Merge pull request #248 from EvgeniiG/small_sky_improvements

Add a "Max Sky Distance" parameter to the procedural sky

Assets/ScriptableRenderPipeline/HDRenderPipeline/Sky/ProceduralSky/ProceduralSkyRenderer.cs

             m_ProceduralSkyMaterial.SetFloat("_WorldRayleighNearScatterPush", -Mathf.Pow(Mathf.Abs(param.worldRayleighNearScatterPush), param.worldScaleExponent) * Mathf.Sign(param.worldRayleighNearScatterPush));
             m_ProceduralSkyMaterial.SetFloat("_WorldRayleighDensity", -param.worldRayleighDensity / 100000f);
             m_ProceduralSkyMaterial.SetFloat("_WorldMieDensity", -param.worldMieDensity / 100000f);
+            m_ProceduralSkyMaterial.SetFloat("_SkyDepth", 1.0f / param.maxSkyDistance);
 
             var rayleighColorM20 = param.worldRayleighColorRamp.Evaluate(0.00f);
             var rayleighColorM10 = param.worldRayleighColorRamp.Evaluate(0.25f);

Assets/ScriptableRenderPipeline/HDRenderPipeline/Sky/ProceduralSky/ProceduralSkySettings.cs

         // public Shader atmosphericShader = null;
         // public Shader occlusionShader   = null;
         public float worldScaleExponent    = 1.0f;
+        public float maxSkyDistance        = 4000.0f;
         public ScatterDebugMode debugMode  = ScatterDebugMode.None;
 
         // Camera   m_currentCamera;
             heightRayleighNearScatterPush = Mathf.Clamp(heightRayleighNearScatterPush, -200f, 300f);
 
             worldScaleExponent            = Mathf.Clamp(worldScaleExponent, 1f, 2f);
+            maxSkyDistance                = Mathf.Clamp(maxSkyDistance, 1.0f, 1000000.0f);
 
             /*
             occlusionBias                = Mathf.Clamp01(occlusionBias);

Assets/ScriptableRenderPipeline/HDRenderPipeline/Sky/ProceduralSky/Resources/SkyProcedural.shader

 
             float4x4 _InvViewProjMatrix;
 
+            float _SkyDepth;
+
             float _DisableSkyOcclusionTest;
 
             float _FlipY;
                 // input.positionCS is SV_Position
                 PositionInputs posInput = GetPositionInput(input.positionCS.xy, _ScreenSize.zw);
 
-                // An arbitrary value attempting to match the size of the sky mesh from the Blacksmith demo.
-                const float skyDepth = 0.00025;
-
-                    float depthRaw     = max(skyDepth, LOAD_TEXTURE2D(_MainDepthTexture, posInput.unPositionSS).r);
-                    float skyTexWeight = (depthRaw > skyDepth) ? 0.0 : 1.0;
+                    float depthRaw     = max(_SkyDepth, LOAD_TEXTURE2D(_MainDepthTexture, posInput.unPositionSS).r);
+                    float skyTexWeight = (depthRaw > _SkyDepth) ? 0.0 : 1.0;
-                    float depthRaw     = skyDepth;
+                    float depthRaw     = _SkyDepth;
-                    depthRaw     = skyDepth;
+                    depthRaw     = _SkyDepth;
                     skyTexWeight = 1.0;
                 }