#include "Factories/MaterialFactoryNew.h"
    #include "AssetRegistry/AssetRegistryModule.h"
    #include "Materials/MaterialExpressionMultiply.h"
    #include "Materials/MaterialExpressionTextureCoordinate.h"
    #include "Materials/MaterialExpressionAppendVector.h"
    #include "Materials/MaterialExpressionScalarParameter.h"
    
    FString MaterialBaseName = "M_Material";
	FString PackageName = "/Game/mat/";
	PackageName += MaterialBaseName;
	UPackage* Package = CreatePackage(NULL, *PackageName);

	// create an unreal material asset
	auto MaterialFactory = NewObject<UMaterialFactoryNew>();
	UMaterial* UnrealMaterial = (UMaterial*)MaterialFactory->FactoryCreateNew(UMaterial::StaticClass(), Package, *MaterialBaseName, RF_Standalone | RF_Public, NULL, GWarn);
	FAssetRegistryModule::AssetCreated(UnrealMaterial);
	Package->FullyLoad();
	Package->SetDirtyFlag(true);

	// Tiling system
	UMaterialExpressionMultiply* Multiply = NewObject<UMaterialExpressionMultiply>(UnrealMaterial);
	UnrealMaterial->Expressions.Add(Multiply);

	// Diffuse
	FStringAssetReference DiffuseAssetPath("/Game/mat/texture/texture");
	UTexture* DiffuseTexture = Cast<UTexture>(DiffuseAssetPath.TryLoad());
	if (DiffuseTexture)
	{
		// make texture sampler
		UMaterialExpressionTextureSample* TextureExpression = NewObject<UMaterialExpressionTextureSample>(UnrealMaterial);
		TextureExpression->Texture = DiffuseTexture;
		TextureExpression->SamplerType = SAMPLERTYPE_Color;
		UnrealMaterial->Expressions.Add(TextureExpression);
		UnrealMaterial->BaseColor.Expression = TextureExpression;

		// Tiling
		TextureExpression->Coordinates.Expression = Multiply;
	}
	// Tiling
	UMaterialExpressionAppendVector* Append = NewObject<UMaterialExpressionAppendVector>(UnrealMaterial);
	UnrealMaterial->Expressions.Add(Append);
	Multiply->B.Expression = Append;

	UMaterialExpressionTextureCoordinate* TexCoords = NewObject<UMaterialExpressionTextureCoordinate>(UnrealMaterial);
	UnrealMaterial->Expressions.Add(TexCoords);
	Multiply->A.Expression = TexCoords;

	UMaterialExpressionScalarParameter* XParam = NewObject<UMaterialExpressionScalarParameter>(UnrealMaterial);
	UMaterialExpressionScalarParameter* YParam = NewObject<UMaterialExpressionScalarParameter>(UnrealMaterial);
	
	UnrealMaterial->Expressions.Add(XParam);
	UnrealMaterial->Expressions.Add(YParam);

	XParam->ParameterName = "TextureRepeatX";
	XParam->DefaultValue = 1;
	YParam->ParameterName = "TextureRepeatY";
	YParam->DefaultValue = 1;
	Append->A.Expression = XParam;
	Append->B.Expression = YParam;

	// let the material update itself if necessary
	UnrealMaterial->PreEditChange(NULL);
	UnrealMaterial->PostEditChange();

	this->SetMaterial(0, UnrealMaterial);

以上代码生成的材质如下图所示：