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2
.obsidian/plugins/various-complements/histories.json vendored
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@ -1 +1 @@
{"c++内存泄漏分析工具":{"c++内存泄漏分析工具":{"internalLink":{"count":1,"lastUpdated":1737361366503}}},"tonemapping":{"tonemapping":{"currentFile":{"count":1,"lastUpdated":1737367609064}}},"body01":{"body01":{"currentFile":{"count":1,"lastUpdated":1738243350947}}},"Games":{"Games":{"currentFile":{"count":1,"lastUpdated":1738586917474}}},"Camera":{"Camera":{"currentFile":{"count":1,"lastUpdated":1739168843622}}}} {"c++内存泄漏分析工具":{"c++内存泄漏分析工具":{"internalLink":{"count":1,"lastUpdated":1737361366503}}},"tonemapping":{"tonemapping":{"currentFile":{"count":1,"lastUpdated":1737367609064}}},"body01":{"body01":{"currentFile":{"count":1,"lastUpdated":1738243350947}}},"Games":{"Games":{"currentFile":{"count":1,"lastUpdated":1738586917474}}},"Camera":{"Camera":{"currentFile":{"count":1,"lastUpdated":1739168843622}}},"DeferredLightVertexShaders":{"DeferredLightVertexShaders":{"currentFile":{"count":1,"lastUpdated":1739267675471}}}}

237
03-UnrealEngine/Rendering/RenderingPipeline/Lighting/Lighting.md
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@ -213,3 +213,240 @@ FComputeLightGridOutput FDeferredShadingSceneRenderer::GatherLightsAndComputeLig
# RenderLights() -> RenderLight() # RenderLights() -> RenderLight()
## InternalRenderLight() ## InternalRenderLight()
## DeferredLightVertexShaders
```c++
// 输入参数.
struct FInputParams
{
float2 PixelPos;
float4 ScreenPosition;
float2 ScreenUV;
float3 ScreenVector;
};
// 派生参数.
struct FDerivedParams
{
float3 CameraVector;
float3 WorldPosition;
};
// 获取派生参数.
FDerivedParams GetDerivedParams(in FInputParams Input, in float SceneDepth)
{
FDerivedParams Out;
#if LIGHT_SOURCE_SHAPE > 0
// With a perspective projection, the clip space position is NDC * Clip.w
// With an orthographic projection, clip space is the same as NDC
float2 ClipPosition = Input.ScreenPosition.xy / Input.ScreenPosition.w * (View.ViewToClip[3][3] < 1.0f ? SceneDepth : 1.0f);
Out.WorldPosition = mul(float4(ClipPosition, SceneDepth, 1), View.ScreenToWorld).xyz;
Out.CameraVector = normalize(Out.WorldPosition - View.WorldCameraOrigin);
#else
Out.WorldPosition = Input.ScreenVector * SceneDepth + View.WorldCameraOrigin;
Out.CameraVector = normalize(Input.ScreenVector);
#endif
return Out;
}
Texture2D<uint> LightingChannelsTexture;
uint GetLightingChannelMask(float2 UV)
{
uint2 IntegerUV = UV * View.BufferSizeAndInvSize.xy;
return LightingChannelsTexture.Load(uint3(IntegerUV, 0)).x;
}
float GetExposure()
{
return View.PreExposure;
}
```
向往文章中的SetupLightDataForStandardDeferred()变为InitDeferredLightFromUniforms()。位于LightDataUniform.ush。
```c++
FDeferredLightData InitDeferredLightFromUniforms(uint InLightType)
{
const bool bIsRadial = InLightType != LIGHT_TYPE_DIRECTIONAL;
FDeferredLightData Out;
Out.TranslatedWorldPosition = GetDeferredLightTranslatedWorldPosition();
Out.InvRadius = DeferredLightUniforms.InvRadius;
Out.Color = DeferredLightUniforms.Color;
Out.FalloffExponent = DeferredLightUniforms.FalloffExponent;
Out.Direction = DeferredLightUniforms.Direction;
Out.Tangent = DeferredLightUniforms.Tangent;
Out.SpotAngles = DeferredLightUniforms.SpotAngles;
Out.SourceRadius = DeferredLightUniforms.SourceRadius;
Out.SourceLength = bIsRadial ? DeferredLightUniforms.SourceLength : 0;
Out.SoftSourceRadius = DeferredLightUniforms.SoftSourceRadius;
Out.SpecularScale = DeferredLightUniforms.SpecularScale;
Out.ContactShadowLength = abs(DeferredLightUniforms.ContactShadowLength);
Out.ContactShadowLengthInWS = DeferredLightUniforms.ContactShadowLength < 0.0f;
Out.ContactShadowCastingIntensity = DeferredLightUniforms.ContactShadowCastingIntensity;
Out.ContactShadowNonCastingIntensity = DeferredLightUniforms.ContactShadowNonCastingIntensity;
Out.DistanceFadeMAD = DeferredLightUniforms.DistanceFadeMAD;
Out.ShadowMapChannelMask = DeferredLightUniforms.ShadowMapChannelMask;
Out.ShadowedBits = DeferredLightUniforms.ShadowedBits;
Out.bInverseSquared = bIsRadial && DeferredLightUniforms.FalloffExponent == 0; // Directional lights don't use 'inverse squared attenuation'
Out.bRadialLight = bIsRadial;
Out.bSpotLight = InLightType == LIGHT_TYPE_SPOT;
Out.bRectLight = InLightType == LIGHT_TYPE_RECT;
Out.RectLightData.BarnCosAngle = DeferredLightUniforms.RectLightBarnCosAngle;
Out.RectLightData.BarnLength = DeferredLightUniforms.RectLightBarnLength;
Out.RectLightData.AtlasData.AtlasMaxLevel = DeferredLightUniforms.RectLightAtlasMaxLevel;
Out.RectLightData.AtlasData.AtlasUVOffset = DeferredLightUniforms.RectLightAtlasUVOffset;
Out.RectLightData.AtlasData.AtlasUVScale = DeferredLightUniforms.RectLightAtlasUVScale;
Out.HairTransmittance = InitHairTransmittanceData();
return Out;
}
```
### DeferredLightPixelMain
```c++
void DeferredLightPixelMain(
#if LIGHT_SOURCE_SHAPE > 0
float4 InScreenPosition : TEXCOORD0,
#else
float2 ScreenUV : TEXCOORD0,
float3 ScreenVector : TEXCOORD1,
#endif
float4 SVPos : SV_POSITION,
out float4 OutColor : SV_Target0
#if STRATA_OPAQUE_ROUGH_REFRACTION_ENABLED
, out float3 OutOpaqueRoughRefractionSceneColor : SV_Target1
, out float3 OutSubSurfaceSceneColor : SV_Target2
#endif
)
{
const float2 PixelPos = SVPos.xy;
OutColor = 0;
#if STRATA_OPAQUE_ROUGH_REFRACTION_ENABLED
OutOpaqueRoughRefractionSceneColor = 0;
OutSubSurfaceSceneColor = 0;
#endif
// Convert input data (directional/local light)
// 计算屏幕UV
FInputParams InputParams = (FInputParams)0;
InputParams.PixelPos = SVPos.xy;
#if LIGHT_SOURCE_SHAPE > 0
InputParams.ScreenPosition = InScreenPosition;
InputParams.ScreenUV = InScreenPosition.xy / InScreenPosition.w * View.ScreenPositionScaleBias.xy + View.ScreenPositionScaleBias.wz;
InputParams.ScreenVector = 0;
#else
InputParams.ScreenPosition = 0;
InputParams.ScreenUV = ScreenUV;
InputParams.ScreenVector = ScreenVector;
#endif
#if STRATA_ENABLED
FStrataAddressing StrataAddressing = GetStrataPixelDataByteOffset(PixelPos, uint2(View.BufferSizeAndInvSize.xy), Strata.MaxBytesPerPixel);
FStrataPixelHeader StrataPixelHeader = UnpackStrataHeaderIn(Strata.MaterialTextureArray, StrataAddressing, Strata.TopLayerTexture);
BRANCH
if (StrataPixelHeader.BSDFCount > 0 // This test is also enough to exclude sky pixels
#if USE_LIGHTING_CHANNELS
//灯光通道逻辑
&& (GetLightingChannelMask(InputParams.ScreenUV) & DeferredLightUniforms.LightingChannelMask)
#endif
)
{
//通过SceneDepth获取的CameraVector以及当前像素的世界坐标
const float SceneDepth = CalcSceneDepth(InputParams.ScreenUV);
const FDerivedParams DerivedParams = GetDerivedParams(InputParams, SceneDepth);
FDeferredLightData LightData = InitDeferredLightFromUniforms(CURRENT_LIGHT_TYPE);
UpdateLightDataColor(LightData, InputParams, DerivedParams);
float3 V =-DerivedParams.CameraVector;
float3 L = LightData.Direction; // Already normalized
float3 ToLight = L;
float LightMask = 1;
if (LightData.bRadialLight)
{
LightMask = GetLocalLightAttenuation(DerivedParams.TranslatedWorldPosition, LightData, ToLight, L);
}
if (LightMask > 0)
{
FShadowTerms ShadowTerms = { StrataGetAO(StrataPixelHeader), 1.0, 1.0, InitHairTransmittanceData() };
float4 LightAttenuation = GetLightAttenuationFromShadow(InputParams, SceneDepth);
float Dither = InterleavedGradientNoise(InputParams.PixelPos, View.StateFrameIndexMod8);
const uint FakeShadingModelID = 0;
const float FakeContactShadowOpacity = 1.0f;
float4 PrecomputedShadowFactors = StrataReadPrecomputedShadowFactors(StrataPixelHeader, PixelPos, SceneTexturesStruct.GBufferETexture);
GetShadowTerms(SceneDepth, PrecomputedShadowFactors, FakeShadingModelID, FakeContactShadowOpacity,
LightData, DerivedParams.TranslatedWorldPosition, L, LightAttenuation, Dither, ShadowTerms);
FStrataDeferredLighting StrataLighting = StrataDeferredLighting(
LightData,
V,
L,
ToLight,
LightMask,
ShadowTerms,
Strata.MaterialTextureArray,
StrataAddressing,
StrataPixelHeader);
OutColor += StrataLighting.SceneColor;
#if STRATA_OPAQUE_ROUGH_REFRACTION_ENABLED
OutOpaqueRoughRefractionSceneColor += StrataLighting.OpaqueRoughRefractionSceneColor;
OutSubSurfaceSceneColor += StrataLighting.SubSurfaceSceneColor;
#endif
}
}
#else // STRATA_ENABLED
FScreenSpaceData ScreenSpaceData = GetScreenSpaceData(InputParams.ScreenUV);
// Only light pixels marked as using deferred shading
BRANCH if (ScreenSpaceData.GBuffer.ShadingModelID > 0
#if USE_LIGHTING_CHANNELS
&& (GetLightingChannelMask(InputParams.ScreenUV) & DeferredLightUniforms.LightingChannelMask)
#endif
)
{
const float SceneDepth = CalcSceneDepth(InputParams.ScreenUV);
const FDerivedParams DerivedParams = GetDerivedParams(InputParams, SceneDepth);
FDeferredLightData LightData = InitDeferredLightFromUniforms(CURRENT_LIGHT_TYPE);
UpdateLightDataColor(LightData, InputParams, DerivedParams);
#if USE_HAIR_COMPLEX_TRANSMITTANCE
if (ScreenSpaceData.GBuffer.ShadingModelID == SHADINGMODELID_HAIR && ShouldUseHairComplexTransmittance(ScreenSpaceData.GBuffer))
{
LightData.HairTransmittance = EvaluateDualScattering(ScreenSpaceData.GBuffer, DerivedParams.CameraVector, -DeferredLightUniforms.Direction);
}
#endif
float Dither = InterleavedGradientNoise(InputParams.PixelPos, View.StateFrameIndexMod8);
float SurfaceShadow = 1.0f;
float4 LightAttenuation = GetLightAttenuationFromShadow(InputParams, SceneDepth);
float4 Radiance = GetDynamicLighting(DerivedParams.TranslatedWorldPosition, DerivedParams.CameraVector, ScreenSpaceData.GBuffer, ScreenSpaceData.AmbientOcclusion, ScreenSpaceData.GBuffer.ShadingModelID, LightData, LightAttenuation, Dither, uint2(InputParams.PixelPos), SurfaceShadow);
OutColor += Radiance;
}
#endif // STRATA_ENABLED
// RGB:SceneColor Specular and Diffuse
// A:Non Specular SceneColor Luminance
// So we need PreExposure for both color and alpha
OutColor.rgba *= GetExposure();
#if STRATA_OPAQUE_ROUGH_REFRACTION_ENABLED
// Idem
OutOpaqueRoughRefractionSceneColor *= GetExposure();
OutSubSurfaceSceneColor *= GetExposure();
#endif
}
#endif
```