[UE5.0] ERROR!! GenerateWeightmapMips, GenerateHeightmapMips, UpdateCollisionHeightData!!!

Development Programming & Scripting C++
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I wrote a C++ code to generate a landscape and compiled it, but I got the error below.
(using the GeneratehHeightmapMips and GenerateWeightmapMips and UpdateCollisionHeightData functions)

Error: GenerateHeightmapMips(maybe) ↓

GenerateLandscape.cpp.obj : error LNK2019: unresolved external symbol "public: void __cdecl ULandscapeComponent::GenerateHeightmapMips(class TArray<struct FColor *,class TSizedDefaultAllocator<32> > &,int,int,int,int,struct FLandscapeTextureDataInfo *)" (?GenerateHeightmapMips@ULandscapeComponent@@QEAAXAEAV?$TArray@PEAUFColor@@V?$TSizedDefaultAllocator@$0CA@@@@@HHHHPEAUFLandscapeTextureDataInfo@@@Z) referenced in function "public: void __cdecl UGenerateLandscape::Import(struct FGuid const &,int,int,int,int,int,int,class TMap<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,0> > const &,wchar_t const * const,class TMap<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,0> > const &,enum ELandscapeImportAlphamapType,class TArray<struct FLandscapeLayer,class TSizedDefaultAllocator<32> > const *)" (?Import@UGenerateLandscape@@QEAAXAEBUFGuid@@HHHHHHAEBV?$TMap@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@QEB_WAEBV?$TMap@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@W4ELandscapeImportAlphamapType@@PEBV?$TArray@UFLandscapeLayer@@V?$TSizedDefaultAllocator@$0CA@@@@@@Z)

Error: GenerateWeightmapMips(maybe) ↓

GenerateLandscape.cpp.obj : error LNK2019: unresolved external symbol "public: static void __cdecl ULandscapeComponent::GenerateWeightmapMips(int,int,class UTexture2D *,struct FColor *)" (?GenerateWeightmapMips@ULandscapeComponent@@SAXHHPEAVUTexture2D@@PEAUFColor@@@Z) referenced in function "public: void __cdecl UGenerateLandscape::Import(struct FGuid const &,int,int,int,int,int,int,class TMap<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,0> > const &,wchar_t const * const,class TMap<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,0> > const &,enum ELandscapeImportAlphamapType,class TArray<struct FLandscapeLayer,class TSizedDefaultAllocator<32> > const *)" (?Import@UGenerateLandscape@@QEAAXAEBUFGuid@@HHHHHHAEBV?$TMap@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@QEB_WAEBV?$TMap@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@W4ELandscapeImportAlphamapType@@PEBV?$TArray@UFLandscapeLayer@@V?$TSizedDefaultAllocator@$0CA@@@@@@Z)

Error: UpdateCollisionHeightData(maybe) ↓

GenerateLandscape.cpp.obj : error LNK2019: unresolved external symbol "public: void __cdecl ULandscapeComponent::UpdateCollisionHeightData(struct FColor const *,struct FColor const *,int,int,int,int,bool,struct FColor const *,bool)" (?UpdateCollisionHeightData@ULandscapeComponent@@QEAAXPEBUFColor@@0HHHH_N01@Z) referenced in function "public: void __cdecl UGenerateLandscape::Import(struct FGuid const &,int,int,int,int,int,int,class TMap<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,0> > const &,wchar_t const * const,class TMap<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,0> > const &,enum ELandscapeImportAlphamapType,class TArray<struct FLandscapeLayer,class TSizedDefaultAllocator<32> > const *)" (?Import@UGenerateLandscape@@QEAAXAEBUFGuid@@HHHHHHAEBV?$TMap@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@QEB_WAEBV?$TMap@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@W4ELandscapeImportAlphamapType@@PEBV?$TArray@UFLandscapeLayer@@V?$TSizedDefaultAllocator@$0CA@@@@@@Z)

Finished Output:

C:\Users\User\Documents\Unreal Projects\Project\Binaries\Win64\UnrealEditor-Project.patch_0.exe : fatal error LNK1120: 3 unresolved externals
Failed to link patch (0.000s) (Exit code: 0x460)

.cpp file ↓

#include "GenerateLandscape.h"
#include "Landscape.h"
#include "LandscapeDataAccess.h"
#include "LandscapeEdit.h"
#include "LandscapeComponent.h"
#include "LandscapeProxy.h"

struct FWeightmapTextureAllocation
{
    int32 X;
    int32 Y;
    int32 ChannelsInUse;
    UTexture2D* Texture;
    FColor* TextureData;

    FWeightmapTextureAllocation(int32 InX, int32 InY, int32 InChannels, UTexture2D* InTexture, FColor* InTextureData)
        : X(InX)
        , Y(InY)
        , ChannelsInUse(InChannels)
        , Texture(InTexture)
        , TextureData(InTextureData)
    {}
};

struct FHeightmapInfo
{
    int32 HeightmapSizeU;
    int32 HeightmapSizeV;
    UTexture2D* HeightmapTexture;
    TArray<FColor*> HeightmapTextureMipData;
};

void UGenerateLandscape::Import(const FGuid& InGuid, int32 InMinX, int32 InMinY, int32 InMaxX, int32 InMaxY, int32 InNumSubsections, int32 InSubsectionSizeQuads, const TMap<FGuid, TArray<uint16>>& InImportHeightData,
    const TCHAR* const InHeightmapFileName, const TMap<FGuid, TArray<FLandscapeImportLayerInfo>>& InImportMaterialLayerInfos, ELandscapeImportAlphamapType InImportMaterialLayerType, const TArray<FLandscapeLayer>* InImportLayers)
{

    int32 dComponentSizeQuads;

    const int32 VertsX = InMaxX - InMinX + 1;
    const int32 VertsY = InMaxY - InMinY + 1;

    dComponentSizeQuads = InNumSubsections * InSubsectionSizeQuads;

    const int32 NumPatchesX = (VertsX - 1);
    const int32 NumPatchesY = (VertsY - 1);

    const int32 NumComponentsX = NumPatchesX / dComponentSizeQuads;
    const int32 NumComponentsY = NumPatchesY / dComponentSizeQuads;

    const int32 ComponentSizeVerts = dNumSubsections * (dSubsectionSizeQuads + 1);
    const int32 ComponentsPerHeightmap = FMath::Min(MAX_HEIGHTMAP_TEXTURE_SIZE / ComponentSizeVerts, 1 << (UTexture2D::GetStaticMinTextureResidentMipCount() - 2));

   // Remember where we have spare texture channels.
   TArray<FWeightmapTextureAllocation> TextureAllocations;
    for (int32 AllocationIndex = 0; AllocationIndex < TextureAllocations.Num(); AllocationIndex++)
    {
        UTexture2D* const WeightmapTexture = TextureAllocations[AllocationIndex].Texture;
        FColor* const BaseMipData = TextureAllocations[AllocationIndex].TextureData;

        // Generate mips for weightmaps
        ULandscapeComponent::GenerateWeightmapMips(dNumSubsections, dSubsectionSizeQuads, WeightmapTexture, BaseMipData);
        WeightmapTexture->Source.UnlockMip(0);

        WeightmapTexture->BeginCachePlatformData();
        WeightmapTexture->ClearAllCachedCookedPlatformData();
        PendingTexturePlatformDataCreation.Add(WeightmapTexture);
    }

    // Generate mipmaps for the components, and create the collision components
    for (int32 ComponentY = 0; ComponentY < NumComponentsY; ComponentY++)
    {
        for (int32 ComponentX = 0; ComponentX < NumComponentsX; ComponentX++)
        {
            const int32 HmX = ComponentX / ComponentsPerHeightmap;
            const int32 HmY = ComponentY / ComponentsPerHeightmap;
            FHeightmapInfo& HeightmapInfo = HeightmapInfos[HmX + HmY * NumHeightmapsX];

            ULandscapeComponent* LandscapeComponent = proxy->LandscapeComponents[ComponentX + ComponentY * NumComponentsX];
            LandscapeComponent->GenerateHeightmapMips(HeightmapInfo.HeightmapTextureMipData, ComponentX == NumComponentsX - 1 ? MAX_int32 : 0, ComponentY == NumComponentsY - 1 ? MAX_int32 : 0);
            LandscapeComponent->UpdateCollisionHeightData(
                HeightmapInfo.HeightmapTextureMipData[LandscapeComponent->CollisionMipLevel],
                LandscapeComponent->SimpleCollisionMipLevel > LandscapeComponent->CollisionMipLevel ? HeightmapInfo.HeightmapTextureMipData[LandscapeComponent->SimpleCollisionMipLevel] : nullptr);
            LandscapeComponent->UpdateCollisionLayerData();
        }
    }
}

.h file ↓

#pragma once

#include "CoreMinimal.h"
#include "UObject/ObjectMacros.h"
#include "Landscape.h"
#include "LandscapeComponent.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "GenerateLandscape.generated.h"

/**
 * 
 */
UCLASS()
class PROJECT_API UGenerateLandscape : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()

public:
	void Import(const FGuid& InGuid, int32 InMinX, int32 InMinY, int32 InMaxX, int32 InMaxY, int32 InNumSubsections, int32 InSubsectionSizeQuads,
		const TMap<FGuid, TArray<uint16>>& InImportHeightData, const TCHAR* const InHeightmapFileName, const TMap<FGuid, TArray<FLandscapeImportLayerInfo>>& InImportMaterialLayerInfos, 
		ELandscapeImportAlphamapType InImportMaterialLayerType, const TArray<struct FLandscapeLayer>* InImportLayers = nullptr);

};

.Build.cs file ↓

using UnrealBuildTool;

public class Project : ModuleRules
{
	public Project(ReadOnlyTargetRules Target) : base(Target)
	{
		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;

		PrivateIncludePaths.AddRange(
			new string[] {
				"E:/Program Files/Epic Games/UE_5.0/Engine/Source/Runtime/Landscape/Private", // for Engine/Private/Collision/PhysXCollision.h
				"E:/Program Files/Epic Games/UE_5.0/Engine/Source/Runtime/Engine/Private",
				"E:/Program Files/Epic Games/UE_5.0/Engine/Shaders/Shared"
			}
		);

		PrivateIncludePathModuleNames.AddRange(
			new string[] {
				"TargetPlatform",
				"DerivedDataCache",
				"Foliage",
				"Renderer",
			}
		);

		PrivateDependencyModuleNames.AddRange(
			new string[] {
				"Core",
				"CoreUObject",
				"ApplicationCore",
				"Engine",
				"RenderCore",
				"RHI",
				"Renderer",
				"Foliage",
				"DeveloperSettings"
			}
		);

		if (Target.bBuildEditor == true)
		{
			PrivateIncludePathModuleNames.Add("LandscapeEditor");

			PrivateDependencyModuleNames.AddRange(
				new string[] {
					"EditorFramework",
					"UnrealEd",
					"MaterialUtilities",
					"SlateCore",
					"Slate",
					"GeometryCore"
				}
			);

			CircularlyReferencedDependentModules.AddRange(
				new string[] {
					"UnrealEd",
					"MaterialUtilities",
				}
			);
		}

		PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "ProceduralMeshComponent", "MeshDescription", "StaticMeshDescription", "ApplicationCore", "Landscape", "LandscapeEditor", "Foliage", "Renderer", "RenderCore", "RHI", "DeveloperSettings" });

	}
}

I should have added the Landscape module to the build module settings, but I cannot link (access) the functions in the module. I am so confused by this. :smiling_face_with_tear:

Even after adding LANDSCAPE_API to the functions defined in the engine source (three functions mentioned earlier) and compiling, the following error occurred.

Error: GenerateHeightmapMips(maybe) ↓

GenerateLandscape.cpp.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __cdecl ULandscapeComponent::GenerateHeightmapMips(class TArray<struct FColor *,class TSizedDefaultAllocator<32> > &,int,int,int,int,struct FLandscapeTextureDataInfo *)" (__imp_?GenerateHeightmapMips@ULandscapeComponent@@QEAAXAEAV?$TArray@PEAUFColor@@V?$TSizedDefaultAllocator@$0CA@@@@@HHHHPEAUFLandscapeTextureDataInfo@@@Z) referenced in function "public: void __cdecl UGenerateLandscape::Import(struct FGuid const &,int,int,int,int,int,int,class TMap<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,0> > const &,wchar_t const * const,class TMap<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,0> > const &,enum ELandscapeImportAlphamapType,class TArray<struct FLandscapeLayer,class TSizedDefaultAllocator<32> > const *)" (?Import@UGenerateLandscape@@QEAAXAEBUFGuid@@HHHHHHAEBV?$TMap@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@QEB_WAEBV?$TMap@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@W4ELandscapeImportAlphamapType@@PEBV?$TArray@UFLandscapeLayer@@V?$TSizedDefaultAllocator@$0CA@@@@@@Z)

Error: GenerateWeightmapMips(maybe) ↓

GenerateLandscape.cpp.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static void __cdecl ULandscapeComponent::GenerateWeightmapMips(int,int,class UTexture2D *,struct FColor *)" (__imp_?GenerateWeightmapMips@ULandscapeComponent@@SAXHHPEAVUTexture2D@@PEAUFColor@@@Z) referenced in function "public: void __cdecl UGenerateLandscape::Import(struct FGuid const &,int,int,int,int,int,int,class TMap<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,0> > const &,wchar_t const * const,class TMap<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,0> > const &,enum ELandscapeImportAlphamapType,class TArray<struct FLandscapeLayer,class TSizedDefaultAllocator<32> > const *)" (?Import@UGenerateLandscape@@QEAAXAEBUFGuid@@HHHHHHAEBV?$TMap@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@QEB_WAEBV?$TMap@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@W4ELandscapeImportAlphamapType@@PEBV?$TArray@UFLandscapeLayer@@V?$TSizedDefaultAllocator@$0CA@@@@@@Z)

Error: UpdateCollisionHeigthData(maybe) ↓

GenerateLandscape.cpp.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __cdecl ULandscapeComponent::UpdateCollisionHeightData(struct FColor const *,struct FColor const *,int,int,int,int,bool,struct FColor const *,bool)" (__imp_?UpdateCollisionHeightData@ULandscapeComponent@@QEAAXPEBUFColor@@0HHHH_N01@Z) referenced in function "public: void __cdecl UGenerateLandscape::Import(struct FGuid const &,int,int,int,int,int,int,class TMap<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<unsigned short,class TSizedDefaultAllocator<32> >,0> > const &,wchar_t const * const,class TMap<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,class FDefaultSetAllocator,struct TDefaultMapHashableKeyFuncs<struct FGuid,class TArray<struct FLandscapeImportLayerInfo,class TSizedDefaultAllocator<32> >,0> > const &,enum ELandscapeImportAlphamapType,class TArray<struct FLandscapeLayer,class TSizedDefaultAllocator<32> > const *)" (?Import@UGenerateLandscape@@QEAAXAEBUFGuid@@HHHHHHAEBV?$TMap@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@GV?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@QEB_WAEBV?$TMap@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@VFDefaultSetAllocator@@U?$TDefaultMapHashableKeyFuncs@UFGuid@@V?$TArray@UFLandscapeImportLayerInfo@@V?$TSizedDefaultAllocator@$0CA@@@@@$0A@@@@@W4ELandscapeImportAlphamapType@@PEBV?$TArray@UFLandscapeLayer@@V?$TSizedDefaultAllocator@$0CA@@@@@@Z)

Finish Output:

C:\Users\User\Documents\Unreal Projects\Project\Binaries\Win64\UnrealEditor-Project.patch_0.exe : fatal error LNK1120: 3 unresolved externals
Failed to link patch (0.000s) (Exit code: 0x460)

Sorry for the long sentence. We would like to thank all the great Unreal Engine developers for their help.