Video Games Development

Unity 3D Game Engine – JS Script – LookAt Camera Target

1. MAIN TOP MENU> Game Object> Create Empty> Inspector> rename it ‘CameraTarget’

2. Hierarchy> Select ‘Main Camera’> Inspector> ‘Add Component’> New script> ‘LookAt.js’

LookAt.js:

#pragma strict

// #################################################################################################
// This complete script can be attached to a camera to make it continuously point at another object.
// ################################################################################################# 

// Camera target public variable START #############################################################
// The target variable shows up as a property in the inspector. Drag another object onto it to make the camera look at it.
var cameraTarget : Transform;
// Camera target public variable END ###############################################################

function Start () {

}
	
function Update() {
	
}
	
function LateUpdate () {
//LateUpdate is called after all Update functions have been called. 
// This is useful to order script execution. For example a follow camera should always be implemented in LateUpdate because it tracks objects that might have moved inside Update.
transform.LookAt(cameraTarget);
}

3. Hierarchy> ‘Main Camera’> Inspector> LookAt.js> DRAG ANd DROP over puiblic variable ‘Camera Target’> the ‘CameraTarget’ empty object you have created at point 1.

4. PLAY the game, while playing from Inspector change ‘CameraTarget’ object position to see the final result.

Unity 3D Game Engine – Camera – Mouse Orbit

1. Inside Hierachy create the objects:

– CameraTarget

– Main Camera, assign MouseOrbit.js

MouseOrbit.js

var target : Transform; // Inspector> Assign the LookAt Camera Target Object
var distance = 10.0;    // distance of the camera from the Target Object

var xSpeed = 250.0; // Speed of x rotation
var ySpeed = 120.0; // Speed of y rotation

var yMinLimit = -20; // y minimum rotation limit
var yMaxLimit = 80;  // y maximum rotation limit

private var x = 0.0;
private var y = 0.0;

private var smooth = 0.0;

function Start () {
    var angles = transform.eulerAngles;
    x = angles.y;
    y = angles.x;

	// Make the rigid body not change rotation
   	if (rigidbody)
		rigidbody.freezeRotation = true;
}

function LateUpdate () {
    if (target) {
    	if(Input.GetMouseButton(0))	{
        	x += Input.GetAxis("Mouse X") * xSpeed * 0.02;
        	y -= Input.GetAxis("Mouse Y") * ySpeed * 0.02;
        }
 		
 		y = ClampAngle(y, yMinLimit, yMaxLimit);
 		       
        var rotation = Quaternion.Euler(y, x, 0);
        var position = rotation * Vector3(0.0, 0.5, -distance) + target.position;
        
        transform.rotation = rotation;
        transform.position = position;
    }
    
    if(Input.GetAxis("Mouse ScrollWheel"))	{
    	smooth += Input.GetAxis("Mouse ScrollWheel");
    }
    distance += smooth;
    if(distance < 1)  // la Camera non si avvicina più di 1 unità
    	distance = 1; 
    if(distance > 6) // la Camera non si allontana più di 6 unità
    	distance = 6; 
    if(smooth != 0)
    	smooth /= 1.2;

}

static function ClampAngle (angle : float, min : float, max : float) {
	if (angle < -360)
		angle += 360;
	if (angle > 360)
		angle -= 360;
	return Mathf.Clamp (angle, min, max);
}

Inspector> Main Camera> CameraOrbit.js> Assign the ‘CameraTarget’ Object to var target.