HDRenderPipeline: Add support for camera features flags

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Camera/HDAdditionalCameraData.cs

             Unlit  // Hard coded path
         };
 
+        public enum ClearColorMode
+        {
+            Sky,
+            BackgroundColor,
+            None
+        };
+
+        public ClearColorMode clearColorMode = ClearColorMode.Sky;
+        [ColorUsage(true, true)]
+        public Color backgroundColorHDR = new Color(0.025f, 0.07f, 0.19f, 0.0f);
+        public bool clearDepth = true;
+
         public RenderingPath    renderingPath;
         [Tooltip("Layer Mask used for the volume interpolation for this camera.")]
         public LayerMask        volumeLayerMask = -1;

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Camera/HDCamera.cs

         // happen, but you never know...
         int m_LastFrameActive;
 
+        public bool clearDepth
+        {
+            get { return m_AdditionalCameraData != null ? m_AdditionalCameraData.clearDepth : camera.clearFlags != CameraClearFlags.Nothing; }
+        }
+
+        public HDAdditionalCameraData.ClearColorMode clearColorMode
+        {
+            get
+            {
+                if (m_AdditionalCameraData != null)
+                {
+                    return m_AdditionalCameraData.clearColorMode;
+                }
+
+                if (camera.clearFlags == CameraClearFlags.Skybox)
+                    return HDAdditionalCameraData.ClearColorMode.Sky;
+                else if (camera.clearFlags == CameraClearFlags.SolidColor)
+                    return HDAdditionalCameraData.ClearColorMode.BackgroundColor;
+                else // None
+                    return HDAdditionalCameraData.ClearColorMode.None;
+            }
+        }
+
+        public Color backgroundColorHDR
+        {
+            get
+            {
+                if (m_AdditionalCameraData != null)
+                {
+                    return m_AdditionalCameraData.backgroundColorHDR;
+                }
+
+                return camera.backgroundColor.linear;
+            }
+        }        
+
         static Dictionary<Camera, HDCamera> s_Cameras = new Dictionary<Camera, HDCamera>();
         static List<Camera> s_Cleanup = new List<Camera>(); // Recycled to reduce GC pressure
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Camera/HDCameraUI.cs

         public static readonly CED.IDrawer[] Inspector = null;
 
         public static readonly CED.IDrawer SectionPrimarySettings = CED.Group(
-            CED.Action(Drawer_FieldBackgroundColor),
+            CED.Action(Drawer_FieldClearColorMode),
+            CED.Action(Drawer_FieldBackgroundColorHDR),
+            CED.Action(Drawer_FieldClearDepth),
             CED.Action(Drawer_FieldCullingMask),
             CED.Action(Drawer_FieldVolumeLayerMask),
             CED.space,
             frameSettingsUI.Update();
         }
 
-        static void Drawer_FieldBackgroundColor(HDCameraUI s, SerializedHDCamera p, Editor owner)
+        static void Drawer_FieldBackgroundColorHDR(HDCameraUI s, SerializedHDCamera p, Editor owner)
-            EditorGUILayout.PropertyField(p.backgroundColor, _.GetContent("Background Color|The Camera clears the screen to this color before rendering."));
+            EditorGUILayout.PropertyField(p.backgroundColorHDR, _.GetContent("Background Color|The BackgroundColor use to clear screen when selecting BackgrounColor before rendering."));
         }
 
         static void Drawer_FieldVolumeLayerMask(HDCameraUI s, SerializedHDCamera p, Editor owner)
             EditorGUILayout.PropertyField(p.depth, _.GetContent("Depth"));
         }
 
+        static void Drawer_FieldClearColorMode(HDCameraUI s, SerializedHDCamera p, Editor owner)
+        {
+            EditorGUILayout.PropertyField(p.clearColorMode, _.GetContent("Clear Mode|The Camera clears the screen to selected mode."));
+        }
+
+        }
+
+        static void Drawer_FieldClearDepth(HDCameraUI s, SerializedHDCamera p, Editor owner)
+        {
+            EditorGUILayout.PropertyField(p.clearDepth, _.GetContent("ClearDepth|The Camera clears the depth buffer before rendering."));
         }
 
         static void Drawer_FieldRenderTarget(HDCameraUI s, SerializedHDCamera p, Editor owner)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/Camera/SerializedHDCamera.cs

         public SerializedObject serializedObject;
         public SerializedObject serializedAdditionalDataObject;
 
-        public SerializedProperty backgroundColor;
+        //public SerializedProperty backgroundColor;
         public SerializedProperty normalizedViewPortRect;
         public SerializedProperty fieldOfView;
         public SerializedProperty orthographic;
         public SerializedProperty targetDisplay;
 #endif
 
+        public SerializedProperty clearColorMode;
+        public SerializedProperty backgroundColorHDR;
+        public SerializedProperty clearDepth;
         public SerializedProperty volumeLayerMask;
         public SerializedFrameSettings frameSettings;
 
             hideFlags.intValue = (int)HideFlags.HideInInspector;
             serializedAdditionalDataObject.ApplyModifiedProperties();
 
-            backgroundColor = serializedObject.FindProperty("m_BackGroundColor");
+            //backgroundColor = serializedObject.FindProperty("m_BackGroundColor");
             normalizedViewPortRect = serializedObject.FindProperty("m_NormalizedViewPortRect");
             nearClippingPlane = serializedObject.FindProperty("near clip plane");
             farClippingPlane = serializedObject.FindProperty("far clip plane");
 
             targetEye = serializedObject.FindProperty("m_TargetEye");
 
+
+            clearColorMode = serializedAdditionalDataObject.Find((HDAdditionalCameraData d) => d.clearColorMode);
+            backgroundColorHDR = serializedAdditionalDataObject.Find((HDAdditionalCameraData d) => d.backgroundColorHDR);
+            clearDepth = serializedAdditionalDataObject.Find((HDAdditionalCameraData d) => d.clearDepth);
             volumeLayerMask = serializedAdditionalDataObject.Find((HDAdditionalCameraData d) => d.volumeLayerMask);
             frameSettings = new SerializedFrameSettings(serializedAdditionalDataObject.FindProperty("m_FrameSettings"));
         }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipeline.cs

                 // Clear depth/stencil and init buffers
                 using (new ProfilingSample(cmd, "Clear Depth/Stencil", CustomSamplerId.ClearDepthStencil.GetSampler()))
                 {
-                    HDUtils.SetRenderTarget(cmd, hdCamera, m_CameraColorBuffer, m_CameraDepthStencilBuffer, ClearFlag.Depth);
+                    if (hdCamera.clearDepth)
+                    {
+                        HDUtils.SetRenderTarget(cmd, hdCamera, m_CameraColorBuffer, m_CameraDepthStencilBuffer, ClearFlag.Depth);
+                    }
+                }
+
+                // Clear the HDR target
+                using (new ProfilingSample(cmd, "Clear HDR target", CustomSamplerId.ClearHDRTarget.GetSampler()))
+                {
+                    if (hdCamera.clearColorMode == HDAdditionalCameraData.ClearColorMode.BackgroundColor ||
+                        // If we want the sky but the sky don't exist, still clear with background color
+                        (hdCamera.clearColorMode == HDAdditionalCameraData.ClearColorMode.Sky && !m_SkyManager.IsSkyValid()))
+                    {
+                        Color clearColor = hdCamera.backgroundColorHDR;
+                        HDUtils.SetRenderTarget(cmd, hdCamera, m_CameraColorBuffer, m_CameraDepthStencilBuffer, ClearFlag.Color, clearColor);
+                    }
                 }
 
                 // Clear the diffuse SSS lighting target
                 }
 
                 // TODO: As we are in development and have not all the setup pass we still clear the color in emissive buffer and gbuffer, but this will be removed later.
-
-                // Clear the HDR target
-                using (new ProfilingSample(cmd, "Clear HDR target", CustomSamplerId.ClearHDRTarget.GetSampler()))
-                {
-                    Color clearColor = hdCamera.camera.backgroundColor.linear; // Need it in linear because we clear a linear fp16 texture.
-                    HDUtils.SetRenderTarget(cmd, hdCamera, m_CameraColorBuffer, m_CameraDepthStencilBuffer, ClearFlag.Color, clearColor);
-                }
 
                 // Clear GBuffers
                 if (!m_FrameSettings.enableForwardRenderingOnly)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Sky/SkyRenderingContext.cs

             return result;
         }
 
-        public void RenderSky(SkyUpdateContext skyContext, HDCamera camera, Light sunLight, RTHandle colorBuffer, RTHandle depthBuffer, CommandBuffer cmd)
+        public void RenderSky(SkyUpdateContext skyContext, HDCamera hdCamera, Light sunLight, RTHandle colorBuffer, RTHandle depthBuffer, CommandBuffer cmd)
-            if (skyContext.IsValid())
+            if (skyContext.IsValid() && hdCamera.clearColorMode == HDAdditionalCameraData.ClearColorMode.Sky)
-                    m_BuiltinParameters.pixelCoordToViewDirMatrix = HDUtils.ComputePixelCoordToWorldSpaceViewDirectionMatrix(camera.camera.fieldOfView * Mathf.Deg2Rad, camera.screenSize, camera.viewMatrix, false);
-                    m_BuiltinParameters.invViewProjMatrix = camera.viewProjMatrix.inverse;
-                    m_BuiltinParameters.screenSize = camera.screenSize;
-                    m_BuiltinParameters.cameraPosWS = camera.camera.transform.position;
+                    m_BuiltinParameters.pixelCoordToViewDirMatrix = HDUtils.ComputePixelCoordToWorldSpaceViewDirectionMatrix(hdCamera.camera.fieldOfView * Mathf.Deg2Rad, hdCamera.screenSize, hdCamera.viewMatrix, false);
+                    m_BuiltinParameters.invViewProjMatrix = hdCamera.viewProjMatrix.inverse;
+                    m_BuiltinParameters.screenSize = hdCamera.screenSize;
+                    m_BuiltinParameters.cameraPosWS = hdCamera.camera.transform.position;
-                    m_BuiltinParameters.hdCamera = camera;
+                    m_BuiltinParameters.hdCamera = hdCamera;
 
                     skyContext.renderer.SetRenderTargets(m_BuiltinParameters);
                     skyContext.renderer.RenderSky(m_BuiltinParameters, false);