Files
UnrealEngine/Engine/Source/Developer/MeshUtilities/Private/SkeletalMeshTools.cpp
2025-05-18 13:04:45 +08:00

616 lines
23 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "SkeletalMeshTools.h"
#include "Engine/SkeletalMesh.h"
#include "MeshBuild.h"
#include "MeshUtilities.h"
#include "OverlappingCorners.h"
#include "RawIndexBuffer.h"
#include "Rendering/SkeletalMeshModel.h"
int32 GUseSkeletalMeshExperimentalChunking = 0;
static FAutoConsoleVariableRef CVarUseSkeletalMeshExperimentalChunking(
TEXT("SkeletalMesh.UseExperimentalChunking"),
GUseSkeletalMeshExperimentalChunking,
TEXT("Whether skeletal mesh will use a experimental chunking algorithm when building LODModel.")
);
namespace SkeletalMeshTools
{
bool AreSkelMeshVerticesEqual( const FSoftSkinBuildVertex& V1, const FSoftSkinBuildVertex& V2, const FOverlappingThresholds& OverlappingThresholds)
{
if(!PointsEqual(V1.Position, V2.Position, OverlappingThresholds))
{
return false;
}
for(int32 UVIdx = 0; UVIdx < MAX_TEXCOORDS; ++UVIdx)
{
if (!UVsEqual(V1.UVs[UVIdx], V2.UVs[UVIdx], OverlappingThresholds))
{
return false;
}
}
if(!NormalsEqual(V1.TangentX, V2.TangentX, OverlappingThresholds))
{
return false;
}
if(!NormalsEqual(V1.TangentY, V2.TangentY, OverlappingThresholds))
{
return false;
}
if(!NormalsEqual(V1.TangentZ, V2.TangentZ, OverlappingThresholds))
{
return false;
}
bool InfluencesMatch = 1;
for(uint32 InfluenceIndex = 0; InfluenceIndex < MAX_TOTAL_INFLUENCES; InfluenceIndex++)
{
if(V1.InfluenceBones[InfluenceIndex] != V2.InfluenceBones[InfluenceIndex] ||
V1.InfluenceWeights[InfluenceIndex] != V2.InfluenceWeights[InfluenceIndex])
{
InfluencesMatch = 0;
break;
}
}
if (V1.Color != V2.Color)
{
return false;
}
if(!InfluencesMatch)
{
return false;
}
return true;
}
void BuildSkeletalMeshChunks( const TArray<SkeletalMeshImportData::FMeshFace>& Faces, const TArray<FSoftSkinBuildVertex>& RawVertices, TArray<FSkeletalMeshVertIndexAndZ>& RawVertIndexAndZ, const FOverlappingThresholds &OverlappingThresholds, TArray<FSkinnedMeshChunk*>& OutChunks, bool& bOutTooManyVerts )
{
FOverlappingCorners OverlappingCorners;
OverlappingCorners.Init(RawVertIndexAndZ.Num());
{
// Sorting function for vertex Z/index pairs
struct FCompareFSkeletalMeshVertIndexAndZ
{
FORCEINLINE bool operator()(const FSkeletalMeshVertIndexAndZ& A, const FSkeletalMeshVertIndexAndZ& B) const
{
return A.Z < B.Z;
}
};
// Sort the vertices by z value
RawVertIndexAndZ.Sort(FCompareFSkeletalMeshVertIndexAndZ());
// Search for duplicates, quickly!
for(int32 i = 0; i < RawVertIndexAndZ.Num(); i++)
{
// only need to search forward, since we add pairs both ways
for(int32 j = i + 1; j < RawVertIndexAndZ.Num(); j++)
{
if(FMath::Abs(RawVertIndexAndZ[j].Z - RawVertIndexAndZ[i].Z) > OverlappingThresholds.ThresholdPosition)
{
// our list is sorted, so there can't be any more dupes
break;
}
// check to see if the points are really overlapping
if(PointsEqual(
RawVertices[RawVertIndexAndZ[i].Index].Position,
RawVertices[RawVertIndexAndZ[j].Index].Position, OverlappingThresholds))
{
OverlappingCorners.Add(RawVertIndexAndZ[i].Index, RawVertIndexAndZ[j].Index);
}
}
}
}
OverlappingCorners.FinishAdding();
TMap<FSkinnedMeshChunk* , TMap<int32, int32> > ChunkToFinalVerts;
uint32 TriangleIndices[3];
for(int32 FaceIndex = 0; FaceIndex < Faces.Num(); FaceIndex++)
{
const SkeletalMeshImportData::FMeshFace& Face = Faces[FaceIndex];
// Find a chunk which matches this triangle.
FSkinnedMeshChunk* Chunk = NULL;
for(int32 i = 0; i < OutChunks.Num(); ++i)
{
if(OutChunks[i]->MaterialIndex == Face.MeshMaterialIndex)
{
Chunk = OutChunks[i];
break;
}
}
if(Chunk == NULL)
{
Chunk = new FSkinnedMeshChunk();
Chunk->MaterialIndex = Face.MeshMaterialIndex;
Chunk->OriginalSectionIndex = OutChunks.Num();
OutChunks.Add(Chunk);
}
TMap<int32, int32>& FinalVerts = ChunkToFinalVerts.FindOrAdd( Chunk );
for(int32 VertexIndex = 0; VertexIndex < 3; ++VertexIndex)
{
int32 WedgeIndex = FaceIndex * 3 + VertexIndex;
const FSoftSkinBuildVertex& Vertex = RawVertices[WedgeIndex];
int32 FinalVertIndex = INDEX_NONE;
const TArray<int32>& DupVerts = OverlappingCorners.FindIfOverlapping(WedgeIndex);
for(int32 k = 0; k < DupVerts.Num(); k++)
{
if(DupVerts[k] >= WedgeIndex)
{
// the verts beyond me haven't been placed yet, so these duplicates are not relevant
break;
}
int32 *Location = FinalVerts.Find(DupVerts[k]);
if(Location != NULL)
{
if(SkeletalMeshTools::AreSkelMeshVerticesEqual(Vertex, Chunk->Vertices[*Location], OverlappingThresholds))
{
FinalVertIndex = *Location;
break;
}
}
}
if(FinalVertIndex == INDEX_NONE)
{
FinalVertIndex = Chunk->Vertices.Add(Vertex);
FinalVerts.Add(WedgeIndex, FinalVertIndex);
}
// set the index entry for the newly added vertex
// TArray internally has int32 for capacity, so no need to test for uint32 as it's larger than int32
TriangleIndices[VertexIndex] = (uint32)FinalVertIndex;
}
if(TriangleIndices[0] != TriangleIndices[1] && TriangleIndices[0] != TriangleIndices[2] && TriangleIndices[1] != TriangleIndices[2])
{
for(uint32 VertexIndex = 0; VertexIndex < 3; VertexIndex++)
{
Chunk->Indices.Add(TriangleIndices[VertexIndex]);
}
}
}
}
namespace PolygonShellsHelper
{
struct FPatchAndBoneInfluence
{
TArray<FBoneIndexType> UniqueBones;
TArray<int32> PatchToChunkWith;
bool bIsParent = false;
};
//This function add every triangles connected to the triangle queue.
//A connected triangle pair must share at least 1 vertex between the two triangles.
//If bConnectByEdge is true, the connected triangle must share at least one edge (two vertex index)
//To have a connected vertex instance pair, the position, NTBs, UVs(channel 0) and color must match.
void AddAdjacentFace(const TArray<uint32>& Indices, const TArray<FSoftSkinBuildVertex>& Vertices, TBitArray<>& FaceAdded, const TMap<int32, TArray<int32>>& VertexIndexToAdjacentFaces, const int32 FaceIndex, TArray<int32>& TriangleQueue, const bool bConnectByEdge)
{
int32 NumFaces = Indices.Num()/3;
check(FaceAdded.Num() == NumFaces);
TMap<int32, int32> AdjacentFaceCommonVertices;
for (int32 Corner = 0; Corner < 3; Corner++)
{
int32 IndiceIndex = FaceIndex * 3 + Corner;
checkSlow(Indices.IsValidIndex(IndiceIndex));
int32 VertexIndex = Indices[IndiceIndex];
checkSlow(Vertices.IsValidIndex(VertexIndex));
const FSoftSkinBuildVertex& SoftSkinVertRef = Vertices[VertexIndex];
const FVector& PositionRef = (FVector)SoftSkinVertRef.Position;
const FVector& TangentXRef = (FVector)SoftSkinVertRef.TangentX;
const FVector& TangentYRef = (FVector)SoftSkinVertRef.TangentY;
const FVector& TangentZRef = (FVector)SoftSkinVertRef.TangentZ;
const FVector2f& UVRef = SoftSkinVertRef.UVs[0];
const FColor& ColorRef = SoftSkinVertRef.Color;
const TArray<int32>& AdjacentFaces = VertexIndexToAdjacentFaces.FindChecked(VertexIndex);
for (int32 AdjacentFaceArrayIndex = 0; AdjacentFaceArrayIndex < AdjacentFaces.Num(); ++AdjacentFaceArrayIndex)
{
const int32 AdjacentFaceIndex = AdjacentFaces[AdjacentFaceArrayIndex];
if (!FaceAdded[AdjacentFaceIndex] && AdjacentFaceIndex != FaceIndex)
{
//Ensure we have position, NTBs, uv and color match to allow a connection.
bool bRealConnection = false;
for (int32 AdjCorner = 0; AdjCorner < 3; AdjCorner++)
{
const int32 IndiceIndexAdj = AdjacentFaceIndex * 3 + AdjCorner;
checkSlow(Indices.IsValidIndex(IndiceIndexAdj));
const int32 VertexIndexAdj = Indices[IndiceIndexAdj];
checkSlow(Vertices.IsValidIndex(VertexIndexAdj));
const FSoftSkinBuildVertex& SoftSkinVertAdj = Vertices[VertexIndexAdj];
if (PositionRef.Equals((FVector)SoftSkinVertAdj.Position, SMALL_NUMBER) &&
TangentXRef.Equals((FVector)SoftSkinVertAdj.TangentX, SMALL_NUMBER) &&
TangentYRef.Equals((FVector)SoftSkinVertAdj.TangentY, SMALL_NUMBER) &&
TangentZRef.Equals((FVector)SoftSkinVertAdj.TangentZ, SMALL_NUMBER) &&
UVRef.Equals(SoftSkinVertAdj.UVs[0], KINDA_SMALL_NUMBER) &&
ColorRef == SoftSkinVertAdj.Color)
{
bRealConnection = true;
break;
}
}
if (!bRealConnection)
{
continue;
}
bool bAddConnected = !bConnectByEdge;
if (bConnectByEdge)
{
int32& AdjacentFaceCommonVerticeCount = AdjacentFaceCommonVertices.FindOrAdd(AdjacentFaceIndex);
AdjacentFaceCommonVerticeCount++;
//Is the connected triangles share 2 vertex index (one edge) not only one vertex
bAddConnected = AdjacentFaceCommonVerticeCount > 1;
}
if (bAddConnected)
{
TriangleQueue.Add(AdjacentFaceIndex);
//Add the face only once by marking the face has computed
FaceAdded[AdjacentFaceIndex] = true;
}
}
}
}
}
//Fill FaceIndexToPatchIndex so every triangle knows its unique island patch index.
//Each island patch have is fill with connected vertexinstance where position, NTBs. UVs and colors are nearly equal.
//@Param bConnectByEdge: If true we need at least 2 vertex index (one edge) to connect 2 triangles. If false we just need one vertex index (bowtie)
void FillPolygonPatch(const TArray<uint32>& Indices, const TArray<FSoftSkinBuildVertex>& Vertices, const TMap<uint32, TArray<FBoneIndexType>>& AlternateBoneIDs, TArray<FPatchAndBoneInfluence>& PatchData, TArray<TArray<uint32>>& PatchIndexToIndices, TMap<int32, TArray<FBoneIndexType>>& BonesPerFace, const int32 MaxBonesPerChunk, const bool bConnectByEdge)
{
const int32 NumIndice = Indices.Num();
const int32 NumFace = NumIndice / 3;
int32 PatchIndex = 0;
//Store a map containing connected faces for each vertex index
TMap<int32, TArray<int32>> VertexIndexToAdjacentFaces;
VertexIndexToAdjacentFaces.Reserve(Vertices.Num());
//Store a map to retrieve bones use per face
BonesPerFace.Reserve(NumFace);
for (int32 FaceIndex = 0; FaceIndex < NumFace; ++FaceIndex)
{
const int32 IndiceOffset = FaceIndex * 3;
TArray<FBoneIndexType>& FaceInfluenceBones = BonesPerFace.FindOrAdd(FaceIndex);
for (int32 Corner = 0; Corner < 3; Corner++)
{
const int32 IndiceIndex = IndiceOffset + Corner;
checkSlow(Indices.IsValidIndex(IndiceIndex));
int32 VertexIndex = Indices[IndiceIndex];
TArray<int32>& AdjacentFaces = VertexIndexToAdjacentFaces.FindOrAdd(VertexIndex);
AdjacentFaces.AddUnique(FaceIndex);
const FSoftSkinBuildVertex& SoftSkinVertex = Vertices[VertexIndex];
for (int32 BoneIndex = 0; BoneIndex < MAX_TOTAL_INFLUENCES; ++BoneIndex)
{
if (SoftSkinVertex.InfluenceWeights[BoneIndex] > 0)
{
FaceInfluenceBones.AddUnique(SoftSkinVertex.InfluenceBones[BoneIndex]);
}
}
//Add the alternate bones
const TArray<FBoneIndexType>* AlternateBones = AlternateBoneIDs.Find(SoftSkinVertex.PointWedgeIdx);
if (AlternateBones)
{
for (int32 InfluenceIndex = 0; InfluenceIndex < AlternateBones->Num(); InfluenceIndex++)
{
FaceInfluenceBones.AddUnique((*AlternateBones)[InfluenceIndex]);
}
}
}
}
//Mark added face so we do not add them more then once
TBitArray<> FaceAdded;
FaceAdded.Init(false, NumFace);
TArray<int32> TriangleQueue;
TriangleQueue.Reserve(100);
//Allocate an array and use it to retrieve the data, we do not know the number of indices per patch so it prevent us doing a huge reserve per patch
//Simply copy the result in PatchIndexToIndices when we finish gathering the patch data.
TArray<uint32> AllocatedPatchIndexToIndices;
AllocatedPatchIndexToIndices.Reserve(NumIndice);
for (int32 FaceIndex = 0; FaceIndex < NumFace; ++FaceIndex)
{
//Skip already added faces
if (FaceAdded[FaceIndex])
{
continue;
}
AllocatedPatchIndexToIndices.Reset();
//Add all the faces connected to the current face index
TriangleQueue.Reset();
TriangleQueue.Add(FaceIndex); //Use a queue to avoid recursive function
FaceAdded[FaceIndex] = true;
while (TriangleQueue.Num() > 0)
{
int32 CurrentTriangleIndex = TriangleQueue.Pop(EAllowShrinking::No);
TArray<FBoneIndexType> BonesToAdd = BonesPerFace[CurrentTriangleIndex];
for (const FBoneIndexType BoneIndex : BonesToAdd)
{
if (!PatchData.IsValidIndex(PatchIndex))
{
PatchData.AddDefaulted(PatchData.Num() - PatchIndex + 1);
}
PatchData[PatchIndex].UniqueBones.AddUnique(BoneIndex);
}
int32 IndiceOffset = CurrentTriangleIndex * 3;
for (int32 Corner = 0; Corner < 3; Corner++)
{
const int32 IndiceIndex = IndiceOffset + Corner;
AllocatedPatchIndexToIndices.Add(IndiceIndex);
}
//The patch should exist at this time
checkSlow(PatchData.IsValidIndex(PatchIndex));
AddAdjacentFace(Indices, Vertices, FaceAdded, VertexIndexToAdjacentFaces, CurrentTriangleIndex, TriangleQueue, bConnectByEdge);
}
//This is a new patch create the data and append the patch result remap
check(!PatchIndexToIndices.IsValidIndex(PatchIndex));
PatchIndexToIndices.AddDefaulted();
check(PatchIndexToIndices.IsValidIndex(PatchIndex));
PatchIndexToIndices[PatchIndex].Append(AllocatedPatchIndexToIndices);
PatchIndex++;
}
}
void RecursiveFillRemapIndices(const TArray<FPatchAndBoneInfluence>& PatchData, const int32 PatchIndex, const TArray<TArray<uint32>>& PatchIndexToIndices, TArray<uint32>& SrcChunkRemapIndicesIndex)
{
SrcChunkRemapIndicesIndex.Append(PatchIndexToIndices[PatchIndex]);
checkSlow(PatchData.IsValidIndex(PatchIndex));
//Do the child patch to chunk with
for (int32 SubPatchIndex = 0; SubPatchIndex < PatchData[PatchIndex].PatchToChunkWith.Num(); ++SubPatchIndex)
{
RecursiveFillRemapIndices(PatchData, PatchData[PatchIndex].PatchToChunkWith[SubPatchIndex], PatchIndexToIndices, SrcChunkRemapIndicesIndex);
}
}
//Sort the shells to a setup that use the less section possible
void GatherShellUsingSameBones(const int32 ParentPatchIndex, TArray<FPatchAndBoneInfluence>& PatchData, TBitArray<>& PatchConsumed, const int32 MaxBonesPerChunk)
{
checkSlow(PatchData.IsValidIndex(ParentPatchIndex));
TArray<FBoneIndexType> UniqueBones = PatchData[ParentPatchIndex].UniqueBones;
PatchData[ParentPatchIndex].bIsParent = true;
if (UniqueBones.Num() > MaxBonesPerChunk)
{
return;
}
for (int32 PatchIndex = ParentPatchIndex + 1; PatchIndex < PatchData.Num(); ++PatchIndex)
{
if (PatchConsumed[PatchIndex])
{
continue;
}
TArray<FBoneIndexType> AddedBones;
for (int32 BoneIndex = 0; BoneIndex < PatchData[PatchIndex].UniqueBones.Num(); ++BoneIndex)
{
FBoneIndexType BoneIndexType = PatchData[PatchIndex].UniqueBones[BoneIndex];
if (!UniqueBones.Contains(BoneIndexType))
{
AddedBones.AddUnique(BoneIndexType);
}
}
if (AddedBones.Num() + UniqueBones.Num() <= MaxBonesPerChunk)
{
UniqueBones.Append(AddedBones);
PatchConsumed[PatchIndex] = true;
//We only support one parent layer, the assumption is we have a hierarchy depth of max 2 (parents, childs)
checkSlow(!PatchData[PatchIndex].bIsParent);
PatchData[ParentPatchIndex].PatchToChunkWith.Add(PatchIndex);
}
}
}
}
void ChunkSkinnedVertices(TArray<FSkinnedMeshChunk*>& Chunks, TMap<uint32, TArray<FBoneIndexType>>& AlternateBoneIDs, int32 MaxBonesPerChunk)
{
#if WITH_EDITORONLY_DATA
//Get the cvar that drive if we use the experimental chunking
bool bUseExperimentalChunking = GUseSkeletalMeshExperimentalChunking != 0;
// Copy over the old chunks (this is just copying pointers).
TArray<FSkinnedMeshChunk*> SrcChunks;
Exchange(Chunks,SrcChunks);
// Sort the chunks by material index.
struct FCompareSkinnedMeshChunk
{
FORCEINLINE bool operator()(const FSkinnedMeshChunk& A,const FSkinnedMeshChunk& B) const
{
return A.MaterialIndex < B.MaterialIndex;
}
};
SrcChunks.Sort(FCompareSkinnedMeshChunk());
TMap<int32, TArray<PolygonShellsHelper::FPatchAndBoneInfluence>> PatchDataPerSrcChunk;
TMap<int32, TArray<TArray<uint32>>> PatchIndexToIndicesPerSrcChunk;
TMap<int32, TMap<int32, TArray<FBoneIndexType>>> PatchIndexToBonesPerFace;
//Find the shells inside chunks
for (int32 ChunkIndex = 0; ChunkIndex < SrcChunks.Num(); ++ChunkIndex)
{
FSkinnedMeshChunk* ChunkToShell = SrcChunks[ChunkIndex];
TArray<uint32>& Indices = ChunkToShell->Indices;
TArray<FSoftSkinBuildVertex>& Vertices = ChunkToShell->Vertices;
TArray<PolygonShellsHelper::FPatchAndBoneInfluence>& PatchData = PatchDataPerSrcChunk.Add(ChunkIndex);
TArray<TArray<uint32>>& PatchIndexToIndices = PatchIndexToIndicesPerSrcChunk.Add(ChunkIndex);
TMap<int32, TArray<FBoneIndexType>>& BonesPerFace = PatchIndexToBonesPerFace.Add(ChunkIndex);
//We need edge connection (2 similar vertex )
const bool bConnectByEdge = true;
PolygonShellsHelper::FillPolygonPatch(Indices, Vertices, AlternateBoneIDs, PatchData, PatchIndexToIndices, BonesPerFace, MaxBonesPerChunk, bConnectByEdge);
}
for (int32 SrcChunkIndex = 0; SrcChunkIndex < SrcChunks.Num(); ++SrcChunkIndex)
{
TArray<PolygonShellsHelper::FPatchAndBoneInfluence>& PatchData = PatchDataPerSrcChunk[SrcChunkIndex];
TBitArray<> PatchConsumed;
PatchConsumed.Init(false, PatchData.Num());
for (int32 PatchIndex = 0; PatchIndex < PatchData.Num(); ++PatchIndex)
{
if (PatchConsumed[PatchIndex])
{
continue;
}
PatchConsumed[PatchIndex] = true;
PolygonShellsHelper::GatherShellUsingSameBones(PatchIndex, PatchData, PatchConsumed, MaxBonesPerChunk);
}
}
// Now split chunks to respect the desired bone limit.
TIndirectArray<TArray<int32> > IndexMaps;
for (int32 SrcChunkIndex = 0; SrcChunkIndex < SrcChunks.Num(); ++SrcChunkIndex)
{
FSkinnedMeshChunk* SrcChunk = SrcChunks[SrcChunkIndex];
SrcChunk->OriginalSectionIndex = SrcChunkIndex;
int32 FirstChunkIndex = Chunks.Num();
//Iterate Indice in the order of the shell patch
TArray<uint32> SrcChunkRemapIndicesIndex;
SrcChunkRemapIndicesIndex.Reserve(SrcChunk->Indices.Num());
TArray<PolygonShellsHelper::FPatchAndBoneInfluence>& PatchData = PatchDataPerSrcChunk[SrcChunkIndex];
const TArray<TArray<uint32>>& PatchIndexToIndices = PatchIndexToIndicesPerSrcChunk[SrcChunkIndex];
const TMap<int32, TArray<FBoneIndexType>>& BonesPerFace = PatchIndexToBonesPerFace[SrcChunkIndex];
for (int32 PatchIndex = 0; PatchIndex < PatchData.Num(); ++PatchIndex)
{
if (!PatchData[PatchIndex].bIsParent)
{
continue;
}
SrcChunkRemapIndicesIndex.Reset();
PolygonShellsHelper::RecursiveFillRemapIndices(PatchData, PatchIndex, PatchIndexToIndices, SrcChunkRemapIndicesIndex);
//Force adding a chunk since we want to control where we cut the model
int32 LastCreatedChunkIndex = FirstChunkIndex;
const int32 PatchInitialChunkIndex = Chunks.Num();
auto CreateChunk = [&SrcChunk, &FirstChunkIndex, &LastCreatedChunkIndex, &Chunks, &IndexMaps](FSkinnedMeshChunk** DestinationChunk)
{
(*DestinationChunk) = new FSkinnedMeshChunk();
LastCreatedChunkIndex = Chunks.Add(*DestinationChunk);
(*DestinationChunk)->MaterialIndex = SrcChunk->MaterialIndex;
(*DestinationChunk)->OriginalSectionIndex = SrcChunk->OriginalSectionIndex;
(*DestinationChunk)->ParentChunkSectionIndex = LastCreatedChunkIndex == FirstChunkIndex ? INDEX_NONE : FirstChunkIndex;
TArray<int32>& IndexMap = *new TArray<int32>();
IndexMaps.Add(&IndexMap);
IndexMap.AddUninitialized(SrcChunk->Vertices.Num());
FMemory::Memset(IndexMap.GetData(), 0xff, IndexMap.GetTypeSize()*IndexMap.Num());
};
//Create a chunk
{
FSkinnedMeshChunk* DestChunk = NULL;
CreateChunk(&DestChunk);
}
//Add Indices to the chunk and add extra chunk only in case the patch use more bone then the maximum specified
for (int32 i = 0; i < SrcChunkRemapIndicesIndex.Num(); i += 3)
{
//We remap the iteration order to avoid cutting polygon shell
int32 IndiceIndex = SrcChunkRemapIndicesIndex[i];
// Find all bones needed by this triangle.
const int32 FaceIndex = (IndiceIndex / 3);
const TArray<FBoneIndexType>& UniqueBones = BonesPerFace.FindChecked(FaceIndex);
// Now find a chunk for them.
FSkinnedMeshChunk* DestChunk = NULL;
int32 DestChunkIndex = bUseExperimentalChunking ? PatchInitialChunkIndex : LastCreatedChunkIndex;
int32 SmallestNumBoneToAdd = MAX_int32;
for (int32 ChunkIndex = DestChunkIndex; ChunkIndex < Chunks.Num(); ++ChunkIndex)
{
const TArray<FBoneIndexType>& BoneMap = Chunks[ChunkIndex]->BoneMap;
int32 NumUniqueBones = 0;
for (int32 j = 0; j < UniqueBones.Num(); ++j)
{
NumUniqueBones += (BoneMap.Contains(UniqueBones[j]) ? 0 : 1);
if (NumUniqueBones == SmallestNumBoneToAdd)
{
//Another previous chunk use less or equal unique bone, avoid searching more
break;
}
}
if (NumUniqueBones + BoneMap.Num() <= MaxBonesPerChunk && NumUniqueBones < SmallestNumBoneToAdd)
{
//Add the vertex to the chunk that can contain it with the less addition.
SmallestNumBoneToAdd = NumUniqueBones;
DestChunkIndex = ChunkIndex;
DestChunk = Chunks[ChunkIndex];
if (SmallestNumBoneToAdd == 0)
{
//This is the best candidate
break;
}
}
}
// If no chunk was found, create one!
if (DestChunk == NULL)
{
CreateChunk(&DestChunk);
//Set back the DestChunkIndex. CreateChunk set the LastCreatedChunkIndex, so we need to update DestChunkIndex to pick
//The right IndexMaps that match the new chunk.
DestChunkIndex = LastCreatedChunkIndex;
}
TArray<int32>& IndexMap = IndexMaps[DestChunkIndex];
// Add the unique bones to this chunk's bone map.
for (int32 j = 0; j < UniqueBones.Num(); ++j)
{
DestChunk->BoneMap.AddUnique(UniqueBones[j]);
}
// For each vertex, add it to the chunk's arrays of vertices and indices.
for (int32 Corner = 0; Corner < 3; Corner++)
{
int32 VertexIndex = SrcChunk->Indices[IndiceIndex + Corner];
int32 DestIndex = IndexMap[VertexIndex];
if (DestIndex == INDEX_NONE)
{
DestIndex = DestChunk->Vertices.Add(SrcChunk->Vertices[VertexIndex]);
FSoftSkinBuildVertex& V = DestChunk->Vertices[DestIndex];
for (int32 InfluenceIndex = 0; InfluenceIndex < MAX_TOTAL_INFLUENCES; InfluenceIndex++)
{
if (V.InfluenceWeights[InfluenceIndex] > 0)
{
int32 MappedIndex = DestChunk->BoneMap.Find(V.InfluenceBones[InfluenceIndex]);
checkSlow(DestChunk->BoneMap.IsValidIndex(MappedIndex));
V.InfluenceBones[InfluenceIndex] = MappedIndex;
}
}
IndexMap[VertexIndex] = DestIndex;
}
DestChunk->Indices.Add(DestIndex);
}
}
}
// Source chunks are no longer needed.
delete SrcChunks[SrcChunkIndex];
SrcChunks[SrcChunkIndex] = NULL;
}
#endif // #if WITH_EDITORONLY_DATA
}
}