/**
* Constructs a raw mesh from legacy render data.
*/
static void BuildRawMeshFromRenderData(
FRawMesh& OutRawMesh,
struct FMeshBuildSettings& OutBuildSettings,
FLegacyStaticMeshRenderData& RenderData,
const TCHAR* MeshName
)
{
FStaticMeshTriangle* RawTriangles = (FStaticMeshTriangle*)RenderData.RawTriangles.Lock(LOCK_READ_ONLY);
bool bBuiltFromRawTriangles = BuildRawMeshFromRawTriangles(
OutRawMesh,
OutBuildSettings,
RawTriangles,
RenderData.RawTriangles.GetElementCount(),
MeshName
);
RenderData.RawTriangles.Unlock();
if (bBuiltFromRawTriangles)
{
return;
}
OutRawMesh.Empty();
FIndexArrayView Indices = RenderData.IndexBuffer.GetArrayView();
int32 NumVertices = RenderData.PositionVertexBuffer.GetNumVertices();
int32 NumTriangles = Indices.Num() / 3;
int32 NumWedges = NumTriangles * 3;
// Copy vertex positions.
{
OutRawMesh.VertexPositions.AddUninitialized(NumVertices);
for (int32 i = 0; i < NumVertices; ++i)
{
OutRawMesh.VertexPositions[i] = RenderData.PositionVertexBuffer.VertexPosition(i);
}
}
// Copy per-wedge texture coordinates.
for (uint32 TexCoordIndex = 0; TexCoordIndex < RenderData.VertexBuffer.GetNumTexCoords(); ++TexCoordIndex)
{
OutRawMesh.WedgeTexCoords[TexCoordIndex].AddUninitialized(NumWedges);
for (int32 i = 0; i < NumWedges; ++i)
{
uint32 VertIndex = Indices[i];
OutRawMesh.WedgeTexCoords[TexCoordIndex][i] = RenderData.VertexBuffer.GetVertexUV(VertIndex, TexCoordIndex);
}
}
// Copy per-wedge colors if they exist.
if (RenderData.ColorVertexBuffer.GetNumVertices() > 0)
{
OutRawMesh.WedgeColors.AddUninitialized(NumWedges);
for (int32 i = 0; i < NumWedges; ++i)
{
uint32 VertIndex = Indices[i];
OutRawMesh.WedgeColors[i] = RenderData.ColorVertexBuffer.VertexColor(VertIndex);
}
}
// Copy per-wedge tangents.
{
OutRawMesh.WedgeTangentX.AddUninitialized(NumWedges);
OutRawMesh.WedgeTangentY.AddUninitialized(NumWedges);
OutRawMesh.WedgeTangentZ.AddUninitialized(NumWedges);
for (int32 i = 0; i < NumWedges; ++i)
{
uint32 VertIndex = Indices[i];
OutRawMesh.WedgeTangentX[i] = RenderData.VertexBuffer.VertexTangentX(VertIndex);
OutRawMesh.WedgeTangentY[i] = RenderData.VertexBuffer.VertexTangentY(VertIndex);
OutRawMesh.WedgeTangentZ[i] = RenderData.VertexBuffer.VertexTangentZ(VertIndex);
}
}
// Copy per-face information.
{
OutRawMesh.FaceMaterialIndices.AddZeroed(NumTriangles);
OutRawMesh.FaceSmoothingMasks.AddZeroed(NumTriangles);
OutRawMesh.WedgeIndices.AddZeroed(NumWedges);
for (int32 SectionIndex = 0; SectionIndex < RenderData.Elements.Num(); ++SectionIndex)
{
const FLegacyStaticMeshElement& Section = RenderData.Elements[SectionIndex];
int32 FirstFace = Section.FirstIndex / 3;
int32 LastFace = FirstFace + Section.NumTriangles;
for (int32 i = FirstFace; i < LastFace; ++i)
{
OutRawMesh.FaceMaterialIndices[i] = Section.MaterialIndex;
// Smoothing group information has been lost but is already baked in to the tangent basis.
for (int32 j = 0; j < 3; ++j)
{
OutRawMesh.WedgeIndices[i * 3 + j] = Indices[i * 3 + j];
}
}
}
}
check(OutRawMesh.IsValid());
OutBuildSettings.bRecomputeNormals = false;
OutBuildSettings.bRecomputeTangents = false;
OutBuildSettings.bRemoveDegenerates = false;
OutBuildSettings.bUseFullPrecisionUVs = RenderData.VertexBuffer.GetUseFullPrecisionUVs();
}
/**
* Constructs a raw mesh from legacy raw triangles.
*/
static bool BuildRawMeshFromRawTriangles(
FRawMesh& OutRawMesh,
FMeshBuildSettings& OutBuildSettings,
struct FStaticMeshTriangle* RawTriangles,
int32 NumTriangles,
const TCHAR* MeshName
)
{
int32 NumWedges = NumTriangles * 3;
OutRawMesh.Empty();
OutRawMesh.FaceMaterialIndices.Empty(NumTriangles);
OutRawMesh.FaceSmoothingMasks.Empty(NumWedges);
OutRawMesh.VertexPositions.Empty(NumWedges);
OutRawMesh.WedgeIndices.Empty(NumWedges);
int32 NumTexCoords = 0;
bool bHaveNormals = false;
bool bHaveTangents = false;
bool bHaveColors = false;
bool bCorruptFlags = false;
bool bCorruptNormals = false;
bool bCorruptTangents = false;
bool bCorruptPositions = false;
for (int32 TriIndex = 0; TriIndex < NumTriangles; ++TriIndex)
{
FStaticMeshTriangle* Tri = RawTriangles + TriIndex;
OutRawMesh.FaceMaterialIndices.Add(Tri->MaterialIndex);
OutRawMesh.FaceSmoothingMasks.Add(Tri->SmoothingMask);
bCorruptFlags |= (RawTriangles[0].bExplicitNormals & 0xFFFFFFFE) != 0
|| (RawTriangles[0].bOverrideTangentBasis & 0xFFFFFFFE) != 0;
for (int32 CornerIndex = 0; CornerIndex < 3; ++CornerIndex)
{
FVector Position = Tri->Vertices[CornerIndex];
OutRawMesh.WedgeIndices.Add(OutRawMesh.VertexPositions.Add(Position));
NumTexCoords = FMath::Max(NumTexCoords, Tri->NumUVs);
bHaveNormals |= Tri->TangentZ[CornerIndex] != FVector::ZeroVector;
bHaveTangents |= (Tri->TangentX[CornerIndex] != FVector::ZeroVector
&& Tri->TangentY[CornerIndex] != FVector::ZeroVector);
bHaveColors |= Tri->Colors[CornerIndex] != FColor::White;
bCorruptPositions |= Position.ContainsNaN();
bCorruptTangents |= Tri->TangentX[CornerIndex].ContainsNaN()
|| Tri->TangentY[CornerIndex].ContainsNaN();
bCorruptNormals |= Tri->TangentZ[CornerIndex].ContainsNaN();
}
}
bool bTooManyTexCoords = NumTexCoords > 8;
NumTexCoords = FMath::Min(NumTexCoords, 8); // FStaticMeshTriangle has at most 8 texture coordinates.
NumTexCoords = FMath::Min<int32>(NumTexCoords, MAX_MESH_TEXTURE_COORDS);
for (int32 TexCoordIndex = 0; TexCoordIndex < FMath::Max(1, NumTexCoords); ++TexCoordIndex)
{
OutRawMesh.WedgeTexCoords[TexCoordIndex].AddZeroed(NumTriangles * 3);
}
for (int32 TriIndex = 0; TriIndex < NumTriangles; ++TriIndex)
{
FStaticMeshTriangle* Tri = RawTriangles + TriIndex;
for (int32 CornerIndex = 0; CornerIndex < 3; ++CornerIndex)
{
for (int32 TexCoordIndex = 0; TexCoordIndex < NumTexCoords; ++TexCoordIndex)
{
FVector2D UV = TexCoordIndex < Tri->NumUVs ? Tri->UVs[CornerIndex][TexCoordIndex] : FVector2D(0.0f,0.0f);
OutRawMesh.WedgeTexCoords[TexCoordIndex][TriIndex * 3 + CornerIndex] = UV;
}
}
}
if (bHaveNormals && !bCorruptNormals)
{
OutRawMesh.WedgeTangentZ.AddZeroed(NumTriangles * 3);
for (int32 TriIndex = 0; TriIndex < NumTriangles; ++TriIndex)
{
if (RawTriangles[TriIndex].bExplicitNormals || RawTriangles[TriIndex].bOverrideTangentBasis)
{
for (int32 CornerIndex = 0; CornerIndex < 3; ++CornerIndex)
{
OutRawMesh.WedgeTangentZ[TriIndex * 3 + CornerIndex] =
RawTriangles[TriIndex].TangentZ[CornerIndex];
}
}
}
}
if (bHaveTangents && !bCorruptTangents)
{
OutRawMesh.WedgeTangentX.AddZeroed(NumTriangles * 3);
OutRawMesh.WedgeTangentY.AddZeroed(NumTriangles * 3);
for (int32 TriIndex = 0; TriIndex < NumTriangles; ++TriIndex)
{
if (RawTriangles[TriIndex].bOverrideTangentBasis)
{
for (int32 CornerIndex = 0; CornerIndex < 3; ++CornerIndex)
{
OutRawMesh.WedgeTangentX[TriIndex * 3 + CornerIndex] =
RawTriangles[TriIndex].TangentX[CornerIndex];
OutRawMesh.WedgeTangentY[TriIndex * 3 + CornerIndex] =
RawTriangles[TriIndex].TangentY[CornerIndex];
}
}
}
}
if (bHaveColors)
{
OutRawMesh.WedgeColors.AddUninitialized(NumTriangles * 3);
for (int32 TriIndex = 0; TriIndex < NumTriangles; ++TriIndex)
{
for (int32 CornerIndex = 0; CornerIndex < 3; ++CornerIndex)
{
OutRawMesh.WedgeColors[TriIndex * 3 + CornerIndex] =
RawTriangles[TriIndex].Colors[CornerIndex];
}
}
}
if (bCorruptPositions || bCorruptFlags || bCorruptNormals || bCorruptTangents || bTooManyTexCoords)
{
UE_LOG(LogStaticMesh,Verbose,TEXT("Legacy raw triangles CORRUPT (%s%s%s%s%s) for %s"),
bCorruptPositions ? TEXT("NaN positions,") : TEXT(""),
bCorruptFlags ? TEXT("flags,") : TEXT(""),
bCorruptNormals ? TEXT("NaN normals,") : TEXT(""),
bCorruptTangents ? TEXT("NaN tangents,") : TEXT(""),
bTooManyTexCoords ? TEXT(">8 texcoords") : TEXT(""),
MeshName
);
}
if (bCorruptPositions)
{
OutRawMesh = FRawMesh();
}
OutBuildSettings.bRecomputeTangents = !bHaveTangents || bCorruptTangents;
OutBuildSettings.bRecomputeNormals = !bHaveNormals || bCorruptNormals;
return !(bCorruptPositions || bCorruptFlags || bTooManyTexCoords) && OutRawMesh.IsValid();
}