58 lines
2.0 KiB
HLSL
58 lines
2.0 KiB
HLSL
// Copyright (c) Wojciech Figat. All rights reserved.
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#ifndef __REFLECTIONS_COMMON__
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#define __REFLECTIONS_COMMON__
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#include "./Flax/GBufferCommon.hlsl"
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// Hit depth (view space) threshold to detect if sky was hit (value above it where 1.0f is default)
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#define REFLECTIONS_HIT_THRESHOLD 0.9f
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float GetSpecularOcclusion(float NoV, float roughnessSq, float ao)
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{
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return saturate(pow(NoV + ao, roughnessSq) - 1 + ao);
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}
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float4 SampleReflectionProbe(float3 viewPos, TextureCube probe, ProbeData data, float3 positionWS, float3 normal, float roughness)
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{
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// Calculate distance from probe to the pixel
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float3 captureVector = positionWS - data.ProbePos;
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float captureVectorLength = length(captureVector);
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// Check if cannot light pixel
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// TODO: maybe remove this check?? - test it out with dozens of probes
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BRANCH
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if (captureVectorLength >= data.ProbeRadius)
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{
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// End
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return 0;
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}
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// Fade out based on distance to capture
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float normalizedDistanceToCapture = saturate(captureVectorLength * data.ProbeInvRadius);
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float distanceAlpha = 1.0 - smoothstep(0.7, 1, normalizedDistanceToCapture);
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float fade = distanceAlpha * data.ProbeBrightness;
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// Calculate reflection vector
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float3 V = normalize(positionWS - viewPos);
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float3 R = reflect(V, normal);
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float3 D = data.ProbeInvRadius * captureVector + R;
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// Sample probe at valid mip level based on surface roughness value
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half mip = ProbeMipFromRoughness(roughness);
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float4 probeSample = probe.SampleLevel(SamplerLinearClamp, D, mip);
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return probeSample * fade;
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}
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// Calculates the reflective environment lighting to multiply the raw reflection color for the specular light (eg. from Env Probe or SSR).
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float3 GetReflectionSpecularLighting(float3 viewPos, GBufferSample gBuffer)
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{
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float3 specularColor = GetSpecularColor(gBuffer);
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float3 V = normalize(viewPos - gBuffer.WorldPos);
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float NoV = saturate(dot(gBuffer.Normal, V));
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return EnvBRDFApprox(specularColor, gBuffer.Roughness, NoV);
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}
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#endif
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