UE5中使用UTexture2D进行纹理绘制

news2024/12/24 2:34:42

在UE中有时需要在CPU阶段操作像素，生成纹理贴图等，此时可以通过UTexture2D来进行处理，例子如下：
在这里插入图片描述

1.CPP部分

首先创建一个蓝图函数库，将UTexture2D的绘制逻辑封装成单个函数：
.h：

#include "CoreMinimal.h"
#include "Engine/Texture2D.h"
#include "Engine/Texture.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "MyBlueprintFunctionLibrary.generated.h"

UCLASS()
class MYPROJECT_API UMyBlueprintFunctionLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()
	
	UFUNCTION(BlueprintCallable, Category = "Texture")
	static UTexture2D* GenTexture(int32 Width, int32 Height);
};

.cpp:

#include "MyBlueprintFunctionLibrary.h"

UTexture2D* UMyBlueprintFunctionLibrary::GenTexture(int32 Width, int32 Height)
{
    // 创建临时纹理
    UTexture2D* NewTexture = UTexture2D::CreateTransient(Width, Height);

    // 配置纹理
    NewTexture->MipGenSettings = TMGS_NoMipmaps;
    NewTexture->CompressionSettings = TC_VectorDisplacementmap;
    NewTexture->SRGB = false;

    // 锁定纹理数据进行写入
    FTexture2DMipMap& Mip = NewTexture->PlatformData->Mips[0];
    void* TextureData = Mip.BulkData.Lock(LOCK_READ_WRITE);

    // 设置三角形的大小
    int32 TriangleSize = Width / 10;  // 每个三角形的宽度和高度

    // 设置默认颜色
    FColor* FormattedImageData = static_cast<FColor*>(TextureData);
    for (int32 y = 0; y < Height; ++y)
    {
        for (int32 x = 0; x < Width; ++x)
        {
            int32 LocalX = x % TriangleSize;
            int32 LocalY = y % TriangleSize;

            // 判断像素是否在当前三角形内
            if (LocalX >= LocalY)  // 这里绘制一个局部的三角形
            {
                FormattedImageData[x + y * Width] = FColor::Red; // 三角形内部像素
            }
            else
            {
                FormattedImageData[x + y * Width] = FColor::Black; // 背景色
            }
        }
    }

    // 解锁纹理数据
    Mip.BulkData.Unlock();
    NewTexture->UpdateResource();

    return NewTexture;
}

需要修改build.cs添加模块引用：

PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;

PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "EnhancedInput", "RenderCore", "RHI", "ProceduralMeshComponent" });