void FPaperSpriteVertex::SetTangentsFromPaperAxes()
{
PackedNormalX = PaperAxisX;
PackedNormalZ = PaperAxisZ;
// store determinant of basis in w component of normal vector
PackedNormalZ.Vector.W = (GetBasisDeterminantSign(PaperAxisX, PaperAxisY, PaperAxisZ) < 0.0f) ? 0 : 255;
}
void URuntimeMeshLibrary::CalculateTangentsForMeshPacked(TArray<FRuntimeMeshBlueprintVertexSimple>& Vertices, const TArray<int32>& Triangles, bool bCreateSmoothNormals)
{
CalculateTangentsForMesh(
[&Triangles](int32 Index) -> int32 { return Triangles[Index]; },
[&Vertices](int32 Index) -> FVector { return Vertices[Index].Position; },
[&Vertices](int32 Index) -> FVector2D { return Vertices[Index].UV0; },
[&Vertices](int32 Index, FVector TangentX, FVector TangentY, FVector TangentZ)
{
Vertices[Index].Normal = TangentZ;
Vertices[Index].Tangent.TangentX = TangentX;
Vertices[Index].Tangent.bFlipTangentY = GetBasisDeterminantSign(TangentX, TangentY, TangentZ) < 0;
},
Vertices.Num(), Vertices.Num(), Triangles.Num(), bCreateSmoothNormals);
}
void URuntimeMeshLibrary::CalculateTangentsForMesh(const TArray<FVector>& Vertices, const TArray<int32>& Triangles, TArray<FVector>& Normals,
const TArray<FVector2D>& UVs, TArray<FRuntimeMeshTangent>& Tangents, bool bCreateSmoothNormals)
{
Normals.SetNum(Vertices.Num());
Tangents.SetNum(Vertices.Num());
CalculateTangentsForMesh(
[&Triangles](int32 Index) -> int32 { return Triangles[Index]; },
[&Vertices](int32 Index) -> FVector { return Vertices[Index]; },
[&UVs](int32 Index) -> FVector2D { return UVs[Index]; },
[&Normals, &Tangents](int32 Index, FVector TangentX, FVector TangentY, FVector TangentZ)
{
Normals[Index] = TangentZ;
Tangents[Index].TangentX = TangentX;
Tangents[Index].bFlipTangentY = GetBasisDeterminantSign(TangentX, TangentY, TangentZ) < 0;
},
Vertices.Num(), UVs.Num(), Triangles.Num(), bCreateSmoothNormals);
}
void URuntimeMeshLibrary::GetStaticMeshSection(UStaticMesh* InMesh, int32 LODIndex, int32 SectionIndex, TArray<FVector>& Vertices, TArray<int32>& Triangles,
TArray<FVector>& Normals, TArray<FVector2D>& UVs, TArray<FColor>& Colors, TArray<FRuntimeMeshTangent>& Tangents)
{
Vertices.Empty();
Triangles.Empty();
Normals.Empty();
UVs.Empty();
Colors.Empty();
Tangents.Empty();
GetStaticMeshSection(InMesh, LODIndex, SectionIndex, 1,
[&Vertices, &Normals, &Tangents](FVector Position, FVector TangentX, FVector TangentY, FVector TangentZ) -> int32
{
int32 NewIndex = Vertices.Add(Position);
Normals.Add(TangentZ);
Tangents.Add(FRuntimeMeshTangent(TangentX, GetBasisDeterminantSign(TangentX, TangentY, TangentZ) < 0));
return NewIndex;
},
[&UVs](int32 Index, int32 UVIndex, FVector2D UV)
{
check(UVIndex == 0);
UVs.SetNum(Index + 1);
UVs[Index] = UV;
},
[&Colors](int32 Index, FColor Color)
{
Colors.SetNum(Index + 1);
Colors[Index] = Color;
},
[&Triangles](int32 Index)
{
Triangles.Add(Index);
},
[](int32 Index)
{
});
}
void URuntimeMeshLibrary::GetStaticMeshSectionPacked(UStaticMesh* InMesh, int32 LODIndex, int32 SectionIndex, TArray<FRuntimeMeshBlueprintVertexSimple>& Vertices, TArray<int32>& Triangles)
{
Vertices.Empty();
Triangles.Empty();
GetStaticMeshSection(InMesh, LODIndex, SectionIndex, 1,
[&Vertices](FVector Position, FVector TangentX, FVector TangentY, FVector TangentZ) -> int32
{
return Vertices.Add(FRuntimeMeshBlueprintVertexSimple(Position, TangentZ, FRuntimeMeshTangent(TangentX, GetBasisDeterminantSign(TangentX, TangentY, TangentZ) < 0), FVector2D::ZeroVector));
},
[&Vertices](int32 Index, int32 UVIndex, FVector2D UV)
{
check(UVIndex == 0);
Vertices[Index].UV0 = UV;
},
[&Vertices](int32 Index, FColor Color)
{
Vertices[Index].Color = Color;
},
[&Triangles](int32 Index)
{
Triangles.Add(Index);
},
[](int32 Index)
{
});
}
