DRTVWR-559 Revert skies to be very close to release and disable tone mapping when probe ambiance is zero.

Hack for desaturating legacy materials has been removed for performance and quality reasons.

Adds a new setting for auto adjusting legacy skies.  This is the PBR "opt out" button.  If disabled, legacy skies will disable tonemapping, automatic probe ambiance, and HDR/exposure.  If enabled, legacy skies will behave as if probe ambiance and HDR scale are 1.0, and ambient will be cut in half.  

HDR scale will act as a sky brightener, but will automatically adjust dynamic exposure so the sky will be properly exposed.  If you want relatively even exposure all the time, set HDR Scale to 1.0.  If you want a high range of exposures between indoor/dark areas and outdoor/bright areas, increase HDR Scale.

Also tuned up SSAO (thanks Rye!).

Reviewed with Brad.

1 files changed, 27 insertions, 16 deletions

diff --git a/indra/newview/pipeline.cpp b/indra/newview/pipeline.cpp
index 9a8597e519..852845edf4 100644
--- a/indra/newview/pipeline.cpp
+++ b/indra/newview/pipeline.cpp
@@ -6751,22 +6751,25 @@ void LLPipeline::generateExposure(LLRenderTarget* src, LLRenderTarget* dst) {
 		static LLStaticHashedString noiseVec("noiseVec");
 		static LLStaticHashedString dynamic_exposure_params("dynamic_exposure_params");
 		static LLCachedControl<F32> dynamic_exposure_coefficient(gSavedSettings, "RenderDynamicExposureCoefficient", 0.175f);
-		static LLCachedControl<F32> dynamic_exposure_min(gSavedSettings, "RenderDynamicExposureMin", 0.125f);
-		static LLCachedControl<F32> dynamic_exposure_max(gSavedSettings, "RenderDynamicExposureMax", 1.3f);
-
-        F32 exposure_max = dynamic_exposure_max;
         LLSettingsSky::ptr_t sky = LLEnvironment::instance().getCurrentSky();
 
-        if (sky->getReflectionProbeAmbiance() > 0.f)
-        { //not a legacy sky, use gamma as a boost to max exposure
-            exposure_max = llmax(exposure_max - 1.f, 0.f);
-            exposure_max *= sky->getGamma();
-            exposure_max += 1.f;
-        }
+        F32 probe_ambiance = LLEnvironment::instance().getCurrentSky()->getReflectionProbeAmbiance();
+        F32 exp_min = 1.f;
+        F32 exp_max = 1.f;
+                
+        if (probe_ambiance > 0.f)
+        {
+            F32 hdr_scale = sqrtf(LLEnvironment::instance().getCurrentSky()->getGamma())*2.f;
 
+            if (hdr_scale > 1.f)
+            {
+                exp_min = 1.f / hdr_scale;
+                exp_max = hdr_scale;
+            }
+        }
 		gExposureProgram.uniform1f(dt, gFrameIntervalSeconds);
 		gExposureProgram.uniform2f(noiseVec, ll_frand() * 2.0 - 1.0, ll_frand() * 2.0 - 1.0);
-		gExposureProgram.uniform3f(dynamic_exposure_params, dynamic_exposure_coefficient, dynamic_exposure_min, exposure_max);
+		gExposureProgram.uniform3f(dynamic_exposure_params, dynamic_exposure_coefficient, exp_min, exp_max);
 
 		mScreenTriangleVB->setBuffer();
 		mScreenTriangleVB->drawArrays(LLRender::TRIANGLES, 0, 3);
@@ -6789,8 +6792,12 @@ void LLPipeline::gammaCorrect(LLRenderTarget* src, LLRenderTarget* dst) {
 
 		// Apply gamma correction to the frame here.
 
+        static LLCachedControl<bool> should_auto_adjust(gSavedSettings, "RenderSkyAutoAdjustLegacy", true);
+        
+        LLSettingsSky::ptr_t psky = LLEnvironment::instance().getCurrentSky();
+
         LLGLSLShader& shader = no_post && gFloaterTools->isAvailable() ? gNoPostGammaCorrectProgram : // no post (no gamma, no exposure, no tonemapping)
-            LLEnvironment::instance().getCurrentSky()->getReflectionProbeAmbiance() == 0.f ? gLegacyPostGammaCorrectProgram :
+            psky->getReflectionProbeAmbiance(should_auto_adjust) == 0.f ? gLegacyPostGammaCorrectProgram :
             gDeferredPostGammaCorrectProgram;
         
         shader.bind();
@@ -7846,14 +7853,18 @@ void LLPipeline::renderDeferredLighting()
             LL_PROFILE_GPU_ZONE("atmospherics");
             bindDeferredShader(soften_shader);
 
-            static LLCachedControl<F32> sky_scale(gSavedSettings, "RenderSkyHDRScale", 1.f);
-            static LLStaticHashedString sky_hdr_scale("sky_hdr_scale");
+            static LLCachedControl<F32> ssao_scale(gSavedSettings, "RenderSSAOIrradianceScale", 0.5f);
+            static LLCachedControl<F32> ssao_max(gSavedSettings, "RenderSSAOIrradianceMax", 0.25f);
+            static LLStaticHashedString ssao_scale_str("ssao_irradiance_scale");
+            static LLStaticHashedString ssao_max_str("ssao_irradiance_max");
+            
+            soften_shader.uniform1f(ssao_scale_str, ssao_scale);
+            soften_shader.uniform1f(ssao_max_str, ssao_max);
 
             LLEnvironment &environment = LLEnvironment::instance();
             soften_shader.uniform1i(LLShaderMgr::SUN_UP_FACTOR, environment.getIsSunUp() ? 1 : 0);
             soften_shader.uniform3fv(LLShaderMgr::LIGHTNORM, 1, environment.getClampedLightNorm().mV);
-            soften_shader.uniform1f(sky_hdr_scale, sky_scale);
-
+            
             soften_shader.uniform4fv(LLShaderMgr::WATER_WATERPLANE, 1, LLDrawPoolAlpha::sWaterPlane.mV);
 
             {