Lightning for AW with ALS support - work in progress

Effects/cloud.eff

@@ -13,6 +13,10 @@
     <moonlight><use>/environment/moonlight</use></moonlight>
     <air_pollution><use>/environment/air-pollution-norm</use></air_pollution>			
     <visibility><use>/environment/visibility-m</use></visibility>
+    <flash><use>/environment/lightning/flash</use></flash>
+    <lightning-pos-x><use>/environment/lightning/lightning-pos-x</use></lightning-pos-x>
+    <lightning-pos-y><use>/environment/lightning/lightning-pos-y</use></lightning-pos-y>
+    <lightning-range><use>/environment/lightning/lightning-range</use></lightning-range>
   </parameters>
   
   <technique n="9">
@@ -118,6 +122,26 @@
         <type>float</type>
         <value><use>visibility</use></value>
       </uniform>
+      <uniform>
+        <name>flash</name>
+        <type>float</type>
+        <value><use>flash</use></value>
+      </uniform>
+      <uniform>
+        <name>lightning_pos_x</name>
+        <type>float</type>
+        <value><use>lightning-pos-x</use></value>
+      </uniform>
+      <uniform>
+        <name>lightning_pos_y</name>
+        <type>float</type>
+        <value><use>lightning-pos-y</use></value>
+      </uniform>
+      <uniform>
+        <name>lightning_range</name>
+        <type>float</type>
+        <value><use>lightning-range</use></value>
+      </uniform>
       <!--<vertex-program-two-side>true</vertex-program-two-side>-->
     </pass>
   </technique>

Effects/rain-layer.eff

@@ -4,15 +4,13 @@
   <parameters>
     <texture n ="0">
     </texture>
-  <range>
+    <range><use>/sim/rendering/clouds3d-vis-range</use></range>   
-      <use>/sim/rendering/clouds3d-vis-range</use>
+    <scattering><use>/rendering/scene/scattering</use></scattering>   
-    </range>   
+    <terminator><use>/environment/terminator-relative-position-m</use></terminator>
-    <scattering>
+    <flash><use>/environment/lightning/flash</use></flash>
-      <use>/rendering/scene/scattering</use>
+    <lightning-pos-x><use>/environment/lightning/lightning-pos-x</use></lightning-pos-x>
-    </scattering>   
+    <lightning-pos-y><use>/environment/lightning/lightning-pos-y</use></lightning-pos-y>
- <terminator>
+    <lightning-range><use>/environment/lightning/lightning-range</use></lightning-range>
-      <use>/environment/terminator-relative-position-m</use>
-    </terminator>
   </parameters>
 <technique n="9">
     <predicate>
@@ -60,8 +58,8 @@
         <wrap-t>clamp</wrap-t>-->
       </texture-unit>
       <program>
-        <vertex-shader>Shaders/rain-layer-lightfield.vert</vertex-shader>
+        <vertex-shader>Shaders/rain-layer-ALS.vert</vertex-shader>
-        <fragment-shader>Shaders/rain-layer-lightfield.frag</fragment-shader>
+        <fragment-shader>Shaders/rain-layer-ALS.frag</fragment-shader>
       </program>
       <uniform>
         <name>baseTexture</name>
@@ -83,7 +81,27 @@
         <type>float</type>
         <value><use>terminator</use></value>
       </uniform>
-      <vertex-program-two-side>true</vertex-program-two-side>
+      <uniform>
+        <name>flash</name>
+        <type>float</type>
+        <value><use>flash</use></value>
+      </uniform>
+      <uniform>
+        <name>lightning_pos_x</name>
+        <type>float</type>
+        <value><use>lightning-pos-x</use></value>
+      </uniform>
+      <uniform>
+        <name>lightning_pos_y</name>
+        <type>float</type>
+        <value><use>lightning-pos-y</use></value>
+      </uniform>
+      <uniform>
+        <name>lightning_range</name>
+        <type>float</type>
+        <value><use>lightning-range</use></value>
+      </uniform>
+      <!--<vertex-program-two-side>true</vertex-program-two-side>-->
     </pass>
   </technique>
   <technique n="10">

Environment/environment.xml

@@ -440,6 +440,15 @@
     <snow-thickness-factor type="double" userarchive="y">1.0</snow-thickness-factor>
   </surface>
 
+ <!-- definitions for lightning functionality -->
+
+ <lightning>
+    <flash type="double" userarchive="n">0.0</flash>
+    <lightning-pos-x type="double" userarchive="n">0.0</lightning-pos-x>
+    <lightning-pos-y type="double" userarchive="n">0.0</lightning-pos-y>
+    <lightning-range type="double" userarchive="n">0.0</lightning-range>
+ </lightning>
+
  <!-- definitions for the detailed precipitation manager -->
  <precipitation-control>
      <rain-droplet-size type="float" userarchive="n">0.015</rain-droplet-size>

Models/Weather/lightning1.xml

@@ -0,0 +1,54 @@
+<?xml version="1.0"?>
+
+<PropertyList>
+ <path>lightning.ac</path>
+ 
+	<effect>
+		<object-name>rect</object-name>
+		<inherits-from>Effects/rain-layer</inherits-from>
+	</effect>
+
+  	<offsets>
+      	 	<x-m> 0.0 </x-m>
+       		<y-m> 0.0</y-m>
+       		<z-m>-1.2 </z-m>
+    	</offsets>
+
+
+<animation>
+  		<type>scale</type>
+  		<x-offset>700.0</x-offset>
+  		<y-offset>700.0</y-offset>
+ 		<z-offset>1000.0</z-offset>
+ </animation>
+
+  <animation>
+    	<type>material</type>
+   	<emission>
+      		<red>   0.9 </red>
+      		<green> 0.9 </green>
+		<blue>  1.0 </blue>
+    	</emission>
+  </animation>
+
+ <animation>
+  <type>select</type>
+  <condition>
+   <greater-than>
+    <property>/environment/lightning/flash</property>
+    <value>0.0</value>
+   </greater-than>
+  </condition>
+ </animation>
+
+<animation>
+  <type>billboard</type>
+  <spherical>false</spherical>
+</animation>
+ 
+<animation>
+  <enable-hot type="bool">false</enable-hot>
+</animation>
+
+
+</PropertyList>

Nasal/local_weather/compat_layer.nas

@@ -618,6 +618,54 @@ model.getNode("load", 1).remove();
 
 }
 
+###########################################################
+# place a  model with control properties
+###########################################################
+
+var place_model_controlled = func(string, path, lat, lon, alt, heading, pitch, roll) {
+
+
+
+var m = props.globals.getNode("models", 1);
+		for (var i = 0; 1; i += 1)
+			if (m.getChild("model", i, 0) == nil)
+				break;
+var model = m.getChild("model", i, 1);
+
+
+setprop("/local-weather/"~string~"/latitude-deg", lat);
+setprop("/local-weather/"~string~"/longitude-deg", lon);
+setprop("/local-weather/"~string~"/elevation-ft", alt);
+setprop("/local-weather/"~string~"/heading-deg", heading);
+setprop("/local-weather/"~string~"/pitch-deg", pitch);
+setprop("/local-weather/"~string~"/roll-deg", roll);
+
+
+
+var cmodel = props.globals.getNode("/local-weather/"~string, 1);
+var latN = cmodel.getNode("latitude-deg",1);
+var lonN = cmodel.getNode("longitude-deg",1);
+var altN = cmodel.getNode("elevation-ft",1);
+var headN = cmodel.getNode("heading-deg",1);
+var pitchN = cmodel.getNode("pitch-deg",1);
+var rollN = cmodel.getNode("roll-deg",1);
+
+
+
+model.getNode("path", 1).setValue(path);
+model.getNode("latitude-deg-prop", 1).setValue(latN.getPath());
+model.getNode("longitude-deg-prop", 1).setValue(lonN.getPath());
+model.getNode("elevation-ft-prop", 1).setValue(altN.getPath());
+model.getNode("heading-deg-prop", 1).setValue(headN.getPath());
+model.getNode("pitch-deg-prop", 1).setValue(pitchN.getPath());
+model.getNode("roll-deg-prop", 1).setValue(rollN.getPath());
+model.getNode("tile-index",1).setValue(0);
+model.getNode("load", 1).remove();
+
+
+#return model;
+}
+
 
 
 

Nasal/local_weather/local_weather.nas

@@ -1667,6 +1667,7 @@ setprop(lw~"buffer-loop-flag",0);
 setprop(lw~"housekeeping-loop-flag",0);
 setprop(lw~"convective-loop-flag",0);
 setprop(lw~"shadow-loop-flag",0);
+setprop(lw~"thunderstorm-loop-flag",0);
 
 weather_dynamics.convective_loop_kill_flag = 1; # long-running loop needs a different scheme to end
 
@@ -1731,6 +1732,7 @@ settimer ( func {
 	setsize(alt_min_array,0);
 	setsize(alt_mean_array,0);
 	setsize(weather_dynamics.cloudShadowArray,0);
+	setsize(local_weather.thunderstormArray,0);
 	setsize(weather_dynamics.cloudShadowCandidateArray,0);
 	setsize(weather_dynamics.tile_convective_altitude,0);
 	setsize(weather_dynamics.tile_convective_strength,0);
@@ -4052,6 +4054,14 @@ if (local_weather.cloud_shadow_flag == 1)
 
 # weather_tile_management.watchdog_loop();
 
+# start thunderstorm management
+
+setprop(lw~"thunderstorm-loop-flag",1);
+
+local_weather.place_model_controlled("lightning", "Models/Weather/lightning1.xml", lat, lon, 0.0, 0.0, 0.0, 0.0);
+
+local_weather.thunderstorm_management_loop();
+
 }
 
 

Nasal/local_weather/weather_tile_management.nas

@@ -17,6 +17,8 @@
 # remove_impostors		to delete a ring of impostors to mimick distant clouds
 # create_impostors		to create a ring of impostors to mimick distant clouds
 # shadow_management_loop	to manage cloud shadow information
+# thunderstorm_management_loop	to manage information on thunderstorm position
+# lightning_strike		to get the timing for a lightning strike to the property tree
 # watchdog loop			(debug helping structure)
 # calc_geo			to get local Cartesian geometry for latitude conversion
 # get_lat			to get latitude from Cartesian coordinates
@@ -1261,6 +1263,86 @@ if (local_weather.debug_output_flag == 1)
 weather_tiles.create_impostor_ring(lat, lon, alt, alpha, type, n);
 }
 
+##################################
+# Thunderstorm positon management
+##################################
+
+var thunderstorm_management_loop = func {
+
+if (local_weather.local_weather_running_flag == 0) {return;}
+
+# compute some general-purpose stuff for the loop
+	
+var eyeLat = lwObserverLat; 
+var eyeLon = lwObserverLon; 
+
+var n = size(thunderstormArray);
+
+#print("We have ",n," storms.");
+
+for (var i = 0; i < n; i=i+1)
+	{
+	var tstorm = thunderstormArray[i];
+
+	var rn = rand();
+	#if (i == 0) {rn = 0;} else {rn = 1;}
+	if (rn < tstorm.strength)
+		{
+		#print("Lightning strike storm ", i,"!");
+
+		var diffx = -(tstorm.lat - eyeLat) * local_weather.lat_to_m;
+		var diffy = (tstorm.lon - eyeLon) * local_weather.lon_to_m ;
+		var offset_x = -3000.0 + rand() * 6000.0; 
+		var offset_y = -3000.0 + rand() * 6000.0; 
+
+		var dist = math.sqrt(diffx * diffx + diffy * diffy) ;
+
+		setprop("/environment/lightning/lightning-pos-x", diffx + offset_x);
+		setprop("/environment/lightning/lightning-pos-y", diffy + offset_y);
+		setprop("/environment/lightning/lightning-range", tstorm.size);
+		setprop("/local-weather/lightning/latitude-deg", tstorm.lat - offset_x * local_weather.m_to_lat);
+		setprop("/local-weather/lightning/longitude-deg", tstorm.lon + offset_y * local_weather.m_to_lon);
+		setprop("/local-weather/lightning/altitude-ft", tstorm.alt);
+		lightning_strike();
+
+		if (dist > 50000.0)
+			{
+			thunderstormArray = delete_from_vector(thunderstormArray,i);
+			print("Removing storm ", i);
+			break;
+			}
+		}
+
+
+	}
+
+
+if (getprop(lw~"thunderstorm-loop-flag") ==1) {settimer( func {thunderstorm_management_loop()}, 1.0);}	
+}
+
+var lightning_strike = func {
+
+var rn = rand();
+
+var repeat = 1;
+
+if (rn > 0.5) {repeat = 2;}
+
+var duration = 0.1 + 0.1 * rand();
+var strength = 0.5 + 1.0 * rand();
+
+setprop("/environment/lightning/flash", strength);
+settimer( func{ setprop("/environment/lightning/flash", 0.0);}, duration);
+
+var duration1 = 0.1 +  0.1 * rand();
+
+if (repeat == 2)
+	{
+	settimer( func{ setprop("/environment/lightning/flash", strength);}, duration + 0.1);
+	settimer( func{ setprop("/environment/lightning/flash", 0.0);}, duration + 0.1 + duration1);
+	}
+
+}
 
 ###############################
 # Cloud shadow management
@@ -1528,6 +1610,7 @@ var cloud_view_distance = getprop(lw~"config/clouds-visible-range-m");
 
 var modelArrays = [];
 var active_tile_list = [];
+var thunderstormArray = [];
 
 # a bunch of variables to be updated per frame used by different
 # routines, managed by the housekeeping loop
@@ -1543,6 +1626,8 @@ var lwTileIndex = 0;
 # hashes to manage clouds in scenery or in the buffer
 #####################################################
 
+
+
 var cloudBufferArray = [];
 
 
@@ -1618,6 +1703,18 @@ var cloudShadow = {
 	},
 };	
 
+var thunderstormHash = {
+	new: func (lat, lon, alt, size, strength) {
+			var t = {parents: [thunderstormHash] };
+		t.lat = lat;
+		t.lon = lon;
+		t.alt = alt;
+		t.size = size;
+		t.strength = strength;
+		return t;
+	},
+};
+
 
 var cloudSceneryArray = [];
 var n_cloudSceneryArray = 0;

Nasal/local_weather/weather_tiles.nas

@@ -1720,7 +1720,7 @@ local_weather.convective_size_bias = 0.3 + rand() * 0.3;
 
 
 # and specify the atmosphere
-	local_weather.set_atmosphere_ipoint(blat, blon, vis + 12000.0, alt+alt_offset, vis + 20000.0, 0.0, alt+alt_offset +20000.0, alt+alt_offset + 25000.0, 0.85, alt+alt_offset, alt+alt_offset + 2500.0); 
+	local_weather.set_atmosphere_ipoint(blat, blon, vis + 12000.0, alt+alt_offset, vis + 20000.0, 0.0, alt+alt_offset +20000.0, alt+alt_offset + 25000.0, 0.75, alt+alt_offset, alt+alt_offset + 2500.0); 
 
 var rn = rand();
 
@@ -4295,18 +4295,34 @@ x = 2.0 * (rand()-0.5) * 12000;
 y = 2.0 * (rand()-0.5) * 12000;
 
 if (rand() > 0.6)
-	{create_medium_thunderstorm(lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, alpha);}
+	{
+	create_medium_thunderstorm(lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, alpha);
+	var ts = local_weather.thunderstormHash.new (lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, 3000.0, 0.2);
+	append(local_weather.thunderstormArray,ts);
+	}
 else	
-	{create_small_thunderstorm(lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, alpha);}
+	{
+	create_small_thunderstorm(lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, alpha);
+	var ts = local_weather.thunderstormHash.new (lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, 1000.0, 0.15);
+	append(local_weather.thunderstormArray,ts);
+	}
 
 if (rand() > 0.5) # we do a second thunderstorm
 	{
 	x = 2.0 * (rand()-0.5) * 12000;
 	y = 2.0 * (rand()-0.5) * 12000;
 	if (rand() > 0.8)
-		{create_medium_thunderstorm(lat+get_lat(x,y,phi), lon+get_lon(x,y,phi), alt, alpha);}
+		{
+		create_medium_thunderstorm(lat+get_lat(x,y,phi), lon+get_lon(x,y,phi), alt, alpha);
+		var ts = local_weather.thunderstormHash.new (lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, 3000.0, 0.2);
+		append(local_weather.thunderstormArray,ts);	
+		}
 	else
-		{create_small_thunderstorm(lat+get_lat(x,y,phi), lon+get_lon(x,y,phi), alt, alpha);}
+		{
+		create_small_thunderstorm(lat+get_lat(x,y,phi), lon+get_lon(x,y,phi), alt, alpha);
+		var ts = local_weather.thunderstormHash.new (lat +get_lat(x,y,phi), lon + get_lon(x,y,phi), alt, 1000.0, 0.15);
+		append(local_weather.thunderstormArray,ts);
+		}
 	}
 
 # the convective layer
@@ -4315,6 +4331,10 @@ var strength = 0.10;
 var n = int(4000 * strength) * 0.5;
 local_weather.cumulus_exclusion_layer(lat, lon, alt, n, 20000.0, 20000.0, alpha, 0.3,2.5 , size(elat), elat, elon, erad);
 
+# some additional cloud cover
+
+create_4_8_sstratus_domains(lat, lon, alt,alpha);
+
 
 # some turbulence in the convection layer
 

Shaders/3dcloud-ALS.vert

@@ -13,6 +13,10 @@ uniform float cloud_self_shading;
 uniform float visibility;
 uniform float moonlight;
 uniform float air_pollution;
+uniform float flash;
+uniform float lightning_pos_x;
+uniform float lightning_pos_y;
+uniform float lightning_range;
 
 attribute vec3 usrAttr1;
 attribute vec3 usrAttr2;
@@ -171,10 +175,21 @@ void main(void)
      
     }
 
+
+
     gl_FrontColor.rgb = intensity * shade * normalize(mix(light_diffuse.rgb, shadedFogColor, smoothstep(0.1,0.4, (1.0 - shade)  ))) ; 
      
+    // lightning
+    vec2 lightningRelVector = relVector.xy - vec2(lightning_pos_x, lightning_pos_y);
+    float rCoord = length(lightningRelVector);
 
 
+    float rn = 0.5 + 0.5 * fract(gl_Color.x);
+    gl_FrontColor.rgb += flash * vec3 (0.43, 0.57, 1.0) * (1.0 - smoothstep(lightning_range, 5.0 * lightning_range, rCoord)) * rn;
+    
+    
+    // fading of cloudlets
+
     if ((fogCoord > (0.9 * detail_range)) && (fogCoord > center_dist) && (shade_factor < 0.7)) {
       // cloudlet is almost at the detail range, so fade it out.
       gl_FrontColor.a = 1.0 - smoothstep(0.9 * detail_range, detail_range, fogCoord);

Shaders/model-interior-ALS-detailed.vert

@@ -230,7 +230,7 @@ else // the faster, full-day version without lightfields
     yprime_alt = -sqrt(2.0 * EarthRadius * hazeLayerAltitude);
 }
  
-// irradiance mapping
+// irradiance mapping for ambient light
   
   float ambient_irradiance_factor = 1.0;
   float steepness = dot(normalize(gl_Normal), vec3 (0.0, 0.0, 1.0));
@@ -253,6 +253,8 @@ else // the faster, full-day version without lightfields
 
   light_ambient = light_ambient * ambient_irradiance_factor;
 
+// residual ambience - comes with its own irradiance map
+
   vec3 residual_ambience = vec3 (residual_ambience_r, residual_ambience_g, residual_ambience_b);
 
   ambient_irradiance_factor = 1.0;
@@ -272,7 +274,10 @@ else // the faster, full-day version without lightfields
 	ambient_irradiance_factor = (1.0 - ra_irradiance_map_strength) + 1.5 * ra_irradiance_map_strength * (1.0 - abs(steepness)) * (0.5 + 0.5 * forwardness);
 	}
 
-  light_ambient.rgb += residual_ambience.rgb * ambient_irradiance_factor;
+  // make sure the residual ambience is only visible when it's dark enough 
+  float residual_fraction = length(residual_ambience.rgb) / (length(light_ambient.rgb + residual_ambience.rgb) + 0.01);
+
+  light_ambient.rgb += residual_ambience.rgb * ambient_irradiance_factor * smoothstep(0.4, 0.6, residual_fraction);
 
 // default lighting based on texture and material using the light we have just computed
 

Shaders/rain-layer-ALS.vert

@@ -8,6 +8,10 @@ uniform float range; // From /sim/rendering/clouds3d-vis-range
 uniform float scattering;
 uniform float terminator;
 uniform float altitude;
+uniform float flash;
+uniform float lightning_pos_x;
+uniform float lightning_pos_y;
+uniform float lightning_range;
 
 
 float shade = 0.8;
@@ -88,6 +92,18 @@ void main(void)
   gl_FrontColor = mix(backlight, gl_LightSource[0].diffuse, n);
   gl_FrontColor += gl_FrontLightModelProduct.sceneColor;
 
+ // two times terminator width governs how quickly light fades into shadow
+  float terminator_width = 200000.0;
+  float earthShade = 0.9 * smoothstep(terminator_width+ terminator, -terminator_width + terminator, yprime_alt) + 0.1;
+  gl_FrontColor.rgb = gl_FrontColor.rgb * earthShade;
+
+  // lightning
+  vec2 lightningRelVector = relVector.xy - vec2(lightning_pos_x, lightning_pos_y);
+  float rCoord = length(lightningRelVector);
+
+    gl_FrontColor.rgb += 2.0 * flash * vec3 (0.43, 0.57, 1.0) * (1.0 - smoothstep(lightning_range, 5.0 * lightning_range, rCoord));
+    gl_FrontColor.rgb = clamp(gl_FrontColor.rgb,0.0,1.0);
+
   // As we get within 100m of the sprite, it is faded out. Equally at large distances it also fades out.
   gl_FrontColor.a = min(smoothstep(100.0, 250.0, fogCoord), 1.0 - smoothstep(range*0.9, range, fogCoord));
   gl_BackColor = gl_FrontColor;
@@ -100,7 +116,7 @@ float fadeScale = 0.05 + 0.2 * log(fogCoord/1000.0);
   if (fadeScale < 0.05) fadeScale = 0.05;
   fogFactor = exp( -gl_Fog.density * 1.0 * fogCoord * fadeScale);
 
-  hazeColor = light_diffuse.xyz;
+  hazeColor = light_diffuse.rgb;
   hazeColor.x = hazeColor.x * 0.83;
   hazeColor.y = hazeColor.y * 0.9; 
   hazeColor = hazeColor * scattering;
@@ -109,14 +125,9 @@ float fadeScale = 0.05 + 0.2 * log(fogCoord/1000.0);
   intensity = length(hazeColor);
   hazeColor = intensity * normalize(mix(hazeColor,  2.0 * vec3 (0.55, 0.6, 0.8), (1.0-smoothstep(0.3,0.8,scattering)))); 
 
- // two times terminator width governs how quickly light fades into shadow
-  float terminator_width = 200000.0;
 
-  // now dim the light
-  float earthShade = 0.9 * smoothstep(terminator_width+ terminator, -terminator_width + terminator, yprime_alt) + 0.1;
 
-  hazeColor = hazeColor * earthShade;
+  hazeColor = clamp(hazeColor * earthShade, 0.0,1.0);
-  gl_FrontColor.xyz = gl_FrontColor.xyz * earthShade;
+
-  gl_BackColor = gl_FrontColor;
 
 }