puzzling code

I came across this code today:

Code (CSharp):

1. // Get the latest webcam shot from outside "Friday's" in Times Square
2. using UnityEngine;
3. using System.Collections;
4.  
5. public class ExampleClass : MonoBehaviour {
6.     public string url = "http://images.earthcam.com/ec_metros/ourcams/fridays.jpg";
7.     IEnumerator Start() {
8.         WWW www = new WWW(url);
9.         yield return www;
10.         Renderer renderer = GetComponent<Renderer>();
11.         renderer.material.mainTexture = www.texture;
12.     }
13. }

It is from here:

https://docs.unity3d.com/ScriptReference/WWW.html


Can someone help me understand it? It seems to run automatically when attached to an object?

I was aware of the “void Start(void)” which gets called automatically but was surprised to see this automatically called.

Thanks.

 

Take a look at this link:

http://answers.unity3d.com/questions/754968/can-monobehaviorstart-return-an-ienumerator-hint-y.html

 

Here is some comments in that code about what it is doing.

Code (csharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class ExampleClass : MonoBehaviour {
5.     // the url to load
6.     public string url = "http://images.earthcam.com/ec_metros/ourcams/fridays.jpg";
7.    
8.     // IEnumerators are things that can run outside of the
9.     // normal Update/FixedUpdate process
10.     // Start can be an IEnumerator, so it can run things and wait to load
11.     IEnumerator Start() {
12.         // create the WWW object and have it load the url from above
13.         WWW www = new WWW(url);
14.         // this waits until that has been loaded.
15.         yield return www;
16.        
17.         // find the renderer of this object
18.         Renderer renderer = GetComponent<Renderer>();
19.         // apply the texture to the mainTexture portion of that material
20.         renderer.material.mainTexture = www.texture;
21.     }
22. }