MyMeshExporter.cpp

#include "MyMeshExporter.h"
#include "RawIndexBuffer.h"
#include "StaticMeshVertexBuffer.h"
#include "PositionVertexBuffer.h"


void UMyMeshExporter::ExportStaticMesh(UStaticMesh* StaticMesh)
{
	const FStaticMeshVertexBuffer& VertexBuffer = StaticMesh->RenderData->LODResources[0].VertexBuffer;
	const FPositionVertexBuffer& PositionVertexBuffer = StaticMesh->RenderData->LODResources[0].PositionVertexBuffer;



	// Build the vertex list
	TArray<FVector> Vertices;
	const int32 VertexCount = PositionVertexBuffer.GetNumVertices();
	for (int32 i = 0; i < VertexCount; i++)
	{
		FVector Vertex = PositionVertexBuffer.VertexPosition(i);
		FVector Normal = VertexBuffer.VertexTangentZ(i);

		// save in your vertex array
		Vertices.Add(Vertex);
	}

	// Build the index list
	TArray<uint32> Indices;  // << Result saved here
	const FRawStaticIndexBuffer& IndexBuffer = StaticMesh->RenderData->LODResources[0].IndexBuffer;
	IndexBuffer.GetCopy(Indices);

	// Optional: If you want the triangle vertices
	{
		int NumIndices = Indices.Num();
		for (int i = 0; i < NumIndices; i += 3) {
			uint32 i0 = Indices[i + 0];
			uint32 i1 = Indices[i + 1];
			uint32 i2 = Indices[i + 2];

			const FVector& v0 = Vertices[i0];
			const FVector& v1 = Vertices[i1];
			const FVector& v2 = Vertices[i2];

			/// ...
		}
	}
}

MyMeshExporter.h

#pragma once

#include "CoreMinimal.h"
#include "MyMeshExporter.generated.h"

class UStaticMesh;

UCLASS(Blueprintable)
class UMyMeshExporter : public UObject {

	GENERATED_BODY()

	UFUNCTION(BlueprintCallable, Category="Exporter")
	static void ExportStaticMesh(UStaticMesh* StaticMesh);

};