diff --git a/indra/llrender/llcubemaparray.cpp b/indra/llrender/llcubemaparray.cpp
index ac48a633c721ec19866edcbc06625934b11fd9e9..7d3a92237b4a0fd69e9746f625835a674b1cb06d 100644
--- a/indra/llrender/llcubemaparray.cpp
+++ b/indra/llrender/llcubemaparray.cpp
@@ -122,7 +122,7 @@ void LLCubeMapArray::allocate(U32 resolution, U32 components, U32 count, BOOL us
 
     bind(0);
 
-    U32 format = components == 4 ? GL_RGBA12 : GL_RGB16F;
+    U32 format = components == 4 ? GL_RGBA16F : GL_RGB16F;
 
     U32 mip = 0;
 
diff --git a/indra/llrender/llimagegl.cpp b/indra/llrender/llimagegl.cpp
index 10da8da05f3bdffccd6985459eb1543055988829..f581ed2dc917339040a624e5f26b5bb4426a77a2 100644
--- a/indra/llrender/llimagegl.cpp
+++ b/indra/llrender/llimagegl.cpp
@@ -42,6 +42,8 @@
 #include "llwindow.h"
 #include "llframetimer.h"
 
+extern LL_COMMON_API bool on_main_thread();
+
 #if !LL_IMAGEGL_THREAD_CHECK
 #define checkActiveThread()
 #endif
@@ -131,7 +133,8 @@ bool LLImageGL::sCompressTextures = false;
 std::set<LLImageGL*> LLImageGL::sImageList;
 
 
-bool LLImageGLThread::sEnabled = false;
+bool LLImageGLThread::sEnabledTextures = false;
+bool LLImageGLThread::sEnabledMedia = false;
 
 //****************************************************************************************************
 //The below for texture auditing use only
@@ -241,14 +244,16 @@ BOOL is_little_endian()
 }
 
 //static 
-void LLImageGL::initClass(LLWindow* window, S32 num_catagories, BOOL skip_analyze_alpha /* = false */, bool multi_threaded /* = false */)
+void LLImageGL::initClass(LLWindow* window, S32 num_catagories, BOOL skip_analyze_alpha /* = false */, bool thread_texture_loads /* = false */, bool thread_media_updates /* = false */)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 	sSkipAnalyzeAlpha = skip_analyze_alpha;
 
-    if (multi_threaded)
+    if (thread_texture_loads || thread_media_updates)
     {
         LLImageGLThread::createInstance(window);
+        LLImageGLThread::sEnabledTextures = thread_texture_loads;
+        LLImageGLThread::sEnabledMedia = thread_media_updates;
     }
 }
 
@@ -259,6 +264,7 @@ void LLImageGL::cleanupClass()
     LLImageGLThread::deleteSingleton();
 }
 
+
 //static
 S32 LLImageGL::dataFormatBits(S32 dataformat)
 {
@@ -1124,9 +1130,20 @@ U32 type_width_from_pixtype(U32 pixtype)
     return type_width;
 }
 
+bool should_stagger_image_set(bool compressed)
+{
+#if LL_DARWIN
+    return false;
+#else
+    // glTexSubImage2D doesn't work with compressed textures on select tested Nvidia GPUs on Windows 10 -Cosmic,2023-03-08
+    // Setting media textures off-thread seems faster when not using sub_image_lines (Nvidia/Windows 10) -Cosmic,2023-03-31
+    return !compressed && on_main_thread();
+#endif
+}
+
 // Equivalent to calling glSetSubImage2D(target, miplevel, x_offset, y_offset, width, height, pixformat, pixtype, src), assuming the total width of the image is data_width
 // However, instead there are multiple calls to glSetSubImage2D on smaller slices of the image
-void subImageLines(U32 target, S32 miplevel, S32 x_offset, S32 y_offset, S32 width, S32 height, U32 pixformat, U32 pixtype, const U8* src, S32 data_width)
+void sub_image_lines(U32 target, S32 miplevel, S32 x_offset, S32 y_offset, S32 width, S32 height, U32 pixformat, U32 pixtype, const U8* src, S32 data_width)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
 
@@ -1222,11 +1239,7 @@ BOOL LLImageGL::setSubImage(const U8* datap, S32 data_width, S32 data_height, S3
 		if (!res) LL_ERRS() << "LLImageGL::setSubImage(): bindTexture failed" << LL_ENDL;
 		stop_glerror();
 
-#if LL_DARWIN || LL_LINUX
-        const bool use_sub_image = false;
-#else
-        const bool use_sub_image = !isCompressed();
-#endif
+        const bool use_sub_image = should_stagger_image_set(isCompressed());
         if (!use_sub_image)
         {
             // *TODO: Why does this work here, in setSubImage, but not in
@@ -1237,7 +1250,7 @@ BOOL LLImageGL::setSubImage(const U8* datap, S32 data_width, S32 data_height, S3
         }
         else
         {
-            subImageLines(mTarget, 0, x_pos, y_pos, width, height, mFormatPrimary, mFormatType, sub_datap, data_width);
+            sub_image_lines(mTarget, 0, x_pos, y_pos, width, height, mFormatPrimary, mFormatType, sub_datap, data_width);
         }
 		gGL.getTexUnit(0)->disable();
 		stop_glerror();
@@ -1491,13 +1504,7 @@ void LLImageGL::setManualImage(U32 target, S32 miplevel, S32 intformat, S32 widt
         LL_PROFILE_ZONE_NUM(height);
 
         free_cur_tex_image();
-#if LL_DARWIN || LL_LINUX
-        const bool use_sub_image = false;
-#else
-        // glTexSubImage2D doesn't work with compressed textures on select tested Nvidia GPUs on Windows 10 -Cosmic,2023-03-08
-        // *TODO: Small chance that glCompressedTexImage2D/glCompressedTexSubImage2D may work better here
-        const bool use_sub_image = !compress;
-#endif
+        const bool use_sub_image = should_stagger_image_set(compress);
         if (!use_sub_image)
         {
             LL_PROFILE_ZONE_NAMED("glTexImage2D alloc + copy");
@@ -1515,7 +1522,7 @@ void LLImageGL::setManualImage(U32 target, S32 miplevel, S32 intformat, S32 widt
             if (src)
             {
                 LL_PROFILE_ZONE_NAMED("glTexImage2D copy");
-                subImageLines(target, miplevel, 0, 0, width, height, pixformat, pixtype, src, width);
+                sub_image_lines(target, miplevel, 0, 0, width, height, pixformat, pixtype, src, width);
             }
         }
         alloc_tex_image(width, height, pixformat);
@@ -2585,7 +2592,6 @@ LLImageGLThread::LLImageGLThread(LLWindow* window)
     , mWindow(window)
 {
     LL_PROFILE_ZONE_SCOPED_CATEGORY_TEXTURE;
-    sEnabled = true;
     mFinished = false;
 
     mContext = mWindow->createSharedContext();
diff --git a/indra/llrender/llimagegl.h b/indra/llrender/llimagegl.h
index 89560084c4b03990f66391f1b6d1570afafc52a4..65922ad033369e8dc46bbd7bc4c0a5397ed71ba2 100644
--- a/indra/llrender/llimagegl.h
+++ b/indra/llrender/llimagegl.h
@@ -291,7 +291,7 @@ class LLImageGL : public LLRefCount
 #endif
 
 public:
-	static void initClass(LLWindow* window, S32 num_catagories, BOOL skip_analyze_alpha = false, bool multi_threaded = false); 
+	static void initClass(LLWindow* window, S32 num_catagories, BOOL skip_analyze_alpha = false, bool thread_texture_loads = false, bool thread_media_updates = false);
 	static void cleanupClass() ;
 
 private:
@@ -333,8 +333,10 @@ class LLImageGL : public LLRefCount
 class LLImageGLThread : public LLSimpleton<LLImageGLThread>, LL::ThreadPool
 {
 public:
-    // follows gSavedSettings "RenderGLMultiThreaded"
-    static bool sEnabled;
+    // follows gSavedSettings "RenderGLMultiThreadedTextures"
+    static bool sEnabledTextures;
+    // follows gSavedSettings "RenderGLMultiThreadedMedia"
+    static bool sEnabledMedia;
     
     LLImageGLThread(LLWindow* window);
 
@@ -353,5 +355,4 @@ class LLImageGLThread : public LLSimpleton<LLImageGLThread>, LL::ThreadPool
     LLAtomicBool mFinished;
 };
 
-
 #endif // LL_LLIMAGEGL_H
diff --git a/indra/llrender/llrendertarget.cpp b/indra/llrender/llrendertarget.cpp
index 6aef1a3bb9734429713dfe58e03b369c064c5fb8..6f36808595b8ef4b1c1eb42cb04a3b3a1939b619 100644
--- a/indra/llrender/llrendertarget.cpp
+++ b/indra/llrender/llrendertarget.cpp
@@ -485,7 +485,7 @@ U32 LLRenderTarget::getNumTextures() const
 
 void LLRenderTarget::bindTexture(U32 index, S32 channel, LLTexUnit::eTextureFilterOptions filter_options)
 {
-    gGL.getTexUnit(channel)->bindManual(mUsage, getTexture(index));
+    gGL.getTexUnit(channel)->bindManual(mUsage, getTexture(index), filter_options == LLTexUnit::TFO_TRILINEAR || filter_options == LLTexUnit::TFO_ANISOTROPIC);
 
     bool isSRGB = false;
     llassert(mInternalFormat.size() > index);
diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index 8fe14d119406b410da352c1c54e864b8bc5db1ec..da6bec110d631eee743ec00cac53822f3e5b6768 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -10386,10 +10386,21 @@
       <key>Value</key>
       <integer>0</integer>
     </map>
-    <key>RenderGLMultiThreaded</key>
+    <key>RenderGLMultiThreadedTextures</key>
     <map>
       <key>Comment</key>
-      <string>Allow OpenGL to use multiple render contexts (reduces frame stutters from loading textures, doesn't play nice with Intel drivers).</string>
+      <string>Allow OpenGL to use multiple render contexts for loading textures (may reduce frame stutters, doesn't play nice with Intel drivers).</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>0</integer>
+    </map>
+    <key>RenderGLMultiThreadedMedia</key>
+    <map>
+      <key>Comment</key>
+      <string>Allow OpenGL to use multiple render contexts for playing media (may reduce frame stutters, doesn't play nice with Intel drivers)</string>
       <key>Persist</key>
       <integer>1</integer>
       <key>Type</key>
@@ -10924,6 +10935,61 @@
       <key>Value</key>
       <integer>3</integer>
     </map>
+  <key>RenderSkyHDRScale</key>
+  <map>
+    <key>Comment</key>
+    <string>Amount to over-brighten sun for HDR effect during the day</string>
+    <key>Persist</key>
+    <integer>1</integer>
+    <key>Type</key>
+    <string>F32</string>
+    <key>Value</key>
+    <real>3.0</real>
+  </map>
+  <key>RenderReflectionProbeMaxLocalLightAmbiance</key>
+  <map>
+    <key>Comment</key>
+    <string>Maximum effective probe ambiance for local lights</string>
+    <key>Persist</key>
+    <integer>1</integer>
+    <key>Type</key>
+    <string>F32</string>
+    <key>Value</key>
+    <real>4.0</real>
+  </map>
+  <key>RenderDynamicExposureMin</key>
+  <map>
+    <key>Comment</key>
+    <string>Minimum dynamic exposure amount</string>
+    <key>Persist</key>
+    <integer>1</integer>
+    <key>Type</key>
+    <string>F32</string>
+    <key>Value</key>
+    <real>0.125</real>
+  </map>
+  <key>RenderDynamicExposureMax</key>
+  <map>
+    <key>Comment</key>
+    <string>Maximum dynamic exposure amount</string>
+    <key>Persist</key>
+    <integer>1</integer>
+    <key>Type</key>
+    <string>F32</string>
+    <key>Value</key>
+    <real>1.3</real>
+  </map>
+  <key>RenderDynamicExposureCoefficient</key>
+  <map>
+    <key>Comment</key>
+    <string>Luminance coefficient for dynamic exposure</string>
+    <key>Persist</key>
+    <integer>1</integer>
+    <key>Type</key>
+    <string>F32</string>
+    <key>Value</key>
+    <real>0.175</real>
+  </map>
     <key>RenderShaderLODThreshold</key>
     <map>
       <key>Comment</key>
diff --git a/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
index 861b78c961733bdfb86790d99256c97c7515dd66..3eda2b90502a399a208baeaeb79bc54d8680c0d1 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/exposureF.glsl
@@ -29,13 +29,13 @@
 
 out vec4 frag_color;
 
-uniform sampler2D diffuseRect;
 uniform sampler2D emissiveRect;
 uniform sampler2D exposureMap;
 
 uniform float dt;
 uniform vec2 noiseVec;
 
+uniform vec3 dynamic_exposure_params;
 
 float lum(vec3 col)
 {
@@ -45,44 +45,11 @@ float lum(vec3 col)
 
 void main() 
 {
-    float step = 1.0/16.0;
+    vec2 tc = vec2(0.5,0.5);
 
-    float start = step;
-    float end = 1.0-step;
-
-    float w = 0.0;
-
-    vec3 col;
-
-    //vec2 nz = noiseVec * step * 0.5;
-
-    for (float x = start; x <= end; x += step)
-    {
-        for (float y = start; y <= end; y += step)
-        {
-            vec2 tc = vec2(x,y); // + nz;
-            vec3 c = texture(diffuseRect, tc).rgb + texture(emissiveRect, tc).rgb;
-            float L = max(lum(c), 0.25);
-
-            float d = length(vec2(0.5)-tc);
-            d = 1.0-d;
-            d *= d;
-            d *= d;
-            d *= d;
-            L *= d;
-
-            w += L;
-
-            col += c * L;
-        }
-    }
-
-    col /= w;
-
-    float L = lum(col);
-
-    float s = clamp(0.175/L, 0.125, 1.3);
+    float L = textureLod(emissiveRect, tc, 8).r;
 
+    float s = clamp(dynamic_exposure_params.x/L, dynamic_exposure_params.y, dynamic_exposure_params.z);
 
     float prev = texture(exposureMap, vec2(0.5,0.5)).r;
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/luminanceF.glsl b/indra/newview/app_settings/shaders/class1/deferred/luminanceF.glsl
new file mode 100644
index 0000000000000000000000000000000000000000..e63e666778a49031f658a9d46759050b56c8ce53
--- /dev/null
+++ b/indra/newview/app_settings/shaders/class1/deferred/luminanceF.glsl
@@ -0,0 +1,52 @@
+/** 
+ * @file luminanceF.glsl
+ *
+ * $LicenseInfo:firstyear=2023&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2023, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+ 
+
+/*[EXTRA_CODE_HERE]*/
+
+// take a luminance sample of diffuseRect and emissiveRect 
+
+out vec4 frag_color;
+
+in vec2 vary_fragcoord;
+
+uniform sampler2D diffuseRect;
+uniform sampler2D emissiveRect;
+
+float lum(vec3 col)
+{
+    vec3 l = vec3(0.2126, 0.7152, 0.0722);
+    return dot(l, col);
+}
+
+void main() 
+{
+    vec2 tc = vary_fragcoord*0.6+0.2;
+    vec3 c = texture(diffuseRect, tc).rgb + texture(emissiveRect, tc).rgb;
+    float L = lum(c);
+
+    frag_color = vec4(L);
+}
+
diff --git a/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl b/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl
index 22e93496d2f801576445c52d24f508dd2a04f3c8..49ff49fdd8bc16b93329542442a58d00c9d841b7 100644
--- a/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl
+++ b/indra/newview/app_settings/shaders/class2/windlight/atmosphericsF.glsl
@@ -36,7 +36,9 @@ vec3 atmosFragLighting(vec3 light, vec3 additive, vec3 atten)
 { 
     light *= atten.r;
     additive = srgb_to_linear(additive*2.0);
-    additive *= sun_up_factor + 1.0;
+    // magic 3.0 here is to match the default RenderSkyHDRScale -- this parameter needs to be plumbed into sky settings or something
+    // so it's available to all shaders that call atmosFragLighting instead of just softenLightF.glsl
+    additive *= sun_up_factor*3.0 + 1.0; 
     light += additive;
     return light;
 }
diff --git a/indra/newview/app_settings/shaders/class2/windlight/atmosphericsHelpersV.glsl b/indra/newview/app_settings/shaders/class2/windlight/atmosphericsHelpersV.glsl
index 257a76c663989516e56edba4417e415895e00935..6ecbfaecb10e8ab3596304579cf8a5a0a3467815 100644
--- a/indra/newview/app_settings/shaders/class2/windlight/atmosphericsHelpersV.glsl
+++ b/indra/newview/app_settings/shaders/class2/windlight/atmosphericsHelpersV.glsl
@@ -54,8 +54,4 @@ vec3 scaleDownLight(vec3 light)
     return (light / scene_light_strength );
 }
 
-vec3 scaleUpLight(vec3 light)
-{
-    return (light * scene_light_strength);
-}
 
diff --git a/indra/newview/app_settings/shaders/class3/deferred/multiPointLightF.glsl b/indra/newview/app_settings/shaders/class3/deferred/multiPointLightF.glsl
index beaea4ce3360e2e7e775a7b8f9224c352548f564..25603b00aabedb29d6c54b11fd6651b2ae0b3904 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/multiPointLightF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/multiPointLightF.glsl
@@ -174,10 +174,7 @@ void main()
         }
     }
 
-    //not sure why, but this line prevents MATBUG-194
-    final_color = max(final_color, vec3(0.0));
-
-    frag_color.rgb = final_color;
+    frag_color.rgb = max(final_color, vec3(0));
     frag_color.a   = 0.0;
 #endif // LOCAL_LIGHT_KILL
 
diff --git a/indra/newview/app_settings/shaders/class3/deferred/pointLightF.glsl b/indra/newview/app_settings/shaders/class3/deferred/pointLightF.glsl
index 215eb696668849cdc0aeb6c600e6e36b8ad8af96..d7c3445d7778401bda2c5211a9081bea9ee649b2 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/pointLightF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/pointLightF.glsl
@@ -149,6 +149,6 @@ void main()
         }
     }
 
-    frag_color.rgb = max(final_color, vec3(0.0));
+    frag_color.rgb = max(final_color, vec3(0));
     frag_color.a = 0.0;
 }
diff --git a/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl b/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl
index e19d780e7fc89ae2d5fb9f04a198850fb1693529..51ab543e6e89c5047a3f8e16d50907aff32060ee 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/softenLightF.glsl
@@ -89,6 +89,8 @@ uniform vec4 waterPlane;
 vec4 applyWaterFogViewLinear(vec3 pos, vec4 color);
 #endif
 
+uniform float sky_hdr_scale;
+
 void calcDiffuseSpecular(vec3 baseColor, float metallic, inout vec3 diffuseColor, inout vec3 specularColor);
 
 vec3 pbrBaseLight(vec3 diffuseColor,
@@ -195,22 +197,17 @@ void main()
         vec3 v = -normalize(pos.xyz);
         color = vec3(1,0,1);
         color = pbrBaseLight(diffuseColor, specularColor, metallic, v, norm.xyz, perceptualRoughness, light_dir, sunlit_linear, scol, radiance, irradiance, colorEmissive, ao, additive, atten);
-
         
         if (do_atmospherics)
         {
-            color = linear_to_srgb(color);
             color = atmosFragLightingLinear(color, additive, atten);
-            color = srgb_to_linear(color);
         }
-        
-        
     }
     else if (!GET_GBUFFER_FLAG(GBUFFER_FLAG_HAS_ATMOS))
     {
         //should only be true of WL sky, just port over base color value
         color = srgb_to_linear(texture2D(emissiveRect, tc).rgb);
-        color *= sun_up_factor + 1.0;
+        color *= sun_up_factor * sky_hdr_scale + 1.0;
     }
     else
     {
diff --git a/indra/newview/featuretable.txt b/indra/newview/featuretable.txt
index da548dd0d46148b89f868a5ab5b0163adcdedb9e..58509b37f3a68248f62c8d79b9fbc11b179afe2d 100644
--- a/indra/newview/featuretable.txt
+++ b/indra/newview/featuretable.txt
@@ -1,4 +1,4 @@
-version 53
+version 54
 // The version number above should be incremented IF AND ONLY IF some
 // change has been made that is sufficiently important to justify
 // resetting the graphics preferences of all users to the recommended
@@ -69,7 +69,8 @@ RenderUseStreamVBO			1	1
 RenderFSAASamples			1	16
 RenderMaxTextureIndex		1	16
 RenderGLContextCoreProfile         1   1
-RenderGLMultiThreaded       1   0
+RenderGLMultiThreadedTextures      1   0
+RenderGLMultiThreadedMedia         1   1
 RenderReflectionProbeResolution 1 128
 RenderScreenSpaceReflections 1  1
 
@@ -308,9 +309,10 @@ list Intel
 RenderAnisotropicLevel			1	0
 RenderFSAASamples			1	0
 RenderGLContextCoreProfile  1   0
+RenderGLMultiThreadedMedia  1   0
 
 list AMD
-RenderGLMultiThreaded       1   1
+RenderGLMultiThreadedTextures       1   1
 
 list GL3
 RenderFSAASamples           0   0
diff --git a/indra/newview/featuretable_mac.txt b/indra/newview/featuretable_mac.txt
index 8732ff230deb0b816227b858b3208025772a9517..c5610b5e41dda7cd685ad28118866dfa824c3f33 100644
--- a/indra/newview/featuretable_mac.txt
+++ b/indra/newview/featuretable_mac.txt
@@ -1,4 +1,4 @@
-version 47
+version 49
 // The version number above should be incremented IF AND ONLY IF some
 // change has been made that is sufficiently important to justify
 // resetting the graphics preferences of all users to the recommended
@@ -44,11 +44,9 @@ RenderGlowResolutionPow		1	9
 RenderMaxPartCount			1	8192
 RenderObjectBump			1	1
 RenderLocalLights			1	1
-RenderTransparentWater      1   1
-RenderReflectionsEnabled    1   1
-RenderReflectionProbeDetail	1	2
 RenderTerrainDetail			1	1
 RenderTerrainLODFactor		1	2.0
+RenderTransparentWater		1	1
 RenderTreeLODFactor			1	1.0
 RenderVBOEnable				1	1
 RenderVBOMappingDisable		1	1
@@ -68,10 +66,13 @@ RenderUseStreamVBO			1	1
 RenderFSAASamples			1	16
 RenderMaxTextureIndex		1	16
 RenderGLContextCoreProfile         1   1
-RenderGLMultiThreaded       1   1
-RenderReflectionProbeResolution 1 128
+RenderGLMultiThreadedTextures      1   0
+RenderGLMultiThreadedMedia         1   0
+RenderReflectionsEnabled    1   1
+RenderReflectionProbeDetail	1	2
 RenderScreenSpaceReflections 1  1
 RenderReflectionProbeCount  1   256
+RenderReflectionProbeResolution 1 128
 
 //
 // Low Graphics Settings
diff --git a/indra/newview/lldrawpoolbump.cpp b/indra/newview/lldrawpoolbump.cpp
index f81b8fd5467d8c1cb553d510f0f6f65a2ff61471..4a11b0f9c90d1c40758a019ec209d27ee9b7cae2 100644
--- a/indra/newview/lldrawpoolbump.cpp
+++ b/indra/newview/lldrawpoolbump.cpp
@@ -1027,7 +1027,7 @@ void LLBumpImageList::onSourceLoaded( BOOL success, LLViewerTexture *src_vi, LLI
 				bump->setExplicitFormat(GL_ALPHA8, GL_ALPHA);
 
 #if LL_BUMPLIST_MULTITHREADED
-                auto tex_queue = LLImageGLThread::sEnabled ? sTexUpdateQueue.lock() : nullptr;
+                auto tex_queue = LLImageGLThread::sEnabledTextures ? sTexUpdateQueue.lock() : nullptr;
 
                 if (tex_queue)
                 { //dispatch creation to background thread
@@ -1139,7 +1139,7 @@ void LLBumpImageList::onSourceLoaded( BOOL success, LLViewerTexture *src_vi, LLI
                 };
 
 #if LL_BUMPLIST_MULTITHREADED
-                auto main_queue = LLImageGLThread::sEnabled ? sMainQueue.lock() : nullptr;
+                auto main_queue = LLImageGLThread::sEnabledTextures ? sMainQueue.lock() : nullptr;
 
                 if (main_queue)
                 { //dispatch texture upload to background thread, issue GPU commands to generate normal map on main thread
diff --git a/indra/newview/llenvironment.cpp b/indra/newview/llenvironment.cpp
index fa140ec0e598777243129133309f4fffbed23e1e..35e5aff474cec328cc244591eff35a81ce86dc66 100644
--- a/indra/newview/llenvironment.cpp
+++ b/indra/newview/llenvironment.cpp
@@ -815,7 +815,7 @@ const F64Seconds LLEnvironment::TRANSITION_SLOW(10.0f);
 const F64Seconds LLEnvironment::TRANSITION_ALTITUDE(5.0f);
 
 const LLUUID LLEnvironment::KNOWN_SKY_SUNRISE("01e41537-ff51-2f1f-8ef7-17e4df760bfb");
-const LLUUID LLEnvironment::KNOWN_SKY_MIDDAY("e4391f43-74d6-d889-19fb-99a4a3ad6c5c");
+const LLUUID LLEnvironment::KNOWN_SKY_MIDDAY("d9950f9a-f693-be73-0384-13ee97b8ca10");
 const LLUUID LLEnvironment::KNOWN_SKY_SUNSET("084e26cd-a900-28e8-08d0-64a9de5c15e2");
 const LLUUID LLEnvironment::KNOWN_SKY_MIDNIGHT("8a01b97a-cb20-c1ea-ac63-f7ea84ad0090");
 
diff --git a/indra/newview/llreflectionmapmanager.cpp b/indra/newview/llreflectionmapmanager.cpp
index 850b293e7c2de94d608d54506170f23a1d16bbfd..9e947774b19a41dc8cd777d9a42101385dd53950 100644
--- a/indra/newview/llreflectionmapmanager.cpp
+++ b/indra/newview/llreflectionmapmanager.cpp
@@ -464,6 +464,13 @@ void LLReflectionMapManager::updateProbeFace(LLReflectionMap* probe, U32 face)
     // hacky hot-swap of camera specific render targets
     gPipeline.mRT = &gPipeline.mAuxillaryRT;
 
+    mLightScale = 1.f;
+    static LLCachedControl<F32> max_local_light_ambiance(gSavedSettings, "RenderReflectionProbeMaxLocalLightAmbiance", 8.f);
+    if (!isRadiancePass() && probe->getAmbiance() > max_local_light_ambiance)
+    {
+        mLightScale = max_local_light_ambiance / probe->getAmbiance();
+    }
+
     if (probe == mDefaultProbe)
     {
         touch_default_probe(probe);
diff --git a/indra/newview/llreflectionmapmanager.h b/indra/newview/llreflectionmapmanager.h
index fef308541dff33edeeb202ef303365c78050882d..9a46af58b35fe4b87d2b15b2158883ee92dc979b 100644
--- a/indra/newview/llreflectionmapmanager.h
+++ b/indra/newview/llreflectionmapmanager.h
@@ -187,5 +187,8 @@ class alignas(16) LLReflectionMapManager
 
     // maximum LoD of reflection probes (mip levels - 1)
     F32 mMaxProbeLOD = 6.f;
+
+    // amount to scale local lights during an irradiance map update (set during updateProbeFace and used by LLPipeline)
+    F32 mLightScale = 1.f;
 };
 
diff --git a/indra/newview/llstartup.cpp b/indra/newview/llstartup.cpp
index 705b5eefa3fed38801d66817648f8a126e45a5ec..caf8bcce00e58e647bc29537a0bc6e6f20779255 100644
--- a/indra/newview/llstartup.cpp
+++ b/indra/newview/llstartup.cpp
@@ -325,7 +325,7 @@ void update_texture_fetch()
 	LLAppViewer::getTextureFetch()->update(1); // unpauses the texture fetch thread
 	gTextureList.updateImages(0.10f);
 
-    if (LLImageGLThread::sEnabled)
+    if (LLImageGLThread::sEnabledTextures)
     {
         std::shared_ptr<LL::WorkQueue> main_queue = LL::WorkQueue::getInstance("mainloop");
         main_queue->runFor(std::chrono::milliseconds(1));
diff --git a/indra/newview/llviewermedia.cpp b/indra/newview/llviewermedia.cpp
index 3ba4d33859af057aca90ebdfa323ba57a745d6a9..2224c909f7ae29e0443773c72d1d630fe6802885 100644
--- a/indra/newview/llviewermedia.cpp
+++ b/indra/newview/llviewermedia.cpp
@@ -2880,7 +2880,7 @@ void LLViewerMediaImpl::update()
     if (preMediaTexUpdate(media_tex, data, data_width, data_height, x_pos, y_pos, width, height))
     {
         // Push update to worker thread
-        auto main_queue = LLImageGLThread::sEnabled ? mMainQueue.lock() : nullptr;
+        auto main_queue = LLImageGLThread::sEnabledMedia ? mMainQueue.lock() : nullptr;
         if (main_queue)
         {
             mTextureUpdatePending = true;
@@ -2969,11 +2969,12 @@ void LLViewerMediaImpl::doMediaTexUpdate(LLViewerMediaTexture* media_tex, U8* da
 
     // wrap "data" in an LLImageRaw but do NOT make a copy
     LLPointer<LLImageRaw> raw = new LLImageRaw(data, media_tex->getWidth(), media_tex->getHeight(), media_tex->getComponents(), true);
-        
+
     // *NOTE: Recreating the GL texture each media update may seem wasteful
     // (note the texture creation in preMediaTexUpdate), however, it apparently
     // prevents GL calls from blocking, due to poor bookkeeping of state of
-    // updated textures by the OpenGL implementation.
+    // updated textures by the OpenGL implementation. (Windows 10/Nvidia)
+    // -Cosmic,2023-04-04
     // Allocate GL texture based on LLImageRaw but do NOT copy to GL
     LLGLuint tex_name = 0;
     media_tex->createGLTexture(0, raw, 0, TRUE, LLGLTexture::OTHER, true, &tex_name);
diff --git a/indra/newview/llviewershadermgr.cpp b/indra/newview/llviewershadermgr.cpp
index 132bd24dad7b15c6e121a6383d17bbeabc938858..3000fe061b4c1c8373620b38ac9954318a5ef2c3 100644
--- a/indra/newview/llviewershadermgr.cpp
+++ b/indra/newview/llviewershadermgr.cpp
@@ -190,6 +190,7 @@ LLGLSLShader			gDeferredCoFProgram;
 LLGLSLShader			gDeferredDoFCombineProgram;
 LLGLSLShader			gDeferredPostGammaCorrectProgram;
 LLGLSLShader			gExposureProgram;
+LLGLSLShader			gLuminanceProgram;
 LLGLSLShader			gFXAAProgram[4];
 LLGLSLShader			gDeferredPostNoDoFProgram;
 LLGLSLShader			gDeferredWLSkyProgram;
@@ -1016,6 +1017,7 @@ BOOL LLViewerShaderMgr::loadShadersDeferred()
 		gDeferredCoFProgram.unload();		
 		gDeferredDoFCombineProgram.unload();
         gExposureProgram.unload();
+        gLuminanceProgram.unload();
 		gDeferredPostGammaCorrectProgram.unload();
         for (auto i = 0; i < 4; ++i)
         {
@@ -2564,6 +2566,18 @@ BOOL LLViewerShaderMgr::loadShadersDeferred()
         llassert(success);
     }
 
+    if (success)
+    {
+        gLuminanceProgram.mName = "Luminance";
+        gLuminanceProgram.mShaderFiles.clear();
+        gLuminanceProgram.clearPermutations();
+        gLuminanceProgram.mShaderFiles.push_back(make_pair("deferred/postDeferredNoTCV.glsl", GL_VERTEX_SHADER));
+        gLuminanceProgram.mShaderFiles.push_back(make_pair("deferred/luminanceF.glsl", GL_FRAGMENT_SHADER));
+        gLuminanceProgram.mShaderLevel = mShaderLevel[SHADER_DEFERRED];
+        success = gLuminanceProgram.createShader(NULL, NULL);
+        llassert(success);
+    }
+
 	if (success)
 	{
 		gDeferredPostGammaCorrectProgram.mName = "Deferred Gamma Correction Post Process";
diff --git a/indra/newview/llviewershadermgr.h b/indra/newview/llviewershadermgr.h
index 7e6595f8e0ad5bcd1805ee131dfe408714fe5edf..69c1e3060eb20a2254944dfa6f161bd7cf566e43 100644
--- a/indra/newview/llviewershadermgr.h
+++ b/indra/newview/llviewershadermgr.h
@@ -241,6 +241,7 @@ extern LLGLSLShader			gFXAAProgram[4];
 extern LLGLSLShader			gDeferredPostNoDoFProgram;
 extern LLGLSLShader			gDeferredPostGammaCorrectProgram;
 extern LLGLSLShader			gExposureProgram;
+extern LLGLSLShader			gLuminanceProgram;
 extern LLGLSLShader			gDeferredAvatarShadowProgram;
 extern LLGLSLShader			gDeferredAvatarAlphaShadowProgram;
 extern LLGLSLShader			gDeferredAvatarAlphaMaskShadowProgram;
diff --git a/indra/newview/llviewertexture.cpp b/indra/newview/llviewertexture.cpp
index 08678999b4a3ce95e6b53b24b5b2de319d38a5a2..03e994f120079e15dd070fe823ffcf802cf717aa 100644
--- a/indra/newview/llviewertexture.cpp
+++ b/indra/newview/llviewertexture.cpp
@@ -1628,7 +1628,7 @@ void LLViewerFetchedTexture::scheduleCreateTexture()
             }
 #endif
             mNeedsCreateTexture = true;
-            auto mainq = LLImageGLThread::sEnabled ? mMainQueue.lock() : nullptr;
+            auto mainq = LLImageGLThread::sEnabledTextures ? mMainQueue.lock() : nullptr;
             if (mainq)
             {
                 ref();
diff --git a/indra/newview/llviewertexturelist.cpp b/indra/newview/llviewertexturelist.cpp
index 336ce2bd5882e4445239dd9c0f9451c0ca748eb2..23c98096610765b0b2304e1ea9320d71e3780321 100644
--- a/indra/newview/llviewertexturelist.cpp
+++ b/indra/newview/llviewertexturelist.cpp
@@ -1242,7 +1242,7 @@ void LLViewerTextureList::decodeAllImages(F32 max_time)
 		LLViewerFetchedTexture* imagep = *iter++;
 		imagep->updateFetch();
 	}
-    std::shared_ptr<LL::WorkQueue> main_queue = LLImageGLThread::sEnabled ? LL::WorkQueue::getInstance("mainloop") : NULL;
+    std::shared_ptr<LL::WorkQueue> main_queue = LLImageGLThread::sEnabledTextures ? LL::WorkQueue::getInstance("mainloop") : NULL;
 	// Run threads
 	S32 fetch_pending = 0;
 	while (1)
@@ -1251,7 +1251,7 @@ void LLViewerTextureList::decodeAllImages(F32 max_time)
 		LLAppViewer::instance()->getImageDecodeThread()->update(1); // unpauses the image thread
 		fetch_pending = LLAppViewer::instance()->getTextureFetch()->update(1); // unpauses the texture fetch thread
 
-        if (LLImageGLThread::sEnabled)
+        if (LLImageGLThread::sEnabledTextures)
         {
             main_queue->runFor(std::chrono::milliseconds(1));
             fetch_pending += main_queue->size();
diff --git a/indra/newview/llviewerwindow.cpp b/indra/newview/llviewerwindow.cpp
index 0c8866e0e30950f11e5d5cbd5df42c1c537fc106..24f5c6de443333686220417e9db29a291dd2151e 100644
--- a/indra/newview/llviewerwindow.cpp
+++ b/indra/newview/llviewerwindow.cpp
@@ -2016,8 +2016,8 @@ LLViewerWindow::LLViewerWindow(const Params& p)
 	}
 		
 	// Init the image list.  Must happen after GL is initialized and before the images that
-	// LLViewerWindow needs are requested.
-    LLImageGL::initClass(mWindow, LLViewerTexture::MAX_GL_IMAGE_CATEGORY, false, gSavedSettings.getBOOL("RenderGLMultiThreaded"));
+	// LLViewerWindow needs are requested, as well as before LLViewerMedia starts updating images.
+    LLImageGL::initClass(mWindow, LLViewerTexture::MAX_GL_IMAGE_CATEGORY, false, gSavedSettings.getBOOL("RenderGLMultiThreadedTextures"), gSavedSettings.getBOOL("RenderGLMultiThreadedMedia"));
 	gTextureList.init();
 	LLViewerTextureManager::init() ;
 	gBumpImageList.init();
diff --git a/indra/newview/pipeline.cpp b/indra/newview/pipeline.cpp
index 1e4f81f237d77982941765b6d5953039a1859450..304ac3ce66ff0e883ef29e6f0da58a79f51ed6ab 100644
--- a/indra/newview/pipeline.cpp
+++ b/indra/newview/pipeline.cpp
@@ -849,7 +849,7 @@ bool LLPipeline::allocateScreenBuffer(U32 resX, U32 resY, U32 samples)
 	if (shadow_detail > 0 || ssao || RenderDepthOfField || samples > 0 || RlvActions::hasPostProcess())
 // [/RLVa:KB]
 	{ //only need mRT->deferredLight for shadows OR ssao OR dof OR fxaa
-		if (!mRT->deferredLight.allocate(resX, resY, screenFormat)) return false;
+		if (!mRT->deferredLight.allocate(resX, resY, GL_RGBA16F)) return false;
 	}
 	else
 	{
@@ -1148,6 +1148,7 @@ void LLPipeline::releaseLUTBuffers()
     mPbrBrdfLut.release();
 
     mExposureMap.release();
+    mLuminanceMap.release();
     mLastExposure.release();
 
 }
@@ -1399,6 +1400,8 @@ void LLPipeline::createLUTBuffers()
     mExposureMap.clear();
     mExposureMap.flush();
 
+    mLuminanceMap.allocate(256, 256, GL_R16F);
+
     mLastExposure.allocate(1, 1, GL_R16F);
 }
 
@@ -5734,6 +5737,14 @@ void LLPipeline::setupHWLights()
         return;
     }
 
+    F32 light_scale = 1.f;
+
+    if (gCubeSnapshot)
+    { //darken local lights when probe ambiance is above 1
+        light_scale = mReflectionMapManager.mLightScale;
+    }
+
+
     LLEnvironment& environment = LLEnvironment::instance();
 	const LLSettingsSky::ptr_t& psky = environment.getCurrentSky();
 
@@ -5833,7 +5844,7 @@ void LLPipeline::setupHWLights()
 			}
 			
             //send linear light color to shader
-			LLColor4  light_color = light->getLightLinearColor();
+            LLColor4  light_color = light->getLightLinearColor() * light_scale;
 			light_color.mV[3] = 0.0f;
 
 			F32 fade = iter->fade;
@@ -7324,6 +7335,43 @@ void LLPipeline::renderFinalize()
             dst.flush();
         }
 
+        // luminance sample and mipmap generation
+        {
+            LL_PROFILE_GPU_ZONE("luminance sample");
+
+            mLuminanceMap.bindTarget();
+
+            LLGLDepthTest depth(GL_FALSE, GL_FALSE);
+
+            gLuminanceProgram.bind();
+
+
+            S32 channel = 0;
+            channel = gLuminanceProgram.enableTexture(LLShaderMgr::DEFERRED_DIFFUSE);
+            if (channel > -1)
+            {
+                screenTarget()->bindTexture(0, channel, LLTexUnit::TFO_POINT);
+            }
+
+            channel = gLuminanceProgram.enableTexture(LLShaderMgr::DEFERRED_EMISSIVE);
+            if (channel > -1)
+            {
+                mGlow[1].bindTexture(0, channel);
+            }
+
+
+            mScreenTriangleVB->setBuffer();
+            mScreenTriangleVB->drawArrays(LLRender::TRIANGLES, 0, 3);
+            mLuminanceMap.flush();
+
+            mLuminanceMap.bindTexture(0, 0, LLTexUnit::TFO_TRILINEAR);
+            glGenerateMipmap(GL_TEXTURE_2D);
+
+            // note -- unbind AFTER the glGenerateMipMap so time in generatemipmap can be profiled under "Luminance"
+            // also note -- keep an eye on the performance of glGenerateMipmap, might need to replace it with a mip generation shader
+            gLuminanceProgram.unbind();
+        }
+
         // exposure sample
         {
             LL_PROFILE_GPU_ZONE("exposure sample");
@@ -7340,24 +7388,16 @@ void LLPipeline::renderFinalize()
                 mLastExposure.flush();
             }
 
-
             mExposureMap.bindTarget();
 
             LLGLDepthTest depth(GL_FALSE, GL_FALSE);
             
             gExposureProgram.bind();
 
-            S32 channel = 0;
-            channel = gExposureProgram.enableTexture(LLShaderMgr::DEFERRED_DIFFUSE);
+            S32 channel = gExposureProgram.enableTexture(LLShaderMgr::DEFERRED_EMISSIVE);
             if (channel > -1)
             {
-                screenTarget()->bindTexture(0, channel, LLTexUnit::TFO_POINT);
-            }
-
-            channel = gExposureProgram.enableTexture(LLShaderMgr::DEFERRED_EMISSIVE);
-            if (channel > -1)
-            {
-                mGlow[1].bindTexture(0, channel);
+                mLuminanceMap.bindTexture(0, channel, LLTexUnit::TFO_TRILINEAR);
             }
 
             channel = gExposureProgram.enableTexture(LLShaderMgr::EXPOSURE_MAP);
@@ -7366,11 +7406,17 @@ void LLPipeline::renderFinalize()
                 mLastExposure.bindTexture(0, channel);
             }
 
+            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);
+
             static LLStaticHashedString dt("dt");
             static LLStaticHashedString noiseVec("noiseVec");
+            static LLStaticHashedString dynamic_exposure_params("dynamic_exposure_params");
             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, dynamic_exposure_max);
+
             mScreenTriangleVB->setBuffer();
             mScreenTriangleVB->drawArrays(LLRender::TRIANGLES, 0, 3);
 
@@ -7938,6 +7984,13 @@ void LLPipeline::renderDeferredLighting()
 
     llassert(!sRenderingHUDs);
 
+    F32 light_scale = 1.f;
+
+    if (gCubeSnapshot)
+    { //darken local lights when probe ambiance is above 1
+        light_scale = mReflectionMapManager.mLightScale;
+    }
+
     LLRenderTarget *screen_target         = &mRT->screen;
     LLRenderTarget* deferred_light_target = &mRT->deferredLight;
 
@@ -8072,9 +8125,13 @@ 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");
+
             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);
 
@@ -8151,7 +8208,7 @@ void LLPipeline::renderDeferredLighting()
                     F32        s = volume->getLightRadius() * 1.5f;
 
                     // send light color to shader in linear space
-                    LLColor3 col = volume->getLightLinearColor();
+                    LLColor3 col = volume->getLightLinearColor() * light_scale;
 
                     if (col.magVecSquared() < 0.001f)
                     {
@@ -8246,7 +8303,7 @@ void LLPipeline::renderDeferredLighting()
                     setupSpotLight(gDeferredSpotLightProgram, drawablep);
 
                     // send light color to shader in linear space
-                    LLColor3 col = volume->getLightLinearColor();
+                    LLColor3 col = volume->getLightLinearColor() * light_scale;
 
                     gDeferredSpotLightProgram.uniform3fv(LLShaderMgr::LIGHT_CENTER, 1, c);
                     gDeferredSpotLightProgram.uniform1f(LLShaderMgr::LIGHT_SIZE, s);
@@ -8321,7 +8378,7 @@ void LLPipeline::renderDeferredLighting()
                     setupSpotLight(gDeferredMultiSpotLightProgram, drawablep);
 
                     // send light color to shader in linear space
-                    LLColor3 col = volume->getLightLinearColor();
+                    LLColor3 col = volume->getLightLinearColor() * light_scale;
 
                     gDeferredMultiSpotLightProgram.uniform3fv(LLShaderMgr::LIGHT_CENTER, 1, center.getF32ptr());
                     gDeferredMultiSpotLightProgram.uniform1f(LLShaderMgr::LIGHT_SIZE, light_size_final);
diff --git a/indra/newview/pipeline.h b/indra/newview/pipeline.h
index a57926337b96ca103b1828a785601ab0c5151aef..b4d5d352efa2066e4e9fb35b6511ef438eadd2f3 100644
--- a/indra/newview/pipeline.h
+++ b/indra/newview/pipeline.h
@@ -662,6 +662,7 @@ class LLPipeline
     LLRenderTarget          mSceneMap;
 
     // exposure map for getting average color in scene
+    LLRenderTarget          mLuminanceMap;
     LLRenderTarget          mExposureMap;
     LLRenderTarget          mLastExposure;