degc</name>
+    <type>noise-spike</type>
+    <max-rate-of-change>0.01667</max-rate-of-change>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>/environment/metar/temperature-sea-level-degc</input>
+    <output>/environment/config/boundary/entry[0]/temperature-sea-level-degc</output>
+    <output>/environment/config/boundary/entry[1]/temperature-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[0]/temperature-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[1]/temperature-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[2]/temperature-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[3]/temperature-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[4]/temperature-sea-level-degc</output>
+  </filter>
+
+  <filter>
+    <!--
+      transfer the sea-level temperature to each layer of
+      interpolation controller. 
+    -->
+    <name>MetarController:dewpoint-sea-level-degc</name>
+    <type>noise-spike</type>
+    <max-rate-of-change>0.01667</max-rate-of-change>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>/environment/metar/dewpoint-sea-level-degc</input>
+    <output>/environment/config/boundary/entry[0]/dewpoint-sea-level-degc</output>
+    <output>/environment/config/boundary/entry[1]/dewpoint-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[0]/dewpoint-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[1]/dewpoint-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[2]/dewpoint-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[3]/dewpoint-sea-level-degc</output>
+    <output>/environment/config/aloft/entry[4]/dewpoint-sea-level-degc</output>
+  </filter>
+
+  <filter>
+    <!--
+      transfer the sea-level temperature to each layer of
+      interpolation controller. We are not very creative here and 
+      use the same visibility for all layers but top three which
+      are left untouched.
+    -->
+    <name>MetarController:visibility-m</name>
+    <type>exponential</type>
+    <filter-time>30</filter-time>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>/environment/metar/min-visibility-m</input>
+    <output>/environment/config/boundary/entry[0]/visibility-m</output>
+    <output>/environment/config/boundary/entry[1]/visibility-m</output>
+    <output>/environment/config/aloft/entry[0]/visibility-m</output>
+    <output>/environment/config/aloft/entry[1]/visibility-m</output>
+  </filter>
+
+  <!-- split the wind vector into it's components -->
+
+  <filter>
+    <name>MetarController:wind-from-north-kt</name>
+    <type>exponential</type>
+    <filter-time>30</filter-time>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>
+      <expression>
+        <cos>
+          <product>
+            <property>/environment/metar/base-wind-dir-deg</property>
+            <value>0.0174533</value>
+          </product>
+        </cos>
+      </expression>
+      <scale>/environment/metar/base-wind-speed-kt</scale>
+    </input>
+    <output>/environment/metar/base-wind-from-north-kt</output>
+  </filter>
+
+  <filter>
+    <name>MetarController:wind-from-east-kt</name>
+    <type>exponential</type>
+    <filter-time>30</filter-time>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>
+      <expression>
+        <sin>
+          <product>
+            <property>/environment/metar/base-wind-dir-deg</property>
+            <value>0.0174533</value>
+          </product>
+        </sin>
+      </expression>
+      <scale>/environment/metar/base-wind-speed-kt</scale>
+    </input>
+    <output>/environment/metar/base-wind-from-east-kt</output>
+  </filter>
+
+  <filter>
+    <name>MetarController::wind-speed-kt</name>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>
+      <expression>
+        <!-- pythagoras in markup language -->
+        <sqrt>
+          <sum>
+            <product>
+              <property>/environment/metar/base-wind-from-east-kt</property>
+              <property>/environment/metar/base-wind-from-east-kt</property>
+            </product>
+            <product>
+              <property>/environment/metar/base-wind-from-north-kt</property>
+              <property>/environment/metar/base-wind-from-north-kt</property>
+            </product>
+          </sum>
+        </sqrt>
+      </expression>
+    </input>
+    <output>/environment/config/boundary/entry[0]/wind-speed-kt</output>
+    <type>gain</type>
+    <gain>1.0</gain>
+  </filter>
+
+  <filter>
+    <name>MetarController:wind-from-heading-deg</name>
+    <enable>
+      <condition>
+        <property>/environment/metar/valid</property>
+      </condition>
+    </enable>
+    <input>
+      <expression>
+        <atan2>
+          <property>/environment/metar/base-wind-from-east-kt</property>
+          <property>/environment/metar/base-wind-from-north-kt</property>
+        </atan2>
+      </expression>
+    </input>
+    <output>/environment/config/boundary/entry[0]/wind-from-heading-deg</output>
+    <type>gain</type>
+    <gain>57.3</gain> <!-- radians to degree -->
+    <period>
+      <min>0</min>
+      <max>360</max>
+    </period>
+  </filter>
+
+  <!-- Adjust the wind-vector for the layers -->
+  <!-- TODO: handle variable winds -->
+  <filter include="layer-heading-offset.xml"/>
+  <filter include="layer-heading-offset.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[0]/wind-heading-change-deg</offset>
+    </input>
+    <output>/environment/config/aloft/entry[0]/wind-from-heading-deg</output>
+  </filter>
+  <filter include="layer-heading-offset.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[1]/wind-heading-change-deg</offset>
+    </input>
+    <output>/environment/config/aloft/entry[1]/wind-from-heading-deg</output>
+  </filter>
+  <filter include="layer-heading-offset.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[2]/wind-heading-change-deg</offset>
+    </input>
+    <output>/environment/config/aloft/entry[2]/wind-from-heading-deg</output>
+  </filter>
+  <filter include="layer-heading-offset.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[3]/wind-heading-change-deg</offset>
+    </input>
+    <output>/environment/config/aloft/entry[3]/wind-from-heading-deg</output>
+  </filter>
+  <filter include="layer-heading-offset.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[4]/wind-heading-change-deg</offset>
+    </input>
+    <output>/environment/config/aloft/entry[4]/wind-from-heading-deg</output>
+  </filter>
+
+  <filter include="layer-speed-change.xml"/>
+  <filter include="layer-speed-change.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[0]/wind-speed-change-rel</offset>
+    </input>
+    <output>/environment/config/aloft/entry[0]/wind-speed-kt</output>
+  </filter>
+  <filter include="layer-speed-change.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[1]/wind-speed-change-rel</offset>
+    </input>
+    <output>/environment/config/aloft/entry[1]/wind-speed-kt</output>
+  </filter>
+  <filter include="layer-speed-change.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[2]/wind-speed-change-rel</offset>
+    </input>
+    <output>/environment/config/aloft/entry[2]/wind-speed-kt</output>
+  </filter>
+  <filter include="layer-speed-change.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[3]/wind-speed-change-rel</offset>
+    </input>
+    <output>/environment/config/aloft/entry[3]/wind-speed-kt</output>
+  </filter>
+  <filter include="layer-speed-change.xml">
+    <input>
+      <offset>/environment/config/aloft/entry[4]/wind-speed-change-rel</offset>
+    </input>
+    <output>/environment/config/aloft/entry[4]/wind-speed-kt</output>
+  </filter>
+
+  <!-- Clouds -->
+  <!-- don't interpolate to/from altitude -9999 -->
+  <filter include="clouds-altitude-set.xml"/>
+  <filter include="clouds-altitude-set.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[1]/elevation-ft</from>
+      <to>/environment/clouds/layer[1]/elevation-ft</to>
+    </params>
+  </filter>
+  <filter include="clouds-altitude-set.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[2]/elevation-ft</from>
+      <to>/environment/clouds/layer[2]/elevation-ft</to>
+    </params>
+  </filter>
+  <filter include="clouds-altitude-set.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[3]/elevation-ft</from>
+      <to>/environment/clouds/layer[3]/elevation-ft</to>
+    </params>
+  </filter>
+  <filter include="clouds-altitude-set.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[4]/elevation-ft</from>
+      <to>/environment/clouds/layer[4]/elevation-ft</to>
+    </params>
+  </filter>
+
+  <filter include="clouds-altitude-interpolate.xml"/>
+  <filter include="clouds-altitude-interpolate.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[1]/elevation-ft</from>
+      <to>/environment/clouds/layer[1]/elevation-ft</to>
+    </params>
+  </filter>
+  <filter include="clouds-altitude-interpolate.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[2]/elevation-ft</from>
+      <to>/environment/clouds/layer[2]/elevation-ft</to>
+    </params>
+  </filter>
+  <filter include="clouds-altitude-interpolate.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[3]/elevation-ft</from>
+      <to>/environment/clouds/layer[3]/elevation-ft</to>
+    </params>
+  </filter>
+  <filter include="clouds-altitude-interpolate.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[4]/elevation-ft</from>
+      <to>/environment/clouds/layer[4]/elevation-ft</to>
+    </params>
+  </filter>
+
+  <filter include="clouds-thickness.xml"/>
+  <filter include="clouds-thickness.xml">
+    <input>/environment/metar/clouds/layer[1]/thickness-ft</input>
+    <output>/environment/clouds/layer[1]/thickness-ft</output>
+  </filter>
+  <filter include="clouds-thickness.xml">
+    <input>/environment/metar/clouds/layer[2]/thickness-ft</input>
+    <output>/environment/clouds/layer[2]/thickness-ft</output>
+  </filter>
+  <filter include="clouds-thickness.xml">
+    <input>/environment/metar/clouds/layer[3]/thickness-ft</input>
+    <output>/environment/clouds/layer[3]/thickness-ft</output>
+  </filter>
+  <filter include="clouds-thickness.xml">
+    <input>/environment/metar/clouds/layer[4]/thickness-ft</input>
+    <output>/environment/clouds/layer[4]/thickness-ft</output>
+  </filter>
+
+  <filter include="clouds-coverage.xml"/>
+  <filter include="clouds-coverage.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[1]/coverage-type</from>
+      <to>environment/clouds/layer[1]/coverage-type</to>
+    </params>
+  </filter>
+  <filter include="clouds-coverage.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[2]/coverage-type</from>
+      <to>environment/clouds/layer[2]/coverage-type</to>
+    </params>
+  </filter>
+  <filter include="clouds-coverage.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[3]/coverage-type</from>
+      <to>environment/clouds/layer[3]/coverage-type</to>
+    </params>
+  </filter>
+  <filter include="clouds-coverage.xml">
+    <params>
+      <from>/environment/metar/clouds/layer[4]/coverage-type</from>
+      <to>environment/clouds/layer[4]/coverage-type</to>
+    </params>
+  </filter>
+</PropertyList>