CustomScreenCapture

ScreenCapture.h:

#pragma once

#include "CoreMinimal.h"

#include "GameFramework/Actor.h"
#include "Classes/Camera/CameraComponent.h"
#include "Classes/Components/SceneCaptureComponent2D.h"
#include "Classes/Engine/TextureRenderTarget2D.h"
#include "CustomScreenCapture.generated.h"

UCLASS()
class RTW_SIMULATION_API ACustomScreenCapture : public AActor
{
    GENERATED_BODY()

public:
    // Sets default values for this actor's properties
    ACustomScreenCapture();

protected:
    // Called when the game starts or when spawned
    virtual void BeginPlay() override;

    // Create the image in texture
    void FillTexture();

    // Textures need to be power of 2
    // Texture has to be a square
    uint32_t internResolution;

    UTextureRenderTarget2D* renderTarget;
    class USceneCaptureComponent2D* sceneCapture;
    class UCameraComponent* OurCamera;

public:
    // Called every frame
    virtual void Tick(float DeltaTime) override;
    UPROPERTY(EditAnywhere, Category = "Output Information", meta = (ClampMin = "32", ClampMax = "4096", UIMin = "32", UIMax = "4096"))
        uint32 resolutionX;

    UPROPERTY(EditAnywhere, Category = "Output Information", meta = (ClampMin = "32", ClampMax = "4096", UIMin = "32", UIMax = "4096"))
        uint32 resolutionY;

    UPROPERTY(EditAnywhere, Category = "Output Information", meta = (ClampMin = "20.0", ClampMax = "179.9", UIMin = "20.0", UIMax = "179.9"))
        float field_of_view;
};


CustomScreenCapture.cpp:

#include "CustomScreenCapture.h"

// Sets default values
ACustomScreenCapture::ACustomScreenCapture()
    : resolutionX(1024)
    , resolutionY(1024)
    , field_of_view(90.0f)
{
    PrimaryActorTick.bCanEverTick = true;
    PrimaryActorTick.TickGroup = TG_PostUpdateWork;
    RootComponent = CreateDefaultSubobject<USceneComponent>(TEXT("RootComponent"));
    OurCamera = CreateDefaultSubobject<UCameraComponent>(TEXT("ViewportCamera"));
    OurCamera->SetupAttachment(RootComponent);
}

void ACustomScreenCapture::BeginPlay()
{
    Super::BeginPlay();

    // Resolution has to be a power of 2. This code finds the lowest RxR resolution which has equal or more pixel than set
    uint32_t higher = std::max(resolutionX, resolutionY);

    higher--;
    higher |= higher >> 1;
    higher |= higher >> 2;
    higher |= higher >> 4;
    higher |= higher >> 8;
    higher |= higher >> 16;
    higher++;

    internResolution = higher;

    OurCamera->FieldOfView = field_of_view;
    renderTarget = NewObject<UTextureRenderTarget2D>();
    renderTarget->InitCustomFormat(internResolution, internResolution, EPixelFormat::PF_B8G8R8A8, true);

    renderTarget->UpdateResourceImmediate();

    sceneCapture = NewObject<USceneCaptureComponent2D>();
    sceneCapture->CaptureSource = SCS_FinalColorLDR;

    sceneCapture->TextureTarget = renderTarget;
    sceneCapture->SetupAttachment(OurCamera);
    sceneCapture->bCaptureEveryFrame = true;
}

// Called every frame
void ACustomScreenCapture::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);

    FillTexture();
}

void ACustomScreenCapture::FillTexture()
{
    sceneCapture->TextureTarget = renderTarget;
    auto RenderTargetResource = renderTarget->GameThread_GetRenderTargetResource();

    if (RenderTargetResource)
    {
        TArray<FColor> buffer8;
        RenderTargetResource->ReadPixels(buffer8);

        UE_LOG(LogTemp, Warning, TEXT("Fill Texture.. This line is for break point reasons"));
    }
}