Use only a single screen space setting for SSR

Updated UI

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Lighting/Reflection/HDScreenSpaceReflectionEditor.cs

 using System.Collections;
 using UnityEngine;
-using UnityEditor;
-using UnityEditor.Experimental.Rendering;
+using UnityEngine.Experimental.Rendering.HDPipeline;
-namespace UnityEngine.Experimental.Rendering.HDPipeline
+namespace UnityEditor.Experimental.Rendering.HDPipeline
 {
     [CanEditMultipleObjects]
     [VolumeComponentEditor(typeof(ScreenSpaceReflection))]
 
         public override void OnInspectorGUI()
         {
-            base.OnInspectorGUI();
+            OnCommonInspectorGUI();
+            var projectionModel = (Lit.ProjectionModel)m_DeferredProjectionModel.value.enumValueIndex;
+            switch (projectionModel)
+            {
+                case Lit.ProjectionModel.HiZ:
+                    EditorGUILayout.Separator();
+                    OnHiZInspectorGUI();
+                    break;
+            }
+        }
-            EditorGUILayout.LabelField(CoreEditorUtils.GetContent("Deferred Settings"));
+        protected override void OnCommonInspectorGUI()
+        {
+            base.OnCommonInspectorGUI();
             PropertyField(m_DeferredProjectionModel, CoreEditorUtils.GetContent("Projection Model"));
         }
     }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Lighting/Reflection/ScreenSpaceLightingEditor.cs

 using System.Collections;
 using UnityEngine;
-using UnityEditor;
-using UnityEditor.Experimental.Rendering;
+using UnityEngine.Experimental.Rendering.HDPipeline;
-namespace UnityEngine.Experimental.Rendering.HDPipeline
+namespace UnityEditor.Experimental.Rendering.HDPipeline
 {
     public class ScreenSpaceLightingEditor : VolumeComponentEditor
     {
 
         public override void OnInspectorGUI()
         {
+            OnCommonInspectorGUI();
+            EditorGUILayout.Separator();
+            OnHiZInspectorGUI();
+        }
+
+        protected virtual void OnHiZInspectorGUI()
+        {
+        }
-            EditorGUILayout.Separator();
+        protected virtual void OnCommonInspectorGUI()
+        {
             EditorGUILayout.LabelField(CoreEditorUtils.GetContent("Common Settings"));
             PropertyField(m_ScreenWeightDistance, CoreEditorUtils.GetContent("Screen Weight Distance"));
         }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Lighting/Reflection/ScreenSpaceRefractionEditor.cs

 using System.Collections;
 using UnityEngine;
-using UnityEditor;
-using UnityEditor.Experimental.Rendering;
+using UnityEngine.Experimental.Rendering.HDPipeline;
-namespace UnityEngine.Experimental.Rendering.HDPipeline
+namespace UnityEditor.Experimental.Rendering.HDPipeline
 {
     [CanEditMultipleObjects]
     [VolumeComponentEditor(typeof(ScreenSpaceRefraction))]

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Material/Lit/LitUI.cs

 
             public static GUIContent UVBaseMappingText = new GUIContent("Base UV mapping", "");
             public static GUIContent texWorldScaleText = new GUIContent("World scale", "Tiling factor applied to Planar/Trilinear mapping");
-            // SSReflection
-            public static GUIContent reflectionProjectionModelText = new GUIContent("SS Reflection Projection Model", "Screen Space Projection Model For Reflections");
 
             // Details
             public static string detailText = "Detail Inputs";
         protected const string kRefractionModel = "_RefractionModel";
         protected MaterialProperty ssrefractionProjectionModel = null;
         protected const string kSSRefractionProjectionModel = "_SSRefractionProjectionModel";
-        protected MaterialProperty ssreflectionProjectionModel = null;
-        protected const string kSSReflectionProjectionModel = "_SSReflectionProjectionModel";
 
         protected override bool showBlendModePopup
         {
             // Transparency
             refractionModel = FindProperty(kRefractionModel, props, false);
             ssrefractionProjectionModel = FindProperty(kSSRefractionProjectionModel, props, false);
-            ssreflectionProjectionModel = FindProperty(kSSReflectionProjectionModel, props, false);
             transmittanceColor = FindProperty(kTransmittanceColor, props, false);
             transmittanceColorMap = FindProperty(kTransmittanceColorMap, props, false);
             atDistance = FindProperty(kATDistance, props, false);
                 DoDistortionInputsGUI();
 
                 --EditorGUI.indentLevel;
-            }
-            else if (surfaceTypeValue == SurfaceType.Opaque)
-            {
-                m_MaterialEditor.ShaderProperty(ssreflectionProjectionModel, Styles.reflectionProjectionModelText);
             }
         }
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightLoop/LightLoop.cs

                         // TODO: Is it possible to setup this outside the loop ? Can figure out how, get this: Property (specularLightingUAV) at kernel index (21) is not set
                         cmd.SetComputeTextureParam(deferredComputeShader, kernel, HDShaderIDs.specularLightingUAV, colorBuffers[0]);
                         cmd.SetComputeTextureParam(deferredComputeShader, kernel, HDShaderIDs.diffuseLightingUAV,  colorBuffers[1]);
-                        cmd.SetComputeIntParam(deferredComputeShader, HDShaderIDs._SSReflectionProjectionModel, (int)ssReflection.deferredProjectionModel.value);
 
                         if (debugDisplaySettings.lightingDebugSettings.debugLightingMode == DebugLightingMode.ScreenSpaceTracingReflection)
                             cmd.SetComputeBufferParam(deferredComputeShader, kernel, HDShaderIDs._DebugScreenSpaceTracingData, debugSSTBuffer);

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/Reflection/ScreenSpaceReflection.cs

 namespace UnityEngine.Experimental.Rendering.HDPipeline
 {
     [Serializable]
-    public sealed class LitProjectionModelParameter : VolumeParameter<Lit.ProjectionModel> { }
+    public sealed class LitProjectionModelParameter : VolumeParameter<Lit.ProjectionModel> 
+    {
+        public LitProjectionModelParameter() : base(Lit.ProjectionModel.Proxy, false) { }
+    }
 
     [Serializable]
     public class ScreenSpaceReflection : ScreenSpaceLighting

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.hlsl

 static const uint kFeatureVariantFlags[NUM_FEATURE_VARIANTS] =
 {
     // Precomputed illumination (no dynamic lights) for all material types
-    /*  0 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_ENV | MATERIAL_FEATURE_MASK_FLAGS,
+    /*  0 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_ENV | LIGHTFEATUREFLAGS_SSREFLECTION | MATERIAL_FEATURE_MASK_FLAGS,
 
     /*  1 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_PUNCTUAL | MATERIALFEATUREFLAGS_LIT_STANDARD,
     /*  2 */ LIGHTFEATUREFLAGS_SKY | LIGHTFEATUREFLAGS_DIRECTIONAL | LIGHTFEATUREFLAGS_AREA | MATERIALFEATUREFLAGS_LIT_STANDARD,

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/Lit.shader

         _ATDistance("Transmittance Absorption Distance", Float) = 1.0
         [ToggleUI] _PreRefractionPass("PreRefractionPass", Float) = 0.0
 
-        // SSReflection
-        [Enum(None, 0, Proxy, 1, HiZ, 2)]_SSReflectionProjectionModel("Reflection Projection Model", Int) = 0
-
         // Stencil state
         [HideInInspector] _StencilRef("_StencilRef", Int) = 2 // StencilLightingUsage.RegularLighting  (fixed at compile time)
         [HideInInspector] _StencilWriteMask("_StencilWriteMask", Int) = 7 // StencilMask.Lighting  (fixed at compile time)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitTessellation.shader

         _ATDistance("Transmittance Absorption Distance", Float) = 1.0
         [ToggleUI] _PreRefractionPass("PreRefractionPass", Float) = 0.0
 
-        // SSReflection
-        [Enum(None, 0, Proxy, 1, HiZ, 2)]_SSReflectionProjectionModel("Reflection Projection Model", Int) = 0
-
         // Stencil state
         [HideInInspector] _StencilRef("_StencilRef", Int) = 2 // StencilLightingUsage.RegularLighting  (fixed at compile time)
         [HideInInspector] _StencilWriteMask("_StencilWriteMask", Int) = 7 // StencilMask.Lighting  (fixed at compile time)