Change Cloud Layer API

com.unity.render-pipelines.high-definition/Documentation~/Override-Cloud-Layer.md

@@ -26,8 +26,8 @@ This example Cloud Map is a read-only **CustomRenderTexture**. This means that,
 
 ## Customizing the Cloud Map
 
-The Cloud Map is a 2D texture in LatLong layout (sometimes called Cylindrical or Equirectangular) that contains cloud color in the RGB channel and cloud coverage in the alpha channel.
-If **Upper Hemisphere Only** is checked, the map is interpreted as being the upper half of a LatLong texture.
+The Cloud Map is a 2D texture in LatLong layout (sometimes called Cylindrical or Equirectangular) that contains cloud opacity in the red channel.
+If **Upper Hemisphere Only** is checked, the map is interpreted as being the upper half of a LatLong texture. It means that it will only conver the sky above the horizon.
 
 <a name="CustomizingFlowmap"></a>
 

com.unity.render-pipelines.high-definition/Runtime/RenderPipelineResources/Shader/DefaultCloudLayerShader.shader

@@ -18,6 +18,8 @@ Shader "Hidden/DefaultCloudLayer"
 
         Pass
         {
+            Name "Cloud Map"
+
             CGPROGRAM
 
             #include "UnityCustomRenderTexture.cginc"

com.unity.render-pipelines.high-definition/Runtime/RenderPipelineResources/Texture/DefaultCloudLayer.asset

@@ -19,7 +19,7 @@ CustomRenderTexture:
   m_AntiAliasing: 1
   m_MipCount: -1
   m_DepthFormat: 0
-  m_ColorFormat: 8
+  m_ColorFormat: 9
   m_MipMap: 0
   m_GenerateMips: 1
   m_SRGB: 0

com.unity.render-pipelines.high-definition/Runtime/Sky/CloudLayer/CloudLayer.cs

@@ -43,7 +43,7 @@ public class CloudLayer : VolumeComponent
         public ClampedFloatParameter    scrollDirection     = new ClampedFloatParameter(0.0f, 0.0f, 360.0f);
         /// <summary>Speed of the distortion.</summary>
         [Tooltip("Sets the cloud scrolling speed. The higher the value, the faster the clouds will move.")]
-        public MinFloatParameter        scrollSpeed         = new MinFloatParameter(2.0f, 0.0f);
+        public MinFloatParameter        scrollSpeed         = new MinFloatParameter(1.0f, 0.0f);
 
 
         private float scrollFactor = 0.0f, lastTime = 0.0f;
@@ -60,9 +60,6 @@ public class CloudLayer : VolumeComponent
         /// <returns>The shader parameters of the cloud layer.</returns>
         public Vector4 GetParameters()
         {
-                scrollFactor += scrollSpeed.value * (Time.time - lastTime) * 0.01f;
-                lastTime = Time.time;
-
                 float rot = -Mathf.Deg2Rad*scrollDirection.value;
                 float upper = upperHemisphereOnly.value ? 1.0f : -1.0f;
                 return new Vector4(upper * (rotation.value / 360.0f + 1), scrollFactor, Mathf.Cos(rot), Mathf.Sin(rot));
@@ -75,6 +72,9 @@ public static void Apply(CloudLayer layer, Material skyMaterial)
         {
             if (layer != null && layer.enabled.value == true)
             {
+                layer.scrollFactor += layer.scrollSpeed.value * (Time.time - layer.lastTime) * 0.01f;
+                layer.lastTime = Time.time;
+
                 Vector4 cloudParam = layer.GetParameters();
                 Vector4 cloudParam2 = layer.tint.value;
                 cloudParam2.w = layer.intensityMultiplier.value;
@@ -112,33 +112,8 @@ public override int GetHashCode()
 
             unchecked
             {
-#if UNITY_2019_3 // In 2019.3, when we call GetHashCode on a VolumeParameter it generate garbage (due to the boxing of the generic parameter)
-                hash = cloudMap.value != null ? hash * 23 + cloudMap.value.GetHashCode() : hash;
-                hash = flowmap.value != null ? hash * 23 + flowmap.value.GetHashCode() : hash;
-                hash = hash * 23 + enabled.value.GetHashCode();
-                hash = hash * 23 + upperHemisphereOnly.value.GetHashCode();
-                hash = hash * 23 + tint.value.GetHashCode();
-                hash = hash * 23 + intensityMultiplier.value.GetHashCode();
-                hash = hash * 23 + rotation.value.GetHashCode();
-                hash = hash * 23 + enableDistortion.value.GetHashCode();
-                hash = hash * 23 + procedural.value.GetHashCode();
-                hash = hash * 23 + scrollDirection.value.GetHashCode();
-                hash = hash * 23 + scrollSpeed.value.GetHashCode();
-
-                hash = cloudMap.value != null ? hash * 23 + cloudMap.overrideState.GetHashCode() : hash;
-                hash = flowmap.value != null ? hash * 23 + flowmap.overrideState.GetHashCode() : hash;
-                hash = hash * 23 + enabled.overrideState.GetHashCode();
-                hash = hash * 23 + upperHemisphereOnly.overrideState.GetHashCode();
-                hash = hash * 23 + tint.overrideState.GetHashCode();
-                hash = hash * 23 + intensityMultiplier.overrideState.GetHashCode();
-                hash = hash * 23 + rotation.overrideState.GetHashCode();
-                hash = hash * 23 + enableDistortion.overrideState.GetHashCode();
-                hash = hash * 23 + procedural.overrideState.GetHashCode();
-                hash = hash * 23 + scrollDirection.overrideState.GetHashCode();
-                hash = hash * 23 + scrollSpeed.overrideState.GetHashCode();
-#else
-                hash = cloudMap.value != null ? hash * 23 + cloudMap.GetHashCode() : hash;
-                hash = flowmap.value != null ? hash * 23 + flowmap.GetHashCode() : hash;
+                hash = hash * 23 + cloudMap.GetHashCode();
+                hash = hash * 23 + flowmap.GetHashCode();
                 hash = hash * 23 + enabled.GetHashCode();
                 hash = hash * 23 + upperHemisphereOnly.GetHashCode();
                 hash = hash * 23 + tint.GetHashCode();
@@ -148,7 +123,6 @@ public override int GetHashCode()
                 hash = hash * 23 + procedural.GetHashCode();
                 hash = hash * 23 + scrollDirection.GetHashCode();
                 hash = hash * 23 + scrollSpeed.GetHashCode();
-#endif
             }
 
             return hash;

com.unity.render-pipelines.high-definition/Runtime/Sky/CloudLayer/CloudLayer.hlsl

@@ -19,12 +19,13 @@ float4 _CloudParam2; // xyz tint, w intensity
 
 #define USE_CLOUD_LAYER         defined(USE_CLOUD_MAP) || (!defined(USE_CLOUD_MAP) && defined(USE_CLOUD_MOTION))
 
-float3 sampleCloud(float3 dir, float3 sky)
+float4 sampleCloud(float3 dir)
 {
     float2 coords = GetLatLongCoords(dir, _CloudUpperHemisphere);
     coords.x = frac(coords.x + _CloudRotation);
-    float4 cloudLayerColor = SAMPLE_TEXTURE2D_LOD(_CloudMap, sampler_CloudMap, coords, 0);
-    return lerp(sky, sky + cloudLayerColor.rgb * _CloudTint * _CloudIntensity, cloudLayerColor.a);
+    float4 cloudLayerColor = SAMPLE_TEXTURE2D_LOD(_CloudMap, sampler_CloudMap, coords, 0).r;
+    cloudLayerColor.rgb *= _CloudTint * _CloudIntensity * cloudLayerColor.a;
+    return cloudLayerColor;
 }
 
 float3 CloudRotationUp(float3 p, float2 cos_sin)
@@ -35,46 +36,53 @@ float3 CloudRotationUp(float3 p, float2 cos_sin)
     return float3(dot(rotDirX, p), p.y, dot(rotDirY, p));
 }
 
-float3 GetDistordedCloudColor(float3 dir, float3 sky)
+float4 GetDistordedCloudColor(float3 dir)
 {
 #if USE_CLOUD_MOTION
-    if (dir.y >= 0 || !_CloudUpperHemisphere)
-    {
-        float2 alpha = frac(float2(_CloudScrollFactor, _CloudScrollFactor + 0.5)) - 0.5;
+    float2 alpha = frac(float2(_CloudScrollFactor, _CloudScrollFactor + 0.5)) - 0.5;
 
 #ifdef USE_CLOUD_MAP
-        float3 tangent = normalize(cross(dir, float3(0.0, 1.0, 0.0)));
-        float3 bitangent = cross(tangent, dir);
+    float3 tangent = normalize(cross(dir, float3(0.0, 1.0, 0.0)));
+    float3 bitangent = cross(tangent, dir);
 
-        float3 windDir = CloudRotationUp(dir, _CloudScrollDirection);
-        float2 flow = SAMPLE_TEXTURE2D_LOD(_CloudFlowmap, sampler_CloudFlowmap, GetLatLongCoords(windDir, _CloudUpperHemisphere), 0).rg * 2.0 - 1.0;
+    float3 windDir = CloudRotationUp(dir, _CloudScrollDirection);
+    float2 flow = SAMPLE_TEXTURE2D_LOD(_CloudFlowmap, sampler_CloudFlowmap, GetLatLongCoords(windDir, _CloudUpperHemisphere), 0).rg * 2.0 - 1.0;
 
-        float3 dd = flow.x * tangent + flow.y * bitangent;
+    float3 dd = flow.x * tangent + flow.y * bitangent;
 #else
-        float3 windDir = CloudRotationUp(float3(0, 0, 1), _CloudScrollDirection);
-        windDir.x *= -1.0;
-        float3 dd = windDir*sin(dir.y*PI*0.5);
+    float3 windDir = CloudRotationUp(float3(0, 0, 1), _CloudScrollDirection);
+    windDir.x *= -1.0;
+    float3 dd = windDir*sin(dir.y*PI*0.5);
 #endif
 
-        // Sample twice
-        float3 color1 = sampleCloud(normalize(dir - alpha.x * dd), sky);
-        float3 color2 = sampleCloud(normalize(dir - alpha.y * dd), sky);
+    // Sample twice
+    float4 color1 = sampleCloud(normalize(dir - alpha.x * dd));
+    float4 color2 = sampleCloud(normalize(dir - alpha.y * dd));
 
-        // Blend color samples
-        sky = lerp(color1, color2, abs(2.0 * alpha.x));
-    }
-    return sky;
+    // Blend color samples
+    return lerp(color1, color2, abs(2.0 * alpha.x));
 
 #else
-    return sampleCloud(dir, sky);
+    return sampleCloud(dir);
 #endif
 }
 
+float GetCloudOpacity(float3 dir)
+{
+#if USE_CLOUD_LAYER
+    if (dir.y >= 0 || !_CloudUpperHemisphere)
+        return GetDistordedCloudColor(dir).a;
+    else
+#endif
+
+    return 0;
+}
+
 float3 ApplyCloudLayer(float3 dir, float3 sky)
 {
 #if USE_CLOUD_LAYER
     if (dir.y >= 0 || !_CloudUpperHemisphere)
-        sky = GetDistordedCloudColor(dir, sky);
+        sky += GetDistordedCloudColor(dir).rgb;
 #endif
 
     return sky;

com.unity.render-pipelines.high-definition/Runtime/Sky/SkyManager.cs

@@ -670,7 +670,7 @@ int ComputeSkyHash(HDCamera camera, SkyUpdateContext skyContext, Light sunLight,
                 sunHash = GetSunLightHashCode(sunLight);
 
             int cloudHash = 0;
-            if (skyContext.cloudLayer != null && skyContext.skyRenderer.SupportCloudLayer)
+            if (skyContext.cloudLayer != null && skyContext.skyRenderer.SupportDynamicCloudLayer)
                 cloudHash = skyContext.cloudLayer.GetHashCode();
 
             // For planar reflections we want to use the parent position for hash.

com.unity.render-pipelines.high-definition/Runtime/Sky/SkyRenderer.cs

@@ -10,7 +10,7 @@ public abstract class SkyRenderer
         /// <summary>Determines if the sky should be rendered when the sun light changes.</summary>
         public bool SupportDynamicSunLight = true;
         /// <summary>Determines if the sky should be rendered when the cloud layer changes.</summary>
-        public bool SupportCloudLayer = true;
+        public bool SupportDynamicCloudLayer = true;
 
         /// <summary>
         /// Called on startup. Create resources used by the renderer (shaders, materials, etc).