Utils_CameraFollow.cpp

#include "UtilsPluginPrivatePCH.h"
#include "Utils/Camera/Utils_CameraFollow.h"
#include "api/Actor.h"
#include "api/Camera.h"
#include "api/Player.h"
#include "api/Debug.h"

UUtils_CameraFollow::UUtils_CameraFollow() {
  bWantsInitializeComponent = true;
  PrimaryComponentTick.bCanEverTick = true;
}

void UUtils_CameraFollow::InitializeComponent() {
  Super::InitializeComponent();
  elapsed = 0.0;
  if (camera) {
    Debug::Trace(this, "No camera bound to UUtils_CameraFollow instance");
  }
}

void UUtils_CameraFollow::TickComponent( float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction ) {
  Super::TickComponent( DeltaTime, TickType, ThisTickFunction );
  if (camera) {
    if (!player) {
      player = api::Player::Local(this).Or(NULL);
      if (player) {
        target = api::Player::Pawn(player);
        LookAtPlayer();
      }
    }
    else {
      elapsed += DeltaTime;
      if (elapsed >= update_interval) {
        TrackPlayer();
        elapsed = 0.0;
      }
    }
  }
}

void UUtils_CameraFollow::LookAtPlayer() {
  api::Player::SetCamera(player, camera);
  api::Camera::LookAt(camera, player);
}

void UUtils_CameraFollow::TrackPlayer() {
  auto cloc = api::Actor::Position(camera);
  auto ploc = api::Actor::Position(target);
  if (follow_x) { cloc.X = ploc.X; }
  if (follow_y) { cloc.Y = ploc.Y; }
  if (follow_z) { cloc.Z = ploc.Z; }
  api::Actor::Move(camera, cloc);
}

Utils_CameraFollow.h

#pragma once

#include "Components/ActorComponent.h"
#include "Camera/CameraActor.h"
#include "Utils_CameraFollow.generated.h"

UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )
class UTILSPLUGIN_API UUtils_CameraFollow : public UActorComponent
{
  GENERATED_BODY()

  private:

    /// Elapsed time since last action
    float elapsed;

    /// Look at the target
    void LookAtPlayer();

    /// Track along with the target
    void TrackPlayer();

  public:

    // Sets default values for this component's properties
    UUtils_CameraFollow();

    // Called when the game starts
    virtual void InitializeComponent() override;

    // Called every frame
    virtual void TickComponent( float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction ) override;

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    ACameraActor *camera;

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    APlayerController *player;

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    APawn *target;

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    float update_interval;

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    bool follow_x;

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    bool follow_y;

    UPROPERTY(EditAnywhere, BlueprintReadWrite)
    bool follow_z;
};