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)
{
});
}
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::CreateBoxMesh(FVector BoxRadius, TArray<FVector>& Vertices, TArray<int32>& Triangles, TArray<FVector>& Normals, TArray<FVector2D>& UVs, TArray<FRuntimeMeshTangent>& Tangents)
{
// Generate verts
FVector BoxVerts[8];
BoxVerts[0] = FVector(-BoxRadius.X, BoxRadius.Y, BoxRadius.Z);
BoxVerts[1] = FVector(BoxRadius.X, BoxRadius.Y, BoxRadius.Z);
BoxVerts[2] = FVector(BoxRadius.X, -BoxRadius.Y, BoxRadius.Z);
BoxVerts[3] = FVector(-BoxRadius.X, -BoxRadius.Y, BoxRadius.Z);
BoxVerts[4] = FVector(-BoxRadius.X, BoxRadius.Y, -BoxRadius.Z);
BoxVerts[5] = FVector(BoxRadius.X, BoxRadius.Y, -BoxRadius.Z);
BoxVerts[6] = FVector(BoxRadius.X, -BoxRadius.Y, -BoxRadius.Z);
BoxVerts[7] = FVector(-BoxRadius.X, -BoxRadius.Y, -BoxRadius.Z);
// Generate triangles (from quads)
Triangles.Reset();
const int32 NumVerts = 24; // 6 faces x 4 verts per face
Vertices.Reset();
Vertices.AddUninitialized(NumVerts);
Normals.Reset();
Normals.AddUninitialized(NumVerts);
Tangents.Reset();
Tangents.AddUninitialized(NumVerts);
Vertices[0] = BoxVerts[0];
Vertices[1] = BoxVerts[1];
Vertices[2] = BoxVerts[2];
Vertices[3] = BoxVerts[3];
ConvertQuadToTriangles(Triangles, 0, 1, 2, 3);
Normals[0] = Normals[1] = Normals[2] = Normals[3] = FVector(0, 0, 1);
Tangents[0] = Tangents[1] = Tangents[2] = Tangents[3] = FRuntimeMeshTangent(0.f, -1.f, 0.f);
Vertices[4] = BoxVerts[4];
Vertices[5] = BoxVerts[0];
Vertices[6] = BoxVerts[3];
Vertices[7] = BoxVerts[7];
ConvertQuadToTriangles(Triangles, 4, 5, 6, 7);
Normals[4] = Normals[5] = Normals[6] = Normals[7] = FVector(-1, 0, 0);
Tangents[4] = Tangents[5] = Tangents[6] = Tangents[7] = FRuntimeMeshTangent(0.f, -1.f, 0.f);
Vertices[8] = BoxVerts[5];
Vertices[9] = BoxVerts[1];
Vertices[10] = BoxVerts[0];
Vertices[11] = BoxVerts[4];
ConvertQuadToTriangles(Triangles, 8, 9, 10, 11);
Normals[8] = Normals[9] = Normals[10] = Normals[11] = FVector(0, 1, 0);
Tangents[8] = Tangents[9] = Tangents[10] = Tangents[11] = FRuntimeMeshTangent(-1.f, 0.f, 0.f);
Vertices[12] = BoxVerts[6];
Vertices[13] = BoxVerts[2];
Vertices[14] = BoxVerts[1];
Vertices[15] = BoxVerts[5];
ConvertQuadToTriangles(Triangles, 12, 13, 14, 15);
Normals[12] = Normals[13] = Normals[14] = Normals[15] = FVector(1, 0, 0);
Tangents[12] = Tangents[13] = Tangents[14] = Tangents[15] = FRuntimeMeshTangent(0.f, 1.f, 0.f);
Vertices[16] = BoxVerts[7];
Vertices[17] = BoxVerts[3];
Vertices[18] = BoxVerts[2];
Vertices[19] = BoxVerts[6];
ConvertQuadToTriangles(Triangles, 16, 17, 18, 19);
Normals[16] = Normals[17] = Normals[18] = Normals[19] = FVector(0, -1, 0);
Tangents[16] = Tangents[17] = Tangents[18] = Tangents[19] = FRuntimeMeshTangent(1.f, 0.f, 0.f);
Vertices[20] = BoxVerts[7];
Vertices[21] = BoxVerts[6];
Vertices[22] = BoxVerts[5];
Vertices[23] = BoxVerts[4];
ConvertQuadToTriangles(Triangles, 20, 21, 22, 23);
Normals[20] = Normals[21] = Normals[22] = Normals[23] = FVector(0, 0, -1);
Tangents[20] = Tangents[21] = Tangents[22] = Tangents[23] = FRuntimeMeshTangent(0.f, 1.f, 0.f);
// UVs
UVs.Reset();
UVs.AddUninitialized(NumVerts);
UVs[0] = UVs[4] = UVs[8] = UVs[12] = UVs[16] = UVs[20] = FVector2D(0.f, 0.f);
UVs[1] = UVs[5] = UVs[9] = UVs[13] = UVs[17] = UVs[21] = FVector2D(0.f, 1.f);
UVs[2] = UVs[6] = UVs[10] = UVs[14] = UVs[18] = UVs[22] = FVector2D(1.f, 1.f);
UVs[3] = UVs[7] = UVs[11] = UVs[15] = UVs[19] = UVs[23] = FVector2D(1.f, 0.f);
}
