2 files changed, 8 insertions, 5 deletions
diff --git a/indra/newview/app_settings/shaders/class1/deferred/cloudsF.glsl b/indra/newview/app_settings/shaders/class1/deferred/cloudsF.glsl
index 60ccfa64db..3fcb416601 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/cloudsF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/cloudsF.glsl
@@ -51,6 +51,7 @@ VARYING vec2 vary_texcoord0;
 VARYING vec2 vary_texcoord1;
 VARYING vec2 vary_texcoord2;
 VARYING vec2 vary_texcoord3;
+VARYING float altitude_blend_factor;
 
 /// Soft clips the light with a gamma correction
 vec3 scaleSoftClip(vec3 light);
@@ -102,10 +103,8 @@ void main()
     alpha1 = 1. - alpha1 * alpha1;
     alpha1 = 1. - alpha1 * alpha1;  
 
-    if (alpha1 < 0.001f)
-    {
-        discard;
-    }
+    alpha1 *= altitude_blend_factor;
+    alpha1 = clamp(alpha1, 0.0, 1.0);
 
     // Compute alpha2, for self shadowing effect
     // (1 - alpha2) will later be used as percentage of incoming sunlight
@@ -119,6 +118,7 @@ void main()
     // Combine
     vec4 color;
     color = (cloudColorSun*(1.-alpha2) + cloudColorAmbient);
+    color.rgb= max(vec3(0), color.rgb);
     color *= 2.;
 
     /// Gamma correct for WL (soft clip effect).
diff --git a/indra/newview/app_settings/shaders/class1/deferred/cloudsV.glsl b/indra/newview/app_settings/shaders/class1/deferred/cloudsV.glsl
index 4beb334f5a..cfe5632ec0 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/cloudsV.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/cloudsV.glsl
@@ -41,6 +41,7 @@ VARYING vec2 vary_texcoord0;
 VARYING vec2 vary_texcoord1;
 VARYING vec2 vary_texcoord2;
 VARYING vec2 vary_texcoord3;
+VARYING float altitude_blend_factor;
 
 // Inputs
 uniform vec3 camPosLocal;
@@ -77,12 +78,15 @@ void main()
 	// Get relative position
 	vec3 P = position.xyz - camPosLocal.xyz + vec3(0,50,0);
 
+        altitude_blend_factor = (P.y > -4096.0) ? 1.0 : 1.0 - clamp(abs(P.y) / max_y, 0.0, 1.0);
+
 	// Set altitude
 	if (P.y > 0.)
 	{
 		P *= (max_y / P.y);
 	}
 	else
+        if (P.y <= 0.0)
 	{
 		P *= (-32000. / P.y);
 	}
@@ -122,7 +126,6 @@ void main()
 	// compiler gets confused.
 	temp1 = exp(-temp1 * temp2.z);
 
-
 	// Compute haze glow
 	temp2.x = dot(Pn, lightnorm.xyz);
 	temp2.x = 1. - temp2.x;