How to get Touch Position on screen
  1. New C++ class inherit from GameViewportClient

  2. Project Settings -> Engine -> General Settings -> Default Classes -> set Game Viewport Client Class as your customized class.

  3. Override function InputTouch

    virtual bool InputTouch(FViewport* Viewport, int32 ControllerId, 
    uint32 Handle, ETouchType::Type Type, const FVector2D& TouchLocation, 
    float Force, FDateTime DeviceTimestamp, uint32 TouchpadIndex) override;

    Argument TouchLocation is the Touch Position.

Mobile Input - Swipe and Pinch

A plugin for Unreal Engine 4 that exposes touches and swipes on mobile devices as events in blueprints

Ultimate Touch Components

Controller Rotation

By default, Controller Rotation is equal to PlayerStart Actor Rotation. So if you change the Rotation of PlayerStart Actor, Controller Rotation would be affected.

How to set the rotation of Controller:

void AController::SetControlRotation(const FRotator& NewRotation)
How create and get Spectator

1st way

Create Spectator:

    DefaultPawnClass = ASpectatorPawn::StaticClass();

Get Spectator:

ASpectatorPawn* APlayerController::GetSpectatorPawn() const;

2nd way