wip: EnkiBillalFulscreen shader

Assets/_Content/Shaders/Postprocess/EnkiBillalFullscreen.hlsl

@@ -0,0 +1,74 @@
+#ifndef ENKI_BILLAL_FULLSCREEN_INCLUDED
+#define ENKI_BILLAL_FULLSCREEN_INCLUDED
+#include "Assets/_Content/Shaders/Include/Noises.hlsl"
+#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DeclareOpaqueTexture.hlsl"
+
+// Gaussian blur on scene color
+// blurRadius controls the spread in pixels — adjust to taste
+float3 SampleSceneColorBlurred(float2 uv, float blurRadius)
+{
+    float3 result = 0;
+    float totalWeight = 0;
+
+    // Gaussian weights for 5 samples (sigma ~ 1.0)
+    float weights[5] = { 0.0625, 0.25, 0.375, 0.25, 0.0625 };
+    float offsets[5] = { -2, -1, 0, 1, 2 };
+
+    float2 texelSize = blurRadius / _ScreenParams.xy;
+
+    // Horizontal pass
+    for (int i = 0; i < 5; i++)
+    {
+        float2 offsetUV = uv + float2(offsets[i] * texelSize.x, 0);
+        result += SAMPLE_TEXTURE2D_X(_CameraOpaqueTexture, sampler_LinearClamp, offsetUV).rgb * weights[i];
+    }
+
+    return result;
+}
+
+void EnkiBillalFullscreen_float
+(
+    float2 UV,
+    out float3 Output
+)
+{
+    float2 screenUV = UV;
+
+    // DEPTH
+    
+    float rawDepth = SampleSceneDepth(screenUV);
+    float depthMeters = LinearEyeDepth(rawDepth, _ZBufferParams); // linear eye-space depth in metres
+    float depth01 = Linear01Depth(rawDepth, _ZBufferParams); // normalised linear depth [0..1]
+
+    // POSITION WORLD SPACE
+    
+    // Remap depth for non-reversed-Z platforms before reconstruction
+    float depthForReconstruct = rawDepth;
+#if !UNITY_REVERSED_Z
+    depthForReconstruct = lerp(UNITY_NEAR_CLIP_VALUE, 1.0, rawDepth);
+#endif
+    // ComputeWorldSpacePosition handles perspective divide and platform differences
+    float3 positionWS = ComputeWorldSpacePosition(screenUV, depthForReconstruct, UNITY_MATRIX_I_VP);
+
+
+    // NORMAL WORLD SPACE
+    
+    // Requires DepthNormals PrePass to be enabled in the URP Renderer
+    float3 normalWS = SampleSceneNormals(screenUV);
+
+    // SCENE COLOR
+    
+    float3 originColor = SampleSceneColor(screenUV);
+    
+    float greyscale = (originColor.x + originColor.y + originColor.z) / 3.0;
+    
+    float3 offsetUV = PerlinColor3D(positionWS * float3(1, 5, 1), 1) * smoothstep(smoothstep(20, 3, depthMeters), 1, greyscale) * .1 / depthMeters;
+    
+    float3 sceneColor = SampleSceneColor(screenUV + offsetUV);
+    //float3 sceneColor = SAMPLE_TEXTURE2D_X(_CameraOpaqueTexture, sampler_PointClamp, screenUV).rgb;
+    
+    // OUTPUT
+    
+    Output = SampleSceneColorBlurred(screenUV, 10);
+}
+#endif