Files
UnrealEngineUWP/Engine/Source/Developer/MeshUtilities/Private/MeshRepresentationCommon.cpp
aurel cordonnier a6e741e007 Merge from Release-Engine-Staging @ 17915896 to Release-Engine-Test
This represents UE4/Main @17911760, Release-5.0 @17915875 and Dev-PerfTest @17914035

[CL 17918595 by aurel cordonnier in ue5-release-engine-test branch]
2021-10-25 20:05:28 -04:00

319 lines
11 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "MeshRepresentationCommon.h"
#include "MeshUtilities.h"
#include "MeshUtilitiesPrivate.h"
#include "DerivedMeshDataTaskUtils.h"
void MeshUtilities::GenerateStratifiedUniformHemisphereSamples(int32 NumSamples, FRandomStream& RandomStream, TArray<FVector3f>& Samples)
{
const int32 NumThetaSteps = FMath::TruncToInt(FMath::Sqrt(NumSamples / (2.0f * (float)PI)));
const int32 NumPhiSteps = FMath::TruncToInt(NumThetaSteps * (float)PI);
Samples.Empty(NumThetaSteps * NumPhiSteps);
for (int32 ThetaIndex = 0; ThetaIndex < NumThetaSteps; ThetaIndex++)
{
for (int32 PhiIndex = 0; PhiIndex < NumPhiSteps; PhiIndex++)
{
const float U1 = RandomStream.GetFraction();
const float U2 = RandomStream.GetFraction();
const float Fraction1 = (ThetaIndex + U1) / (float)NumThetaSteps;
const float Fraction2 = (PhiIndex + U2) / (float)NumPhiSteps;
const float R = FMath::Sqrt(1.0f - Fraction1 * Fraction1);
const float Phi = 2.0f * (float)PI * Fraction2;
// Convert to Cartesian
Samples.Add(FVector3f(FMath::Cos(Phi) * R, FMath::Sin(Phi) * R, Fraction1));
}
}
}
// [Frisvad 2012, "Building an Orthonormal Basis from a 3D Unit Vector Without Normalization"]
FMatrix44f MeshRepresentation::GetTangentBasisFrisvad(FVector3f TangentZ)
{
FVector3f TangentX;
FVector3f TangentY;
if (TangentZ.Z < -0.9999999f)
{
TangentX = FVector3f(0, -1, 0);
TangentY = FVector3f(-1, 0, 0);
}
else
{
float A = 1.0f / (1.0f + TangentZ.Z);
float B = -TangentZ.X * TangentZ.Y * A;
TangentX = FVector3f(1.0f - TangentZ.X * TangentZ.X * A, B, -TangentZ.X);
TangentY = FVector3f(B, 1.0f - TangentZ.Y * TangentZ.Y * A, -TangentZ.Y);
}
FMatrix44f LocalBasis;
LocalBasis.SetIdentity();
LocalBasis.SetAxis(0, TangentX);
LocalBasis.SetAxis(1, TangentY);
LocalBasis.SetAxis(2, TangentZ);
return LocalBasis;
}
#if USE_EMBREE
void EmbreeFilterFunc(const struct RTCFilterFunctionNArguments* args)
{
FEmbreeGeometry* EmbreeGeometry = (FEmbreeGeometry*)args->geometryUserPtr;
FEmbreeTriangleDesc Desc = EmbreeGeometry->TriangleDescs[RTCHitN_primID(args->hit, 1, 0)];
FEmbreeIntersectionContext& IntersectionContext = *static_cast<FEmbreeIntersectionContext*>(args->context);
IntersectionContext.ElementIndex = Desc.ElementIndex;
}
void EmbreeErrorFunc(void* userPtr, RTCError code, const char* str)
{
FString ErrorString;
TArray<TCHAR, FString::AllocatorType>& ErrorStringArray = ErrorString.GetCharArray();
ErrorStringArray.Empty();
int32 StrLen = FCStringAnsi::Strlen(str);
int32 Length = FUTF8ToTCHAR_Convert::ConvertedLength(str, StrLen);
ErrorStringArray.AddUninitialized(Length + 1); // +1 for the null terminator
FUTF8ToTCHAR_Convert::Convert(ErrorStringArray.GetData(), ErrorStringArray.Num(), reinterpret_cast<const ANSICHAR*>(str), StrLen);
ErrorStringArray[Length] = TEXT('\0');
UE_LOG(LogMeshUtilities, Error, TEXT("Embree error: %s Code=%u"), *ErrorString, (uint32)code);
}
#endif
void MeshRepresentation::SetupEmbreeScene(
FString MeshName,
const FSourceMeshDataForDerivedDataTask& SourceMeshData,
const FStaticMeshLODResources& LODModel,
const TArray<FSignedDistanceFieldBuildMaterialData>& MaterialBlendModes,
bool bGenerateAsIfTwoSided,
FEmbreeScene& EmbreeScene)
{
const uint32 NumIndices = SourceMeshData.IsValid() ? SourceMeshData.GetNumIndices() : LODModel.IndexBuffer.GetNumIndices();
const int32 NumTriangles = NumIndices / 3;
const uint32 NumVertices = SourceMeshData.IsValid() ? SourceMeshData.GetNumVertices() : LODModel.VertexBuffers.PositionVertexBuffer.GetNumVertices();
EmbreeScene.NumIndices = NumTriangles;
TArray<FkDOPBuildCollisionTriangle<uint32> > BuildTriangles;
#if USE_EMBREE
EmbreeScene.bUseEmbree = true;
if (EmbreeScene.bUseEmbree)
{
EmbreeScene.EmbreeDevice = rtcNewDevice(nullptr);
rtcSetDeviceErrorFunction(EmbreeScene.EmbreeDevice, EmbreeErrorFunc, nullptr);
RTCError ReturnErrorNewDevice = rtcGetDeviceError(EmbreeScene.EmbreeDevice);
if (ReturnErrorNewDevice != RTC_ERROR_NONE)
{
UE_LOG(LogMeshUtilities, Warning, TEXT("GenerateSignedDistanceFieldVolumeData failed for %s. Embree rtcNewDevice failed. Code: %d"), *MeshName, (int32)ReturnErrorNewDevice);
return;
}
EmbreeScene.EmbreeScene = rtcNewScene(EmbreeScene.EmbreeDevice);
rtcSetSceneFlags(EmbreeScene.EmbreeScene, RTC_SCENE_FLAG_NONE);
RTCError ReturnErrorNewScene = rtcGetDeviceError(EmbreeScene.EmbreeDevice);
if (ReturnErrorNewScene != RTC_ERROR_NONE)
{
UE_LOG(LogMeshUtilities, Warning, TEXT("GenerateSignedDistanceFieldVolumeData failed for %s. Embree rtcNewScene failed. Code: %d"), *MeshName, (int32)ReturnErrorNewScene);
rtcReleaseDevice(EmbreeScene.EmbreeDevice);
return;
}
}
#endif
TArray<int32> FilteredTriangles;
FilteredTriangles.Empty(NumTriangles);
if (SourceMeshData.IsValid())
{
for (int32 TriangleIndex = 0; TriangleIndex < NumTriangles; ++TriangleIndex)
{
const uint32 I0 = SourceMeshData.TriangleIndices[TriangleIndex * 3 + 0];
const uint32 I1 = SourceMeshData.TriangleIndices[TriangleIndex * 3 + 1];
const uint32 I2 = SourceMeshData.TriangleIndices[TriangleIndex * 3 + 2];
const FVector3f V0 = SourceMeshData.VertexPositions[I0];
const FVector3f V1 = SourceMeshData.VertexPositions[I1];
const FVector3f V2 = SourceMeshData.VertexPositions[I2];
const FVector3f TriangleNormal = ((V1 - V2) ^ (V0 - V2));
const bool bDegenerateTriangle = TriangleNormal.SizeSquared() < SMALL_NUMBER;
if (!bDegenerateTriangle)
{
FilteredTriangles.Add(TriangleIndex);
}
}
}
else
{
for (int32 TriangleIndex = 0; TriangleIndex < NumTriangles; ++TriangleIndex)
{
const FIndexArrayView Indices = LODModel.IndexBuffer.GetArrayView();
const uint32 I0 = Indices[TriangleIndex * 3 + 0];
const uint32 I1 = Indices[TriangleIndex * 3 + 1];
const uint32 I2 = Indices[TriangleIndex * 3 + 2];
const FVector3f V0 = LODModel.VertexBuffers.PositionVertexBuffer.VertexPosition(I0);
const FVector3f V1 = LODModel.VertexBuffers.PositionVertexBuffer.VertexPosition(I1);
const FVector3f V2 = LODModel.VertexBuffers.PositionVertexBuffer.VertexPosition(I2);
const FVector3f TriangleNormal = ((V1 - V2) ^ (V0 - V2));
const bool bDegenerateTriangle = TriangleNormal.SizeSquared() < SMALL_NUMBER;
if (!bDegenerateTriangle)
{
bool bTriangleIsOpaqueOrMasked = false;
for (int32 SectionIndex = 0; SectionIndex < LODModel.Sections.Num(); SectionIndex++)
{
const FStaticMeshSection& Section = LODModel.Sections[SectionIndex];
if ((uint32)(TriangleIndex * 3) >= Section.FirstIndex && (uint32)(TriangleIndex * 3) < Section.FirstIndex + Section.NumTriangles * 3)
{
if (MaterialBlendModes.IsValidIndex(Section.MaterialIndex))
{
bTriangleIsOpaqueOrMasked = !IsTranslucentBlendMode(MaterialBlendModes[Section.MaterialIndex].BlendMode);
}
break;
}
}
if (bTriangleIsOpaqueOrMasked)
{
FilteredTriangles.Add(TriangleIndex);
}
}
}
}
const int32 NumBufferVerts = 1; // Reserve extra space at the end of the array, as embree has an internal bug where they read and discard 4 bytes off the end of the array
EmbreeScene.Geometry.VertexArray.Empty(NumVertices + NumBufferVerts);
EmbreeScene.Geometry.VertexArray.AddUninitialized(NumVertices + NumBufferVerts);
const int32 NumFilteredIndices = FilteredTriangles.Num() * 3;
EmbreeScene.Geometry.IndexArray.Empty(NumFilteredIndices);
EmbreeScene.Geometry.IndexArray.AddUninitialized(NumFilteredIndices);
FVector3f* EmbreeVertices = EmbreeScene.Geometry.VertexArray.GetData();
uint32* EmbreeIndices = EmbreeScene.Geometry.IndexArray.GetData();
EmbreeScene.Geometry.TriangleDescs.Empty(FilteredTriangles.Num());
for (int32 FilteredTriangleIndex = 0; FilteredTriangleIndex < FilteredTriangles.Num(); FilteredTriangleIndex++)
{
uint32 I0, I1, I2;
FVector3f V0, V1, V2;
const int32 TriangleIndex = FilteredTriangles[FilteredTriangleIndex];
if (SourceMeshData.IsValid())
{
I0 = SourceMeshData.TriangleIndices[TriangleIndex * 3 + 0];
I1 = SourceMeshData.TriangleIndices[TriangleIndex * 3 + 1];
I2 = SourceMeshData.TriangleIndices[TriangleIndex * 3 + 2];
V0 = SourceMeshData.VertexPositions[I0];
V1 = SourceMeshData.VertexPositions[I1];
V2 = SourceMeshData.VertexPositions[I2];
}
else
{
const FIndexArrayView Indices = LODModel.IndexBuffer.GetArrayView();
I0 = Indices[TriangleIndex * 3 + 0];
I1 = Indices[TriangleIndex * 3 + 1];
I2 = Indices[TriangleIndex * 3 + 2];
V0 = LODModel.VertexBuffers.PositionVertexBuffer.VertexPosition(I0);
V1 = LODModel.VertexBuffers.PositionVertexBuffer.VertexPosition(I1);
V2 = LODModel.VertexBuffers.PositionVertexBuffer.VertexPosition(I2);
}
bool bTriangleIsTwoSided = false;
for (int32 SectionIndex = 0; SectionIndex < LODModel.Sections.Num(); SectionIndex++)
{
const FStaticMeshSection& Section = LODModel.Sections[SectionIndex];
if ((uint32)(TriangleIndex * 3) >= Section.FirstIndex && (uint32)(TriangleIndex * 3) < Section.FirstIndex + Section.NumTriangles * 3)
{
if (MaterialBlendModes.IsValidIndex(Section.MaterialIndex))
{
bTriangleIsTwoSided = MaterialBlendModes[Section.MaterialIndex].bTwoSided;
}
break;
}
}
if (EmbreeScene.bUseEmbree)
{
EmbreeIndices[FilteredTriangleIndex * 3 + 0] = I0;
EmbreeIndices[FilteredTriangleIndex * 3 + 1] = I1;
EmbreeIndices[FilteredTriangleIndex * 3 + 2] = I2;
EmbreeVertices[I0] = V0;
EmbreeVertices[I1] = V1;
EmbreeVertices[I2] = V2;
FEmbreeTriangleDesc Desc;
// Store bGenerateAsIfTwoSided in material index
Desc.ElementIndex = bGenerateAsIfTwoSided || bTriangleIsTwoSided ? 1 : 0;
EmbreeScene.Geometry.TriangleDescs.Add(Desc);
}
else
{
BuildTriangles.Add(FkDOPBuildCollisionTriangle<uint32>(
// Store bGenerateAsIfTwoSided in material index
bGenerateAsIfTwoSided || bTriangleIsTwoSided ? 1 : 0,
V0,
V1,
V2));
}
}
#if USE_EMBREE
if (EmbreeScene.bUseEmbree)
{
RTCGeometry Geometry = rtcNewGeometry(EmbreeScene.EmbreeDevice, RTC_GEOMETRY_TYPE_TRIANGLE);
EmbreeScene.Geometry.InternalGeometry = Geometry;
rtcSetSharedGeometryBuffer(Geometry, RTC_BUFFER_TYPE_VERTEX, 0, RTC_FORMAT_FLOAT3, EmbreeVertices, 0, sizeof(FVector3f), NumVertices);
rtcSetSharedGeometryBuffer(Geometry, RTC_BUFFER_TYPE_INDEX, 0, RTC_FORMAT_UINT3, EmbreeIndices, 0, sizeof(uint32) * 3, FilteredTriangles.Num());
rtcSetGeometryUserData(Geometry, &EmbreeScene.Geometry);
rtcSetGeometryIntersectFilterFunction(Geometry, EmbreeFilterFunc);
rtcCommitGeometry(Geometry);
rtcAttachGeometry(EmbreeScene.EmbreeScene, Geometry);
rtcReleaseGeometry(Geometry);
rtcCommitScene(EmbreeScene.EmbreeScene);
RTCError ReturnError = rtcGetDeviceError(EmbreeScene.EmbreeDevice);
if (ReturnError != RTC_ERROR_NONE)
{
UE_LOG(LogMeshUtilities, Warning, TEXT("GenerateSignedDistanceFieldVolumeData failed for %s. Embree rtcCommitScene failed. Code: %d"), *MeshName, (int32)ReturnError);
return;
}
}
else
#endif
{
EmbreeScene.kDopTree.Build(BuildTriangles);
}
}
void MeshRepresentation::DeleteEmbreeScene(FEmbreeScene& EmbreeScene)
{
#if USE_EMBREE
if (EmbreeScene.bUseEmbree)
{
rtcReleaseScene(EmbreeScene.EmbreeScene);
rtcReleaseDevice(EmbreeScene.EmbreeDevice);
}
#endif
}