ue4讀取灰度圖生成三維地形mesh

新建ue c++工程。

在Build.cs中添加"ProceduralMeshComponent"模塊。

在 uproject中添加"ProceduralMeshComponent"模塊。

 

建立材質，傳入grass貼圖

 

 

導入灰度圖資源

 

 

建立繼承自Actor的類 ATerrainCreateActor，並建立藍圖類對象

將藍圖對象拖入場景，設置其灰度貼圖參數、Z值縮放比例參數、材質參數

 

最終效果

 

 

ATerrainCreateActor類代碼以下

 

頭文件

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "ProceduralMeshComponent.h"
#include "TerrainCreateActor.generated.h"

UCLASS()
class UETERRAIN_API ATerrainCreateActor : public AActor
{
	GENERATED_BODY()
	
public:	 
	ATerrainCreateActor(); 
private:
	UPROPERTY(VisibleAnywhere)
		UProceduralMeshComponent * mesh;//自定義mesh 
	UPROPERTY(EditAnywhere)
		UTexture2D * grayTexture;//傳入灰度圖
	UPROPERTY(EditAnywhere)
		float zScale;//z值係數 
	UPROPERTY(EditAnywhere)
		UMaterial* meshMat;//材質

protected:
	 
	virtual void BeginPlay() override;  

public:	
	 
	virtual void Tick(float DeltaTime) override;

	 
	
};

源文件

 

#include "TerrainCreateActor.h"
 
ATerrainCreateActor::ATerrainCreateActor()
{ 
	PrimaryActorTick.bCanEverTick = true;  
	mesh = CreateDefaultSubobject<UProceduralMeshComponent>(TEXT("terrainMesh"));
	RootComponent = mesh; 
	mesh->bUseAsyncCooking = true;
}
 
void ATerrainCreateActor::BeginPlay()
{
	Super::BeginPlay();

	//讀取灰度圖像素信息
	FTexture2DMipMap* MyMipMap = &grayTexture->PlatformData->Mips[0];
	FByteBulkData* RawImageData = &MyMipMap->BulkData;
	FColor* FormatedImageData = static_cast<FColor*>(RawImageData->Lock(LOCK_READ_ONLY)); 
	uint32 TextureWidth = MyMipMap->SizeX, TextureHeight = MyMipMap->SizeY; 
	//mesh基礎信息
	TArray<FVector> vertices;
	TArray<int32> Triangles;
	TArray<FVector> normals;
	TArray<FVector2D> UV0;
	TArray<FProcMeshTangent> tangents; 
	TArray<FLinearColor> vertexColors; 
	for (size_t i = 0; i < TextureWidth; i++)
	{
		for (size_t j = 0; j < TextureHeight; j++)
		{
			//根據顏色設定頂點z值
			FColor PixelColor = FormatedImageData[j * TextureWidth + i];
			float tempZ = (PixelColor .B* 299 + PixelColor .G* 587 + PixelColor.R * 114 + 500) / 1000;//rgb轉灰度
			tempZ *= zScale;
			vertices.Add(FVector(i*5, j*5, tempZ));  //頂點
			normals.Add(FVector(0, 0, 1));//法線 
			UV0.Add(FVector2D((float)i/(float)TextureWidth, (float)j/(float)TextureHeight));//uv
			//UV0.Add(FVector2D(i,j));//uv
			tangents.Add(FProcMeshTangent(1, 0, 0));//切線
			vertexColors.Add(FLinearColor(0.75, 0.75, 0.75, 1.0)); //頂點顏色

			if (j < TextureHeight - 1 && i < TextureWidth - 1)
			{
				//三角索引  此處按照vertice的添加順序肯定索引
				Triangles.Add(i*TextureHeight + j);
				Triangles.Add(i*TextureHeight + j + 1);
				Triangles.Add(i*TextureHeight + j + TextureHeight);

				Triangles.Add(i*TextureHeight + j + TextureHeight);
				Triangles.Add(i*TextureHeight + j + 1);
				Triangles.Add(i*TextureHeight + j + TextureHeight + 1);
			}
		}
	} 
	 

	RawImageData->Unlock();  

	//建立mesh 
	mesh->CreateMeshSection_LinearColor(0, vertices, Triangles, normals, UV0, vertexColors, tangents, true);
	mesh->ContainsPhysicsTriMeshData(true);
	mesh->SetMaterial(0, meshMat);
}
 
void ATerrainCreateActor::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime); 
}
  

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