First stab at moving atmospheric var calcs to its own utility shader.

Still some work to go here.  Largely related to how certain values (i.e., SSAO mix values) are supplied.  But so far, so good.

--HG--
branch : OPEN-340

2 files changed, 121 insertions, 1 deletions

diff --git a/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl b/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
new file mode 100644
index 0000000000..2854fb8139
--- /dev/null
+++ b/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
@@ -0,0 +1,116 @@
+uniform vec4 gamma;

+uniform vec4 lightnorm;

+uniform vec4 sunlight_color;

+uniform vec4 moonlight_color;

+uniform int sun_up_factor;

+uniform vec4 ambient;

+uniform vec4 blue_horizon;

+uniform vec4 blue_density;

+uniform float haze_horizon;

+uniform float haze_density;

+uniform float cloud_shadow;

+uniform float density_multiplier;

+uniform float distance_multiplier;

+uniform float max_y;

+uniform vec4 glow;

+uniform float scene_light_strength;

+uniform mat3 ssao_effect_mat;

+uniform int no_atmo;

+uniform float sun_moon_glow_factor;

+

+vec3 nothing() {

+    return vec3(0, 0, 0);

+}

+

+void calcAtmosphericVars(vec3 inPositionEye, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten) {

+

+    vec3 P = inPositionEye;

+   

+    //(TERRAIN) limit altitude

+    if (P.y > max_y) P *= (max_y / P.y);

+    if (P.y < -max_y) P *= (-max_y / P.y); 

+

+    vec3 tmpLightnorm = lightnorm.xyz;

+

+    vec3 Pn = normalize(P);

+    float Plen = length(P);

+

+    vec4 temp1 = vec4(0);

+    vec3 temp2 = vec3(0);

+    vec4 blue_weight;

+    vec4 haze_weight;

+    vec4 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;

+    vec4 light_atten;

+

+    //sunlight attenuation effect (hue and brightness) due to atmosphere

+    //this is used later for sunlight modulation at various altitudes

+    light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y);

+        //I had thought blue_density and haze_density should have equal weighting,

+        //but attenuation due to haze_density tends to seem too strong

+

+    temp1 = blue_density + vec4(haze_density);

+    blue_weight = blue_density / temp1;

+    haze_weight = vec4(haze_density) / temp1;

+

+    //(TERRAIN) compute sunlight from lightnorm only (for short rays like terrain)

+    temp2.y = max(0.0, tmpLightnorm.y);

+    if (temp2.y > 0.001f)

+    {

+        temp2.y = 1. / temp2.y;

+    }

+    temp2.y = max(0.001f, temp2.y);

+    sunlight *= exp(-light_atten * temp2.y);

+

+    // main atmospheric scattering line integral

+    temp2.z = Plen * density_multiplier;

+

+    // Transparency (-> temp1)

+    // ATI Bugfix -- can't store temp1*temp2.z*distance_multiplier in a variable because the ati

+    // compiler gets confused.

+    temp1 = exp(-temp1 * temp2.z * distance_multiplier);

+

+    //final atmosphere attenuation factor

+    atten = temp1.rgb;

+    

+    //compute haze glow

+    //(can use temp2.x as temp because we haven't used it yet)

+    temp2.x = dot(Pn, tmpLightnorm.xyz);

+    temp2.x = 1. - temp2.x;

+        //temp2.x is 0 at the sun and increases away from sun

+    temp2.x = max(temp2.x, .03);    //was glow.y

+        //set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)

+    temp2.x *= glow.x;

+        //higher glow.x gives dimmer glow (because next step is 1 / "angle")

+    temp2.x = pow(temp2.x, glow.z);

+        //glow.z should be negative, so we're doing a sort of (1 / "angle") function

+

+    //add "minimum anti-solar illumination"

+    temp2.x += .25;

+

+    temp2.x *= sun_moon_glow_factor;

+    

+    //increase ambient when there are more clouds

+    vec4 tmpAmbient = ambient + (vec4(1.) - ambient) * cloud_shadow * 0.5;

+    

+    /*  decrease value and saturation (that in HSV, not HSL) for occluded areas

+     * // for HSV color/geometry used here, see http://gimp-savvy.com/BOOK/index.html?node52.html

+     * // The following line of code performs the equivalent of:

+     * float ambAlpha = tmpAmbient.a;

+     * float ambValue = dot(vec3(tmpAmbient), vec3(0.577)); // projection onto <1/rt(3), 1/rt(3), 1/rt(3)>, the neutral white-black axis

+     * vec3 ambHueSat = vec3(tmpAmbient) - vec3(ambValue);

+     * tmpAmbient = vec4(RenderSSAOEffect.valueFactor * vec3(ambValue) + RenderSSAOEffect.saturationFactor *(1.0 - ambFactor) * ambHueSat, ambAlpha);

+     */

+    tmpAmbient = vec4(mix(ssao_effect_mat * tmpAmbient.rgb, tmpAmbient.rgb, ambFactor), tmpAmbient.a);

+

+    //haze color

+        additive =

+        vec3(blue_horizon * blue_weight * (sunlight*(1.-cloud_shadow) + tmpAmbient)

+      + (haze_horizon * haze_weight) * (sunlight*(1.-cloud_shadow) * temp2.x

+          + tmpAmbient));

+

+    //brightness of surface both sunlight and ambient

+    sunlit = vec3(sunlight.rgb);

+    amblit = vec3(tmpAmbient * .25);

+    additive  = normalize(additive);

+    additive *= vec3(1.0 - exp(-temp2.z * distance_multiplier)) * 0.5;

+}
\ No newline at end of file
diff --git a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
index 8814587fbc..4c7c50315f 100644
--- a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
@@ -72,6 +72,8 @@ vec3 atmosFragLighting(vec3 l, vec3 additive, vec3 atten);
 vec3 fullbrightScaleSoftClipFrag(vec3 l, vec3 add, vec3 atten);
 vec3 scaleSoftClipFrag(vec3 l);
 
+void calcAtmosphericVars(vec3 inPositionEye, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten);
+
 vec3 atmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
 vec3 fullbrightAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
 vec3 fullbrightShinyAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
@@ -79,6 +81,8 @@ vec3 fullbrightShinyAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
 vec4 getPositionWithDepth(vec2 pos_screen, float depth);
 vec4 getPosition(vec2 pos_screen);
 
+vec3 nothing();
+
 #ifdef WATER_FOG
 vec4 applyWaterFogView(vec3 pos, vec4 color);
 #endif
@@ -121,7 +125,7 @@ void main()
         vec3 additive;
         vec3 atten;
     
-        calcFragAtmospherics(pos.xyz, ambocc, sunlit, amblit, additive, atten);
+        calcAtmosphericVars(pos.xyz, ambocc, sunlit, amblit, additive, atten);
 
         float ambient = da;
         ambient *= 0.5;