SL-10856

Modify calc of sunlight to avoid clipping in gamma correct on values outside 0-1 range.

Modify shaders to put back ambient clamp tuned to be close to ambient contrib in low/mid lighting.

indra/llinventory/llsettingssky.cpp

@@ -32,6 +32,10 @@
 #include "llfasttimer.h"
 #include "v3colorutil.h"
 
+#if LL_WINDOWS
+#pragma optimize("", off)
+#endif
+
 //=========================================================================
 namespace
 {
@@ -1276,8 +1280,10 @@ void LLSettingsSky::calculateLightSettings() const
     LLColor3 tmpAmbient = ambient + (smear(1.f) - ambient) * cloud_shadow;
 
     //brightness of surface both sunlight and ambient
-    mSunDiffuse = gammaCorrect(componentMult(sunlight,   light_transmittance));
-    mSunAmbient = gammaCorrect(componentMult(tmpAmbient, light_transmittance));
+    // reduce range to 0 - 1 before gamma correct to prevent clipping
+    // then restore to full 0 - 3 range before storage
+    mSunDiffuse = gammaCorrect(componentMult(sunlight * 0.33333f,   light_transmittance)) * 3.0f;
+    mSunAmbient = gammaCorrect(componentMult(tmpAmbient * 0.33333f, light_transmittance)) * 3.0f;
 
     F32 moon_brightness = getIsMoonUp() ? getMoonBrightness() : 0.001f;
 

indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl

@@ -223,8 +223,7 @@ void main()
     float ambient = da;
     ambient *= 0.5;
     ambient *= ambient;
-    //ambient = max(getAmbientClamp(), ambient); // keeps shadows dark
-    ambient = 1.0 - ambient;
+    ambient = min(getAmbientClamp(), 1.0 - ambient);
 
     vec3 sun_contrib = min(final_da, shadow) * sunlit;
 

indra/newview/app_settings/shaders/class1/deferred/materialF.glsl

@@ -320,8 +320,7 @@ void main()
     float ambient = da;
     ambient *= 0.5;
     ambient *= ambient;
-    //ambient = max(getAmbientClamp(), ambient);
-    ambient = 1.0 - ambient;
+    ambient = min(getAmbientClamp(), 1.0 - ambient);
 
     vec3 sun_contrib = min(final_da, shadow) * sunlit;
    

indra/newview/app_settings/shaders/class1/deferred/softenLightF.glsl

@@ -106,8 +106,7 @@ void main()
         float ambient = da;
         ambient *= 0.5;
         ambient *= ambient;
-        //ambient = max(getAmbientClamp(), ambient);
-        ambient = 1.0 - ambient;
+        ambient = min(getAmbientClamp(), 1.0 - ambient);
 
         vec3 sun_contrib = final_da * sunlit;
 

indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl

@@ -44,7 +44,7 @@ uniform float sun_moon_glow_factor;
 
 float getAmbientClamp()
 {
-    return 0.66f;
+    return 0.2f;
 }
 
 void calcAtmosphericVars(vec3 inPositionEye, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten) {
@@ -137,7 +137,7 @@ void calcAtmosphericVars(vec3 inPositionEye, float ambFactor, out vec3 sunlit, o
           + tmpAmbient));
 
     //brightness of surface both sunlight and ambient
-    sunlit = sunlight.rgb * 0.5;
-    amblit = tmpAmbient.rgb * .25;
+    sunlit = sunlight.rgb;
+    amblit = tmpAmbient.rgb;
     additive *= vec3(1.0 - temp1);
 }

indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl

@@ -116,8 +116,7 @@ void main()
         float ambient = da;
         ambient *= 0.5;
         ambient *= ambient;
-        //ambient = max(getAmbientClamp(), ambient);
-        ambient = 1.0 - ambient;
+        ambient = min(getAmbientClamp(), 1.0 - ambient);
 
         vec3 sun_contrib = min(scol, final_da) * sunlit;
 

indra/newview/app_settings/shaders/class3/lighting/lightV.glsl

@@ -32,7 +32,7 @@ vec4 sumLights(vec3 pos, vec3 norm, vec4 color);
 vec4 calcLighting(vec3 pos, vec3 norm, vec4 color)
 {
 	vec4 c = sumLights(pos, norm, color);
-    c.rgb += atmosAmbient() * color.rgb;
+    c.rgb += atmosAmbient() * color.rgb * 0.25;
     return c; 
 }