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03-UnrealEngine/Gameplay/Gameplay/UProceduralMeshComponent实时载入StaticMesh.md

@@ -0,0 +1,152 @@
+---
+title: Untitled
+date: 2025-01-05 11:32:25
+excerpt: 
+tags: 
+rating: ⭐
+---
+# UProceduralMeshComponent
+使用现在StaticMesh构建PMC，PMC的MaterialSection是正常的。
+1. UKismetProceduralMeshLibrary::CopyProceduralMeshFromStaticMeshComponent()
+
+```c++
+void UKismetProceduralMeshLibrary::CopyProceduralMeshFromStaticMeshComponent(UStaticMeshComponent* StaticMeshComponent, int32 LODIndex, UProceduralMeshComponent* ProcMeshComponent, bool bCreateCollision)
+{
+	if( StaticMeshComponent != nullptr && 
+		StaticMeshComponent->GetStaticMesh() != nullptr &&
+		ProcMeshComponent != nullptr )
+	{
+		UStaticMesh* StaticMesh = StaticMeshComponent->GetStaticMesh();
+
+		//// MESH DATA
+
+		int32 NumSections = StaticMesh->GetNumSections(LODIndex);
+		for (int32 SectionIndex = 0; SectionIndex < NumSections; SectionIndex++)
+		{
+			// Buffers for copying geom data
+			TArray<FVector> Vertices;
+			TArray<int32> Triangles;
+			TArray<FVector> Normals;
+			TArray<FVector2D> UVs;
+			TArray<FVector2D> UVs1;
+			TArray<FVector2D> UVs2;
+			TArray<FVector2D> UVs3;
+			TArray<FProcMeshTangent> Tangents;
+
+			// Get geom data from static mesh
+			GetSectionFromStaticMesh(StaticMesh, LODIndex, SectionIndex, Vertices, Triangles, Normals, UVs, Tangents);
+
+			// Create section using data
+			TArray<FLinearColor> DummyColors;
+			ProcMeshComponent->CreateMeshSection_LinearColor(SectionIndex, Vertices, Triangles, Normals, UVs, UVs1, UVs2, UVs3, DummyColors, Tangents, bCreateCollision);
+		}
+
+		//// SIMPLE COLLISION
+
+		// Clear any existing collision hulls
+		ProcMeshComponent->ClearCollisionConvexMeshes();
+
+		if (StaticMesh->GetBodySetup() != nullptr)
+		{
+			// Iterate over all convex hulls on static mesh..
+			const int32 NumConvex = StaticMesh->GetBodySetup()->AggGeom.ConvexElems.Num();
+			for (int ConvexIndex = 0; ConvexIndex < NumConvex; ConvexIndex++)
+			{
+				// Copy convex verts to ProcMesh
+				FKConvexElem& MeshConvex = StaticMesh->GetBodySetup()->AggGeom.ConvexElems[ConvexIndex];
+				ProcMeshComponent->AddCollisionConvexMesh(MeshConvex.VertexData);
+			}
+		}
+
+		//// MATERIALS
+
+		for (int32 MatIndex = 0; MatIndex < StaticMeshComponent->GetNumMaterials(); MatIndex++)
+		{
+			ProcMeshComponent->SetMaterial(MatIndex, StaticMeshComponent->GetMaterial(MatIndex));
+		}
+	}
+}
+```
+
+```c++
+void UKismetProceduralMeshLibrary::GetSectionFromStaticMesh(UStaticMesh* InMesh, int32 LODIndex, int32 SectionIndex, TArray<FVector>& Vertices, TArray<int32>& Triangles, TArray<FVector>& Normals, TArray<FVector2D>& UVs, TArray<FProcMeshTangent>& Tangents)
+{
+	if(	InMesh != nullptr )
+	{
+		if (!InMesh->bAllowCPUAccess)
+		{
+			FMessageLog("PIE").Warning()
+				->AddToken(FTextToken::Create(LOCTEXT("GetSectionFromStaticMeshStart", "Calling GetSectionFromStaticMesh on")))
+				->AddToken(FUObjectToken::Create(InMesh))
+				->AddToken(FTextToken::Create(LOCTEXT("GetSectionFromStaticMeshEnd", "but 'Allow CPU Access' is not enabled. This is required for converting StaticMesh to ProceduralMeshComponent in cooked builds.")));
+		}
+
+		if (InMesh->GetRenderData() != nullptr && InMesh->GetRenderData()->LODResources.IsValidIndex(LODIndex))
+		{
+			const FStaticMeshLODResources& LOD = InMesh->GetRenderData()->LODResources[LODIndex];
+			if (LOD.Sections.IsValidIndex(SectionIndex))
+			{
+				// Empty output buffers
+				Vertices.Reset();
+				Triangles.Reset();
+				Normals.Reset();
+				UVs.Reset();
+				Tangents.Reset();
+
+				// Map from vert buffer for whole mesh to vert buffer for section of interest
+				TMap<int32, int32> MeshToSectionVertMap;
+
+				const FStaticMeshSection& Section = LOD.Sections[SectionIndex];//获取指定的MeshSection
+				const uint32 OnePastLastIndex = Section.FirstIndex + Section.NumTriangles * 3;//计算最后一个VertexIndex
+				FIndexArrayView Indices = LOD.IndexBuffer.GetArrayView();//获得IndexArray
+
+				//遍历所有IndexBuffer，并且复制顶点
+				for (uint32 i = Section.FirstIndex; i < OnePastLastIndex; i++)
+				{
+					uint32 MeshVertIndex = Indices[i];//取得VertexIndex
+
+					// See if we have this vert already in our section vert buffer, and copy vert in if not 
+					// 从VertexBuffers.StaticMeshVertexBuffer中读取并且添加Vertex Position、Normal、UVs、Tangents；构建MeshToSectionVertMap作为缓存，如果能在Map找到则直接返回Index。
+					int32 SectionVertIndex = GetNewIndexForOldVertIndex(MeshVertIndex, MeshToSectionVertMap, LOD.VertexBuffers, Vertices, Normals, UVs, Tangents);
+
+					// Add to index buffer
+					Triangles.Add(SectionVertIndex);
+				}
+			}
+		}
+	}
+}
+
+static int32 GetNewIndexForOldVertIndex(int32 MeshVertIndex, TMap<int32, int32>& MeshToSectionVertMap, const FStaticMeshVertexBuffers& VertexBuffers, TArray<FVector>& Vertices, TArray<FVector>& Normals, TArray<FVector2D>& UVs, TArray<FProcMeshTangent>& Tangents)
+{
+	int32* NewIndexPtr = MeshToSectionVertMap.Find(MeshVertIndex);
+	if (NewIndexPtr != nullptr)
+	{
+		return *NewIndexPtr;
+	}
+	else
+	{
+		// Copy position
+		int32 SectionVertIndex = Vertices.Add((FVector)VertexBuffers.PositionVertexBuffer.VertexPosition(MeshVertIndex));
+
+		// Copy normal
+		Normals.Add(FVector4(VertexBuffers.StaticMeshVertexBuffer.VertexTangentZ(MeshVertIndex)));
+		check(Normals.Num() == Vertices.Num());
+
+		// Copy UVs
+		UVs.Add(FVector2D(VertexBuffers.StaticMeshVertexBuffer.GetVertexUV(MeshVertIndex, 0)));
+		check(UVs.Num() == Vertices.Num());
+
+		// Copy tangents
+		FVector4 TangentX = (FVector4)VertexBuffers.StaticMeshVertexBuffer.VertexTangentX(MeshVertIndex);
+		FProcMeshTangent NewTangent(TangentX, TangentX.W < 0.f);
+		Tangents.Add(NewTangent);
+		check(Tangents.Num() == Vertices.Num());
+
+		MeshToSectionVertMap.Add(MeshVertIndex, SectionVertIndex);
+
+		return SectionVertIndex;
+	}
+}
+```
+## CreateMeshSection_LinearColor

03-UnrealEngine/Gameplay/PuerTS/Puerts（二）——打包笔记.md

@@ -6,7 +6,5 @@ tags:
 rating: ⭐
 ---
 # 打包流程
-
 生成的js脚本不是ue资产文件(`*.asset`)，需要手动设置打包。
-
 到“项目设置/打包/Additional Not-Asset Directories to Package”，把Content下的“JavaScript”目录添加进去。