SL-19538 Followup -- scrub all possible sources of NaNs, make dynamic exposure controls not persist, limit exposure range, and do a debug gl pass.

47 files changed, 70 insertions, 101 deletions

diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index 44a86dd22a..7d15214ccb 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -10452,7 +10452,7 @@
     <key>Comment</key>
     <string>Amount to over-brighten sun for HDR effect during the day</string>
     <key>Persist</key>
-    <integer>1</integer>
+    <integer>0</integer>
     <key>Type</key>
     <string>F32</string>
     <key>Value</key>
@@ -10463,7 +10463,7 @@
     <key>Comment</key>
     <string>Maximum effective probe ambiance for local lights</string>
     <key>Persist</key>
-    <integer>1</integer>
+    <integer>0</integer>
     <key>Type</key>
     <string>F32</string>
     <key>Value</key>
@@ -10474,7 +10474,7 @@
     <key>Comment</key>
     <string>Minimum dynamic exposure amount</string>
     <key>Persist</key>
-    <integer>1</integer>
+    <integer>0</integer>
     <key>Type</key>
     <string>F32</string>
     <key>Value</key>
@@ -10485,7 +10485,7 @@
     <key>Comment</key>
     <string>Maximum dynamic exposure amount</string>
     <key>Persist</key>
-    <integer>1</integer>
+    <integer>0</integer>
     <key>Type</key>
     <string>F32</string>
     <key>Value</key>
@@ -10496,7 +10496,7 @@
     <key>Comment</key>
     <string>Luminance coefficient for dynamic exposure</string>
     <key>Persist</key>
-    <integer>1</integer>
+    <integer>0</integer>
     <key>Type</key>
     <string>F32</string>
     <key>Value</key>
diff --git a/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl b/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl
index 93a85cad40..cc79b450ac 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/blurLightF.glsl
@@ -115,7 +115,7 @@ void main()
     col /= defined_weight.xyxx;
     //col.y *= col.y;
     
-    frag_color = col;
+    frag_color = max(col, vec4(0));
 
 #ifdef IS_AMD_CARD
     // If it's AMD make sure the GLSL compiler sees the arrays referenced once by static index. Otherwise it seems to optimise the storage awawy which leads to unfun crashes and artifacts.
diff --git a/indra/newview/app_settings/shaders/class1/deferred/bumpF.glsl b/indra/newview/app_settings/shaders/class1/deferred/bumpF.glsl
index 749ec3a6ac..c18bca066d 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/bumpF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/bumpF.glsl
@@ -25,11 +25,7 @@
 
 /*[EXTRA_CODE_HERE]*/
  
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform float minimum_alpha;
 uniform sampler2D diffuseMap;
@@ -65,4 +61,5 @@ void main()
 		//frag_data[1] = vec4(vec3(vertex_color.a), vertex_color.a+(1.0-vertex_color.a)*vertex_color.a); // spec - from former class3 - maybe better, but not so well tested
 		vec3 nvn = normalize(tnorm);
 		frag_data[2] = vec4(encode_normal(nvn), vertex_color.a, GBUFFER_FLAG_HAS_ATMOS);
+        frag_data[3] = vec4(0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
index 4bf16b50bf..aa61e10c7f 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/deferredUtil.glsl
@@ -531,7 +531,7 @@ vec3 pbrPunctual(vec3 diffuseColor, vec3 specularColor,
     specContrib *= NdotL;
     specContrib = max(specContrib, vec3(0));
 
-    return color;
+    return clamp(color, vec3(0), vec3(10));
 }
 
 vec3 pbrPunctual(vec3 diffuseColor, vec3 specularColor, 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskF.glsl b/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskF.glsl
index 3bf148502c..afc05b8bb5 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskF.glsl
@@ -25,11 +25,7 @@
 
 /*[EXTRA_CODE_HERE]*/
 
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform float minimum_alpha;
 
@@ -54,5 +50,6 @@ void main()
 	frag_data[1] = vec4(0,0,0,0); // spec
 	vec3 nvn = normalize(vary_normal);
 	frag_data[2] = vec4(encode_normal(nvn.xyz), 0.0, GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskIndexedF.glsl b/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskIndexedF.glsl
index e15239b59d..078197f9a8 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskIndexedF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskIndexedF.glsl
@@ -25,11 +25,7 @@
 
 /*[EXTRA_CODE_HERE]*/
 
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 VARYING vec3 vary_normal;
 
@@ -53,4 +49,5 @@ void main()
 	frag_data[1] = vec4(0,0,0,0);
 	vec3 nvn = normalize(vary_normal);
 	frag_data[2] = vec4(encode_normal(nvn.xyz), 0.0, GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskNoColorF.glsl b/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskNoColorF.glsl
index b0ff233414..307dda6b73 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskNoColorF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/diffuseAlphaMaskNoColorF.glsl
@@ -25,11 +25,7 @@
  
 /*[EXTRA_CODE_HERE]*/
 
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform float minimum_alpha;
 
@@ -53,5 +49,6 @@ void main()
 	frag_data[1] = vec4(0,0,0,0); // spec
 	vec3 nvn = normalize(vary_normal);
 	frag_data[2] = vec4(encode_normal(nvn.xyz), 0.0, GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/diffuseF.glsl b/indra/newview/app_settings/shaders/class1/deferred/diffuseF.glsl
index b2d2e2fa71..24e290c614 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/diffuseF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/diffuseF.glsl
@@ -25,11 +25,7 @@
 
 /*[EXTRA_CODE_HERE]*/
  
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform sampler2D diffuseMap;
 
@@ -47,5 +43,6 @@ void main()
 	//frag_data[1] = vec4(vec3(vertex_color.a), vertex_color.a+(1.0-vertex_color.a)*vertex_color.a); // spec - from former class3 - maybe better, but not so well tested
 	vec3 nvn = normalize(vary_normal);
 	frag_data[2] = vec4(encode_normal(nvn.xyz), vertex_color.a, GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/diffuseIndexedF.glsl b/indra/newview/app_settings/shaders/class1/deferred/diffuseIndexedF.glsl
index b4bc114dd5..be870b2424 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/diffuseIndexedF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/diffuseIndexedF.glsl
@@ -25,11 +25,7 @@
 
 /*[EXTRA_CODE_HERE]*/
 
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 VARYING vec3 vary_normal;
 VARYING vec4 vertex_color;
@@ -49,4 +45,5 @@ void main()
 	frag_data[1] = vec4(spec, vertex_color.a); // spec
 	vec3 nvn = normalize(vary_normal);
 	frag_data[2] = vec4(encode_normal(nvn.xyz), vertex_color.a, GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/deferred/emissiveF.glsl b/indra/newview/app_settings/shaders/class1/deferred/emissiveF.glsl
index fb97cd95b4..17e24a2bf2 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/emissiveF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/emissiveF.glsl
@@ -41,6 +41,6 @@ void main()
 	vec4 color = diffuseLookup(vary_texcoord0.xy)*vertex_color;
 	color.rgb = fullbrightAtmosTransport(color.rgb);
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
index 3eda2b9050..7ed8e4c8ce 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
@@ -55,6 +55,6 @@ void main()
 
     s = mix(prev, s, min(dt*2.0*abs(prev-s), 0.04));
     
-    frag_color = vec4(s, s, s, dt);
+    frag_color = max(vec4(s, s, s, dt), vec4(0.0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/fullbrightF.glsl b/indra/newview/app_settings/shaders/class1/deferred/fullbrightF.glsl
index 03df9fd4a1..b5eae3a1d5 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/fullbrightF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/fullbrightF.glsl
@@ -92,7 +92,6 @@ void main()
     
 #endif
 
-    frag_color.rgb = color.rgb;
-    frag_color.a   = color.a;
+    frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/highlightF.glsl b/indra/newview/app_settings/shaders/class1/deferred/highlightF.glsl
index 75f914cb02..74df43b7c3 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/highlightF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/highlightF.glsl
@@ -23,11 +23,7 @@
  * $/LicenseInfo$
  */
  
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform vec4 color;
 uniform sampler2D diffuseMap;
@@ -39,4 +35,5 @@ void main()
 	frag_data[0] = color*texture2D(diffuseMap, vary_texcoord0.xy);
 	frag_data[1] = vec4(0.0);
 	frag_data[2] = vec4(0.0, 1.0, 0.0, GBUFFER_FLAG_SKIP_ATMOS);
+    frag_data[3] = vec4(0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/deferred/impostorF.glsl b/indra/newview/app_settings/shaders/class1/deferred/impostorF.glsl
index 51afda2791..5e67442b3a 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/impostorF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/impostorF.glsl
@@ -25,11 +25,7 @@
 
 /*[EXTRA_CODE_HERE]*/
 
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform float minimum_alpha;
 
@@ -58,4 +54,5 @@ void main()
 	frag_data[0] = vec4(col.rgb, 0.0);
 	frag_data[1] = spec;
 	frag_data[2] = vec4(encode_normal(norm.xyz),0,GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/deferred/materialF.glsl b/indra/newview/app_settings/shaders/class1/deferred/materialF.glsl
index 4b98e6708f..4dee23372f 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/materialF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/materialF.glsl
@@ -32,7 +32,7 @@
 #if (DIFFUSE_ALPHA_MODE == DIFFUSE_ALPHA_MODE_BLEND)
 out vec4 frag_color;
 #else
-out vec4 frag_data[3];
+out vec4 frag_data[4];
 #endif
 
 void main()
@@ -44,6 +44,7 @@ void main()
     frag_data[0] = vec4(0.5, 0, 1, 0);    // gbuffer is sRGB for legacy materials
     frag_data[1] = vec4(0); // XYZ = Specular color. W = Specular exponent.
     frag_data[2] = vec4(0); // XY = Normal.  Z = Env. intensity. W = 1 skip atmos (mask off fog)
+    frag_data[3] = vec4(0);
 #endif
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/pbropaqueF.glsl b/indra/newview/app_settings/shaders/class1/deferred/pbropaqueF.glsl
index 6659e67a7a..8e5a6c90e0 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/pbropaqueF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/pbropaqueF.glsl
@@ -101,10 +101,10 @@ void main()
     //emissive = vNt * 0.5 + 0.5;
     //emissive = tnorm*0.5+0.5;
     // See: C++: addDeferredAttachments(), GLSL: softenLightF
-    frag_data[0] = vec4(col, 0.0);                                                   // Diffuse
-    frag_data[1] = vec4(spec.rgb,vertex_color.a);                                    // PBR linear packed Occlusion, Roughness, Metal.
-    frag_data[2] = vec4(encode_normal(tnorm), vertex_color.a, GBUFFER_FLAG_HAS_PBR); // normal, environment intensity, flags
-    frag_data[3] = vec4(emissive,0);                                                // PBR sRGB Emissive
+    frag_data[0] = max(vec4(col, 0.0), vec4(0));                                                   // Diffuse
+    frag_data[1] = max(vec4(spec.rgb,vertex_color.a), vec4(0));                                    // PBR linear packed Occlusion, Roughness, Metal.
+    frag_data[2] = max(vec4(encode_normal(tnorm), vertex_color.a, GBUFFER_FLAG_HAS_PBR), vec4(0)); // normal, environment intensity, flags
+    frag_data[3] = max(vec4(emissive,0), vec4(0));                                                // PBR sRGB Emissive
 }
 
 #else
diff --git a/indra/newview/app_settings/shaders/class1/deferred/postDeferredGammaCorrect.glsl b/indra/newview/app_settings/shaders/class1/deferred/postDeferredGammaCorrect.glsl
index bdbc0056f8..3cfad5498b 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/postDeferredGammaCorrect.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/postDeferredGammaCorrect.glsl
@@ -190,10 +190,7 @@ void main()
     vec3 seed = (diff.rgb+vec3(1.0))*vec3(tc.xy, tc.x+tc.y);
     vec3 nz = vec3(noise(seed.rg), noise(seed.gb), noise(seed.rb));
     diff.rgb += nz*0.003;
-    //diff.rgb = nz;
-
-    //float exp_sample = texture(exposureMap, vec2(0.5,0.5)).r;
-    //diff.g = exp_sample;
-    frag_color = diff;
+    
+    frag_color = max(diff, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/terrainF.glsl b/indra/newview/app_settings/shaders/class1/deferred/terrainF.glsl
index d6c14c48c9..3464212c84 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/terrainF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/terrainF.glsl
@@ -25,11 +25,7 @@
  
 /*[EXTRA_CODE_HERE]*/
 
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform sampler2D detail_0;
 uniform sampler2D detail_1;
@@ -64,5 +60,6 @@ void main()
     frag_data[1] = vec4(0.0,0.0,0.0,-1.0);
     vec3 nvn = normalize(vary_normal);
     frag_data[2] = vec4(encode_normal(nvn.xyz), 0.0, GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/treeF.glsl b/indra/newview/app_settings/shaders/class1/deferred/treeF.glsl
index dc0e5b0ce3..d857e47b90 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/treeF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/treeF.glsl
@@ -25,11 +25,7 @@
 
 /*[EXTRA_CODE_HERE]*/
 
-#ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
-#else
-#define frag_data gl_FragData
-#endif
+out vec4 frag_data[4];
 
 uniform sampler2D diffuseMap;
 
@@ -53,4 +49,5 @@ void main()
 	frag_data[1] = vec4(0,0,0,0);
 	vec3 nvn = normalize(vary_normal);
 	frag_data[2] = vec4(encode_normal(nvn.xyz), 0.0, GBUFFER_FLAG_HAS_ATMOS);
+    frag_data[3] = vec4(0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/effects/glowF.glsl b/indra/newview/app_settings/shaders/class1/effects/glowF.glsl
index c1f6af9f57..301e8aba26 100644
--- a/indra/newview/app_settings/shaders/class1/effects/glowF.glsl
+++ b/indra/newview/app_settings/shaders/class1/effects/glowF.glsl
@@ -56,5 +56,5 @@ void main()
 	col += kern[6] * texture2D(diffuseMap, vary_texcoord2.zw);	
 	col += kern[7] * texture2D(diffuseMap, vary_texcoord3.zw);	
 	
-	frag_color = vec4(col.rgb * glowStrength, col.a);
+	frag_color = max(vec4(col.rgb * glowStrength, col.a), vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/interface/alphamaskF.glsl b/indra/newview/app_settings/shaders/class1/interface/alphamaskF.glsl
index f520f301d9..69c1983b4d 100644
--- a/indra/newview/app_settings/shaders/class1/interface/alphamaskF.glsl
+++ b/indra/newview/app_settings/shaders/class1/interface/alphamaskF.glsl
@@ -44,5 +44,5 @@ void main()
 		discard;
 	}
 
-	frag_color = col;
+	frag_color = max(col, vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/interface/clipF.glsl b/indra/newview/app_settings/shaders/class1/interface/clipF.glsl
index ac2bc8703b..9454bbf21e 100644
--- a/indra/newview/app_settings/shaders/class1/interface/clipF.glsl
+++ b/indra/newview/app_settings/shaders/class1/interface/clipF.glsl
@@ -42,5 +42,5 @@ void main()
 		discard;
 	}
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/interface/debugF.glsl b/indra/newview/app_settings/shaders/class1/interface/debugF.glsl
index 67c6baddbb..cb8d6a8c03 100644
--- a/indra/newview/app_settings/shaders/class1/interface/debugF.glsl
+++ b/indra/newview/app_settings/shaders/class1/interface/debugF.glsl
@@ -33,5 +33,5 @@ uniform vec4 color;
 
 void main() 
 {
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/interface/gaussianF.glsl b/indra/newview/app_settings/shaders/class1/interface/gaussianF.glsl
index 188fac5460..eca591d387 100644
--- a/indra/newview/app_settings/shaders/class1/interface/gaussianF.glsl
+++ b/indra/newview/app_settings/shaders/class1/interface/gaussianF.glsl
@@ -49,5 +49,5 @@ void main()
         col += texture(diffuseRect, tc).rgb * w[i];
     }
 
-    frag_color = vec4(col, 0.0);
+    frag_color = max(vec4(col, 0.0), vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/interface/highlightF.glsl b/indra/newview/app_settings/shaders/class1/interface/highlightF.glsl
index 6cc9bbbea2..58c9e5ad0a 100644
--- a/indra/newview/app_settings/shaders/class1/interface/highlightF.glsl
+++ b/indra/newview/app_settings/shaders/class1/interface/highlightF.glsl
@@ -36,5 +36,5 @@ VARYING vec2 vary_texcoord0;
 
 void main() 
 {
-	frag_color = color*texture2D(diffuseMap, vary_texcoord0.xy);
+	frag_color = max(color*texture2D(diffuseMap, vary_texcoord0.xy), vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl b/indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl
index a1839d4a67..cd5d97c785 100644
--- a/indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl
+++ b/indra/newview/app_settings/shaders/class1/interface/radianceGenF.glsl
@@ -162,6 +162,6 @@ vec4 prefilterEnvMap(vec3 R)
 void main()
 {		
 	vec3 N = normalize(vary_dir);
-	frag_color = prefilterEnvMap(N);
+	frag_color = max(prefilterEnvMap(N), vec4(0));
 }
 // =============================================================================================================
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskF.glsl
index b2c83a0f44..eaf0f71b41 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskF.glsl
@@ -51,6 +51,6 @@ void default_lighting()
 	color.rgb = atmosLighting(color.rgb);
 	color.rgb = scaleSoftClip(color.rgb);
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskNonIndexedF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskNonIndexedF.glsl
index d87403c78f..fc76c0cc00 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskNonIndexedF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightAlphaMaskNonIndexedF.glsl
@@ -54,6 +54,6 @@ void default_lighting()
 
 	color.rgb = scaleSoftClip(color.rgb);
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightF.glsl
index 9fd189358b..6b86d717da 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightF.glsl
@@ -43,6 +43,6 @@ void default_lighting()
 
 	color.rgb = scaleSoftClip(color.rgb);
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightNonIndexedF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightNonIndexedF.glsl
index f9c7ad2ab3..59c1bc1446 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightNonIndexedF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightNonIndexedF.glsl
@@ -45,6 +45,6 @@ void default_lighting()
 
 	color.rgb = scaleSoftClip(color.rgb);
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskF.glsl
index 9c89c09573..7da8e9054a 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskF.glsl
@@ -50,6 +50,6 @@ void default_lighting_water()
 
 	color.rgb = atmosLighting(color.rgb);
 
-	frag_color = applyWaterFog(color);
+	frag_color = max(applyWaterFog(color), vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskNonIndexedF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskNonIndexedF.glsl
index 9de7a03180..f767c17f86 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskNonIndexedF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightWaterAlphaMaskNonIndexedF.glsl
@@ -54,6 +54,6 @@ void default_lighting_water()
 
 	color = applyWaterFog(color);
 	
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightWaterF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightWaterF.glsl
index 57ed993a66..2530bdcc74 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightWaterF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightWaterF.glsl
@@ -41,6 +41,6 @@ void default_lighting_water()
 
 	color.rgb = atmosLighting(color.rgb);
 
-	frag_color = applyWaterFog(color);
+	frag_color = max(applyWaterFog(color), vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/lighting/lightWaterNonIndexedF.glsl b/indra/newview/app_settings/shaders/class1/lighting/lightWaterNonIndexedF.glsl
index af5da1411b..7f112d7435 100644
--- a/indra/newview/app_settings/shaders/class1/lighting/lightWaterNonIndexedF.glsl
+++ b/indra/newview/app_settings/shaders/class1/lighting/lightWaterNonIndexedF.glsl
@@ -43,6 +43,6 @@ void default_lighting_water()
 
 	color.rgb = atmosLighting(color.rgb);
 
-	frag_color = applyWaterFog(color);
+	frag_color = max(applyWaterFog(color), vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class1/objects/bumpF.glsl b/indra/newview/app_settings/shaders/class1/objects/bumpF.glsl
index d55f0db530..1deb374cd0 100644
--- a/indra/newview/app_settings/shaders/class1/objects/bumpF.glsl
+++ b/indra/newview/app_settings/shaders/class1/objects/bumpF.glsl
@@ -40,5 +40,5 @@ void main()
 	float tex0 = texture2D(texture0, vary_texcoord0.xy).a;
 	float tex1 = texture2D(texture1, vary_texcoord1.xy).a;
 
-	frag_color = vec4(tex0+(1.0-tex1)-0.5);
+	frag_color = max(vec4(tex0+(1.0-tex1)-0.5), vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/objects/impostorF.glsl b/indra/newview/app_settings/shaders/class1/objects/impostorF.glsl
index add437d144..467a9949e4 100644
--- a/indra/newview/app_settings/shaders/class1/objects/impostorF.glsl
+++ b/indra/newview/app_settings/shaders/class1/objects/impostorF.glsl
@@ -44,5 +44,5 @@ void main()
 		discard;
 	}
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/objects/previewF.glsl b/indra/newview/app_settings/shaders/class1/objects/previewF.glsl
index 284da3d0ac..687d6b7482 100644
--- a/indra/newview/app_settings/shaders/class1/objects/previewF.glsl
+++ b/indra/newview/app_settings/shaders/class1/objects/previewF.glsl
@@ -37,5 +37,5 @@ VARYING vec2 vary_texcoord0;
 void main()
 {
 	vec4 color = texture2D(diffuseMap,vary_texcoord0.xy) * vertex_color;
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class1/objects/previewPhysicsF.glsl b/indra/newview/app_settings/shaders/class1/objects/previewPhysicsF.glsl
index 3a5e6fdf7c..b56fc97a85 100644
--- a/indra/newview/app_settings/shaders/class1/objects/previewPhysicsF.glsl
+++ b/indra/newview/app_settings/shaders/class1/objects/previewPhysicsF.glsl
@@ -38,5 +38,5 @@ VARYING vec2 vary_texcoord0;
 
 void main()
 {
-    frag_color = texture2D(diffuseMap,vary_texcoord0.xy) * color;
+    frag_color = max(texture2D(diffuseMap,vary_texcoord0.xy) * color, vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl b/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl
index 70be9a9029..53552870ae 100644
--- a/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl
@@ -306,6 +306,6 @@ void main()
     color.rgb = linear_to_srgb(color.rgb);
 #endif
 
-    frag_color = color;
+    frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class2/interface/irradianceGenF.glsl b/indra/newview/app_settings/shaders/class2/interface/irradianceGenF.glsl
index d21af946e0..0753e73dc8 100644
--- a/indra/newview/app_settings/shaders/class2/interface/irradianceGenF.glsl
+++ b/indra/newview/app_settings/shaders/class2/interface/irradianceGenF.glsl
@@ -209,6 +209,6 @@ void main()
 
     color = filterColor(vary_dir);
     
-    frag_color = color;
+    frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class2/interface/reflectionprobeF.glsl b/indra/newview/app_settings/shaders/class2/interface/reflectionprobeF.glsl
index 986b233e0b..c858531998 100644
--- a/indra/newview/app_settings/shaders/class2/interface/reflectionprobeF.glsl
+++ b/indra/newview/app_settings/shaders/class2/interface/reflectionprobeF.glsl
@@ -38,5 +38,5 @@ void main()
     float depth        = getDepth(tc.xy);
     vec4  pos          = getPositionWithDepth(tc, depth);
 
-    frag_color = sampleReflectionProbesDebug(pos.xyz);
+    frag_color = max(sampleReflectionProbesDebug(pos.xyz), vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class3/deferred/fullbrightShinyF.glsl b/indra/newview/app_settings/shaders/class3/deferred/fullbrightShinyF.glsl
index f6bed16c84..6b7dc7ac1d 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/fullbrightShinyF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/fullbrightShinyF.glsl
@@ -92,6 +92,6 @@ void main()
 
 	color.a = 1.0;
 
-	frag_color = color;
+	frag_color = max(color, vec4(0));
 }
 
diff --git a/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl b/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl
index 02ab4494f6..1aef971d3a 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/materialF.glsl
@@ -183,7 +183,7 @@ vec3 calcPointLightOrSpotLight(vec3 light_col, vec3 npos, vec3 diffuse, vec4 spe
 
 #else
 #ifdef DEFINE_GL_FRAGCOLOR
-out vec4 frag_data[3];
+out vec4 frag_data[4];
 #else
 #define frag_data gl_FragData
 #endif
@@ -412,13 +412,14 @@ void main()
     color = temp.rgb;
 #endif
 
-    frag_color = vec4(color, al);
+    frag_color = max(vec4(color, al), vec4(0));
 
 #else // mode is not DIFFUSE_ALPHA_MODE_BLEND, encode to gbuffer 
     // deferred path               // See: C++: addDeferredAttachment(), shader: softenLightF.glsl
     frag_data[0] = vec4(diffcol.rgb, emissive);        // gbuffer is sRGB for legacy materials
     frag_data[1] = vec4(spec.rgb, glossiness);           // XYZ = Specular color. W = Specular exponent.
     frag_data[2] = vec4(encode_normal(norm), env, GBUFFER_FLAG_HAS_ATMOS);;   // XY = Normal.  Z = Env. intensity. W = 1 skip atmos (mask off fog)
+    frag_data[3] = vec4(0);
 #endif
 }
 
diff --git a/indra/newview/app_settings/shaders/class3/deferred/screenSpaceReflPostF.glsl b/indra/newview/app_settings/shaders/class3/deferred/screenSpaceReflPostF.glsl
index 742f528cb1..f1865a77e2 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/screenSpaceReflPostF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/screenSpaceReflPostF.glsl
@@ -73,7 +73,7 @@ void main()
     vec4 diffuse = texture2D(diffuseRect, tc);
     vec3 specCol = spec.rgb;
 
-    frag_color = texture(diffuseMap, tc);
+    vec4 fcol = texture(diffuseMap, tc);
 
     if (GET_GBUFFER_FLAG(GBUFFER_FLAG_HAS_PBR)) 
     {
@@ -94,5 +94,6 @@ void main()
 
     collectedColor.rgb *= specCol.rgb;
 
-    frag_color += collectedColor * w;
+    fcol += collectedColor * w;
+    frag_color = max(fcol, vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl b/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl
index 99beb0d890..e1206cc844 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl
@@ -270,6 +270,6 @@ void main()
         color       = fogged.rgb;
     #endif
 
-    frag_color.rgb = color.rgb; //output linear since local lights will be added to this shader's results
+    frag_color.rgb = max(color.rgb, vec3(0)); //output linear since local lights will be added to this shader's results
     frag_color.a = 0.0;
 }
diff --git a/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl b/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl
index 83454631d4..21c30012ab 100644
--- a/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl
+++ b/indra/newview/app_settings/shaders/class3/environment/underWaterF.glsl
@@ -77,5 +77,5 @@ void main()
     vec4 fb = vec4(waterFogColorLinear, 0.0);
 #endif
     
-	frag_color = applyWaterFogViewLinearNoClip(vary_position, fb, vec3(1));
+	frag_color = max(applyWaterFogViewLinearNoClip(vary_position, fb, vec3(1)), vec4(0));
 }
diff --git a/indra/newview/app_settings/shaders/class3/environment/waterF.glsl b/indra/newview/app_settings/shaders/class3/environment/waterF.glsl
index ec0439fa97..3d4f4fc17b 100644
--- a/indra/newview/app_settings/shaders/class3/environment/waterF.glsl
+++ b/indra/newview/app_settings/shaders/class3/environment/waterF.glsl
@@ -286,6 +286,6 @@ void main()
 
     float spec = min(max(max(punctual.r, punctual.g), punctual.b), 0.05);
     
-    frag_color = vec4(color, spec); //*sunAngle2);
+    frag_color = max(vec4(color, spec), vec4(0));
 }