diff --git a/Effects/cloud.eff b/Effects/cloud.eff
index 8a8f1db85..8e2d830e7 100644
--- a/Effects/cloud.eff
+++ b/Effects/cloud.eff
@@ -57,8 +57,8 @@
         <wrap-t>clamp</wrap-t>
       </texture-unit>
       <program>
-        <vertex-shader>Shaders/3dcloud-lightfield.vert</vertex-shader>
-        <fragment-shader>Shaders/3dcloud-lightfield.frag</fragment-shader>
+        <vertex-shader>Shaders/3dcloud-ALS.vert</vertex-shader>
+        <fragment-shader>Shaders/3dcloud-ALS.frag</fragment-shader>
         <attribute>
           <name>usrAttr1</name>
           <index>10</index>
diff --git a/Nasal/local_weather/compat_layer.nas b/Nasal/local_weather/compat_layer.nas
index bcd4f98f6..98c085849 100644
--- a/Nasal/local_weather/compat_layer.nas
+++ b/Nasal/local_weather/compat_layer.nas
@@ -655,6 +655,7 @@ var p = props.Node.new({ "layer" : 0,
 			 "min-bottom-lighting-factor": c.bottom_shade,
 			 "min-middle-lighting-factor": c.middle_shade,
 			 "min-top-lighting-factor": c.top_shade,
+			 "alpha-factor": c.alpha_factor,
 			 "min-shade-lighting-factor": c.bottom_shade,
 			 "texture": c.texture_sheet,
 			 "num-textures-x": c.num_tex_x,
diff --git a/Nasal/local_weather/local_weather.nas b/Nasal/local_weather/local_weather.nas
index b95aac1af..5e4e2061e 100644
--- a/Nasal/local_weather/local_weather.nas
+++ b/Nasal/local_weather/local_weather.nas
@@ -1553,6 +1553,7 @@ if (path == "new") # we have to switch to new cloud generating routines
 	local_weather.cloudAssembly.lon = lon;
 	local_weather.cloudAssembly.alt = alt;	
 	local_weather.cloudAssembly.top_shade = top_shade;
+	local_weather.cloudAssembly.alpha_factor = alpha_factor;
 
 	#print(lat," ",long, " ", alt);
 
@@ -3382,22 +3383,22 @@ var v2 = v0 * (1.2 + rand() * 0.2);
 var d2 = d0 + dsign * (3.0 * rand() + 2.0);
 
 var v3 = v0 * (1.3 + rand() * 0.4) + 5.0;
-var d3 = d0 + dsign * (3.0 * rand() + dsign * 4.0);
+var d3 = d0 + dsign * (3.0 * rand()  + 4.0);
 
 var v4 = v0 * (1.7 + rand() * 0.5) + 10.0;
-var d4 = d0 + dsign * (4.0 * rand() + dsign * 8.0);
+var d4 = d0 + dsign * (4.0 * rand()  + 8.0);
 
 var v5 = v0 * (1.7 + rand() * 0.5) + 20.0;
-var d5 = d0 + dsign * (4.0 * rand() + dsign * 10.0);
+var d5 = d0 + dsign * (4.0 * rand() +  10.0);
 
 var v6 = v0 * (1.7 + rand() * 0.5) + 40.0;
-var d6 = d0 + dsign * (4.0 * rand() + dsign * 12.0);
+var d6 = d0 + dsign * (4.0 * rand() +  12.0);
 
 var v7 = v0 * (2.0 + rand() * 0.7) + 50.0;
-var d7 = d0 + dsign * (4.0 * rand() + dsign * 13.0);
+var d7 = d0 + dsign * (4.0 * rand() +  13.0);
 
 var v8 = v0 * (2.0 + rand() * 0.7) + 55.0;;
-var d8 = d0 + dsign * (5.0 * rand() + dsign * 14.0);
+var d8 = d0 + dsign * (5.0 * rand() +  14.0);
 
 var w = windIpoint.new(lat, lon, d0, v0, d1, v1, d2, v2, d3, v3, d4, v4, d5, v5, d6, v6, d7, v7, d8, v8);
 
@@ -4563,6 +4564,10 @@ if (lowest_layer_turbulence < 0.0) {lowest_layer_turbulence = 0.0;}
 
 var top_shade = 1.0;
 
+# global cloud transparency
+
+var alpha_factor = 1.0;
+
 # global cloud size scale;
 
 var cloud_size_scale = 1.0;
diff --git a/Shaders/3dcloud-lightfield.frag b/Shaders/3dcloud-ALS.frag
similarity index 100%
rename from Shaders/3dcloud-lightfield.frag
rename to Shaders/3dcloud-ALS.frag
diff --git a/Shaders/3dcloud-lightfield.vert b/Shaders/3dcloud-ALS.vert
similarity index 99%
rename from Shaders/3dcloud-lightfield.vert
rename to Shaders/3dcloud-ALS.vert
index 3dda46881..29ffc489e 100644
--- a/Shaders/3dcloud-lightfield.vert
+++ b/Shaders/3dcloud-ALS.vert
@@ -17,6 +17,7 @@ uniform float air_pollution;
 attribute vec3 usrAttr1;
 attribute vec3 usrAttr2;
 
+float alpha_factor = usrAttr1.r;
 float shade_factor = usrAttr1.g;
 float cloud_height = usrAttr1.b;
 float bottom_factor = usrAttr2.r;
@@ -237,6 +238,7 @@ void main(void)
    
     gl_FrontColor.rgb = gl_FrontColor.rgb +  moonLightColor * (1.0 - smoothstep(0.4, 0.5, earthShade));
     hazeColor.rgb = hazeColor.rgb + moonLightColor * (1.0 - smoothstep(0.4, 0.5, earthShade));
+    gl_FrontColor.a = gl_FrontColor.a * alpha_factor; 
     gl_BackColor = gl_FrontColor;
   }
 }