void FDecalRendering::BuildVisibleDecalList(const FScene& Scene, const FViewInfo& View, EDecalRenderStage DecalRenderStage, FTransientDecalRenderDataList& OutVisibleDecals)
{
QUICK_SCOPE_CYCLE_COUNTER(BuildVisibleDecalList);
OutVisibleDecals.Empty(Scene.Decals.Num());
const float FadeMultiplier = CVarDecalFadeScreenSizeMultiplier.GetValueOnRenderThread();
const EShaderPlatform ShaderPlatform = View.GetShaderPlatform();
const bool bIsPerspectiveProjection = View.IsPerspectiveProjection();
// Build a list of decals that need to be rendered for this view in SortedDecals
for (const FDeferredDecalProxy* DecalProxy : Scene.Decals)
{
bool bIsShown = true;
if (!DecalProxy->IsShown(&View))
{
bIsShown = false;
}
const FMatrix ComponentToWorldMatrix = DecalProxy->ComponentTrans.ToMatrixWithScale();
// can be optimized as we test against a sphere around the box instead of the box itself
const float ConservativeRadius = FMath::Sqrt(
ComponentToWorldMatrix.GetScaledAxis(EAxis::X).SizeSquared() +
ComponentToWorldMatrix.GetScaledAxis(EAxis::Y).SizeSquared() +
ComponentToWorldMatrix.GetScaledAxis(EAxis::Z).SizeSquared());
// can be optimized as the test is too conservative (sphere instead of OBB)
if(ConservativeRadius < SMALL_NUMBER || !View.ViewFrustum.IntersectSphere(ComponentToWorldMatrix.GetOrigin(), ConservativeRadius))
{
bIsShown = false;
}
if (bIsShown)
{
FTransientDecalRenderData Data(Scene, DecalProxy, ConservativeRadius);
// filter out decals with blend modes that are not supported on current platform
if (IsBlendModeSupported(ShaderPlatform, Data.DecalBlendMode))
{
if (bIsPerspectiveProjection && Data.DecalProxy->Component->FadeScreenSize != 0.0f)
{
float Distance = (View.ViewMatrices.ViewOrigin - ComponentToWorldMatrix.GetOrigin()).Size();
float Radius = ComponentToWorldMatrix.GetMaximumAxisScale();
float CurrentScreenSize = ((Radius / Distance) * FadeMultiplier);
// fading coefficient needs to increase with increasing field of view and decrease with increasing resolution
// FadeCoeffScale is an empirically determined constant to bring us back roughly to fraction of screen size for FadeScreenSize
const float FadeCoeffScale = 600.0f;
float FOVFactor = ((2.0f/View.ViewMatrices.ProjMatrix.M[0][0]) / View.ViewRect.Width()) * FadeCoeffScale;
float FadeCoeff = Data.DecalProxy->Component->FadeScreenSize * FOVFactor;
float FadeRange = FadeCoeff * 0.5f;
float Alpha = (CurrentScreenSize - FadeCoeff) / FadeRange;
Data.FadeAlpha = FMath::Min(Alpha, 1.0f);
}
EDecalRenderStage LocalDecalRenderStage = FDecalRenderingCommon::ComputeRenderStage(ShaderPlatform, Data.DecalBlendMode);
// we could do this test earlier to avoid the decal intersection but getting DecalBlendMode also costs
if (View.Family->EngineShowFlags.ShaderComplexity || (DecalRenderStage == LocalDecalRenderStage && Data.FadeAlpha>0.0f) )
{
OutVisibleDecals.Add(Data);
}
}
}
}
if (OutVisibleDecals.Num() > 0)
{
// Sort by sort order to allow control over composited result
// Then sort decals by state to reduce render target switches
// Also sort by component since Sort() is not stable
struct FCompareFTransientDecalRenderData
{
FORCEINLINE bool operator()(const FTransientDecalRenderData& A, const FTransientDecalRenderData& B) const
{
if (B.DecalProxy->SortOrder != A.DecalProxy->SortOrder)
{
return A.DecalProxy->SortOrder < B.DecalProxy->SortOrder;
}
// bHasNormal here is more important then blend mode because we want to render every decals that output normals before those that read normal.
if (B.bHasNormal != A.bHasNormal)
{
return B.bHasNormal < A.bHasNormal; // < so that those outputting normal are first.
}
if (B.DecalBlendMode != A.DecalBlendMode)
{
return (int32)B.DecalBlendMode < (int32)A.DecalBlendMode;
}
// Batch decals with the same material together
if (B.MaterialProxy != A.MaterialProxy)
{
return B.MaterialProxy < A.MaterialProxy;
}
return (PTRINT)B.DecalProxy->Component < (PTRINT)A.DecalProxy->Component;
}
};
// Sort decals by blend mode to reduce render target switches
OutVisibleDecals.Sort(FCompareFTransientDecalRenderData());
}
}
void FRCPassPostProcessDeferredDecals::Process(FRenderingCompositePassContext& Context)
{
FRHICommandListImmediate& RHICmdList = Context.RHICmdList;
const bool bShaderComplexity = Context.View.Family->EngineShowFlags.ShaderComplexity;
const bool bDBuffer = IsDBufferEnabled();
const bool bStencilSizeThreshold = CVarStencilSizeThreshold.GetValueOnRenderThread() >= 0;
SCOPED_DRAW_EVENT(RHICmdList, PostProcessDeferredDecals);
if(RenderStage == 0)
{
// before BasePass, only if DBuffer is enabled
check(bDBuffer);
// DBuffer: Decal buffer
FPooledRenderTargetDesc Desc(FPooledRenderTargetDesc::Create2DDesc(GSceneRenderTargets.GBufferA->GetDesc().Extent,
PF_B8G8R8A8,
TexCreate_None,
TexCreate_ShaderResource | TexCreate_RenderTargetable,
false));
if(!GSceneRenderTargets.DBufferA)
{
GRenderTargetPool.FindFreeElement(Desc, GSceneRenderTargets.DBufferA, TEXT("DBufferA"));
}
if(!GSceneRenderTargets.DBufferB)
{
GRenderTargetPool.FindFreeElement(Desc, GSceneRenderTargets.DBufferB, TEXT("DBufferB"));
}
Desc.Format = PF_R8G8;
if(!GSceneRenderTargets.DBufferC)
{
GRenderTargetPool.FindFreeElement(Desc, GSceneRenderTargets.DBufferC, TEXT("DBufferC"));
}
// we assume views are non overlapping, then we need to clear only once in the beginning, otherwise we would need to set scissor rects
// and don't get FastClear any more.
bool bFirstView = Context.View.Family->Views[0] == &Context.View;
if(bFirstView)
{
SCOPED_DRAW_EVENT(RHICmdList, DBufferClear);
// could be optimized
SetRenderTarget(RHICmdList, GSceneRenderTargets.DBufferA->GetRenderTargetItem().TargetableTexture, FTextureRHIParamRef());
RHICmdList.Clear(true, FLinearColor(0, 0, 0, 1), false, (float)ERHIZBuffer::FarPlane, false, 0, FIntRect());
SetRenderTarget(RHICmdList, GSceneRenderTargets.DBufferB->GetRenderTargetItem().TargetableTexture, FTextureRHIParamRef());
// todo: some hardware would like to have 0 or 1 for faster clear, we chose 128/255 to represent 0 (8 bit cannot represent 0.5f)
RHICmdList.Clear(true, FLinearColor(128.0f / 255.0f, 128.0f / 255.0f, 128.0f / 255.0f, 1), false, (float)ERHIZBuffer::FarPlane, false, 0, FIntRect());
SetRenderTarget(RHICmdList, GSceneRenderTargets.DBufferC->GetRenderTargetItem().TargetableTexture, FTextureRHIParamRef());
// R:roughness, G:roughness opacity
RHICmdList.Clear(true, FLinearColor(0, 1, 0, 1), false, (float)ERHIZBuffer::FarPlane, false, 0, FIntRect());
}
}
// this cast is safe as only the dedicated server implements this differently and this pass should not be executed on the dedicated server
const FViewInfo& View = Context.View;
const FSceneViewFamily& ViewFamily = *(View.Family);
FScene& Scene = *(FScene*)ViewFamily.Scene;
if(!Scene.Decals.Num())
{
// to avoid the stats showing up
return;
}
TArray<FTransientDecalRenderData, SceneRenderingAllocator> SortedDecals;
SortedDecals.Empty(Scene.Decals.Num());
// Build a list of decals that need to be rendered for this view in SortedDecals
for (TSparseArray<FDeferredDecalProxy*>::TConstIterator It(Scene.Decals); It; ++It)
{
FDeferredDecalProxy* DecalProxy = *It;
bool bIsShown = true;
// Handle the decal actor having bHidden set when we are in the editor, in G mode
#if WITH_EDITOR
if (View.Family->EngineShowFlags.Editor)
#endif
{
if (!DecalProxy->DrawInGame)
{
bIsShown = false;
}
}
const FMatrix ComponentToWorldMatrix = DecalProxy->ComponentTrans.ToMatrixWithScale();
// can be optimized as we test against a sphere around the box instead of the box itself
const float ConservativeRadius = FMath::Sqrt(
ComponentToWorldMatrix.GetScaledAxis( EAxis::X ).SizeSquared() * FMath::Square(GDefaultDecalSize.X) +
ComponentToWorldMatrix.GetScaledAxis( EAxis::Y ).SizeSquared() * FMath::Square(GDefaultDecalSize.Y) +
ComponentToWorldMatrix.GetScaledAxis( EAxis::Z ).SizeSquared() * FMath::Square(GDefaultDecalSize.Z));
// can be optimized as the test is too conservative (sphere instead of OBB)
if(ConservativeRadius < SMALL_NUMBER || !View.ViewFrustum.IntersectSphere(ComponentToWorldMatrix.GetOrigin(), ConservativeRadius))
{
bIsShown = false;
}
if (bIsShown)
{
FTransientDecalRenderData Data(Scene, DecalProxy);
uint32 DecalRenderStage = ComputeRenderStage(Data.DecalBlendMode);
// we could do this test earlier to avoid the decal intersection but getting DecalBlendMode also costs
if (Context.View.Family->EngineShowFlags.ShaderComplexity || RenderStage == DecalRenderStage)
{
SortedDecals.Add(Data);
}
}
}
if(SortedDecals.Num() > 0)
{
FIntRect SrcRect = View.ViewRect;
FIntRect DestRect = View.ViewRect;
bool bStencilDecals = true;
#if DBUFFER_DONT_USE_STENCIL_YET
if(RenderStage == 0)
{
bStencilDecals = false;
}
#endif
// Setup a stencil mask to prevent certain pixels from receiving deferred decals
if(bStencilDecals)
{
StencilDecalMask(RHICmdList, View);
}
// Sort by sort order to allow control over composited result
// Then sort decals by state to reduce render target switches
// Also sort by component since Sort() is not stable
struct FCompareFTransientDecalRenderData
{
FORCEINLINE bool operator()( const FTransientDecalRenderData& A, const FTransientDecalRenderData& B ) const
{
if (B.DecalProxy->SortOrder != A.DecalProxy->SortOrder)
{
return A.DecalProxy->SortOrder < B.DecalProxy->SortOrder;
}
if (B.DecalBlendMode != A.DecalBlendMode)
{
return (int32)B.DecalBlendMode < (int32)A.DecalBlendMode;
}
if (B.bHasNormal != A.bHasNormal)
{
return B.bHasNormal < A.bHasNormal;
}
// Batch decals with the same material together
if (B.MaterialProxy != A.MaterialProxy )
{
return B.MaterialProxy < A.MaterialProxy;
}
return (PTRINT)B.DecalProxy->Component < (PTRINT)A.DecalProxy->Component;
}
};
// Sort decals by blend mode to reduce render target switches
SortedDecals.Sort( FCompareFTransientDecalRenderData() );
// optimization to have less state changes
int32 LastDecalBlendMode = -1;
int32 LastDecalHasNormal = -1; // Decal state can change based on its normal property.(SM5)
ERenderTargetMode LastRenderTargetMode = RTM_Unknown;
int32 WasInsideDecal = -1;
const ERHIFeatureLevel::Type SMFeatureLevel = Context.GetFeatureLevel();
SCOPED_DRAW_EVENT(RHICmdList, Decals);
INC_DWORD_STAT_BY(STAT_Decals, SortedDecals.Num());
enum EDecalResolveBufferIndex
{
SceneColorIndex,
GBufferAIndex,
GBufferBIndex,
GBufferCIndex,
DBufferAIndex,
DBufferBIndex,
DBufferCIndex,
ResolveBufferMax,
};
FTextureRHIParamRef TargetsToResolve[ResolveBufferMax] = { nullptr };
for (int32 DecalIndex = 0, DecalCount = SortedDecals.Num(); DecalIndex < DecalCount; DecalIndex++)
{
const FTransientDecalRenderData& DecalData = SortedDecals[DecalIndex];
const FDeferredDecalProxy& DecalProxy = *DecalData.DecalProxy;
const FMatrix ComponentToWorldMatrix = DecalProxy.ComponentTrans.ToMatrixWithScale();
// Set vertex shader params
const FMaterialShaderMap* MaterialShaderMap = DecalData.MaterialResource->GetRenderingThreadShaderMap();
FScaleMatrix DecalScaleTransform(GDefaultDecalSize);
FTranslationMatrix PreViewTranslation(View.ViewMatrices.PreViewTranslation);
FMatrix FrustumComponentToClip = DecalScaleTransform * ComponentToWorldMatrix * PreViewTranslation * View.ViewMatrices.TranslatedViewProjectionMatrix;
// can be optimized as we test against a sphere around the box instead of the box itself
const float ConservativeRadius = FMath::Sqrt(
ComponentToWorldMatrix.GetScaledAxis( EAxis::X ).SizeSquared() * FMath::Square(GDefaultDecalSize.X) +
ComponentToWorldMatrix.GetScaledAxis( EAxis::Y ).SizeSquared() * FMath::Square(GDefaultDecalSize.Y) +
ComponentToWorldMatrix.GetScaledAxis( EAxis::Z ).SizeSquared() * FMath::Square(GDefaultDecalSize.Z));
EDecalBlendMode DecalBlendMode = DecalData.DecalBlendMode;
bool bStencilThisDecal = bStencilDecals;
#if DBUFFER_DONT_USE_STENCIL_YET
if(ComputeRenderStage(DecalBlendMode) == 0)
{
bStencilThisDecal = false;
}
#endif
ERenderTargetMode CurrentRenderTargetMode = ComputeRenderTargetMode(DecalBlendMode);
if(bShaderComplexity)
{
CurrentRenderTargetMode = RTM_SceneColor;
// we want additive blending for the ShaderComplexity mode
DecalBlendMode = DBM_Emissive;
}
// fewer rendertarget switches if possible
if(CurrentRenderTargetMode != LastRenderTargetMode)
{
LastRenderTargetMode = CurrentRenderTargetMode;
switch(CurrentRenderTargetMode)
{
case RTM_SceneColorAndGBuffer:
{
TargetsToResolve[SceneColorIndex] = GSceneRenderTargets.GetSceneColor()->GetRenderTargetItem().TargetableTexture;
TargetsToResolve[GBufferAIndex] = GSceneRenderTargets.GBufferA->GetRenderTargetItem().TargetableTexture;
TargetsToResolve[GBufferBIndex] = GSceneRenderTargets.GBufferB->GetRenderTargetItem().TargetableTexture;
TargetsToResolve[GBufferCIndex] = GSceneRenderTargets.GBufferC->GetRenderTargetItem().TargetableTexture;
SetRenderTargets(RHICmdList, 4, TargetsToResolve, GSceneRenderTargets.GetSceneDepthSurface(), ESimpleRenderTargetMode::EExistingColorAndDepth, FExclusiveDepthStencil::DepthRead_StencilWrite);
}
break;
case RTM_GBufferNormal:
TargetsToResolve[GBufferAIndex] = GSceneRenderTargets.GBufferA->GetRenderTargetItem().TargetableTexture;
SetRenderTarget(RHICmdList, TargetsToResolve[GBufferAIndex], GSceneRenderTargets.GetSceneDepthSurface(), ESimpleRenderTargetMode::EExistingColorAndDepth, FExclusiveDepthStencil::DepthRead_StencilWrite);
break;
case RTM_SceneColor:
TargetsToResolve[SceneColorIndex] = GSceneRenderTargets.GetSceneColor()->GetRenderTargetItem().TargetableTexture;
SetRenderTarget(RHICmdList, TargetsToResolve[SceneColorIndex], GSceneRenderTargets.GetSceneDepthSurface(), ESimpleRenderTargetMode::EExistingColorAndDepth, FExclusiveDepthStencil::DepthRead_StencilWrite);
break;
case RTM_DBuffer:
{
TargetsToResolve[DBufferAIndex] = GSceneRenderTargets.DBufferA->GetRenderTargetItem().TargetableTexture;
TargetsToResolve[DBufferBIndex] = GSceneRenderTargets.DBufferB->GetRenderTargetItem().TargetableTexture;
TargetsToResolve[DBufferCIndex] = GSceneRenderTargets.DBufferC->GetRenderTargetItem().TargetableTexture;
SetRenderTargets(RHICmdList, 3, &TargetsToResolve[DBufferAIndex], GSceneRenderTargets.GetSceneDepthSurface(), ESimpleRenderTargetMode::EExistingColorAndDepth, FExclusiveDepthStencil::DepthRead_StencilWrite);
}
break;
default:
check(0);
break;
}
Context.SetViewportAndCallRHI(DestRect);
// we need to reset the stream source after any call to SetRenderTarget (at least for Metal, which doesn't queue up VB assignments)
RHICmdList.SetStreamSource(0, GUnitCubeVertexBuffer.VertexBufferRHI, sizeof(FVector4), 0);
}
bool bThisDecalUsesStencil = false;
if (bStencilThisDecal)
{
if (bStencilSizeThreshold)
{
// note this is after a SetStreamSource (in if CurrentRenderTargetMode != LastRenderTargetMode) call as it needs to get the VB input
bThisDecalUsesStencil = RenderPreStencil(Context, MaterialShaderMap, ComponentToWorldMatrix, FrustumComponentToClip);
WasInsideDecal = -1;
LastDecalBlendMode = -1;
}
}
const bool bBlendStateChange = DecalBlendMode != LastDecalBlendMode;// Has decal mode changed.
const bool bDecalNormalChanged = GSupportsSeparateRenderTargetBlendState && // has normal changed for SM5 stain/translucent decals?
(DecalBlendMode == DBM_Translucent || DecalBlendMode == DBM_Stain) &&
(int32)DecalData.bHasNormal != LastDecalHasNormal;
// fewer blend state changes if possible
if (bBlendStateChange || bDecalNormalChanged)
{
LastDecalBlendMode = DecalBlendMode;
LastDecalHasNormal = (int32)DecalData.bHasNormal;
SetDecalBlendState(RHICmdList, SMFeatureLevel, RenderStage, (EDecalBlendMode)LastDecalBlendMode, DecalData.bHasNormal);
}
{
TShaderMapRef<FDeferredDecalVS> VertexShader(Context.GetShaderMap());
SetShader(Context, bShaderComplexity, DecalData, *VertexShader);
VertexShader->SetParameters(RHICmdList, View, FrustumComponentToClip);
const int32 IsInsideDecal = ((FVector)View.ViewMatrices.ViewOrigin - ComponentToWorldMatrix.GetOrigin()).SizeSquared() < FMath::Square(ConservativeRadius * 1.05f + View.NearClippingDistance * 2.0f) + ( bThisDecalUsesStencil ) ? 2 : 0;
if ( WasInsideDecal != IsInsideDecal )
{
WasInsideDecal = IsInsideDecal;
if ( !(IsInsideDecal & 1) )
{
// Render backfaces with depth tests disabled since the camera is inside (or close to inside) the light function geometry
RHICmdList.SetRasterizerState(View.bReverseCulling ? TStaticRasterizerState<FM_Solid, CM_CCW>::GetRHI() : TStaticRasterizerState<FM_Solid, CM_CW>::GetRHI());
if(bStencilDecals)
{
// Enable stencil testing, only write to pixels with stencil of 0
if ( bThisDecalUsesStencil )
{
RHICmdList.SetDepthStencilState(TStaticDepthStencilState<
false,CF_Always,
true,CF_Equal,SO_Zero,SO_Zero,SO_Zero,
true,CF_Equal,SO_Zero,SO_Zero,SO_Zero,
0xff, 0x7f
>::GetRHI(), 1);
}
else
{
RHICmdList.SetDepthStencilState(TStaticDepthStencilState<
false,CF_Always,
true,CF_Equal,SO_Keep,SO_Keep,SO_Keep,
false,CF_Always,SO_Keep,SO_Keep,SO_Keep,
0x80,0x00>::GetRHI(), 0);
}
}
else
{
RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_Always, true>::GetRHI(), 0);
}
}
else
{
// Render frontfaces with depth tests on to get the speedup from HiZ since the camera is outside the light function geometry
if(bStencilDecals)
{
// Render frontfaces with depth tests on to get the speedup from HiZ since the camera is outside the light function geometry
// Enable stencil testing, only write to pixels with stencil of 0
if ( bThisDecalUsesStencil )
{
RHICmdList.SetDepthStencilState(TStaticDepthStencilState<
false,CF_DepthNearOrEqual,
true,CF_Equal,SO_Zero,SO_Zero,SO_Zero,
true,CF_Equal,SO_Zero,SO_Zero,SO_Zero,
0xff, 0x7f
>::GetRHI(), 1);
}
else
{
RHICmdList.SetDepthStencilState(TStaticDepthStencilState<
false,CF_DepthNearOrEqual,
true,CF_Equal,SO_Keep,SO_Keep,SO_Keep,
false,CF_Always,SO_Keep,SO_Keep,SO_Keep,
0x80,0x00>::GetRHI(), 0);
}
RHICmdList.SetRasterizerState(View.bReverseCulling ? TStaticRasterizerState<FM_Solid, CM_CW>::GetRHI() : TStaticRasterizerState<FM_Solid, CM_CCW>::GetRHI());
}
else
{
RHICmdList.SetDepthStencilState(TStaticDepthStencilState<false, CF_DepthNearOrEqual>::GetRHI(), 0);
}
RHICmdList.SetRasterizerState(View.bReverseCulling ? TStaticRasterizerState<FM_Solid, CM_CW>::GetRHI() : TStaticRasterizerState<FM_Solid, CM_CCW>::GetRHI());
}
}
RHICmdList.DrawIndexedPrimitive(GUnitCubeIndexBuffer.IndexBufferRHI, PT_TriangleList, 0, 0, 8, 0, GUnitCubeIndexBuffer.GetIndexCount() / 3, 1);
}
}
// we don't modify stencil but if out input was having stencil for us (after base pass - we need to clear)
// Clear stencil to 0, which is the assumed default by other passes
RHICmdList.Clear(false, FLinearColor::White, false, (float)ERHIZBuffer::FarPlane, true, 0, FIntRect());
// resolve the targets we wrote to.
FResolveParams ResolveParams;
for (int32 i = 0; i < ResolveBufferMax; ++i)
{
if (TargetsToResolve[i])
{
RHICmdList.CopyToResolveTarget(TargetsToResolve[i], TargetsToResolve[i], true, ResolveParams);
}
}
}
if(RenderStage == 0)
{
// before BasePass
GRenderTargetPool.VisualizeTexture.SetCheckPoint(RHICmdList, GSceneRenderTargets.DBufferA);
GRenderTargetPool.VisualizeTexture.SetCheckPoint(RHICmdList, GSceneRenderTargets.DBufferB);
GRenderTargetPool.VisualizeTexture.SetCheckPoint(RHICmdList, GSceneRenderTargets.DBufferC);
}
}
