Unity Camera Controller for easy Editor Scene-view style navigation in 3D scenes, or FPS-style

SceneViewCamera3D.cs

using UnityEngine;

/// <summary>SceneViewCamera3D class
/// Based on free asset "Ghost Free Roam Camera" by Goosey Gamez
/// https://www.assetstore.unity3d.com/en/#!/content/19250
/// That asset has no copyright or license info in its readme and modifications are encouraged
/// Modified by: Beard or Die
/// Date: 2018-01-12
/// GOAL: A quick camera controller for debugging 3D scenes
/// Flexible enough for FPS-style movement, or Unity Editor-style movement (default)
/// Probably not suitable for production
/// </summary>
[RequireComponent(typeof(Camera))]
public class SceneViewCamera3D : MonoBehaviour
{
    [SerializeField] private float initialSpeed = 10f;
    [SerializeField] private float increaseSpeed = 1.25f;

    [SerializeField] private bool isEnabled = true;
    [SerializeField] private bool allowMovement = true;
	[SerializeField] private bool allowRotation = false;
	[SerializeField] private bool allowRotationOnRightClick = true;
	[SerializeField] private bool cursorVisibleByDefault = true;
	
	[SerializeField] private bool allowMiddleClickPanning = true;
	[Range(1f,360f)][SerializeField] private float middleClickPanningSpeed = 12f;

    [SerializeField] private KeyCode forwardButton = KeyCode.W;
    [SerializeField] private KeyCode backwardButton = KeyCode.S;
    [SerializeField] private KeyCode rightButton = KeyCode.D;
    [SerializeField] private KeyCode leftButton = KeyCode.A;

    [SerializeField] private float cursorSensitivity = 0.025f;
    [SerializeField] private bool cursorToggleAllowed = false;
    [SerializeField] private KeyCode cursorToggleButton = KeyCode.Escape;

    private float currentSpeed = 0f;
    private bool moving = false;
	private bool togglePressed = false;
	private Vector3 currCameraPosition;
    
	[Range(-360,360)][SerializeField] private float minAngle = 89f;
	[Range(-360,360)][SerializeField] private float maxAngle = 271f;

    private void OnEnable()
    {
        if (cursorToggleAllowed && isEnabled)
        {
	        Cursor.lockState = CursorLockMode.Locked;
            Cursor.visible = false;
        }
    }

    private void Update()
    {
        if (!isEnabled) return;
        if (allowMovement)
        {
            bool lastMoving = moving;
            Vector3 deltaPosition = Vector3.zero;

            if (moving)
                currentSpeed += increaseSpeed * Time.deltaTime;

            moving = false;

	        CheckMove(forwardButton, ref deltaPosition, transform.forward, false, false);
	        CheckMove(backwardButton, ref deltaPosition, -transform.forward, false, false);
	        CheckMove(rightButton, ref deltaPosition, transform.right, false, false);
	        CheckMove(leftButton, ref deltaPosition, -transform.right, false, false);
	        
	        if (Input.GetAxis("Mouse ScrollWheel") > 0f ) // forward
	        {
	        	CheckMove(forwardButton, ref deltaPosition, transform.forward*2, true, false);
	        }
	        else if (Input.GetAxis("Mouse ScrollWheel") < 0f ) // backwards
	        {
		        CheckMove(backwardButton, ref deltaPosition, -transform.forward*2, false, true);
	        }

            if (moving)
            {
                if (moving != lastMoving)
                    currentSpeed = initialSpeed;

                transform.position += deltaPosition * currentSpeed * Time.deltaTime;
            }
            else currentSpeed = 0f;  
        }

        if (allowRotation)
        {
            Vector3 eulerAngles = transform.eulerAngles;
            eulerAngles.x += -Input.GetAxis("Mouse Y") * 359f * cursorSensitivity;
            eulerAngles.y += Input.GetAxis("Mouse X") * 359f * cursorSensitivity;
	        if (eulerAngles.x < minAngle  || eulerAngles.x > maxAngle) {
		        transform.eulerAngles = eulerAngles;
	        }
        }
        
	    if (allowRotationOnRightClick && Input.GetMouseButton(1))
	    {
		    Vector3 eulerAngles = transform.eulerAngles;
		    eulerAngles.x += -Input.GetAxis("Mouse Y") * 359f * cursorSensitivity;
		    eulerAngles.y += Input.GetAxis("Mouse X") * 359f * cursorSensitivity;
		    if (eulerAngles.x < minAngle  || eulerAngles.x > maxAngle) {
			    transform.eulerAngles = eulerAngles;
		    }
	    }
	    
	    if(allowMiddleClickPanning && Input.GetMouseButtonDown(2))
	    {
	    	currCameraPosition = gameObject.transform.position;
	    }
	    
	    if(allowMiddleClickPanning && Input.GetMouseButton(2))
	    {
	    	gameObject.transform.position = new Vector3(currCameraPosition.x + Input.GetAxis("Mouse X") * middleClickPanningSpeed * cursorSensitivity, currCameraPosition.y - Input.GetAxis("Mouse Y") * middleClickPanningSpeed * cursorSensitivity, currCameraPosition.z);
	    	currCameraPosition = gameObject.transform.position;
	    }

        if (cursorToggleAllowed)
        {
            if (Input.GetKey(cursorToggleButton))
            {
                if (!togglePressed)
                {
                    togglePressed = true;
	                Cursor.lockState = (Cursor.lockState == CursorLockMode.None) ? CursorLockMode.Locked : CursorLockMode.None;
                    Cursor.visible = !Cursor.visible;
                }
            }
            else togglePressed = false;
        }
        else
        {
            togglePressed = false;
	        if(!cursorVisibleByDefault) Cursor.visible = false;
        }
    }

	private void CheckMove(KeyCode keyCode, ref Vector3 deltaPosition, Vector3 directionVector, bool forceForward, bool forceBackward)
    {
	    if (Input.GetKey(keyCode) || forceBackward || forceForward)
        {
            moving = true;
            deltaPosition += directionVector;
        }
    }
    
}