Files
UnrealEngine/Engine/Shaders/Private/ShadowDepthVertexShader.usf
2025-05-18 13:04:45 +08:00

351 lines
11 KiB
HLSL

// Copyright Epic Games, Inc. All Rights Reserved.
/*=============================================================================
ShadowDepthVertexShader.usf: Vertex & Geometry shader for writing shadow depth.
=============================================================================*/
// needs to before Common.usf
#define SHADOW_DEPTH_SHADER 1
#define USE_STENCIL_LOD_DITHER 0
#ifndef ENABLE_NON_NANITE_VSM
#error "ENABLE_NON_NANITE_VSM should be defined to either 0 or 1!"
#endif
#if ENABLE_NON_NANITE_VSM
#define VIRTUAL_SM_ENABLED (!(ONEPASS_POINTLIGHT_SHADOW || PERSPECTIVE_CORRECT_DEPTH))
#else
#define VIRTUAL_SM_ENABLED 0
#endif
// Need to get the definition of nanite packed view for generated unform buffer (which is pulled in by Common.ush)
#include "Nanite/NanitePackedNaniteView.ush"
#include "Common.ush"
// Reroute SceneTexturesStruct uniform buffer references to the shadow depth pass uniform buffer
#if FEATURE_LEVEL >= FEATURE_LEVEL_SM5
#define PassStruct ShadowDepthPass
#define SceneTexturesStruct ShadowDepthPass.SceneTextures
#else
#define PassStruct MobileShadowDepthPass
#define MobileSceneTextures MobileShadowDepthPass.SceneTextures
#endif
#include "/Engine/Generated/Material.ush"
#include "/Engine/Generated/VertexFactory.ush"
#include "ShadowDepthCommon.ush"
//
#ifndef VF_USE_VSM_CONSTANT_BIAS
#define VF_USE_VSM_CONSTANT_BIAS 0
#endif
#if VIRTUAL_SM_ENABLED
#include "Nanite/NaniteDataDecode.ush"
#include "SceneData.ush"
#include "VirtualShadowMaps/VirtualShadowMapPageAccessCommon.ush"
#endif // VIRTUAL_SM_ENABLED
void SetShadowDepthOutputs(
float4x4 WorldToClipMatrix,
float4x4 WorldToShadowMatrix,
float4 WorldPosition,
float3 WorldVertexNormal,
out float4 OutPosition,
out float ShadowDepth
#if PERSPECTIVE_CORRECT_DEPTH
, out float OutDepthBias
#endif
)
{
OutPosition = mul(WorldPosition, WorldToClipMatrix);
// Clamp the vertex to the near plane if it is in front of the near plane
// This has problems if some vertices of a triangle get clamped and others do not, also causes artifacts with non-ortho projections
if (PassStruct.bClampToNearPlane > 0 && OutPosition.z > OutPosition.w)
{
OutPosition.z = 0.999999f;
OutPosition.w = 1.0f;
}
#if ONEPASS_POINTLIGHT_SHADOW
const float3 ViewDirection = -normalize(mul(WorldPosition, WorldToShadowMatrix).xyz);
const float3 ViewNormal = mul(float4(WorldVertexNormal,0), WorldToShadowMatrix).xyz;
const float NoL = abs(dot(ViewDirection, ViewNormal));
#else
const float NoL = abs(dot(
float3(WorldToShadowMatrix[0].z, WorldToShadowMatrix[1].z, WorldToShadowMatrix[2].z),
WorldVertexNormal));
#endif
const float MaxSlopeDepthBias = PassStruct.ShadowParams.z;
const float Slope = clamp(abs(NoL) > 0 ? sqrt(saturate(1 - NoL*NoL)) / NoL : MaxSlopeDepthBias, 0, MaxSlopeDepthBias);
const float SlopeDepthBias = PassStruct.ShadowParams.y;
const float SlopeBias = SlopeDepthBias * Slope;
const float ConstantDepthBias = PassStruct.ShadowParams.x;
const float DepthBias = SlopeBias + ConstantDepthBias;
#if PERSPECTIVE_CORRECT_DEPTH
ShadowDepth = OutPosition.z;
OutDepthBias = DepthBias;
#elif ONEPASS_POINTLIGHT_SHADOW
ShadowDepth = 0;
//OutPosition.z += DepthBias;
#else
// Output linear, normalized depth
const float InvMaxSubjectDepth = PassStruct.ShadowParams.w;
#if PLATFORM_NEEDS_PRECISE_SHADOW_DEPTH
precise
#endif
float AdjustedDepth = ( 1 - OutPosition.z * InvMaxSubjectDepth ) + DepthBias;
ShadowDepth = AdjustedDepth;
OutPosition.z = AdjustedDepth;
#endif
}
/**
* Load physical page offset and perform the needed scale and bias to render the instance into the given physical page,
* with the correct clipping set up.
*/
#if VIRTUAL_SM_ENABLED
void ScaleBiasClipToPhysicalSmPage(FNaniteView NaniteView, inout float4 PositionClip, inout float4 ClipPlanesInOut, FPageInfo PageInfo)
{
float2 vClip = PositionClip.xy;
float2 vUV = vClip * float2(0.5, -0.5) + 0.5 * PositionClip.w;
float2 vPixels = vUV * ( uint(VSM_VIRTUAL_MAX_RESOLUTION_XY) >> NaniteView.TargetMipLevel );
{
//PointClip.xy = NaniteView.ClipSpaceScaleOffset.xy * PointClip.xy + NaniteView.ClipSpaceScaleOffset.zw * PointClip.w;
float2 Scale = exp2( -NaniteView.TargetMipLevel );
PositionClip.xy *= Scale;
PositionClip.xy += ( Scale * float2(1,-1) + float2(-1,1) ) * PositionClip.w;
}
{
// Clip to uncached page rect
uint4 PageRect = PassStruct.UncachedPageRectBounds[ NaniteView.TargetLayerIndex * VSM_MAX_MIP_LEVELS + NaniteView.TargetMipLevel ];
float2 MinClip = vPixels - ( PageRect.xy + 0 ) * VSM_PAGE_SIZE * PositionClip.w;
float2 MaxClip = -vPixels + ( PageRect.zw + 1 ) * VSM_PAGE_SIZE * PositionClip.w;
ClipPlanesInOut.xy = MinClip;
ClipPlanesInOut.zw = MaxClip;
}
}
void TransformToVirtualSmPage(inout float4 PointClip, inout float4 ClipPlanesInOut, FPageInfo PageInfo, float3 PointTranslatedWorld)
{
// Load nanite view and perform transform to SM space.
FNaniteView NaniteView = UnpackNaniteView(PassStruct.PackedNaniteViews[PageInfo.ViewId]);
PointTranslatedWorld += DFFastSubtractDemote( NaniteView.PreViewTranslation, ResolvedView.PreViewTranslation );
PointClip = mul( float4( PointTranslatedWorld, 1 ), NaniteView.TranslatedWorldToClip );
// Clamp the vertex to the near plane if it is in front of the near plane
// This has problems if some vertices of a triangle get clamped and others do not, also causes artifacts with non-ortho projections
if (PassStruct.bClampToNearPlane > 0 && PointClip.z > PointClip.w)
{
PointClip.z = 0.999999f;
PointClip.w = 1.0f;
}
ScaleBiasClipToPhysicalSmPage(NaniteView, PointClip, ClipPlanesInOut, PageInfo);
#if VF_USE_VSM_CONSTANT_BIAS
{
const float ConstantDepthBias = VertexFactoryGetNonNaniteVirtualShadowMapConstantDepthBias();
PointClip.z = clamp(PointClip.z + ConstantDepthBias * NaniteView.ViewToClip[2][2], -PointClip.w, PointClip.w);
}
#endif
}
#endif // VIRTUAL_SM_ENABLED
uint bUseGpuSceneInstancing;
#if VERTEXSHADER && ONEPASS_POINTLIGHT_SHADOW
uint LayerId;
#endif
void Main(
FVertexFactoryInput Input,
out FShadowDepthVSToPS OutParameters,
#if VIRTUAL_SM_ENABLED
out nointerpolation uint PackedPageInfo : TEXCOORD8,
#endif
out float4 OutPosition : SV_POSITION
#if ONEPASS_POINTLIGHT_SHADOW
, out uint LayerIndex : SV_RenderTargetArrayIndex
#endif
#if VIRTUAL_SM_ENABLED
// OLA-TODO: this collides with instanced stereo, which thankfully is not used with shadow maps, so should be fine, presumably.
, out float4 OutVirtualSmPageClip : SV_ClipDistance
#endif // VIRTUAL_SM_ENABLED
)
{
ResolvedView = ResolveView();
FVertexFactoryIntermediates VFIntermediates = GetVertexFactoryIntermediates(Input);
float4 WorldPos = VertexFactoryGetWorldPosition(Input, VFIntermediates);
#if USE_WORLD_POSITION_EXCLUDING_SHADER_OFFSETS && !IS_NANITE_PASS
OutParameters.PixelPositionExcludingWPO = WorldPos.xyz;
#endif
half3x3 TangentToLocal = VertexFactoryGetTangentToLocal(Input, VFIntermediates);
FMaterialVertexParameters VertexParameters = GetMaterialVertexParameters(Input, VFIntermediates, WorldPos.xyz, TangentToLocal);
const float3 WorldNormal = VertexFactoryGetWorldNormal(Input, VFIntermediates);
WorldPos.xyz += GetMaterialWorldPositionOffset(VertexParameters);
ApplyMaterialFirstPersonTransform(VertexParameters, WorldPos.xyz);
#if ONEPASS_POINTLIGHT_SHADOW
OutPosition = WorldPos;
#if INTERPOLATE_VF_ATTRIBUTES
// Masked materials need texture coords to clip
OutParameters.FactoryInterpolants = VertexFactoryGetInterpolantsVSToPS(Input, VFIntermediates, VertexParameters);
#endif
#if INTERPOLATE_POSITION
OutParameters.PixelPosition = WorldPos.xyz;
#endif
LayerIndex = bUseGpuSceneInstancing ? VertexFactoryGetViewIndex(VFIntermediates) : LayerId;
OutPosition = mul(WorldPos, PassStruct.ShadowViewProjectionMatrices[LayerIndex]);
#else
float Dummy;
SetShadowDepthOutputs(
PassStruct.ProjectionMatrix,
PassStruct.ViewMatrix,
WorldPos,
WorldNormal,
OutPosition,
#if !PERSPECTIVE_CORRECT_DEPTH
Dummy
#else
OutParameters.ShadowDepth,
OutParameters.DepthBias
#endif
);
#if INTERPOLATE_VF_ATTRIBUTES
// Masked materials need texture coords to clip
OutParameters.FactoryInterpolants = VertexFactoryGetInterpolantsVSToPS(Input, VFIntermediates, VertexParameters);
#endif
#if INTERPOLATE_POSITION
OutParameters.PixelPosition = WorldPos.xyz;
#endif
#if !PERSPECTIVE_CORRECT_DEPTH && !COMPILER_SUPPORTS_EMPTY_STRUCTS
OutParameters.Dummy = 0;
#endif
#endif
#if VIRTUAL_SM_ENABLED
PackedPageInfo = 0;
OutVirtualSmPageClip = float4(1.0f, 1.0f, 1.0f, 1.0f);
if (PassStruct.bRenderToVirtualShadowMap != 0)
{
// Get the offset from which we loaded the instance ID
uint InstanceIdIndex = VertexFactoryGetInstanceIdLoadIndex(VFIntermediates);
PackedPageInfo = InstanceCulling.PageInfoBuffer[InstanceIdIndex];
FPageInfo PageInfo = UnpackPageInfo(PackedPageInfo);
TransformToVirtualSmPage(OutPosition, OutVirtualSmPageClip, PageInfo, WorldPos.xyz);
}
#endif // VIRTUAL_SM_ENABLED
}
#if POSITION_ONLY
void PositionOnlyMain(
in FPositionAndNormalOnlyVertexFactoryInput Input,
#if ONEPASS_POINTLIGHT_SHADOW
out uint LayerIndex : SV_RenderTargetArrayIndex,
#endif
out FShadowDepthVSToPS OutParameters,
#if VIRTUAL_SM_ENABLED
out nointerpolation uint PackedPageInfo : TEXCOORD8,
#endif
out float4 OutPosition : SV_POSITION
#if VIRTUAL_SM_ENABLED
// OLA-TODO: this collides with instanced stereo, which thankfully is not used with shadow maps, so should be fine, presumably.
, out float4 OutVirtualSmPageClip : SV_ClipDistance
#endif // VIRTUAL_SM_ENABLED
)
{
ResolvedView = ResolveView();
float4 WorldPos = VertexFactoryGetWorldPosition(Input);
#if USE_WORLD_POSITION_EXCLUDING_SHADER_OFFSETS && !IS_NANITE_PASS
OutParameters.PixelPositionExcludingWPO = WorldPos.xyz;
#endif
#if INTERPOLATE_VF_ATTRIBUTES
OutParameters.FactoryInterpolants = (FVertexFactoryInterpolantsVSToPS)0;
#endif
float3 WorldNormal = VertexFactoryGetWorldNormal(Input);
#if ONEPASS_POINTLIGHT_SHADOW
LayerIndex = bUseGpuSceneInstancing ? VertexFactoryGetViewIndex(Input) : LayerId;
OutPosition = mul(WorldPos, PassStruct.ShadowViewProjectionMatrices[LayerIndex]);
#else // !ONEPASS_POINTLIGHT_SHADOW
float ShadowDepth;
SetShadowDepthOutputs(
PassStruct.ProjectionMatrix,
PassStruct.ViewMatrix,
WorldPos,
WorldNormal,
OutPosition,
#if PERSPECTIVE_CORRECT_DEPTH
OutParameters.ShadowDepth,
OutParameters.DepthBias
#else
ShadowDepth
#endif
);
#if !PERSPECTIVE_CORRECT_DEPTH && !COMPILER_SUPPORTS_EMPTY_STRUCTS
OutParameters.Dummy = 0;
#endif
#endif // ONEPASS_POINTLIGHT_SHADOW
#if INTERPOLATE_POSITION
OutParameters.PixelPosition = WorldPos.xyz;
#endif
#if VIRTUAL_SM_ENABLED
PackedPageInfo = 0;
OutVirtualSmPageClip = float4(1.0f, 1.0f, 1.0f, 1.0f);
if (PassStruct.bRenderToVirtualShadowMap != 0)
{
// Get the offset from which we loaded the instance ID
uint InstanceIdIndex = VertexFactoryGetInstanceIdLoadIndex(Input);
// TODO: Maybe offset index to local buffer for this? We may not want to use a global since most passes are not supporting this
// Or perhaps both are different, as they are managed somewhat differently anyway, maybe.
PackedPageInfo = InstanceCulling.PageInfoBuffer[InstanceIdIndex];
FPageInfo PageInfo = UnpackPageInfo(PackedPageInfo);
TransformToVirtualSmPage(OutPosition, OutVirtualSmPageClip, PageInfo, WorldPos.xyz);
}
#endif // VIRTUAL_SM_ENABLED
}
#endif // POSITION_ONLY