Cleanup HDRI sky code

com.unity.render-pipelines.high-definition/HDRP/Editor/Sky/HDRISky/HDRISkyEditor.cs

         public override void OnInspectorGUI()
         {
             EditorGUI.BeginChangeCheck();
-            PropertyField(m_hdriSky);
-            if (EditorGUI.EndChangeCheck())
-                GetUpperHemisphereLuxValue();
+                PropertyField(m_hdriSky);
+    
+                EditorGUILayout.Space();
+                
+                PropertyField(m_IntensityMode);
-
-            EditorGUILayout.Space();
-            
-            PropertyField(m_IntensityMode);
+            if (EditorGUI.EndChangeCheck())
+                GetUpperHemisphereLuxValue();
 
             if (m_IntensityMode.value.enumValueIndex == (int)SkyIntensityMode.Lux)
             {

com.unity.render-pipelines.high-definition/HDRP/RenderPipeline/HDStringConstants.cs

         public static readonly int _Cubemap = Shader.PropertyToID("_Cubemap");
         public static readonly int _InvOmegaP = Shader.PropertyToID("_InvOmegaP");
         public static readonly int _SkyParam = Shader.PropertyToID("_SkyParam");
-        public static readonly int _SkyIntensity = Shader.PropertyToID("_SkyIntensity");
         public static readonly int _PixelCoordToViewDirWS = Shader.PropertyToID("_PixelCoordToViewDirWS");
 
         public static readonly int _Size = Shader.PropertyToID("_Size");

com.unity.render-pipelines.high-definition/HDRP/Sky/HDRISky/HDRISky.shader

     TEXTURECUBE(_Cubemap);
     SAMPLER(sampler_Cubemap);
 
-    TEXTURE2D(_SkyIntensity);
-    SAMPLER(sampler_SkyIntensity);
-
     float4   _SkyParam; // x exposure, y multiplier, z rotation, w lux
     float4x4 _PixelCoordToViewDirWS; // Actually just 3x3, but Unity can only set 4x4
 
         float3 rotDirY = float3(sinPhi, 0, cosPhi);
         dir = float3(dot(rotDirX, dir), dir.y, dot(rotDirY, dir));
 
-        float intensity = _SkyParam.w / SAMPLE_TEXTURE2D_LOD(_SkyIntensity, sampler_SkyIntensity, float2(0.5, 0.5), 0).x;
-        float3 skyColor = ClampToFloat16Max(SAMPLE_TEXTURECUBE_LOD(_Cubemap, sampler_Cubemap, dir, 0).rgb * exp2(_SkyParam.x) * _SkyParam.y * intensity);
+        float3 skyColor = ClampToFloat16Max(SAMPLE_TEXTURECUBE_LOD(_Cubemap, sampler_Cubemap, dir, 0).rgb * exp2(_SkyParam.x) * _SkyParam.y);
         return float4(skyColor, 1.0);
     }
 

com.unity.render-pipelines.high-definition/HDRP/Sky/HDRISky/HDRISkyRenderer.cs

             }
         }
         
-        public override void UpdateSky(BuiltinSkyParameters builtinParams)
-        {
-            using (new ProfilingSample(builtinParams.commandBuffer, "Get hdri skybox intensity"))
-            {
-                // if (m_HdriSkyParams.updateHDRISkyIntensity)
-            }
-        }
-
-            float lux = (m_HdriSkyParams.skyIntensityMode == SkyIntensityMode.Lux) ? m_HdriSkyParams.lux.value : 1;
-            float multiplier = (m_HdriSkyParams.skyIntensityMode == SkyIntensityMode.Exposure) ? m_HdriSkyParams.multiplier.value : 1;
+            float luxMultiplier = m_HdriSkyParams.desiredLuxValue.value / m_HdriSkyParams.upperHemisphereLuxValue.value;
+            float multiplier = (m_HdriSkyParams.skyIntensityMode == SkyIntensityMode.Exposure) ? m_HdriSkyParams.multiplier.value : luxMultiplier;
-            m_SkyHDRIMaterial.SetVector(HDShaderIDs._SkyParam, new Vector4(exposure, multiplier, -m_HdriSkyParams.rotation, lux)); // -rotation to match Legacy...
+            m_SkyHDRIMaterial.SetVector(HDShaderIDs._SkyParam, new Vector4(exposure, multiplier, -m_HdriSkyParams.rotation, 0.0f)); // -rotation to match Legacy...
-                // Bind a white texture if the intensity mode isn't lux so we sample an intensity of 1
-                // if (m_HdriSkyParams.skyIntensityMode == SkyIntensityMode.Lux)
-                    // m_SkyHDRIMaterial.SetTexture(HDShaderIDs._SkyIntensity, m_IntensityTexture);
-                // else
-                    m_SkyHDRIMaterial.SetTexture(HDShaderIDs._SkyIntensity, Texture2D.whiteTexture);
-    
                 // This matrix needs to be updated at the draw call frequency.
                 m_PropertyBlock.SetMatrix(HDShaderIDs._PixelCoordToViewDirWS, builtinParams.pixelCoordToViewDirMatrix);
     

com.unity.render-pipelines.high-definition/HDRP/Sky/SkyRenderer.cs

         public abstract void RenderSky(BuiltinSkyParameters builtinParams, bool renderForCubemap, bool renderSunDisk);
         public abstract bool IsValid();
 
-        public virtual void  UpdateSky(BuiltinSkyParameters builtinParams) {}
-
         protected float GetExposure(SkySettings skySettings, DebugDisplaySettings debugSettings)
         {
             float debugExposure = 0.0f;

com.unity.render-pipelines.high-definition/HDRP/Sky/SkyRenderingContext.cs

                 m_BuiltinParameters.colorBuffer = m_SkyboxCubemapRT;
                 m_BuiltinParameters.depthBuffer = null;
                 m_BuiltinParameters.hdCamera = null;
-                
-                skyContext.renderer.UpdateSky(m_BuiltinParameters);
 
                 CoreUtils.SetRenderTarget(m_BuiltinParameters.commandBuffer, m_SkyboxCubemapRT, ClearFlag.None, 0, (CubemapFace)i);
                 skyContext.renderer.RenderSky(m_BuiltinParameters, true, skyContext.skySettings.includeSunInBaking);
                 {
                     using (new ProfilingSample(cmd, "Sky Environment Pass"))
                     {
-                        skyContext.skySettings.updateHDRISkyIntensity.value = true;
-
                         using (new ProfilingSample(cmd, "Update Env: Generate Lighting Cubemap"))
                         {
                             RenderSkyToCubemap(skyContext);
                     m_BuiltinParameters.depthBuffer = depthBuffer;
                     m_BuiltinParameters.hdCamera = hdCamera;
                     m_BuiltinParameters.debugSettings = debugSettings;
-
-                    skyContext.renderer.UpdateSky(m_BuiltinParameters);
 
                     skyContext.renderer.SetRenderTargets(m_BuiltinParameters);
                     // When rendering the visual sky for reflection probes, we need to remove the sun disk if skySettings.includeSunInBaking is false.

com.unity.render-pipelines.high-definition/HDRP/Sky/SkySettings.cs

         public EnvUpdateParameter       updateMode = new EnvUpdateParameter(EnvironementUpdateMode.OnChanged);
         [Tooltip("If environment update is set to realtime, period in seconds at which it is updated (0.0 means every frame).")]
         public MinFloatParameter        updatePeriod = new MinFloatParameter(0.0f, 0.0f);
-        [HideInInspector]
-        public BoolParameter            updateHDRISkyIntensity = new BoolParameter(false);
         [Tooltip("If set to true, the sun disk will be used in baked lighting (ambient and reflection probes).")]
         public BoolParameter            includeSunInBaking = new BoolParameter(false);
 
                 hash = hash * 23 + rotation.GetHashCode();
                 hash = hash * 23 + exposure.GetHashCode();
                 hash = hash * 23 + multiplier.GetHashCode();
-                hash = hash * 23 + lux.GetHashCode();
+                hash = hash * 23 + desiredLuxValue.GetHashCode();
 
                 // TODO: Fixme once we switch to .Net 4.6+
                 //>>>