Factor out the procedural sky shader

Assets/ScriptableRenderLoop/HDRenderLoop/Sky/Resources/SkyHDRI.shader

             #include "Common.hlsl"
             #include "CommonLighting.hlsl"
             #include "Assets/ScriptableRenderLoop/HDRenderLoop/ShaderVariables.hlsl"
-            #include "AtmosphericScattering.hlsl"
 
             TEXTURECUBE(_Cubemap);
             SAMPLERCUBE(sampler_Cubemap);
                 float3 rotDirY = float3(sinPhi, 0, cosPhi);
                 dir = float3(dot(rotDirX, dir), dir.y, dot(rotDirY, dir));
 
-                /*
-                Coordinate coord = GetCoordinate(input.positionCS.xy, _ScreenSize.zw);
-
-                // If the sky box is too far away (depth set to 0), the resulting look is too foggy.
-                const float skyDepth = 0.01;
-
-                #ifdef PERFORM_SKY_OCCLUSION_TEST
-                    // Determine whether the sky is occluded by the scene geometry.
-                    // Do not perform blending with the environment map if the sky is occluded.
-                    float rawDepth     = max(skyDepth, LOAD_TEXTURE2D(_CameraDepthTexture, coord.unPositionSS).r);
-                    float skyTexWeight = (rawDepth > skyDepth) ? 0.0 : 1.0;
-                #else
-                    float rawDepth     = skyDepth;
-                    float skyTexWeight = 1.0;
-                #endif
-
-                float3 positionWS = UnprojectToWorld(rawDepth, coord.positionSS, _InvViewProjMatrix);
-
-                float4 c1, c2, c3;
-                VolundTransferScatter(positionWS, c1, c2, c3);
-
-                float4 coord1 = float4(c1.rgb + c3.rgb, max(0.f, 1.f - c1.a - c3.a));
-                float3 coord2 = c2.rgb;
-
-                float sunCos = dot(normalize(dir), _SunDirection);
-                float miePh  = MiePhase(sunCos, _MiePhaseAnisotropy);
-
-                float2 occlusion  = float2(1.0, 1.0); // TODO.
-                float  extinction = coord1.a;
-                float3 scatter    = coord1.rgb * occlusion.x + coord2 * miePh * occlusion.y;
-
-                #ifdef ATMOSPHERICS_DEBUG
-                    switch (_AtmosphericsDebugMode)
-                    {
-                        case ATMOSPHERICS_DBG_RAYLEIGH:           return c1;
-                        case ATMOSPHERICS_DBG_MIE:                return c2 * miePh;
-                        case ATMOSPHERICS_DBG_HEIGHT:             return c3;
-                        case ATMOSPHERICS_DBG_SCATTERING:         return float4(scatter, 0.0);
-                        case ATMOSPHERICS_DBG_OCCLUSION:          return float4(occlusion.xy, 0.0, 0.0);
-                        case ATMOSPHERICS_DBG_OCCLUDEDSCATTERING: return float4(scatter, 0.0);
-                    }
-                #endif
-
-                */
-
-
-                // Apply extinction to the scene color when performing alpha-blending.
-                //return float4(skyColor * (skyTexWeight * extinction) + scatter, extinction);
             }
 
             ENDHLSL

Assets/ScriptableRenderLoop/HDRenderLoop/Sky/Resources/SkyProcedural.shader

+Shader "Hidden/HDRenderLoop/SkyHDRI"
+{
+    SubShader
+    {
+        Pass
+        {
+            ZWrite Off
+            ZTest LEqual
+            Blend One Zero
+
+            HLSLPROGRAM
+            #pragma target 5.0
+            #pragma only_renderers d3d11 // TEMP: unitl we go futher in dev
+
+            #pragma vertex Vert
+            #pragma fragment Frag
+
+            #pragma multi_compile _ ATMOSPHERICS_DEBUG
+            #pragma multi_compile _ ATMOSPHERICS_OCCLUSION_FULLSKY
+            #pragma multi_compile _ PERFORM_SKY_OCCLUSION_TEST
+
+            #ifndef PERFORM_SKY_OCCLUSION_TEST
+                #define IS_RENDERING_SKY
+            #endif
+
+            #include "Color.hlsl"
+            #include "Common.hlsl"
+            #include "CommonLighting.hlsl"
+            #include "Assets/ScriptableRenderLoop/HDRenderLoop/ShaderVariables.hlsl"
+            #include "AtmosphericScattering.hlsl"
+
+            TEXTURECUBE(_Cubemap);
+            SAMPLERCUBE(sampler_Cubemap);
+
+            float4x4 _InvViewProjMatrix;
+            float4   _SkyParam; // x exposure, y multiplier, z rotation
+
+            struct Attributes
+            {
+                float3 positionCS : POSITION;
+                float3 eyeVector : NORMAL;
+            };
+
+            struct Varyings
+            {
+                float4 positionCS : SV_POSITION;
+                float3 eyeVector : TEXCOORD0;
+            };
+
+            Varyings Vert(Attributes input)
+            {
+                // TODO: implement SV_vertexID full screen quad
+                Varyings output;
+                output.positionCS = float4(input.positionCS.xy, UNITY_RAW_FAR_CLIP_VALUE, 1.0);
+                output.eyeVector  = input.eyeVector;
+
+                return output;
+            }
+
+            float4 Frag(Varyings input) : SV_Target
+            {
+                float3 dir = normalize(input.eyeVector);
+
+                // Rotate direction
+                float phi = DegToRad(_SkyParam.z);
+                float cosPhi, sinPhi;
+                sincos(phi, sinPhi, cosPhi);
+                float3 rotDirX = float3(cosPhi, 0, -sinPhi);
+                float3 rotDirY = float3(sinPhi, 0, cosPhi);
+                dir = float3(dot(rotDirX, dir), dir.y, dot(rotDirY, dir));
+
+                Coordinate coord = GetCoordinate(input.positionCS.xy, _ScreenSize.zw);
+
+                // If the sky box is too far away (depth set to 0), the resulting look is too foggy.
+                const float skyDepth = 0.01;
+
+                #ifdef PERFORM_SKY_OCCLUSION_TEST
+                    // Determine whether the sky is occluded by the scene geometry.
+                    // Do not perform blending with the environment map if the sky is occluded.
+                    float rawDepth     = max(skyDepth, LOAD_TEXTURE2D(_CameraDepthTexture, coord.unPositionSS).r);
+                    float skyTexWeight = (rawDepth > skyDepth) ? 0.0 : 1.0;
+                #else
+                    float rawDepth     = skyDepth;
+                    float skyTexWeight = 1.0;
+                #endif
+
+                float3 positionWS = UnprojectToWorld(rawDepth, coord.positionSS, _InvViewProjMatrix);
+
+                float4 c1, c2, c3;
+                VolundTransferScatter(positionWS, c1, c2, c3);
+
+                float4 coord1 = float4(c1.rgb + c3.rgb, max(0.f, 1.f - c1.a - c3.a));
+                float3 coord2 = c2.rgb;
+
+                float sunCos = dot(normalize(dir), _SunDirection);
+                float miePh  = MiePhase(sunCos, _MiePhaseAnisotropy);
+
+                float2 occlusion  = float2(1.0, 1.0); // TODO.
+                float  extinction = coord1.a;
+                float3 scatter    = coord1.rgb * occlusion.x + coord2 * miePh * occlusion.y;
+
+                #ifdef ATMOSPHERICS_DEBUG
+                    switch (_AtmosphericsDebugMode)
+                    {
+                        case ATMOSPHERICS_DBG_RAYLEIGH:           return c1;
+                        case ATMOSPHERICS_DBG_MIE:                return c2 * miePh;
+                        case ATMOSPHERICS_DBG_HEIGHT:             return c3;
+                        case ATMOSPHERICS_DBG_SCATTERING:         return float4(scatter, 0.0);
+                        case ATMOSPHERICS_DBG_OCCLUSION:          return float4(occlusion.xy, 0.0, 0.0);
+                        case ATMOSPHERICS_DBG_OCCLUDEDSCATTERING: return float4(scatter, 0.0);
+                    }
+                #endif
+
+                float3 skyColor = ClampToFloat16Max(SAMPLE_TEXTURECUBE_LOD(_Cubemap, sampler_Cubemap, dir, 0).rgb * exp2(_SkyParam.x) * _SkyParam.y);
+
+                // Apply extinction to the scene color when performing alpha-blending.
+                return float4(skyColor * (skyTexWeight * extinction) + scatter, extinction);
+            }
+
+            ENDHLSL
+        }
+
+    }
+    Fallback Off
+}

Assets/ScriptableRenderLoop/HDRenderLoop/Sky/Resources/SkyProcedural.shader.meta

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+guid: f96d105ca709d5c499b4886b48313d60
+timeCreated: 1481041226
+licenseType: Pro
+ShaderImporter:
+  defaultTextures: []
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: