diff --git a/Effects/cloud.eff b/Effects/cloud.eff
index ae8a04c7f..33c0842dc 100644
--- a/Effects/cloud.eff
+++ b/Effects/cloud.eff
@@ -29,6 +29,189 @@
<display_ysize><use>/sim/startup/ysize</use></display_ysize>
</parameters>
+ <technique n="8">
+ <predicate>
+ <and>
+ <property>/sim/rendering/shaders/skydome</property>
+ <less-equal>
+ <value type="float">1.0</value>
+ <shader-language/>
+ </less-equal>
+ <less-equal>
+ <value type="float">1.0</value>
+ <float-property>/sim/rendering/shaders/clouds</float-property>
+ </less-equal>
+ </and>
+ </predicate>
+ <pass n="0">
+ <!-- This is apparently not used, so maybe we'll blow it way soon. -->
+ <lighting>true</lighting>
+ <material>
+ <ambient type="vec4d">0.5 0.5 0.5 1.0</ambient>
+ <diffuse type="vec4d">0.5 0.5 0.5 1.0</diffuse>
+ <color-mode>off</color-mode>
+ </material>
+ <alpha-test>
+ <comparison>greater</comparison>
+ <reference type="float">0.01</reference>
+ </alpha-test>
+ <shade-model>smooth</shade-model>
+ <blend>
+ <source>src-alpha</source>
+ <destination>one-minus-src-alpha</destination>
+ </blend>
+ <depth>
+ <write-mask>false</write-mask>
+ </depth>
+ <render-bin>
+ <bin-number>10</bin-number>
+ <bin-name>DepthSortedBin</bin-name>
+ </render-bin>
+ <texture-unit>
+ <unit>0</unit>
+ <type>2d</type>
+ <image><use>texture[0]/image</use></image>
+ <wrap-s>clamp</wrap-s>
+ <wrap-t>clamp</wrap-t>
+ </texture-unit>
+ <program>
+ <vertex-shader>Shaders/3dcloud-ALS-detailed.vert</vertex-shader>
+ <fragment-shader>Shaders/3dcloud-ALS-detailed.frag</fragment-shader>
+ <fragment-shader>Shaders/filters-ALS.frag</fragment-shader>
+ <fragment-shader>Shaders/noise.frag</fragment-shader>
+ <attribute>
+ <name>usrAttr1</name>
+ <index>10</index>
+ </attribute>
+ <attribute>
+ <name>usrAttr2</name>
+ <index>11</index>
+ </attribute>
+ </program>
+ <uniform>
+ <name>baseTexture</name>
+ <type>sampler-2d</type>
+ <value type="int">0</value>
+ </uniform>
+ <uniform>
+ <name>range</name>
+ <type>float</type>
+ <value><use>range</use></value>
+ </uniform>
+ <uniform>
+ <name>detail_range</name>
+ <type>float</type>
+ <value><use>detail</use></value>
+ </uniform>
+ <uniform>
+ <name>scattering</name>
+ <type>float</type>
+ <value><use>scattering</use></value>
+ </uniform>
+ <uniform>
+ <name>terminator</name>
+ <type>float</type>
+ <value><use>terminator</use></value>
+ </uniform>
+ <uniform>
+ <name>altitude</name>
+ <type>float</type>
+ <value><use>altitude</use></value>
+ </uniform>
+ <uniform>
+ <name>cloud_self_shading</name>
+ <type>float</type>
+ <value><use>cloud_self_shading</use></value>
+ </uniform>
+ <uniform>
+ <name>moonlight</name>
+ <type>float</type>
+ <value><use>moonlight</use></value>
+ </uniform>
+ <uniform>
+ <name>air_pollution</name>
+ <type>float</type>
+ <value><use>air_pollution</use></value>
+ </uniform>
+ <uniform>
+ <name>visibility</name>
+ <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>
+ <uniform>
+ <name>gamma</name>
+ <type>float</type>
+ <value><use>gamma</use></value>
+ </uniform>
+ <uniform>
+ <name>brightness</name>
+ <type>float</type>
+ <value><use>brightness</use></value>
+ </uniform>
+ <uniform>
+ <name>use_filtering</name>
+ <type>bool</type>
+ <value><use>use_filtering</use></value>
+ </uniform>
+ <uniform>
+ <name>use_night_vision</name>
+ <type>bool</type>
+ <value><use>use_night_vision</use></value>
+ </uniform>
+ <uniform>
+ <name>use_IR_vision</name>
+ <type>bool</type>
+ <value><use>use_IR_vision</use></value>
+ </uniform>
+ <uniform>
+ <name>delta_T</name>
+ <type>float</type>
+ <value><use>delta_T</use></value>
+ </uniform>
+ <uniform>
+ <name>fact_grey</name>
+ <type>float</type>
+ <value><use>fact_grey</use></value>
+ </uniform>
+ <uniform>
+ <name>fact_black</name>
+ <type>float</type>
+ <value><use>fact_black</use></value>
+ </uniform>
+ <uniform>
+ <name>display_xsize</name>
+ <type>int</type>
+ <value><use>display_xsize</use></value>
+ </uniform>
+ <uniform>
+ <name>display_ysize</name>
+ <type>int</type>
+ <value><use>display_ysize</use></value>
+ </uniform>
+ <!--<vertex-program-two-side>true</vertex-program-two-side>-->
+ </pass>
+ </technique>
+
<technique n="9">
<predicate>
<and>
diff --git a/Shaders/3dcloud-ALS-detailed.frag b/Shaders/3dcloud-ALS-detailed.frag
new file mode 100644
index 000000000..61c627d7f
--- /dev/null
+++ b/Shaders/3dcloud-ALS-detailed.frag
@@ -0,0 +1,84 @@
+#version 120
+
+uniform sampler2D baseTexture;
+uniform float scattering;
+
+varying float fogFactor;
+varying float mie_frag;
+varying float mie_frag_mod;
+varying float z_pos;
+varying float bottom_shade;
+
+varying vec3 internal_pos;
+varying vec3 hazeColor;
+
+vec3 filter_combined (in vec3 color) ;
+
+void main(void)
+{
+ vec4 base = texture2D( baseTexture, gl_TexCoord[0].st);
+ if (base.a < 0.02)
+ discard;
+
+ float mie_factor = 0.0;
+ float geo_factor = 1.0;
+
+ float mie_sign = 1.0;
+ if (mie_frag < 0.0) {mie_sign = -1.0;}
+
+ if (mie_sign > 0.0)
+ {mie_factor = smoothstep(0.8, 1.0, mie_frag);}
+ else
+ {mie_factor = -1.0 * (1.0 - smoothstep(-1.0, -0.8, mie_frag));}
+
+ mie_factor *= mie_frag_mod;
+
+ // suppress effect in cloud center
+
+ float z_bias = 0.2 * (1.0 - smoothstep(2.0, 3.0, z_pos));
+
+ geo_factor *= smoothstep(-0.9 - z_bias, -0.4 - z_bias, internal_pos.x) * (1.0 -smoothstep(0.4 + z_bias, 0.9 + z_bias, internal_pos.x));
+ geo_factor *= smoothstep(-0.9 - z_bias, -0.4 - z_bias, internal_pos.y) * (1.0 -smoothstep(0.4 + z_bias, 0.9 + z_bias, internal_pos.y));
+ geo_factor *= smoothstep(0, 0.3, internal_pos.z) * (1.0 - smoothstep(0.5, 1.2, internal_pos.z));
+
+ if (mie_sign > 0.0)
+ {
+ mie_factor *=(1.0 -geo_factor);
+ }
+
+ float transparency = smoothstep(0.0, 0.7, base.a);
+ float opacity = smoothstep(0.7, 1.0, base.a);
+
+ float inverse_mie = 0.0;
+
+ if ((opacity == 0.0) && (mie_sign > 0.0)) // Mie forward scattering enhancing light
+ {mie_factor *= (1.0 - pow(transparency, 2.0));}
+ else if ((opacity == 0.0) && (mie_sign < 0.0)) // Mie forward scattering reducing reflected light
+ {
+ inverse_mie = (1.0 - pow(transparency, 2.0)) * smoothstep(0.65, 0.8, scattering);
+ inverse_mie *= (1.0 - smoothstep(-1.0, -0.5, mie_frag));
+ }
+ else if (mie_sign > 0.0) // bulk light absorption
+ {mie_factor *= - 4.0 * pow(opacity, 2.0);}
+
+
+ // darken the bulk of the away-facing cloud
+
+ float bulk_shade_factor = (1.0 - 0.6 * geo_factor * smoothstep(0.5, 1.0, mie_frag));
+ bulk_shade_factor -= 0.3 * smoothstep(0.5, 1.0, mie_frag) * (1.0 - mie_frag_mod) * (1.0 - smoothstep(0.4, 0.5, bottom_shade));
+
+
+ float mie_enhancement = 1.0 + clamp(mie_factor, 0.0, 1.0);
+ mie_enhancement = mie_enhancement * bulk_shade_factor;
+
+ vec4 finalColor = base * gl_Color;
+ finalColor.rgb *= mie_enhancement * (1.0 - 0.4 * inverse_mie);
+ finalColor.rgb = max(finalColor.rgb, gl_Color.rgb * 1.2 * bottom_shade);
+
+ finalColor.rgb = mix(hazeColor, finalColor.rgb, fogFactor );
+ finalColor.rgb = filter_combined(finalColor.rgb);
+
+
+ gl_FragColor.rgb = finalColor.rgb;
+ gl_FragColor.a = mix(0.0, finalColor.a, 1.0 - 0.5 * (1.0 - fogFactor));
+}
diff --git a/Shaders/3dcloud-ALS-detailed.vert b/Shaders/3dcloud-ALS-detailed.vert
new file mode 100644
index 000000000..946d06023
--- /dev/null
+++ b/Shaders/3dcloud-ALS-detailed.vert
@@ -0,0 +1,293 @@
+// -*-C++-*-
+#version 120
+
+varying float fogFactor;
+varying vec3 hazeColor;
+varying float mie_frag;
+varying float mie_frag_mod;
+varying vec3 internal_pos;
+varying float bottom_shade;
+varying float z_pos;
+
+uniform float range; // From /sim/rendering/clouds3d-vis-range
+uniform float detail_range; // From /sim/rendering/clouds3d_detail-range
+uniform float scattering;
+uniform float terminator;
+uniform float altitude;
+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;
+
+float alpha_factor = usrAttr1.r;
+float shade_factor = usrAttr1.g;
+float cloud_height = usrAttr1.b;
+float bottom_factor = usrAttr2.r;
+float middle_factor = usrAttr2.g;
+float top_factor = usrAttr2.b;
+
+const float EarthRadius = 5800000.0;
+
+// light_func is a generalized logistic function fit to the light intensity as a function
+// of scaled terminator position obtained from Flightgear core
+
+float light_func (in float x, in float a, in float b, in float c, in float d, in float e)
+{
+x = x-0.5;
+
+
+// use the asymptotics to shorten computations
+if (x > 30.0) {return e;}
+if (x < -15.0) {return 0.03;}
+
+
+return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d));
+}
+
+
+float mie_func (in float x, in float Mie)
+{
+return x + 2.0 * x * Mie * (1.0 -0.8*x) * (1.0 -0.8*x);
+}
+
+void main(void)
+{
+
+
+ //shade_factor = shade_factor * cloud_self_shading;
+ //top_factor = top_factor * cloud_self_shading;
+ //shade_factor = min(shade_factor, top_factor);
+ //middle_factor = min(middle_factor, top_factor);
+ //bottom_factor = min(bottom_factor, top_factor);
+
+ float intensity;
+ float mix_factor;
+
+ bottom_shade = bottom_factor;
+
+ vec3 shadedFogColor = vec3(0.55, 0.67, 0.88);
+ vec3 moonLightColor = vec3 (0.095, 0.095, 0.15) * moonlight * scattering;
+ gl_TexCoord[0] = gl_MultiTexCoord0;
+ vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0);
+ vec4 l = gl_ModelViewMatrixInverse * vec4(0.0,0.0,1.0,1.0);
+ vec3 u = normalize(ep.xyz - l.xyz);
+
+ // Find a rotation matrix that rotates 1,0,0 into u. u, r and w are
+ // the columns of that matrix.
+ vec3 absu = abs(u);
+ vec3 r = normalize(vec3(-u.y, u.x, 0.0));
+ vec3 w = cross(u, r);
+
+ // Do the matrix multiplication by [ u r w pos]. Assume no
+ // scaling in the homogeneous component of pos.
+ gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+ gl_Position.xyz = gl_Vertex.x * u;
+ gl_Position.xyz += gl_Vertex.y * r;
+ gl_Position.xyz += gl_Vertex.z * w;
+ // Apply Z scaling to allow sprites to be squashed in the z-axis
+ gl_Position.z = gl_Position.z * gl_Color.w;
+
+ // Now shift the sprite to the correct position in the cloud.
+ gl_Position.xyz += gl_Color.xyz;
+
+ internal_pos = gl_Position.xyz/ cloud_height;
+
+
+ // Determine a lighting normal based on the vertex position from the
+ // center of the cloud, so that sprite on the opposite side of the cloud to the sun are darker.
+ float n = dot(normalize(-gl_LightSource[0].position.xyz),
+ normalize(vec3(gl_ModelViewMatrix * vec4(- gl_Position.x, - gl_Position.y, - gl_Position.z, 0.0))));
+
+ // prepare suppression of shadeward Mie terms
+ float n1 = dot(normalize(-gl_LightSource[0].position.xyz),
+ normalize(vec3(gl_ModelViewMatrix * vec4(- gl_Color.x, - gl_Color.y, - gl_Color.z, 0.0))));
+
+ //z_pos = dot(normalize(-gl_LightSource[0].position.xyz),
+ // vec3(gl_ModelViewMatrix * vec4(- gl_Position.x, - gl_Position.y, - gl_Position.z, 0.0)))/cloud_height;
+
+
+ float mie_suppress = smoothstep(0.0, 0.3, n1);
+
+ // Determine the position - used for fog and shading calculations
+ float fogCoord = length(vec3(gl_ModelViewMatrix * vec4(gl_Color.x, gl_Color.y, gl_Color.z, 1.0)));
+ float center_dist = length(vec3(gl_ModelViewMatrix * vec4(0.0,0.0,0.0,1.0)));
+
+ z_pos = (fogCoord - center_dist)/cloud_height;
+
+ if ((fogCoord > detail_range) && (fogCoord > center_dist) && (shade_factor < 0.7)) {
+ // More than detail_range away, so discard all sprites on opposite side of
+ // cloud center by shifting them beyond the view fustrum
+ gl_Position = vec4(0.0,0.0,10.0,1.0);
+ gl_FrontColor.a = 0.0;
+ } else {
+
+ // Determine the shading of the vertex. We shade it based on it's position
+ // in the cloud relative to the sun, and it's vertical position in the cloud.
+ float shade = mix(shade_factor, top_factor, smoothstep(-0.3, 0.3, n));
+ //if (n < 0) {
+ // shade = mix(top_factor, shade_factor, abs(n));
+ //}
+
+ if (gl_Position.z < 0.5 * cloud_height) {
+ shade = min(shade, mix(bottom_factor, middle_factor, gl_Position.z * 2.0 / cloud_height));
+ } else {
+ shade = min(shade, mix(middle_factor, top_factor, gl_Position.z * 2.0 / cloud_height - 1.0));
+ }
+
+ //float h = gl_Position.z / cloud_height;
+ //if (h < 0.5) {
+ // shade = min(shade, mix(bottom_factor, middle_factor, smoothstep(0.0, 0.5, h)));
+ //} else {
+ // shade = min(shade, mix(middle_factor, top_factor, smoothstep(2.0 * (h - 0.5)));
+ // }
+
+ // Final position of the sprite
+ vec3 relVector = gl_Position.xyz - ep.xyz;
+ gl_Position = gl_ModelViewProjectionMatrix * gl_Position;
+
+
+ // Light at the final position
+
+ // first obtain normal to sun position
+
+ vec3 lightFull = (gl_ModelViewMatrixInverse * gl_LightSource[0].position).xyz;
+ vec3 lightHorizon = normalize(vec3(lightFull.x,lightFull.y, 0.0));
+
+
+
+ // yprime is the distance of the vertex into sun direction, corrected for altitude
+ // the altitude correction is clamped to reasonable values, sometimes altitude isn't parsed correctly, leading
+ // to overbright or overdark clouds
+ // float vertex_alt = clamp(altitude * 0.30480 + relVector.z,1000.0,10000.0);
+ float vertex_alt = clamp(altitude + relVector.z, 300.0, 10000.0);
+ float yprime = -dot(relVector, lightHorizon);
+ float yprime_alt = yprime -sqrt(2.0 * EarthRadius * vertex_alt);
+
+ // two times terminator width governs how quickly light fades into shadow
+ float terminator_width = 200000.0;
+ float earthShade = 1.0- 0.9* smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt);
+ float earthShadeFactor = 1.0 - smoothstep(0.4, 0.5, earthShade);
+
+ // compute the light at the position
+ vec4 light_diffuse;
+
+ float lightArg = (terminator-yprime_alt)/100000.0;
+
+ light_diffuse.b = light_func(lightArg -1.2 * air_pollution, 1.330e-05, 0.264, 2.227, 1.08e-05, 1.0);
+ light_diffuse.g = light_func(lightArg -0.6 * air_pollution, 3.931e-06, 0.264, 3.827, 7.93e-06, 1.0);
+ light_diffuse.r = light_func(lightArg, 8.305e-06, 0.161, 3.827, 3.04e-05, 1.0);
+ light_diffuse.a = 1.0;
+
+ //light_diffuse *= cloud_self_shading;
+ intensity = (1.0 - (0.8 * (1.0 - earthShade))) * length(light_diffuse.rgb);
+ light_diffuse.rgb = intensity * normalize(mix(light_diffuse.rgb, shadedFogColor, (1.0 - smoothstep(0.5,0.9, min(scattering, cloud_self_shading) ))));
+
+ // correct ambient light intensity and hue before sunrise
+ if (earthShade < 0.6)
+ {
+ light_diffuse.rgb = intensity * normalize(mix(light_diffuse.rgb, shadedFogColor, 1.0 -smoothstep(0.1, 0.6,earthShade ) ));
+
+ }
+
+
+
+ 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);
+
+ vec3 flash_color = vec3 (0.43, 0.57, 1.0);
+ float flash_factor = flash;
+
+ if (flash == 2)
+ {
+ flash_color = vec3 (0.8, 0.7, 0.4);
+ flash_factor = 1;
+ }
+
+ float rn = 0.5 + 0.5 * fract(gl_Color.x);
+ gl_FrontColor.rgb += flash_factor * flash_color * (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);
+ } else {
+ // 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(10.0, 100.0, fogCoord), 1.0 - smoothstep(0.9 * range, range, fogCoord));
+ }
+ gl_FrontColor.a = gl_FrontColor.a * (1.0 - smoothstep(visibility, 3.0* visibility, fogCoord));
+
+ fogFactor = exp(-fogCoord/visibility);
+
+ // haze of ground haze shader is slightly bluish
+ hazeColor = light_diffuse.rgb;
+ hazeColor.r = hazeColor.r * 0.83;
+ hazeColor.g = hazeColor.g * 0.9;
+ hazeColor = hazeColor * scattering;
+
+
+ // Mie correction
+ float Mie = 0.0;
+ float MieFactor = dot(normalize(lightFull), normalize(relVector));
+
+
+ mie_frag = MieFactor;
+ mie_frag_mod = mie_suppress * (1.0 - smoothstep(0.4, 0.6, bottom_factor)) * (1.0 - smoothstep(detail_range, 1.5 * detail_range, fogCoord)) * smoothstep(0.65, 0.8, scattering)
+ * smoothstep(0.7, 1.0, top_factor);
+
+
+ if (bottom_factor < 0.4) {mie_frag_mod = 0.0;}
+
+ if (bottom_factor > 0.4)
+ {
+ MieFactor = dot(normalize(lightFull), normalize(relVector));
+ Mie = 1.5 * smoothstep(0.9,1.0, MieFactor) * smoothstep(0.6, 0.8, bottom_factor) * (1.0-earthShadeFactor) ;
+ //if (MieFactor < 0.0) {Mie = - Mie;}
+ }
+ //else {Mie = 0.0;}
+
+ if (Mie > 0.0)
+ {
+ hazeColor.r = mie_func(hazeColor.r, Mie);
+ hazeColor.g = mie_func(hazeColor.g, 0.8* Mie);
+ hazeColor.b = mie_func(hazeColor.b, 0.5* Mie);
+
+ gl_FrontColor.r = mie_func(gl_FrontColor.r, Mie);
+ gl_FrontColor.g = mie_func(gl_FrontColor.g, 0.8* Mie);
+ gl_FrontColor.b = mie_func(gl_FrontColor.b, 0.5*Mie);
+ }
+ else if (MieFactor < 0.0)
+ {
+ float thickness_reduction = smoothstep(0.4, 0.8, bottom_factor) ;
+ float light_reduction = dot (lightFull, lightHorizon);
+ light_reduction *= light_reduction;
+
+ float factor_b = 0.8 + 0.2 * (1.0 - smoothstep(0.0, 0.7, -MieFactor) * thickness_reduction * light_reduction) ;
+ float factor_r = 0.6 + 0.4 * (1.0 - smoothstep(0.0, 0.7, -MieFactor) * thickness_reduction * light_reduction) ;
+ float factor_g = 0.65 + 0.35 * (1.0 - smoothstep(0.0, 0.7, -MieFactor) * thickness_reduction * light_reduction) ;
+ hazeColor.r *= factor_r;
+ hazeColor.g *= factor_g;
+ hazeColor.b *= factor_b;
+
+ gl_FrontColor.r *= factor_r;
+ gl_FrontColor.g *= factor_g;
+ gl_FrontColor.b *= factor_b;
+ }
+
+ gl_FrontColor.rgb = gl_FrontColor.rgb + moonLightColor * earthShadeFactor;
+ hazeColor.rgb = hazeColor.rgb + moonLightColor * earthShadeFactor;
+ gl_FrontColor.a = gl_FrontColor.a * alpha_factor;
+ gl_BackColor = gl_FrontColor;
+ }
+}
diff --git a/defaults.xml b/defaults.xml
index 40e436971..d40f7d2f5 100644
--- a/defaults.xml
+++ b/defaults.xml
@@ -128,6 +128,7 @@ Started September 2000 by David Megginson, david@megginson.com
<filtering type="int">8</filtering>
<shaders>
<custom-settings type="bool" userarchive="y">false</custom-settings>
+ <clouds type="float" userarchive="y">0.0</clouds>
<generic type="float" userarchive="y">1.0</generic>
<landmass type="float" userarchive="y">1.0</landmass>
<model type="float" userarchive="y">1.0</model>
diff --git a/gui/dialogs/shaders-lightfield.xml b/gui/dialogs/shaders-lightfield.xml
index edc13c1a4..58f7ae83f 100644
--- a/gui/dialogs/shaders-lightfield.xml
+++ b/gui/dialogs/shaders-lightfield.xml
@@ -45,6 +45,32 @@
</hrule>
</group>
+ <group>
+ <layout>hbox</layout>
+ <halign>right</halign>
+
+ <text>
+ <halign>left</halign>
+ <label>Clouds</label>
+ </text>
+ <slider>
+ <name>cloud</name>
+ <min>0.0</min>
+ <max>1.0</max>
+ <step>1.0</step>
+ <fraction>0.17</fraction>
+ <live>true</live>
+ <property>/sim/rendering/shaders/clouds</property>
+ <binding>
+ <command>dialog-apply</command>
+ <object-name>cloud</object-name>
+ </binding>
+ </slider>
+ <empty>
+ <pref-width>55</pref-width>
+ </empty>
+ </group>
+
<group>
<layout>hbox</layout>
<halign>right</halign>