New Script FlyCamera add to any camera obj: instant unity editor style wasd rightclick debug cam

FlyCamera.cs

using UnityEngine;
using System.Collections;

public class FlyCamera : MonoBehaviour {
	
	/*
    Writen by Windexglow 11-13-10.  Use it, edit it, steal it I don't care.  
    Converted to C# 27-02-13 - no credit wanted.
    Simple flycam I made, since I couldn't find any others made public.  
    Made simple to use (drag and drop, done) for regular keyboard layout  
    wasd : basic movement
    shift : Makes camera accelerate
    space : Moves camera on X and Z axis only.  So camera doesn't gain any height*/
	
	
	public float mainSpeed = 100.0f; //regular speed
	public float shiftAdd = 250.0f; //multiplied by how long shift is held.  Basically running
	public float maxShift = 1000.0f; //Maximum speed when holdin gshift
	public float camSens = 0.25f; //How sensitive it with mouse
	public bool rotateOnlyIfMousedown = true;
	public bool movementStaysFlat = true;

	private Vector3 lastMouse = new Vector3(255, 255, 255); //kind of in the middle of the screen, rather than at the top (play)
	private float totalRun= 1.0f;

	void Awake() {
		Debug.Log ("FlyCamera Awake() - RESETTING CAMERA POSITION"); // nop?
		// nop:
		//transform.position.Set(0,8,-32);
		//transform.rotation.Set(15,0,0,1);
		transform.position = new Vector3(0,8,-32);
		transform.rotation = Quaternion.Euler(25,0,0);
	}


	void Update () {

		if (Input.GetMouseButtonDown(1))
		{
			lastMouse = Input.mousePosition; // $CTK reset when we begin
		}

		if (!rotateOnlyIfMousedown || 
		    (rotateOnlyIfMousedown && Input.GetMouseButton(1)))
		{
			lastMouse = Input.mousePosition - lastMouse ;
			lastMouse = new Vector3(-lastMouse.y * camSens, lastMouse.x * camSens, 0 );
			lastMouse = new Vector3(transform.eulerAngles.x + lastMouse.x , transform.eulerAngles.y + lastMouse.y, 0);
			transform.eulerAngles = lastMouse;
			lastMouse =  Input.mousePosition;
			//Mouse  camera angle done.  
		}

		//Keyboard commands
		float f = 0.0f;
		Vector3 p = GetBaseInput();
		if (Input.GetKey (KeyCode.LeftShift)){
			totalRun += Time.deltaTime;
			p  = p * totalRun * shiftAdd;
			p.x = Mathf.Clamp(p.x, -maxShift, maxShift);
			p.y = Mathf.Clamp(p.y, -maxShift, maxShift);
			p.z = Mathf.Clamp(p.z, -maxShift, maxShift);
		}
		else{
			totalRun = Mathf.Clamp(totalRun * 0.5f, 1f, 1000f);
			p = p * mainSpeed;
		}
		
		p = p * Time.deltaTime;
		Vector3 newPosition = transform.position;
		if (Input.GetKey(KeyCode.Space) 
		    || (movementStaysFlat && !(rotateOnlyIfMousedown && Input.GetMouseButton(1)))){ //If player wants to move on X and Z axis only
			transform.Translate(p);
			newPosition.x = transform.position.x;
			newPosition.z = transform.position.z;
			transform.position = newPosition;
		}
		else{
			transform.Translate(p);
		}
		
	}
	
	private Vector3 GetBaseInput() { //returns the basic values, if it's 0 than it's not active.
		Vector3 p_Velocity = new Vector3();
		if (Input.GetKey (KeyCode.W)){
			p_Velocity += new Vector3(0, 0 , 1);
		}
		if (Input.GetKey (KeyCode.S)){
			p_Velocity += new Vector3(0, 0, -1);
		}
		if (Input.GetKey (KeyCode.A)){
			p_Velocity += new Vector3(-1, 0, 0);
		}
		if (Input.GetKey (KeyCode.D)){
			p_Velocity += new Vector3(1, 0, 0);
		}
		return p_Velocity;
	}
}

How to make camera to stop when it collides with an other collider?
(I know that need to attach collider to camera...)

Thanks for sharing this!
Works great out of the box.
The X and Z axis constrained motion seems to be buggy, though.
It does not appear to work when using the mouse, while when not using the mouse it is not possible to move along the Y axis anyway.
This makes the feature look kind of useless, or am I missing something?
Edit: does work, sorry.

I added q and e to move down and up in my fork (https://gist.github.com/Mahelita/f82d5b574ab6333f0c834178582280c3), just like in the Unity scene editor.
This incidentally also seems to give a purpose to the X and Z axis constrained motion.

Thank you, updated it to the new Unity input system https://gist.github.com/bison--/f97644377bd7f09e43d96547f67fda8a