Added an "exclude skybox" option to fog

Author: Chman

PostProcessing/Editor/Models/FogModelEditor.cs

@@ -13,6 +13,7 @@ public class FogModelEditor : PostProcessingModelEditor
         SerializedProperty m_Density;
         SerializedProperty m_Start;
         SerializedProperty m_End;
+        SerializedProperty m_ExcludeSkybox;
 
         public override void OnEnable()
         {
@@ -21,11 +22,13 @@ public override void OnEnable()
             m_Density = FindSetting((Settings x) => x.density);
             m_Start = FindSetting((Settings x) => x.start);
             m_End = FindSetting((Settings x) => x.end);
+            m_ExcludeSkybox = FindSetting((Settings x) => x.excludeSkybox);
         }
 
         public override void OnInspectorGUI()
         {
             EditorGUILayout.PropertyField(m_Color);
+            EditorGUILayout.PropertyField(m_ExcludeSkybox);
             EditorGUILayout.PropertyField(m_Mode);
 
             EditorGUI.indentLevel++;

PostProcessing/Resources/Shaders/Fog.shader

@@ -59,6 +59,18 @@ Shader "Hidden/Post FX/Fog"
         {
             half4 color = tex2D(_MainTex, i.uv);
 
+            float depth = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, i.uv);
+            depth = Linear01Depth(depth);
+            float dist = ComputeDistance(depth) - _Start;
+            half fog = 1.0 - ComputeFog(dist);
+
+            return lerp(color, _FogColor, fog);
+        }
+
+        half4 FragFogExcludeSkybox(Varyings i) : SV_Target
+        {
+            half4 color = tex2D(_MainTex, i.uv);
+
             float depth = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, i.uv);
             depth = Linear01Depth(depth);
             float skybox = depth < SKYBOX_THREASHOLD_VALUE;
@@ -83,5 +95,15 @@ Shader "Hidden/Post FX/Fog"
 
             ENDCG
         }
+
+        Pass
+        {
+            CGPROGRAM
+
+                #pragma vertex VertFog
+                #pragma fragment FragFogExcludeSkybox
+
+            ENDCG
+        }
     }
 }

PostProcessing/Runtime/Components/FogComponent.cs

@@ -84,7 +84,7 @@ public override void PopulateCommandBuffer(CommandBuffer cb)
 
             cb.GetTemporaryRT(Uniforms._TempRT, context.width, context.height, 24, FilterMode.Bilinear, fbFormat);
             cb.Blit(BuiltinRenderTextureType.CameraTarget, Uniforms._TempRT);
-            cb.Blit(Uniforms._TempRT, BuiltinRenderTextureType.CameraTarget, material);
+            cb.Blit(Uniforms._TempRT, BuiltinRenderTextureType.CameraTarget, material, settings.excludeSkybox ? 1 : 0);
             cb.ReleaseTemporaryRT(Uniforms._TempRT);
         }
     }

PostProcessing/Runtime/Models/FogModel.cs

@@ -23,6 +23,9 @@ public struct Settings
             [Tooltip("Controls the distance from the camera where the fog will completely obscure objects in the Scene.")]
             public float end;
 
+            [Tooltip("Should the fog affect the skybox?")]
+            public bool excludeSkybox;
+
             public static Settings defaultSettings
             {
                 get
@@ -33,7 +36,8 @@ public static Settings defaultSettings
                         mode = FogMode.Exponential,
                         density = 0.001f,
                         start = 0f,
-                        end = 600f
+                        end = 600f,
+                        excludeSkybox = true
                     };
                 }
             }