chunk 1: core gameplay scripts scenes runtime assets

Assets/Volumetric/Shaders/DepthAwareGaussianBlur.hlsl

@@ -0,0 +1,58 @@
+#include "./DeclareDownsampledDepthTexture.hlsl"
+
+#define KERNEL_RADIUS 4
+#define BLUR_DEPTH_FALLOFF 0.5
+
+static const float KernelWeights[] = { 0.2026, 0.1790, 0.1240, 0.0672, 0.0285 };
+
+// Blurs the RGB channels of the given texture using depth aware gaussian blur, which uses the half resolution camera depth to apply weights to the blur.
+// The alpha channel is not blurred so the original value is returned.
+float4 DepthAwareGaussianBlur(float2 uv, float2 dir, TEXTURE2D_X(textureToBlur), SAMPLER(sampler_TextureToBlur), float2 textureToBlurTexelSizeXy)
+{
+    float4 centerSample = SAMPLE_TEXTURE2D_X(textureToBlur, sampler_TextureToBlur, uv);
+    float centerRawDepth = SampleDownsampledSceneDepthConsiderReversedZ(uv);
+    float centerLinearEyeDepth = LinearEyeDepth(centerRawDepth, _ZBufferParams);
+
+    float3 rgbResult = centerSample.rgb * KernelWeights[0];
+    float weights = KernelWeights[0];
+
+    float2 texelSizeTimesDir = textureToBlurTexelSizeXy * dir;
+
+    UNITY_UNROLL
+    for (int i = -KERNEL_RADIUS; i < 0; ++i)
+    {
+        float2 uvOffset = (float)i * texelSizeTimesDir;
+        float2 uvSample = uv + uvOffset;
+
+        float rawDepth = SampleDownsampledSceneDepthConsiderReversedZ(uvSample);
+        float linearEyeDepth = LinearEyeDepth(rawDepth, _ZBufferParams);
+        float depthDiff = abs(centerLinearEyeDepth - linearEyeDepth);
+        float r2 = BLUR_DEPTH_FALLOFF * depthDiff;
+        float g = exp(-r2 * r2);
+        float weight = g * KernelWeights[-i];
+
+        float3 rgb = SAMPLE_TEXTURE2D_X(textureToBlur, sampler_TextureToBlur, uvSample).rgb;
+        rgbResult += (rgb * weight);
+        weights += weight;
+    }
+
+    UNITY_UNROLL
+    for (i = 1; i <= KERNEL_RADIUS; ++i)
+    {
+        float2 uvOffset = (float)i * texelSizeTimesDir;
+        float2 uvSample = uv + uvOffset;
+
+        float rawDepth = SampleDownsampledSceneDepthConsiderReversedZ(uvSample);
+        float linearEyeDepth = LinearEyeDepth(rawDepth, _ZBufferParams);
+        float depthDiff = abs(centerLinearEyeDepth - linearEyeDepth);
+        float r2 = BLUR_DEPTH_FALLOFF * depthDiff;
+        float g = exp(-r2 * r2);
+        float weight = g * KernelWeights[i];
+
+        float3 rgb = SAMPLE_TEXTURE2D_X(textureToBlur, sampler_TextureToBlur, uvSample).rgb;
+        rgbResult += (rgb * weight);
+        weights += weight;
+    }
+
+    return float4(rgbResult / weights, centerSample.a);
+}