UE5中使用UTexture2D进行纹理绘制

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：

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" });

2.蓝图部分

新建材质球暴露材质参数img1：

创建Actor类型蓝图，添加一个Mesh类组件，这里添加一个Cube：

使用刚刚的GenTexture节点创建材质纹理，运行后即可查看效果。

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https://dev.epicgames.com/documentation/en-us/unreal-engine/API/Runtime/Engine/Engine/UTexture2D