Make sun specularity behavior more intuitive (bug #6190)

Remove sun visibility influence on object specularity
Subdue sun visibility influence on water specularity

CHANGELOG.md

@@ -22,6 +22,7 @@
     Bug #5977: Fatigueless NPCs' corpse underwater changes animation on game load
     Bug #6025: Subrecords cannot overlap records
     Bug #6027: Collisionshape becomes spiderweb-like when the mesh is too complex
+    Bug #6190: Unintuitive sun specularity time of day dependence
     Bug #6222: global map cell size can crash openmw if set to too high a value
     Bug #6313: Followers with high Fight can turn hostile
     Bug #6427: Enemy health bar disappears before damaging effect ends

apps/openmw/mwrender/renderingmanager.cpp

@@ -702,7 +702,7 @@ namespace MWRender
     {
         // need to wrap this in a StateUpdater?
         mSunLight->setDiffuse(diffuse);
-        mSunLight->setSpecular(specular);
+        mSunLight->setSpecular(osg::Vec4f(specular.x(), specular.y(), specular.z(), specular.w() * sunVis));
 
         mPostProcessor->getStateUpdater()->setSunColor(diffuse);
         mPostProcessor->getStateUpdater()->setSunVis(sunVis);

apps/openmw/mwworld/weather.cpp

@@ -789,8 +789,7 @@ namespace MWWorld
         mRendering.configureFog(
             mResult.mFogDepth, underwaterFog, mResult.mDLFogFactor, mResult.mDLFogOffset / 100.0f, mResult.mFogColor);
         mRendering.setAmbientColour(mResult.mAmbientColor);
-        mRendering.setSunColour(
-            mResult.mSunColor, mResult.mSunColor * mResult.mGlareView * glareFade, mResult.mGlareView * glareFade);
+        mRendering.setSunColour(mResult.mSunColor, mResult.mSunColor, mResult.mGlareView * glareFade);
 
         mRendering.getSkyManager()->setWeather(mResult);
 

files/shaders/compatibility/water.frag

@@ -43,6 +43,7 @@ const float SCATTER_AMOUNT = 0.3;                  // amount of sunlight scatter
 const vec3 SCATTER_COLOUR = vec3(0.0,1.0,0.95);    // colour of sunlight scattering
 
 const vec3 SUN_EXT = vec3(0.45, 0.55, 0.68);       //sunlight extinction
+const float SUN_SPEC_FADING_THRESHOLD = 0.15;       // visibility at which sun specularity starts to fade
 
 const float SPEC_HARDNESS = 256.0;                 // specular highlights hardness
 
@@ -172,6 +173,8 @@ void main(void)
     vec3 waterColor = WATER_COLOR * sunFade;
 
     vec4 sunSpec = lcalcSpecular(0);
+    // alpha component is sun visibility; we want to start fading specularity when visibility is low
+    sunSpec.a = min(1.0, sunSpec.a / SUN_SPEC_FADING_THRESHOLD);
 
     // artificial specularity to make rain ripples more noticeable
     vec3 skyColorEstimate = vec3(max(0.0, mix(-0.3, 1.0, sunFade)));
@@ -179,7 +182,7 @@ void main(void)
 
 #if REFRACTION
     // no alpha here, so make sure raindrop ripple specularity gets properly subdued
-    rainSpecular *= clamp(fresnel*6.0 + specular * sunSpec.w, 0.0, 1.0);
+    rainSpecular *= clamp(fresnel*6.0 + specular * sunSpec.a, 0.0, 1.0);
 
     // refraction
     vec3 refraction = sampleRefractionMap(screenCoords - screenCoordsOffset).rgb;
@@ -200,7 +203,7 @@ void main(void)
     vec3 scatterColour = mix(SCATTER_COLOUR*vec3(1.0,0.4,0.0), SCATTER_COLOUR, clamp(1.0-exp(-sunHeight*SUN_EXT), 0.0, 1.0));
     vec3 lR = reflect(lVec, lNormal);
     float lightScatter = clamp(dot(lVec,lNormal)*0.7+0.3, 0.0, 1.0) * clamp(dot(lR, vVec)*2.0-1.2, 0.0, 1.0) * SCATTER_AMOUNT * sunFade * clamp(1.0-exp(-sunHeight), 0.0, 1.0);
-    gl_FragData[0].xyz = mix( mix(refraction,  scatterColour,  lightScatter),  reflection,  fresnel) + specular * sunSpec.xyz + rainSpecular;
+    gl_FragData[0].xyz = mix(mix(refraction,  scatterColour,  lightScatter), reflection, fresnel) + specular * sunSpec.rgb * sunSpec.a + rainSpecular;
     gl_FragData[0].w = 1.0;
 
     // wobbly water: hard-fade into refraction texture at extremely low depth, with a wobble based on normal mapping
@@ -213,8 +216,8 @@ void main(void)
     shoreOffset = clamp(mix(shoreOffset, 1.0, clamp(linearDepth / WOBBLY_SHORE_FADE_DISTANCE, 0.0, 1.0)), 0.0, 1.0);
     gl_FragData[0].xyz = mix(rawRefraction, gl_FragData[0].xyz, shoreOffset);
 #else
-    gl_FragData[0].xyz = mix(reflection,  waterColor,  (1.0-fresnel)*0.5) + specular * sunSpec.xyz + rainSpecular;
-    gl_FragData[0].w = clamp(fresnel*6.0 + specular * sunSpec.w, 0.0, 1.0);     //clamp(fresnel*2.0 + specular * gl_LightSource[0].specular.w, 0.0, 1.0);
+    gl_FragData[0].xyz = mix(reflection,  waterColor,  (1.0-fresnel)*0.5) + specular * sunSpec.rgb  * sunSpec.a + rainSpecular;
+    gl_FragData[0].w = clamp(fresnel*6.0 + specular * sunSpec.a, 0.0, 1.0);     //clamp(fresnel*2.0 + specular * gl_LightSource[0].specular.a, 0.0, 1.0);
 #endif
 
     gl_FragData[0] = applyFogAtDist(gl_FragData[0], radialDepth, linearDepth, far);