Mobile camera script to rotate and pinch to zoom

Hi everyone,

Can some lend a hand to a noobie? I'm trying to modify this script to work on a mobile/touch screen. I want it to rotate and zoom using pinching. The rotating part works but not the pinch to zoom. If I use two fingures, it moves offscreen without zooming. Any ideas? Thanks.

Code (CSharp):

1. using UnityEngine;
2. using UnityEngine.UI;// we need this namespace in order to access UI elements within our script
3. using System.Collections;
4.  
5. public class MoveCamera : MonoBehaviour
6.     // Credit to damien_oconnell from http://forum.unity3d.com/threads/39513-Click-drag-camera-movement
7.     // for using the mouse displacement for calculating the amount of camera movement and panning code.
8.    
9. {
10.     //
11.     // VARIABLES
12.     //
13.    
14.     public float turnSpeed = 4.0f;        // Speed of camera turning when mouse moves in along an axis
15.     public float panSpeed = 4.0f;        // Speed of the camera when being panned
16.     public float zoomSpeed = 4.0f;        // Speed of the camera going back and forth
17.    
18.     private Vector3 mouseOrigin;    // Position of cursor when mouse dragging starts
19.     private bool isPanning;        // Is the camera being panned?
20.     private bool isRotating;    // Is the camera being rotated?
21.     private bool isZooming;        // Is the camera zooming?
22.    
23.     //
24.     // UPDATE
25.     //
26.    
27.     void Update ()
28.     {
29.         // Get the left mouse button
30.         if(Input.GetMouseButtonDown(0))
31.         {
32.             // Get mouse origin
33.             mouseOrigin = Input.mousePosition;
34.             isRotating = true;
35.         }
36.        
37.         // Get the right mouse button
38.         if(Input.GetMouseButtonDown(1))
39.         {
40.             // Get mouse origin
41.             mouseOrigin = Input.mousePosition;
42.             isPanning = true;
43.         }
44.        
45.         // Get the middle mouse button
46.         if(Input.GetMouseButtonDown(2))
47.         {
48.             // Get mouse origin
49.             mouseOrigin = Input.mousePosition;
50.             isZooming = true;
51.         }
52.        
53.         // Disable movements on button release
54.         if (!Input.GetMouseButton(0)) isRotating=false;
55.         if (!Input.GetMouseButton(1)) isPanning=false;
56.         if (!Input.GetMouseButton(2)) isZooming=false;
57.        
58.         // Rotate camera along X and Y axis
59.         if (isRotating)
60.         {
61.             Vector3 pos = Camera.main.ScreenToViewportPoint(Input.mousePosition - mouseOrigin);
62.            
63.             transform.RotateAround(transform.position, transform.right, pos.y * turnSpeed);
64.             transform.RotateAround(transform.position, Vector3.up, -pos.x * turnSpeed);
65.         }
66.        
67.         // Move the camera on it's XY plane
68.         if (isPanning)
69.         {
70.             Vector3 pos = Camera.main.ScreenToViewportPoint(Input.mousePosition - mouseOrigin);
71.            
72.             Vector3 move = new Vector3(pos.x * panSpeed, pos.y * panSpeed, 0);
73.             transform.Translate(move, Space.Self);
74.         }
75.        
76.         // Move the camera linearly along Z axis
77.         if (isZooming)
78.         {
79.             Vector3 pos = Camera.main.ScreenToViewportPoint(Input.mousePosition - mouseOrigin);
80.            
81.             Vector3 move = pos.y * zoomSpeed * transform.forward;
82.             transform.Translate(move, Space.World);
83.         }
84.     }
85. }

 

Input.GetMouseButton is designed for.... a mouse. As it happens, Unity does emulate a mouse when on a touch screen, but only one button (0) and only one finger at a time.

If you ever need more control than that (and with pinch to zoom, you do), then you'll need to use Input.touches. This will give you an array of touches (one for each finger on the screen), which each contain their own position and state data. To handle pinch to zoom, you'll need to store a number indicating the distance between your fingers on the previous frame. You'll check to see if Input.touchCount == 2, and if it is, you:

1. Calculate the pixel distance between the fingers;
2. If it's the first consecutive frame where .touchCount == 2, move the camera by some multiplier times newdistance / previousDistance
3. Save newDistance into previousDistance for use in the next frame

 

This is old but most likely still relevant: http://wiki.unity3d.com/index.php/DetectTouchMovement

 

That's a pretty handy script.

 

Thanks StarManta and larku!

@StarManta - Not sure how to implement that code into the existing script. Not sure if you could lend a hand :/

@larku - I tried your script but it only allowed for zooming...not both zooming and rotating. Thanks anyway.

 

Umm, that script explicitly handles both rotating (turn) and zooming.

But even if it didn't, I intended for you to use the concepts in that script to build your own solution - though as it already does both it could be dropped in and used.

 

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