UnrealEngineUWP/Engine/Shaders/Private/RayTracing/RayTracingReflectionsCommon.ush

// Copyright Epic Games, Inc. All Rights Reserved.

/*=============================================================================================
	RayTracingReflectionsCommon.ush: Common functions for ray traced Reflections
===============================================================================================*/

#pragma once

#include "../Common.ush"

// Note that the values stored in this will be accumulations across all valid samples and will not be normalized or averaged
// until after splitting into their own individual textures
struct FImaginaryReflectionGBufferData
{
	float3 WorldNormal;
	// Not DeviceZ so that it can be linearly interpolated in world space
	float SceneDepth;
	float2 Velocity;
	// Required for averaging to account for the fact that not all samples may hit a valid imaginary surface
	uint ValidSamples;
};

float GetRoughnessFade(float Roughness, float MaxRoughness)
{
	float RoughnessMaskScale = -2.0 / MaxRoughness;
	return saturate(Roughness * RoughnessMaskScale + 2.0);
}