Added global fog toggle.

ScriptableRenderPipeline/HDRenderPipeline/Debug/DebugDisplay.cs

 
             DebugMenuManager.instance.AddDebugItem<bool>("Rendering", "Display Opaque",() => renderingDebugSettings.displayOpaqueObjects, (value) => renderingDebugSettings.displayOpaqueObjects = (bool)value);
             DebugMenuManager.instance.AddDebugItem<bool>("Rendering", "Display Transparency",() => renderingDebugSettings.displayTransparentObjects, (value) => renderingDebugSettings.displayTransparentObjects = (bool)value);
+            DebugMenuManager.instance.AddDebugItem<bool>("Rendering", "Enable Atmospheric Scattering",() => renderingDebugSettings.enableAtmosphericScattering, (value) => renderingDebugSettings.enableAtmosphericScattering = (bool)value);
             DebugMenuManager.instance.AddDebugItem<bool>("Rendering", "Enable Distortion",() => renderingDebugSettings.enableDistortion, (value) => renderingDebugSettings.enableDistortion = (bool)value);
             DebugMenuManager.instance.AddDebugItem<bool>("Rendering", "Enable Subsurface Scattering",() => renderingDebugSettings.enableSSSAndTransmission, (value) => renderingDebugSettings.enableSSSAndTransmission = (bool)value);
             DebugMenuManager.instance.AddDebugItem<int>("Rendering", kFullScreenDebugMode, () => (int)fullScreenDebugMode, (value) => fullScreenDebugMode = (FullScreenDebugMode)value, DebugItemFlag.None, new DebugItemHandlerIntEnum(DebugDisplaySettings.renderingFullScreenDebugStrings, DebugDisplaySettings.renderingFullScreenDebugValues));
         public bool enableDistortion = true;
         public bool enableGaussianPyramid = true;
         public bool enableSSSAndTransmission = true;
+        public bool enableAtmosphericScattering = true;
     }
 
     public enum ShadowMapDebugMode

ScriptableRenderPipeline/HDRenderPipeline/HDRenderPipeline.cs

 
         void RenderSky(HDCamera hdCamera, CommandBuffer cmd)
         {
-            m_SkyManager.RenderSky(hdCamera, m_LightLoop.GetCurrentSunLight(), m_CameraColorBufferRT, m_CameraDepthStencilBufferRT, cmd);
+            m_SkyManager.RenderSky(hdCamera, m_LightLoop.GetCurrentSunLight(), m_CameraColorBufferRT, m_CameraDepthStencilBufferRT, cmd, m_DebugDisplaySettings);
             m_SkyManager.RenderOpaqueAtmosphericScattering(cmd);
         }
 

ScriptableRenderPipeline/HDRenderPipeline/Sky/AtmosphericScattering/AtmosphericScattering.cs

             return type != FogType.None;
         }
 
-        public void PushShaderParameters(CommandBuffer cmd)
+        public void PushShaderParameters(CommandBuffer cmd, RenderingDebugSettings renderingDebug)
-            cmd.SetGlobalFloat(m_TypeParam, (float)type);
+            if(renderingDebug.enableAtmosphericScattering)
+                cmd.SetGlobalFloat(m_TypeParam, (float)type);
+            else
+                cmd.SetGlobalFloat(m_TypeParam, (float)FogType.None);
             // Fog Color
             cmd.SetGlobalFloat(m_ColorModeParam, (float)colorMode);
             cmd.SetGlobalColor(m_FogColorParam, fogColor);

ScriptableRenderPipeline/HDRenderPipeline/Sky/SkyManager.cs

             }
         }
 
-        public void RenderSky(HDCamera camera, Light sunLight, RenderTargetIdentifier colorBuffer, RenderTargetIdentifier depthBuffer, CommandBuffer cmd)
+        public void RenderSky(HDCamera camera, Light sunLight, RenderTargetIdentifier colorBuffer, RenderTargetIdentifier depthBuffer, CommandBuffer cmd, DebugDisplaySettings debugSettings)
         {
             using (new ProfilingSample(cmd, "Sky Pass"))
             {
-                    m_SkySettings.atmosphericScatteringSettings.PushShaderParameters(cmd);
+                    m_SkySettings.atmosphericScatteringSettings.PushShaderParameters(cmd, debugSettings.renderingDebugSettings);
 
                     m_BuiltinParameters.commandBuffer = cmd;
                     m_BuiltinParameters.sunLight = sunLight;