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2026-03-05 00:14:42 +08:00

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2.2 KiB
HLSL

// Crest Water System
// Copyright © 2024 Wave Harmonic. All rights reserved.
#ifndef CREST_WATER_REFLECTION_H
#define CREST_WATER_REFLECTION_H
#include "Packages/com.waveharmonic.crest/Runtime/Shaders/Library/Macros.hlsl"
#include "Packages/com.waveharmonic.crest/Runtime/Shaders/Surface/Utility.hlsl"
float4 _Crest_ReflectionPositionNormal[2];
Texture2DArray _Crest_ReflectionTexture;
SamplerState sampler_Crest_ReflectionTexture;
m_CrestNameSpace
half4 PlanarReflection
(
const Texture2DArray i_ReflectionsTexture,
const SamplerState i_ReflectionsSampler,
const half i_Intensity,
const half i_Smoothness,
const half i_Roughness,
const half3 i_NormalWS,
const half i_NormalStrength,
const half3 i_ViewDirectionWS,
const float2 i_PositionNDC,
const bool i_Underwater
)
{
half3 planeNormal = half3(0.0, i_Underwater ? -1.0 : 1.0, 0.0);
half3 reflected = reflect(-i_ViewDirectionWS, lerp(planeNormal, i_NormalWS, i_NormalStrength));
reflected.y = -reflected.y;
float4 positionCS = mul(UNITY_MATRIX_VP, half4(reflected, 0.0));
#if UNITY_UV_STARTS_AT_TOP
positionCS.y = -positionCS.y;
#endif
float2 positionNDC = positionCS.xy * rcp(positionCS.w) * 0.5 + 0.5;
// Cancel out distortion if out of bounds. We could make this nicer by doing an edge fade but the improvement is
// barely noticeable. Edge fade requires recalculating the above a second time.
{
float4 positionAndNormal = _Crest_ReflectionPositionNormal[i_Underwater];
if (dot(positionNDC - positionAndNormal.xy, positionAndNormal.zw) < 0.0)
{
positionNDC = lerp(i_PositionNDC, positionNDC, 0.25);
}
}
const half roughness = PerceptualSmoothnessToPerceptualRoughness(i_Smoothness);
const half level = PerceptualRoughnessToMipmapLevel(roughness, i_Roughness);
half4 reflection = i_ReflectionsTexture.SampleLevel(sampler_Crest_ReflectionTexture, float3(positionNDC, i_Underwater), level);
// If more than four layers are used on the terrain, they will appear black if HDR
// is enabled on the planar reflection camera. Alpha is probably a negative value.
reflection.a = saturate(reflection.a);
reflection.a *= i_Intensity;
return reflection;
}
m_CrestNameSpaceEnd
#endif